ArticlePDF Available

Abstract and Figures

Covid-19 has spread all over the world since it originated from Wuhan City, China in late 2019.While a careful search for an effective treatment is still ongoing , nutritional strategies to promote immunity to possibly face the infection should not be ignored. Recently, there has been an increased interest on fermented foods due to their enhanced nutritional values and health benefits.In Nigeria, the most common of these traditional fermented foods are; tuber based fermented products (Fufu, Garri, Lafun), cereal based foods and beverages (Kwunu, Pito, Agidi, Pap or Akamu), vegetable-based fermented condiments (Ogiri, Dawadawa, Ugba) and animal fermented products (Nono and Kilishi). In addition to their improved nutritional quality, these fermented foods may also deliver viable microbes know as probiotics to balance the gut microbioata and therefore have the potential to boost immunity which in turn protects the body against infectious diseases like Covid-19 and other diseases.
Content may be subject to copyright.
International Journal of Applied Science and Research
127 Copyright © 2020 IJASR All rights reserved
Traditional fermented foodsin Nigeria and Covid-19: A Possible Approach for Boosting Immune
P.N. Anyiam1*, P.N. Onwuegbuchu2, C.L. Ekemezie3
1Department of Biochemistry, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike,
PMB 7262, Umuahia, Nigeria
2Department of Microbiology, Faculty of Biological Sciences, Abia State University, P.M.B 2000, Uturu, Abia State,
3Department of Microbiology, College Of Natural Sciences, Michael Okpara University of Agriculture, Umudike,
PMB 7262, Umuahia, Nigeria
IJASR 2020
Abstract: Covid-19 has spread all over the world since itoriginated from Wuhan City, China in late 2019.While a
careful search for an effective treatment is still on-going, nutritional strategies to promote immunity to possibly face
the infection should not be ignored. Recently, there hasbeen anincreased interest on fermented foodsdue to their
enhanced nutritional values and health benefits.In Nigeria, the most common of these traditional fermented foods
are; tuber based fermented products (Fufu, Garri, Lafun), cereal based foods and beverages (Kwunu, Pito, Agidi, Pap or
Akamu), vegetable-based fermented condiments (Ogiri, Dawadawa, Ugba) and animal fermented products
(NonoandKilishi). In addition to their improved nutritional quality, these fermented foods may also deliver viable
microbes know as probiotics to balance the gut microbioataand therefore have the potential to boost immunity
which in turn protects the body against infectious diseases like Covid-19 and other diseases.
Keywords: Covid-19, Fermented foods, Health benefits, Immune system, Nutrition, Probiotics
1. Introduction
Since the beginning of Covid-19 outbreakwhich is caused by a severe acute respiratory syndromecoronavirus 2
(SARS-CoV-2)-in late 2019 from Wuhan City,China, it has spread all over the world exhibiting large and significant
geographical variations in the number of infected people and death rates between and within countries[1].Ithas also
brought social and economic crisis not just in Nigeria but also in other developing countries, which is rapidly
exacerbating theon-going food insecurity in the country.Malnutrition and other co-morbidities (such as Diabetes,
cancer hypertension, tuberculosis, obesity) are considered risk factors for complications in people with Covid-
19[2,3]mainly due to a compromised immune system with oxidative stress as a common pathway.
Thoughdemographic factors such as such as age, sex, occupation and education level, seasonal variations, immunity
and timing of interventions are more relevant factors that are associated with increased incidence of Covid-19 and
its mortality rate[4], other factors like nutrition, probiotics, nutraceuticals, environment and diet should not be
ignored completely because these factors can as well beof interesting options in mitigating the impact of Covid-19
and preventing itscomorbidity.While a deep search for effective vaccines or drugswhich can be able to interfere with
the SARS-CoV-2 pathway is on-going, nutritional strategies to boost the immunity against the infection and its
spreadare imperative.
Certain fermented foods may deliver viable microbes with the potential of providing some health benefit to the host
by boosting the immunity [4]. Such foods have long been an integral part oflocal cultures and traditions of human
diet in developing countries [5,6]due to their nutritional and health benefits.Fermented foods are a very diverse
family of foods, which differ in their nutritional values, microbiological compositions and metabolites with potential
health effects[7]. Fermentation itself is a food processing technology whereby the growth and metabolic activities of
microorganisms are used to transform and preserve foods. It is an inexpensiveand simple process that requires
comparatively little energy, prolongs the shelf life of the original food, and making food nutrients more digestible[8-
10]. Production methods of different traditional fermented foods were passed down to subsequent generations in
different regions as family traditions where they are generally produced using plant or animalingredients in
combination with microorganisms which are either sourced spontaneously from the environment, or carefully kept
as starter cultures.
International Journal of Applied Science and Research
128 Copyright © 2020 IJASR All rights reserved
Mostrural communities in Nigeria are economically depending on fermented foods as the primary source of
nutrition for nourishment, as well as for cultural traditional practices, since the major staples in the region (Cassava,
yam, maize) though provide enough calories butthey are poor in essential nutrients needed to support life
[8,11].Each region in Nigeria has its own distinctiveness in terms of food culture and heritage where fermented
foods are included which depends on type of raw food material available in that particular place, which play very
important role in the socio-economics development of the country as well as make major contributions to the
protein requirements of the rural population which couldplay a mitigating role against the economic effects of
Covid-19 especially on food security by reducing the rate of malnutrition and hunger in the region.
Despite the importance and potential health benefits of fermented foods in Nigeria, their preparation methodsstill
remains a household art till date.Very little is known about these traditional fermented foods and their benefitsdue
to scarcity of informationin the literature and the fact that they are only knownto those people residing in the area
where such foods are produced and consumed. Therefore, this reviewis aimed at assessing the standard methods of
preparation and consumption of common traditional fermented foods in Nigeria, and also discussed thehealth
benefitsassociated with the consumption of these fermented foods.
1.1 Traditional fermented Foodsin Nigeria: Production methods
A wide range of fermented foods and beverages are produced in Nigeria. Such foodsare derived from the local
staples (cassava, yam, rice, maize, wheat etc.) whichare prevalent in various localities within the country. Many
names are applied to these traditional fermented foods throughout Nigeria which differ by region and ethnic
groups. Most common fermented foods produced from these staples in Nigeria are; Garri, Fufu, Lafun, Amala,
Massa, Agidiand Ogi (Akamu). Fermented beverages include Kwunu, Mmanya-ngwo (palm wine), Pito, Burukutu and
fermented condiments include Dawadawa and ogiri.Fermented animal products include Nono (fermented milk),
WashainuandKilishi (fermented meat) (Table 1). These fermented foods are inexpensive and affordable for many
individuals in the community.They are of sociocultural and nutritional value and are marketed for income
generation. Most of the traditional fermented foods are primarily produced at household level usingN largely
uncontrolled spontaneous inoculation methods in which microorganisms associated with the raw food material and
the processing environment serve as inoculants [12]. The preparation method and mode of consumption of these
fermented foods are highlighted according to food types;
1.2 Fermented Tubers (Cassava and yam meal)
1.2.1 Garri: Thisis a high energy food commonly consumed in Southern parts of Nigeria but it is also popular
among the inhabitants of Northern and Eastern Nigeria. Itisa creamy-white granular flour with a slightly sour taste
made from fermented gelatinized fresh cassava tubers. Nigeria is one of the leading producers of cassava in the
world with an annual production of 35-40 million metric tons [9,12]. Over 40 varieties of cassava are grown in
Nigeria and cassava is the most important dietary staple in the country accounting for majority of all food crops
consumed in Nigeria [9,12]. Despite its vast potentials, the presence of hydrogen cyanide (HCN) is the most
important problem limiting cassava utilization in the country [9]. Many varieties of cassava grown in the country are
poisonous due to presence of HCN and would cause death in man and animals if consumed directly without
fermentation which detoxifies HCN.
In preparation of garrifrom cassava, the tubers are harvested, cleaned, peeled and washed in clean water. The
washed cassava is groundin a mill and the pulp is transferred into a cloth bag and tied before being subjected to
heavy pressure at room temperature for 3 or 4 days to remove excess water and ferment. The fermented pulp is
then sieved and dry-fried with or without palm oiladded (optional) to produce garri flour. The flour can be
reconstituted in hot water into a paste, cooled and consumed with various soups and stews or it can be soaked in
cold water with salt or sugar added before consumptionwith groundnut or coconut as snack.The flour, when
properly fried and stored away from moisture, has a shelf life of about three months.
1.2.2 Fufu (Fermented Cassava meal)
Fufu is a fermented white paste made also from cassava which is ranked next to garri as an indigenous food of most
Nigerians. It is widely consumed in Eastern Nigeria, especially among the Igbos but also available in the Western
part of the nation. In preparation of fufu, thecassava tubers are peeled, washed, cut into thick chucks (say 20cm
long) and soaked in water in earthen ware pots or plastic bucket for 4 to 5 days. During cold weather, the tubers
International Journal of Applied Science and Research
129 Copyright © 2020 IJASR All rights reserved
should be properly submerged in the waterand the container may be kept closer to the cooking stand in the
kitchento fasten the fermentation and softening process.
During this period, the cassava tuber ferments and softens, releasing the poisonous hydrogen cyanide (HCN) in the
soaked water and producing a characteristic flavor [9]. The softened tubers are then disintegrated in clean water,
sieved and the starchy particles that go through the sieves are allowed to settle for about one or two hours. The
water is decanted while the sediments is packed into a cloth and bag, tied, squeezed and subjected to heavy pressure
to expel excess water. The resulting starch is rolled into balls, cooked in boiling water (100oc) for about 30 to 40
minutes. The cooked mass is pounded in a mortar with a pestle to producefufu paste which can be eaten with sauce,
soup or stew.
1.2.3 Lafun or Elubo (Cassava Flour)
Lafun is a fibrous powdery form of fermented cassava similar to fufu but the production process slightly differs from
that of fufu. It is commonly produced and consumed in Western States of Nigeria and is also available in Eastern
part of the country. Lafunis prepared from cassava tuber. Basically, the cassava tuber is peeled and soaked in water
for 3 to 4 days to ferment. Afterwards, the soaked water is drained off and the fermented cassava dried in the sun.
The dried product is ground in a mill into flour known as Elubo. The flour is added into boiling water with constant
stirring until a smooth thick paste is formed. The paste is allowed to cool and is then served with any kind of
vegetable sauce or soups.When properly stored, lafun have a shelf-life of up to six months [9].
1.2.4 Amala (Fermented Yam flour)
Amala is a popular food consumed in Western Nigeria. It is prepared from yam (Discoreaspp) tuber. Theyam tuber is
washed and peeled, then cut into very thin slices and left in the sun on a tray or mat for 4 to 5 days to ferment and
dry. The dried yam slices are milled into flour then cooked for few minutes in hot water with constant stirring until
thick dark brown dough like paste (amala) is formed. The characteristic flavor and dark color of amala which is
found objectionable by some people is due to enzymatic and non-enzymatic browning reactions and the presence of
polyphenols in the yam [9], which can be minimized or prevented completely by blanching the yam slices in boiling
water for 2 minutesbefore fermentation or drying to inactivate the enzyme responsible for the browning reactions.
1.3 Cereal based fermented food products
Generally, grains lack some basic nutrients such as essential amino acids and certain vitamins [9,10]. Fermentation
of cereals is a simple way to improve their nutritional value as well as their sensory and functional qualities [10].
Fermentation decreases the level of carbohydrates and non-digestible polysaccharides and oligosaccharides in
cereals and increases the synthesis of certain amino acids and the bioavailability of the vitamins [13]. In addition,
fermentation also significantly reduces the content of non-nutrients in cereals, such as polyphenols, phytates and
tannins [10]and increases the content of nutrients like free amino acids and their derivatives. The activities of some
enzymes such as amylase, phytase, hemicellulase and protease increase, which results in improved shelf-life,
digestibility and nutritional value [13]. It has been noted that during fermentation, cereals also have increased
antioxidants activity [14]. Some of the cereal based fermented foods in Nigeria are as follows;
1.3.1 Ogi/Akamu/pap (Fermented maize starch)
Ogi (Akamu or pap) is another traditional fermented food consumed in Nigeria which is prepared from fermented
maize (Zea mays). It is a staple cereal product of mainly the theYorubas, and is the first natural food given to babies
at weaning [9]. The process of preparation basically consists of soaking the maize in water for one to three days to
ferment and develop a characteristic odour. The softened maize is washed, ground into a meal with a blender or
mill. The ground material is mixed with water and sieved to remove parts of the hull and other fibrous materials.
The filtrate which is almost pure starch suspension is placed in a pot so that starchy material sediments at the
bottom of the pot. The supernatant is decanted and the wet starch poured into cloth bags, squeezed and dewatered
until a semi-solid corn starch is produced. This is stored in a cool place from where samples can be taken from the
stock and cooked into ogi or akamu which is usually served hot with table sugar to enhance the taste and can be eaten
withakara (bean cake), fried yam or bread.
1.3.2 Massa (fermented rice meal)
International Journal of Applied Science and Research
130 Copyright © 2020 IJASR All rights reserved
Massa is a fermented product made from rice or millet. It is consumed in various forms by all groups especially in
Northern States of Nigeria. It is the principal ingredients for a variety of cereal-based foods and is a good source of
income for the women who prepare the traditional product for sale. The problem of Massa apart from the short
shelf-life is that of low protein content [9]. However, cowpea, groundnut or soybeans flour could be added into
Massa during preparations to improveits nutritional quality. Basically, Massa is prepared from rice flour. The raw rice
is firstly soaked in water for 8 hours or overnight and washed. Then blend together with already precooked rice with
a gradual addition of water while controlling the texture and thickness. Add the yeast and set the mixture aside for 5
to 8 hours or overnight to ferment. After the fermentation process is completed, fry the batter in batches with little
oil in a pan until they turn golden brown. Massa can be served with honey, sauce or any condiment of choice.
1.4 Fermented beverages:
1.4.1 Kwunu: This is a non-alcoholic fermented beverage prepared from millet andwidely consumed in Northern
parts of Nigeria. To prepare kwunu, first, the millet is ground in a mortar with pestle to remove the husk and release
the kernels. The kernels are washed and left to dry on a mat under the sun for 8-12 hours. The dried kernels are
then ground into flour and mixed with little cold water before pouring it into a pot of hot water with constant
stirring until a thick smooth paste is formed. The paste is left to ferment for 1 to 3 days so as to develop a sour
flavor after which it can be consumed. The flour can also be made into a watery gruel known as kwunuzaki and
consumed hot or cold with ginger, pepper and sugar to taste. The product has a shelf-life of about 24 hours at
ambient temperature, which can be extended to 8 days by pasteurization at 60 0C for 1 hour [9] and stored under
refrigeration condition.
1.4.2 Pito/burukutu
Pito is cream colored liquor while burukutu is a brown colored suspension, both of which are brewed from sorghum,
millet, maize or a mixture of these cereals. Both drinks are brewed concurrently by fermentation of malted or
germinated cereals. For instance, sorghum grains are soaked in water for 24hrs, drained and kept for 2 days to
germinate. After sprouting, the grains are sun dried and ground into flour. The flour is mixed with water and boiled
for 3 to 4 hours to form slurry. The boiled mash is allowed to settle at the bottom and water is decanted while the
sediment which is a thick brown suspension is known as burukutu. Each fraction is decanted into a clean calabash
pot where it is allowed to stand and ferment for 24 hours at room temperature for proper flavor development, after
which the drink can then be consumed. Pito and burukutu are widely consumed in Northern Nigeria. The alcoholic
content of burukutu is slightly higher than that of pito.
1.4.3 Mmanya-ngwo (Palm wine)
Thisis the fermented sap of palm tree which is obtained in Nigeria by the tapping of the inflorescence of the palm
tree. The wine is a milky suspension of microorganisms (especially yeasts) in a fermenting palm sap. It is a popular
refreshing and nourishing beverage consumed in most parts of Nigeria, especially Southern and Eastern Nigeria,
and is also a major ingredient in the manufacture of local bread because of its naturally high content of yeasts. Fresh
palm wine is sweet and has virtually zero alcohol contents, but the palm sap ferments easily and become sour in few
hours after collection.
1.5 Fermented condiments
The fermentation of fruits and vegetablesis very popular as a means of preservation in various local communities in
Nigeria, because untreated fruits and vegetables are highly perishable.The fermentation of fruits and vegetables is
mainly by lactic acid fermentation that acts spontaneously when conditions are favorable for the fermenters,
especially lactic acid bacteria, which are the dominant microorganism in this type of fermentation [8, 15, 16]. The
conventional substrates for condiments productions from vegetables are diverse and each can be produced from
more than one raw material. The methods employed in the production of these condiments foods differ slightly
from one region of the country to another because these processes are based on traditional systems. Common
traditional fermented condiments in Nigeria are as follow;
1.5.1 Dawadawa or Iru:
This is an important fermented food condiment and protein source produced from African locust bean
(Parkiabiglobosa) and consumed extensively throughout Nigeria as a condiment to add flavor to various dishes and
International Journal of Applied Science and Research
131 Copyright © 2020 IJASR All rights reserved
soups. In the unfermented state, African locust bean is non-edible because it contains high quantity of trypsin
inhibitors and flatulence causing oligosaccharides which are anti-nutrients [8,9]. After fermentation, the hard
inedible beans are converted into a soft and palatable nutritious condiment with a sweet pleasant flavor and
improved vitamin content. Basically, production of Dawadawa consists of boiling the locust bean seeds for 1 to 2
days to soften the hard seed coat.
After softening, the seed coats are removed by finger pressure, releasing the cotyledons which are reheated for up to
2 hours. After the second boiling, the cooked water is decanted and the cotyledons spread in basket lined with
blanched banana leaves. The seeds are also covered with several layers of banana leaves and left 2 or 3 days to
ferment in the natural heat of the tropics. Wood ash may also be added which is then sun dried for 2 days before
consumption. When properly dried, Dawadawa can be kept for up to a year in a shelf under tropical conditions [8].
Production of Dawadawaprovides useful nutritional supplements in a nutrient deficient region at a little cost in
capital among traditional processing techniques. In poor families, it can be consumed generously as a low cost
substitute to meat.
1.5.2 Ogiri:
This is also a fermented condimentprepared from the castor seed (Ricinuscommunis) which is a major oil seed
common in Africa and other parts of the tropics [8]. Different types of ogiri exist depending on the starting raw.
Such as Ogiri-uguwhich is made from fluted pumpkin (Telfaireaoccidentalis) seeds whereas Ogiri-egusi is prepared from
melon (citrullus vulgaris) seeds. All types of ogirihave similar preparation method. Raw castor seed is not edible
because of its toxic constituents such as ricin and hemagglutinis as well as trypsin inhibitor [9]. However, the seed
can be fermented and detoxified into a seasoning called Ogiri, used as a condiment in soups or stews. Basically, the
preparation consists of dehaulling the castor seeds, wrapping the dehaulled seeds in blanched plantain leaves and
boiling for to 8 hours and allowed for 4 days to ferment. Later, the seeds are mixed with ash from burnt palm leaves
and then ground into a paste. The resulting paste is rewrapped and left for another 3 days to complete the
fermentation process. Heat and characteristic foul odour from the product indicates that fermentation has been
1.5.3 Ugba (fermented African oil bean)
Ugba is prepared from oil bean (Pentaclethramacrophylla) seeds and are eaten by many people in Eastern Nigeria, which
comprises mainly the Igbo ethnic groups as well as other ethnic groups in Southern Nigeria. The condiment is
produced in a traditional way at home with rudimentary utensils and can be also consumed either as snacks, salads
or as a soup flavor. The unfermented oil bean seed is bitter to taste and contains a toxic alkaloid. Fermentation
renders the Ugba seed nutritious and non-toxic [9].
To prepare Ugba, the seeds are boiled in water for over 12 hours to soften the hard seed coats. The boiled seeds are
then dehaulled to produce the cotyledons or kernels while the seed coats are discarded. The kernels are cut into long
narrow slices (about 0.2 cm thick), washed, boiled for 1 or 2 hours to remove the bittering substances and the cook
water discarded. Then the Ugba slices are soaked overnight (12 hours) in a pan fully covered with water. The soaked
water which also contains part of the bitter substance is now discarded and the sliced samples washed and placed in
a basket to drain completely. Then the Ugba is placed in small portions in blanched banana leaves, wrapped and left
to ferment for 2 to 3 days at room temperature. Fermentation for more than 4 days produces very soft Ugba used
only in soups.
Table 1: Traditional fermented foods in Nigeria
Fermented food
Raw material
Type of product
Cassava tuber
Cassava tuber
All region
Cassava tuber
Rice or Maize
Oil bean
African Locust bean
International Journal of Applied Science and Research
132 Copyright © 2020 IJASR All rights reserved
Castor or Melon seed
Palm sap
Cow milk
Cow meat
1.6 Fermented Meat products:
Fermentation of meat produces desirable organoleptic properties, such as aroma, texture and taste [17], good
nutritional valueand important health benefits [18]. A popular Nigerian locally prepared meat product is known as
Kilishi.It is the most popular traditional dry-cured semi-fermented meat product in Nigeria which is made from
whole muscle of cow. It is the cheapest means of preserving meat and widely consumed and enjoyed by mostly
Northern Nigerians. The production ofKilishi involves drying, curing and pressing the meat and then adding a
cemenpowder-which is a traditional spice made from the combination of red pepper and garlic [9]. Many physical,
microbial, biochemical and organoleptic changes occur during the production of kilishi, such as proteolysis, which
increases the levels of free amino acids, and the addition of cemenimproves the taste and flavor of Kilishi
1.6.2 Nono/Maishanu
Nono is a cow milk-based fermented delicious and refreshing beverage which is widely produced in Northern
Nigeria for nutrition and income generation. It varies according to sociocultural and taste preferences and generally
practiced among the Fulani herdsmen. Traditionally, milk is obtained freshly from cow and boiled for 3hrs and
inoculated with a little of leftover as starter and then is allowed to ferment for 24 hours at room temperature.
During fermentation, some of the lactose is converted to lactic acid by the fermenting microorganisms. At the end
of the fermentation, the milk butter (Maishanu) is removed by churning for further use and the remaining sour milk
which is nono has youghurt-like taste and is usually taken with sugar. It is an excellent source of proteins and
minerals especially, calcium, phosphorous and vitamins [9]. It is more readily available in the northern states of
Nigeria. The collected Nono can also be molded into Wara (soft cheese) which is also delicious.
2.1 Nutritional benefits of fermented foods
Nutritional benefits associated with food fermentation include extension of shelf life, enhancement of food quality
and nutrients, improving digestibility and bioavailability of nutrients, enhancement of the sensory properties (flavor,
aroma and texture, taste, colour), reduction in toxic and anti-nutritional factors, decreases in cooking time and
energy requirement and delivery of probiotic bacteria [4,10,19]. Lactic acid bacteria and yeast create a low moisture
content and pH which are unfavorable conditions for growth of spoilage and pathogenic microorganismsthat may
decompose or spoil the food, thereby extending the shelf-life of the foods, especially for highly perishable foods.
Fermentation can also enhance nutritional properties in a safe and effective manner. The enzymatic activity of the
raw material and the metabolic activity of microorganisms in fermented food can change the nutritive and bioactive
properties of the food matrices in a manner that has beneficial consequences for human health.Traditional
fermented foods are among the most affordable sources of vitamins, minerals and plant-based proteins, which are
essential for good health [10]. During fermentation, bacteria synthesize vitamins, minerals, organic acids and
produce biologically active peptides with enzymes such as proteinase and peptidase and remove some non-nutrients
[9,10].The B-vitamins including folate (B9), riboflavin (B3), and cobalamin (B12) are synthesized from various non-
vitamin precursors by certain bacteria during fermentation [20,21]. The microorganisms involved in the
fermentation of indigenous foods also improve the sensory properties by producing favorable volatile end products
which promote the growth of fermenting bacteria and protect against pathogenic microorganisms [22].
Also during fermentation, microbial amylase hydrolyses carbohydrate into sugars which are then readily digestible
by humans. Galactinase, (another microbial enzyme) soften the texture of the seeds and liberate sugars for digestion
[23]. Most legumes which contain large amount of non-digestible carbohydrates are associated with abdominal
distention and flatulence in humans but fermentation reduces the total flatus in legumes [10]. In most fermented
high protein products, the extent of protein hydrolysis is one of the most important factors responsible for texture
and flavor seen after fermentation. Soluble low molecular weight peptides and amino acids that contribute to flavor
are also produced through the enzymatic breakdown of proteins [10,24]. Some polysaccharides produced
International Journal of Applied Science and Research
133 Copyright © 2020 IJASR All rights reserved
duringfermentation act as prebiotics which are further fermented by the microbiota in the colon to favorable short
chain fatty acids with health benefits.
Additionally, fermentation results in the removal of toxic or undesirable food constituents such as phytic acid (9,10]
which is an anti-nutritional compound that chelates divalent importantmetal ions reducing their absorption and
bioavailability. The reduction of pH as a result of lactate production during fermentation optimizes endogenous
phytase activity thus removing most phytate and increase the bioavailability of essential mineralsthat helps maintain
immune system.
2.2 Fermented foods and probiotics
Microorganisms contributing to the food fermentation process have recently been associated with many health
benefits and these microorganisms (probiotics)have become another focus of attention in nutrition and wellbeing.
By definition, probiotics are live microorganisms that when administered in adequate amounts confer a health
benefit on the host [25,26]. Studies have found that the intake of probiotics resulted in minor but consistent
improvements in several metabolic risk factors in subjects with metabolic diseases and particularly in insulin
resistance [1,4,27].
Different types of bacteria (e.g, Lactobacillus, Bifidobacterium, Streptococcus, Bacillus) and yeast or mold (e.g, Saccharomyces,
Aspergillus, Candida) are used as probiotics [28]and studies showed that indigenous fermented foods and beverages
may serve as a suitable carrier for these probiotics. Many fermented foods and beverages products are processed
such that viable microorganisms are present at the time of consumption and a relatively large fraction of those
microbes survives passage through the human digestive tract [29,30]. The ingestion of fermented foods containing
probiotics potentially increase the numbers of microbes in the diet by up to 10, 000-fold [31] and consuming these
fermented foods could be equivalent to introducing new beneficial microorganisms into the intestinalmicrobiota.
It is very important to note that fermented foods are not same as probioticsbecause not all fermented foods contain
live microorganisms. Taking beer and wine as example, which undergo further steps after production that removes
the organisms and other fermented foods such as bread are heated at higher temperature which inactivates the
microorganisms in the food. Therefore, the strain composition and stability of the microorganisms in traditional
fermented foods arenot clearly understood [7]. However, when fermented foods and beverages are supplemented
with probiotic bacteria, they serve as nutraceuticals and provide numerous extra nutritional and health benefits.
2.3 Health Benefits Associated with Fermented Foods
In the past, the health benefits of fermented foods were unknown and so many people primarily used fermentation
only to preservefoods and improve theirsensory qualities.Recently, it is increasingly understood that these fermented
foods also promote human health in ways that are not directly attributable to the starting unfermented food
materials. Nowadays, fermented foods have become an important part of the diet in many cultures and have
recently emerged as a novel functional food with many health benefits that gobeyond basic nutrition. Fermented
foods generally have the potential to lower the risk of carcinogenesis, atherosclerosis, oxidation, tumors, obesity
[32], inflammation [27], mutagenesis, hypercholesterolemia effects [33], stimulating the immune system [34,35]and
alleviating the symptoms of lactose intolerance [36].
Recent human clinical studies on fermented foods support this possibility. For instance, large cohort investigations
revealed strong associations between consumption of fermented foods and weight maintenance [37,38].Another
long-term prospective study shows reductions in risk of cardiovascular diseases and overall mortality from frequent
yogurt consumption [39]. Similarly, An et al.,[40]and Choi et al., [33] showed that kimchi ( a fermented food)
possesses health beneficial effects especially on people with pre-diabetes by inducing insulin sensitivity and
decreasing insulin resistance.In addition,fermented rice has been shown tohave beneficial effect on hypertension
and metabolic syndrome and may prevent some lifestyle diseases [41]. Another similar study showed
thatfermentedfoodsreduce fatigue and stresses [42] and protects against oxidative stress induced by DNA damage
[43]. Also, fermented foods have been proved to help the liver against the free radicals produced by copper
accumulation [44].
The health benefits provided by fermented foods could be attributable to the bioactive compounds formed during
fermentation process and other metabolites produced by the microorganisms responsible for fermentation
[45].Physiologically-active peptides with different functionalities, phytochemicals, free amino acids and their
International Journal of Applied Science and Research
134 Copyright © 2020 IJASR All rights reserved
derivatives,volatile compounds and organic acids are all produced by various microorganisms during the food
fermentation [9,10]. Due to their bioactivities, these peptides possess the potential to be used in the formulation of
health enhancing nutraceuticals that may play different physiological roles in the body. For instance, conjugated
linoleic acidwhich is a metabolite produced during fermentation; have a blood pressure lowering effect [46].
Another bioactive compound called exopolysaccharideisnatural polymer of sugars that are produced biologically by
various microorganisms during fermentation [47,48]. Due to the potential health benefits associated with
exopolysaccharides, which include anti-oxidant, anti-diabetic, anti-carcinogenes, cholesterol lowering and
immunomodulatory properties, the compound has recently become a focus of interest by researchers [49,50].
Free amino acids and its neurotransmitter derivatives (Gama-aminobutyric acid-GABA) which regulate blood
pressure against cardiovascular and cancer and also possessimmuno-modulatory function are synthesized during
fermentation [51]. The free amino acids and GABA contents of fermented foods also contribute to its anti-diabetic
and anti-oxidant properties [52] and havealso been shown to have potential chemo-preventive[53], hypolipidemic
and anti-inflammatory effects [54]. Lactic acid (a major end-product of food fermentation) has been reported to
reduce pro-inflammatory cytokine secretion in a dose dependent manner [55]and also alters redox status by
reducing the reactive oxygen species burden in intestinal enterocytes [56].
Apart from the bioactive compounds which are produced during food fermentation, several studies have shown
that probiotics contained in fermented foodsalso provides several health benefits [10,24,28]. For example, ingestion
of vibrant probiotics through fermented foods is found to cause significant positive improvements in balancing
intestinal permeability [57], having direct effects on metabolic syndromes, atherosclerosis, inflammatory bowel
diseases [27], colon cancer enhanced immune system and improve gastrointestinal function [4,10]and indirect
effects on depression, anger, anxiety and levels of stress hormones [58].Studies have revealed that Lactobacillus
sppwhich are common organisms in fermented foods could reduce the risk of infections, including bacterial
vaginosis [59,60]. It could also reduce the occurrence of gonorrhoea, chlamydia, and other sexually transmitted
diseases and diarrhoea [61]. Many fermented foods are high in vitamin C and iron, both of which help the body to
fight against infection by contributing to a healthy immune system.
2.4 Effect of fermented foods on human immune system
Imbalance in the gut microbiota is associated with the pathogenesis of various diseases [1,62,63], including
hypertension, diabetes mellitus, cancer, obesity and cardiovascular diseases which are considered risk factors for
complications in people with Covid-19. Different levels of evidence have supported the role of nutrition and
fermented foods in balancing and promoting immunity [1,4,28,64,]andrecent reports have shown that some of the
countries with low Covid-19 mortality rate are those with a relatively high national consumption of traditional
fermented foods [3,4]. The human gut is home for over 200 species of bacteria collectively known as the gut
microbiotawhichlive mutually in gut of humans [62]. These microbes help break down food in the intestines, aid in
the digestion process, help fight off disease, and boost the immune system [3,63]. The immune isthe group of cells
and molecules that protect us from disease by monitoring our body and responding to any foreign substances they
perceive as threats, particularly infectious microbes [10].
Recently, fermented foods have regained popularity as part of diets due to the interest in their significant impact on
the gut microbiota balance and immune system. The importance of the interactions between the gut microbiota and
the immune system is clearly highlighted by the fact that majority (about 80 per cent) of the body’s immune cells are
found in the human gut[4,63]. As a consequence, the immune system and the gut microbiota developed a
mutualistic relationship regulating one another and cooperating to support each other.This means that when gut
health is imbalanced, it is difficult for the body’s immune system to function properly [65,66] and this may increase
predisposition to inflammatory and immune-mediated diseases.According to Stiemsmaet al.,[67], frequent
consumption of fermented foodswhich contain probiotics may help improve the immune system’s function by
balancing the human gut microbiota.
The administration of probiotics through fermented foods has been shown to alter the composition and
functionality of the gut microbiota thereby modulating the immune system to fight infections and diseases [4,10,65].
Moreover, having an active and natural variety of microorganisms in the gut may improve general health since the
good and healthy microorganisms in the gut make food more digestible through their enzymes which also help also
to maintain immune system [65]. Therefore, probiotics contained in fermented indigenous food may restore the
International Journal of Applied Science and Research
135 Copyright © 2020 IJASR All rights reserved
composition of the gut microbiome and introduce beneficial functions to gut microbial communities and thereby
boosting the immune system to fight infections [67].
Apart from the effects of probioticson gut bacteria, the systemic effects of bioactive peptides which are produced
during fermentation also possess some immuno-modulatory effects [10]. In a study to determine the serum cytokine
profiles of healthy volunteers after consuming Kefir (fermented beverage), it was reported that immune cells (TNF-
α) levels were increased with Kefir consumption, though the increase was not significant [68]. Again, consumption
offermented foods and beverages improves the bio-accessibility and bioavailability of food bioactive components,
supplying dietary fibers, essential micronutrients, enzymes and organic acids, all of which are crucial in boosting the
immune system. Short chain fatty acids which are produced from insoluble dietary fibers by certain microbial
species in fermented foods also promote the activity of regulatory T-cells which prevent inflammatory reactions by
suppressing the abnormal activation of other immune cells [1], thereby playing a very important part in maintaining
immune tolerance and self-antigens.
In fact, the human microbiotawhich is related to immunity is a key contributor to many aspects of human health
and its composition is largely influenced by diet we eat [69]. A healthy interaction between the immune system and
the gut microbiota is crucial for the maintenance of the body’s homeostasis, immunity and wellbeing [65]. If we eat
nothing but overly processed and difficult to digest foods, then the fermentation process will occur within the
gastrointestinal track resulting into gas, bloating, diarrhea, and constipation which might possibly lead to other
diseases like cancer. However, providing the body with predigested foods such as fermented foods will help the
existing microbes within to do the job they need to do, which includes stimulating the immune system to function
properly. This is why it is important to take good care of our gut and this starts with what we eat [69]. Taking into
considerations the benefits of these traditional fermented foods, utilizing them properly at larger scale could
mitigate the economic effects of Covid-19 especially on food security and also help boost the immunity to possibly
face the infection.
3. Conclusion
Fermented foods are increasingly understood for their properties that extended well beyond preservation and
sensory attributes. They offer additional health benefits and enhanced nutrient availability far beyond the
unfermented material. Fermented foods have the potentials to boost the immune system to possibly face the
infection by balancing the gut microbiota which is linked with immunity. Nigerian traditional fermented foods and
beverages if properly developed as standard commercial products could also play a major role in the national food
security especially during and post Covid-19 by mitigating the economic effects of the pandemic in the country.
Without being a promise of efficacy against Covid-19, incorporating these locally fermented foods and beverages
into diets may help to minimize gut inflammation and enhance immunity to possibly lower the severity or the
duration of infection episodes pending when an effective vaccines or drugswhich can interfere withthe
virusmetabolismsis discovered.
4. Acknowledgement
The authors are thankful to the MobilitéUniversitaire en Afrique (MOUNAF) projectof the Intra-Africa Academic
Mobility Scheme of European union for the financial support.
Ethics statement
There are no ethical concerns in thisreview article
5. Author contributions
P.N.A reviewed the literature and wrote the manuscript. P.N.O and C.O.E read and revised the manuscript. P.N.A
wasresponsible for the concept, preparation and submission of the final article.
6. Conflict of Interest
The authors declare no conflicts of interest
International Journal of Applied Science and Research
136 Copyright © 2020 IJASR All rights reserved
1) Adriane E C Antunes, Gabriel Vinderola, Douglas Xavier Santos, Katia Sivieri (2020) Potential
contribution of beneficial microbes to face the Covid-19 pandemic, Food Research International; 156, 109577
2) Zabetakis I, Lordan R, Norton C, Tsoupras A (2020) COVID-19: The Inflammation Link and the Role of
Nutrition in Potential Mitigation. Nutrients. 2020;12(5).
3) Bousquet J, Anto J, Iaccarino G, Czarlewski W, Haahtela T, Anto A, et al (2020). Is diet partly responsible
for differences in Covid-19 death rates between and within countries? ClinTransl Allergy.2020.
4) Susana C Fonseca, Ioar Rivas, Dora Romanguera, Marcos Quijal, WiencyyslawaCzarlewski, Alain Vidal et al
(2020) Association between consumption of fermented vegetables and Covid-19 mortality at a country level
in Europe.
5) Borresen E C, A J Henderson, A Kumar, T L Weir, E P Ryan(2012) Fermented foods: patented approaches
and formulations for nutritional supplementation and health promotion. Recent Patents on Food, Nutrition &
Agriculture 4 (2):13440.
6) Narzary Y, Brahma J, Brahma C, Das S (2016). A study on indigenous fermented foods and beverages of
Kokrajhar, Assam, India. Journal of Ethnic Foods;3(4):28491.
7) Tamang J P ( 2010) Diversity of fermented foods. Fermented Foods and Beverages of the World, eds. pp.
4172. CRC Press: New York.
8) Achi O K (2005)Traditional fermented protein condiments in Nigeria. African Journal of Biotechnology; vol., 4
(13), 1612-1621
9) Egwim Evans, Amanabo Musa, YahayaAbubakar, Bello Mainuna (2013) Nigerian indigenous fermented
foods; process and prospects. Intech; 153 -180
10) Maria L Marco, Dustin Heeney, SylvicBinda, Christopher J. Cifelliet al., (2017) Health benefits of fermented
foods: Microbiota and beyond. Current opinion in Biotechnology, 44: 94-102
11) Anukam KC, Reid G (2009) African traditional fermented foods and probiotics. J. Med. Food; 12, 1177
12) Food and Agriculture Organization of the United Nations. (2017) “Nigeria at a glance”. FAO; Available at
13) Blandino A, Al-Aseeri M,Pandiella S, Cantero D, Webb C(2003) Cereal-based fermented foods and
beverages. Food Research International; 36 (6):52743.
14) Đorđevic TM, Siler-Marinkovic SS, Dimitrijevic-Brankovic SI ( 2010) Effect of fermentation on
antioxidant properties of some cereals and pseudo cereals. Food Chemistry; 119 (3):95763.
15) Gupta S, Abu-GhannamN (2012) Probiotic fermentation of plant based products: possibilities and
opportunities. Critical Reviews in Food Science and Nutrition;52(2):18399.
16) Nguyen DT L,VanHoorde K, Cnockaert M, De Brandt E,Aerts M, Vandamme P(2013)A description of the
Lactic acid bacteriamicrobiota associated with the production of traditional fermented vegetables in Vietnam.
International Journal of Food Microbiology 163 (1):1927.
17) Giyatmi,Irianto H (2017) Enzymes in Fermented Fish. Advances in food and nutrition research, marine
enzymes biotechnology: production and industrial applications, part III application of marine enzymes,
eds.K.Se-Kwon and T.Fidel,Academic Press vol.80,199216.
18) Adjou E S, Degnon R G, Dahouenon-Ahoussi E, Soumanou MM, Sohounhloue DC (2017) Improvement
of fermented fish flour quality using essential oil extracted from fresh leaves of Pimentaracemosa (Mill.) JW
Moore. Natural Products and Bioprospecting;7(4):299305.
19) Hwang J, Kim J, Moon H, Yang J, Kim M(2017) Determination of sodium contents in traditional
fermented foods in Korea. Journal of Food Composition and Analysis; 56:1104.
20) Chamlagain B, Edelmann M, Kariluoto S, Ollilainen V, Piironen V (2015) Ultra-high performance liquid
chromatographic and mass spectrometric analysis of active vitamin B12 in cells of Propionibacteriumand
fermented cereal matrices. Food Chem;166; 630-638.
21) Russo P, CapozziV, Arena MP, Spadaccino G, Duenas MT, Lopez P, Fiocco D, Spano G (2014)
Riboflavin-overproducing strains of Lactobacillus fermentum for riboflavin-enriched bread.
ApplMicrobiolBiotechnol; 98:3691-3700.
22) Bleve G, Tufariello M, Durante M,Perbellini E,Ramires FA, Grieco F, Cappello MS, De Domenico S,Mita
G et al., (2014)Physico-chemical and microbiological characterization of spontaneous fermentation of
Cellina di Nardo and Leccino table olives. Frontiers in Microbiology 5:570.
23) Kiers JL, Van Laekan AEA, Rombouts FM, Nout MJR (2000)In vitro digestibility of Bacillus fermented soya
bean. Int. Food Microbiol. 60:163-169.
International Journal of Applied Science and Research
137 Copyright © 2020 IJASR All rights reserved
24) NevinSanlier, BusraBasarGokcen, AybukeCeylunSezgin (2017) Health benefits of fermented foods. Critical
Reviews in food science and nutritional; vol.1, 1 to 22
25) Flavera C Prado, Jose LParada, Ashok Padey, Carlos R, Soccal (2008) Trendsinnon-diary
probioticbeverages. Food research international; vol. 41 (2), 111-123
26) JPTamang (2009)Himalayan Fermented Foods: Microbiology, Nutrition and Ethnic Values, CRCPress,
NewDelhi, India.
27) LoreaBaroja M, Kirjavainen PV, Hekmat S, Reid G (2007)Anti-inflammatory effects of probiotic yogurt in
inflammatory bowel disease patients. ClinExpImmunol; 149:470-479
28) Gille D, Schmid A, Walther B, VergèresG (2018) Fermented Food and Non-Communicable Chronic
Diseases: A Review. Nutrients2018, 10, 448.
29) Derrien M, van HylckamaVlieg JET (2015) Fate, activity, and impact of ingested bacteria within the human
gut microbiota. Trends Microbiol; 23:354-366
30) Kim JY, Choi EY, Hong YH, Song YO, Han JS, Lee SS, Han ES, Kim TW, Choi IS, Cho KK (2016)
Changes in Korean adult females’ intestinal microbiota resulting from kimchi intake. J Nutr Food Sci 2016;
31) Lang JM, Eisen JA, Zivkovic AM (2014) The microbes we eat: abundance and taxonomy of microbes
consumed in a day’s worth of meals for three diet types. PeerJ., 2014
32) Dahiya DK, RenukaPuniya M,Shandilya UK, Dhewa T, Kumar N, Kumar S, Puniya AK, Shukla P (201)
Gut Microbiota Modulation and Its Relationship with Obesity Using Prebiotic Fibers and Probiotics: A
Review. Front. Microbiol, vol. 8, 563.
33) Choi IH, Noh JS, Han J, Kim H.J, Han E, Song YO (2013)Kimchi, a fermented vegetable, improves serum
lipid profiles in healthy young adults: randomized clinical trial. Journal of Medicinal Food; 16 (3):223229.
34) Corsetti A,Perpetuini G, Schirone M,Tofalo R, Suzzi G (2012)Application of starter cultures to table olive
fermentation: an overview on the experimental studies. Frontiers in Microbiology 3:248.
35) Park KY, JK Jeong, YE Lee, JW Daily, (2014) Health benefits of kimchi (Korean fermented vegetables) as a
probiotic food. Journal of Medicinal Food; 17 (1):620.
36) Tamang JP, Kailasapathy K(2010) Fermented foods and beverages of the world. CRC press.
37) Kim EK, An SY, Lee MS, Kim TH, Lee HK,HwangWS, Choe SJ, Kim TY, Han SJ, Kim HJ(2011)
Fermented kimchi reduces body weight and improves metabolic parameters in overweight and obese
patients. Nutrition Research; 31(6):43643.
38) Mozaffarian D (2011) Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J
Med; 364:2392-2404.
39) Eussen SJPM, van Dongen MCJM, Wijckmans N, den Biggelaar L, Oude Elferink SJWH, Singh-Povel CM,
Schram MT, Sep SJS, van der Kallen CJ, Koster A et al. (2016) Consumption of dairy foods in relation to
impaired glucose metabolism and type 2 diabetes mellitus: the Maastricht Study. Br J Nutr;115:1453-1461.
40) An SY, Lee MS,Jeon JY, Ha ES, Kim TH, Yoon JY, Ok CO, Lee HK, Hwang WS,Choe SJ (2013)
Beneficial effects of fresh and fermented kimchi in prediabetic individuals. Annals of Nutrition and
41) Alauddin M, Shirakawa H, Koseki T, Kijima N, BudijantoS, Islam J, Goto T, Komai M (2016) Fermented
rice bran supplementation mitigates metabolic syndrome in stroke-prone spontaneously hypertensive rats.
BMC Complementary and Alternative Medicine; 16(1):442
42) Kim KK, Yu D Kang, Suh H(2002) Anti-stress and anti-fatigue effect of fermented rice bran. Phytotherapy
Research; 16(7)
43) Kong EL, BK Lee, I Ginjom, PM Nissom (2015) DNA damage inhibitory effect and phytochemicals of
fermented red brown rice extract. Asian Pacific Journal of Tropical Disease; vol. 5 (9):73236.
44) Baek S, Park S, Lee H(2005)Hypocholesterolemic action of fermented brown rice supplement in
cholesterol-fed rats: cholesterol loweringaction of fermented brown rice. Journal of Food Science-Chicago;70
45) MeliniF, Melini V, Luziatelli F, Ficca AG, Ruzzi M (2019) Health-Promoting Components in
FermentedFoods: An Up-to-Date Systematic Review. Nutrients;11(5).
46) Hayes M, García-Vaquero M (2016) Bioactive Compounds from Fermented Food Products. In Novel
Food Fermentation Technologies; Ojha, K., Tiwari, B., Eds.; Food Engineering Series; Springer: Cham,Switzerland,
47) Patel A, Prajapat J. B(2013) Food and health applications of exopolysaccharides produced by lactic acid
bacteria. Advances in Dairy Research; 1(2):17.
International Journal of Applied Science and Research
138 Copyright © 2020 IJASR All rights reserved
48) Deepak V, Ramachandran S,Balahmar RM, Pandian SR K, Sivasubramaniam DS, Nellaiah H, Sundar K
(2016) In vitro evaluation of anticancer properties of exopolysaccharides from Lactobacillus acidophilus in
colon cancer cell lines. In Vitro Cellular & Developmental Biology-Animal;52(2):16373.
49) Nampoothiri KM,Beena DJ, Vasanthakumari DS, IsmailB(2017) Health benefits of exopolysaccharides in
fermented foods. Boston: Academic Press;4962..
50) Wu MH, Pan TM, Wu YJ, Chang SJ, Chang MS, Hu CY(2010)Exopolysaccharide activities from probiotic
bifidobacterium: Immunomodulatory effects (on J774A. 1 macrophages) and antimicrobial properties.
International Journal of Food Microbiology; 144 (1):104110.
51) Becerra-Tomas N, Guasch-Ferre M, Quilez J, Merino J, Ferre R, Diaz-Lopez A, Bullo M, Hernandez-
Alonso P, Palau-Galindo A, Salas-Salvado J (2015) Effect of functional bread rich in potassium, gamma-
aminobutyric acid and angiotensin-converting enzyme inhibitors on blood pressure, glucose metabolism
and endothelial function: a double-blind randomized crossover clinical trial. Medicine (Baltimore) 2015
52) Yeap SK, N. Mohd Ali, H. MohdYusof, N B Alitheen, BK Beh, WY Ho, SP Koh, K Long
(2012)Antihyperglycemic effects of fermented and non-fermented mung bean extracts on alloxan-
induceddiabetic mice. BioMed Research International 2012.
53) Yeap SK, H. MohdYusof, NE Mohamad, BK Beh, WY Ho, NM Ali, SP Koh, K Long(2013) In vivo
immunomodulation and lipid peroxidation activities contributed to chemoprevention effects of fermented
mung bean against breast cancer. Evidence-Based Complementary and Alternative Medicine 2013.
54) Mohd Ali N, H MohdYusof, K Long, SK Yeap, WY Ho, BK Beh, SP Koh, MP Abdullah, NB Alitheen
(2012) Antioxidant and hepatoprotective effect of aqueous extract of germinated and fermented mung bean
on ethanol-mediated liver damage. BioMed Research International 2013: 693613, p.9.
55) Iraporda C, Errea A, Romanin DE, Cayet D, Pereyra E, Pignataro O, Sirard JC, Garrote GL, Abraham AG,
Rumbo M (2015) Lactate and short chain fatty acids produced by microbial fermentation downregulate
pro-inflammatory responses in intestinal epithelial cells and myeloid cells. Immunobiology; 220 (3):1161-1169.
56) KahlertS, Junnikkala S, Renner L, Hynonen U, Hartig R, Nossol C, Barta-Boszormenyi A, Da¨ nicke S,
Souffrant WB, Palva A et al., (2016) Physiological concentration of exogenous lactate reduces antimycin a
triggered oxidative stress in intestinal epithelial cell line IPEC-1 and IPEC-J2 in vitro. PLOS ONE 2016
57) Hiippala K, Jouhten H, Ronkainen A, Hartikainen A, Kailunanen V, Jalanka J, Satokari R (2018)The
potential of gut commensals in reinforcing intestinal barrier function and alleviating inflammation.Nutrients;
10, 988
58) Heidari F, Abbaszadeh S,Mirak SEM (2017) Evaluation Effect of Combination Probiotics and Antibiotics
in the prevention of Recurrent Urinary Tract Infection (UTI) in Women. Biomed. Pharmacol. J.;vol10, 691
59) Reid G, Beuerman D, Heinemann C, Bruce A W (2001a) Probiotic Lactobacillus dose required to restore and
maintain a normal vaginal flora. FEMS Immunol Med Nlicrobiol; 32:37-41.
60) Cadieux P, Burton J, Kang CY(2002). Lactobacillus strains and vaginal ecology. JAMA; 287:1940-1941.
61) Adebolu TT, Olodun A O, Ihunweze B C (2007) Evaluation of ogiliquor fromdifferent grains for
antibacterial activities against some common pathogens. Afr. J. Biotech. 6 (9): 1140-1143.
62) Rooks MG, Garrett WS (2016) Gut microbiota, metabolites and host immunity. Nature Reviews Immunology;
16(6), 341352
63) Vandana UK, Barlaskar NH, Gulzar ABM, Laskar IH, Kumar D, Paul P, et al. (2020) Linking gut
microbiota with the human diseases. Bioinformation;16(2):196-208
64) Iddir M, Brito A, Dingeo G, Fernandez Del Campo SS, Samouda H, La Frano MR, et al. (2020)
Strengtheningthe Immune System and Reducing Inflammation and Oxidative Stress through Diet and
Nutrition:Considerations during the COVID-19 Crisis. Nutrients;12(6)
65) Ashraf R, Shah N P (2014). Immune system stimulation by probiotic microorganisms.Critical Reviews in Food
Science and Nutrition; 54(7), 938956.
66) Opazo MC, Ortega-Rocha, EM, Coronado-Arrázola I; Bonifaz LC, Boudin H, Neunlist M,Bueno SM,
Kalergis AM, Riedel CA (2018) Intestinal Microbiota Influences Non-intestinal Related Autoimmune
Diseases. Front. Microbiol; 9, 432.
67) Stiemsma L, Nakamur RE, Nguyen JG, Michels KB (2020) Does consumption of fermented foods modify
the human gut microbiota? J. Nutr. 150 (7): 1680-1692
68) Adiloglu A, NGonulates, MIsler, A Senol(2013)The effect of kefir consumption on human immune system:
a cytokine study. MikrobiyolojiBulteni; 47 (2):27381.
69) Zmora, Suez J, Elinav E (2019) You are what you eat: Diet, health and the gut microbiota. Nature Reviews
Gastroenterology &Hepatology; 16(1), 3556.
... This dependence is not surprising given that these foods are readily available and affordable [102]. Depending on the kind of raw food found in a particular location, each region has its typical fermented foods, which significantly contribute to its socioeconomic growth [104,105]. The locally fermented foods can be classified based on food type (staple, condiments or beverages) or raw material (tuber, legumes, cereals, dairy, fish and tree sap). ...
... M. esculenta and M. utilissima). Across the continent, garri, amala, lafun, elubo, fufu, abacha (Nigeria), attieke, placali(Côte d'Ivoire), kokonte, agbelima (Ghana); myiodo, atangana, kumkum, bobolo (Cameroun), maphumu, makaka (Malawi), kivunde (Tanzania), chickwanghe (Zaire), mboung (Gabon), mangbele (Central African Republic) are all obtained from cassava fermentation [103][104][105][106][107][108][109][110]. The processing techniques of some of these foods are similar with slight variations based on country or tribe. ...
... In addition, dawadawa/iru (Nigeria), soumbala (Burkina-Faso), netetu (Senegal), kinda (Sierra Leone), kpalugu (Ghana) are all obtained through the fermentation of African locust bean seeds (Parkia biglobosa) [101,112,128]. These foods are widely used as condiments in most local dishes to enhance the flavor and serve as cheap meat substitutes in low-income households [104]. The commonly associated microorganisms are the Bacillus group (B. ...
Full-text available
The current paper focuses on the impact of probiotics, African fermented foods and bioactive peptides on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection severity and related viral infections. Using probiotics or bioactive peptides as therapeutic adjuncts appears superior to standard care alone. Probiotics play critical roles in innate and adaptive immune modulation by balancing the gut microbiota to combat viral infections, secondary bacterial infections and microbial dysbiosis. African fermented foods contain abundant potential probiotic microorganisms such as the lactic acid bacteria (LAB), Saccharomyces, and Bacillus. More so, fermented food-derived bioactive peptides play vital roles in preventing cardiovascular diseases, hypertension, lung injury, diabetes, and other COVID-19 comorbidities. Regularly incorporating potential probiotics and bioactive peptides into diets should enable a build-up of the benefits in the body system that may result in a better prognosis, especially in COVID-19 patients with underlying complexities. Despite the reported therapeutic potentials of probiotics and fermented foods, numerous setbacks exist regarding their application in disease management. These shortfalls underscore an evident need for more studies to evaluate the specific potentials of probiotics and traditional fermented foods in ameliorating SARS-CoV-2 and other viral infections.
... Fermentation is an effective and sustainable food processing method that increases the shelf-life and organoleptic properties of food (such as taste and flavor) [17] . It also improves bioavailability of nutrients in source foods by eliminating antinutritional factors [18][19][20] . ...
... It also improves bioavailability of nutrients in source foods by eliminating antinutritional factors [18][19][20] . It helps in promoting general health through fermenting bacteria that serves as food probiotics [17] . Fermentation process has also been reported to induce pH reduction and organic acids production [ 13 , 14 ]. ...
Fermented Macrotermes nigeriensis-Cassava mahewu (MECM) has the potential to contribute substantially to nutrition security due to its enhanced protein and micronutrient contents. However, changes related to fermentation time during processing are important factors that could affect the nutritional quality. This study determined the influence of fermentation time (0 h to 48 h) on nutritional (protein, Fe, Zn, Ca and ascorbic acid), anti-nutritional factors (phytate oxalate and tannins) and protein digestibility of freeze-dried fermented MECM using in-vitro digestion methods and standard procedures. Cassava flour was replaced with M. nigeriensis powder at 70:30% and fermented for 0, 12, 24, 42 and 48 h to obtain MECM. Results showed a decrease (P < 0.05) in pH (6.45–3.65) and increase in titratable acidity (TTA) (0.10–0.38%) with increasing fermentation time. Fermentation for 42 h enhanced (P < 0.05) protein (21.02%), Fe (52.69%), Zn (69.46%), ascorbate (125.71%) and protein digestibility (62.42%) higher than other fermented samples. Fermentation for 48 h resulted in highest reduction (P < 0.05) in Phytate (64.16%), oxalate (76.11%) and tannins (41.32%). Fermenting MECM at 42 h is an effective means of improving its nutritional qualities, while at same time providing better conditions for degrading inhibitors of minerals absorption.
... Kefirdeki laktik asit bakterilerinin, laktozu fermente ederek laktik asit oluşturarak ortamın pH'sında düşüş meydana getirmektedirler. Oluşan bu laktik asit ise ürünü diğer hastalık yapıcı mikroorganizmalara karşı ve bağırsak hücre duvarına koruma sağlamaktadır (Ismaiel, Ghaly, & El-Naggar, 2011;Anyiam, Onwuegbuchu, & Ekemezie, 2020). Fermentasyon sonucunda oluşan laktik asidin yaklaşık %90'nının L(+) laktik asit olması, kefirin vücuda yarayışlılığını daha da artırmaktadır (Harald, 1985). ...
... Proteinlerin fermentasyonu sonucu oluşan biyoaktif peptidler (katasin, vanilin, salisilik asit ve ferulik asit) ise antimikrobiyel ve antioksidant özellik göstermektedir (Ebner, Arslan, Fedorova, Hoffmann, Küçükçetin, & Pischetsrieder, 2015). Bu biyoaktif bileşenler, bağırsaktaki bağışıklık hücre sayısında artış sağlamaktadır (Anyiam, Onwuegbuchu, & Ekemezie, 2020). Kefirdeki bileşenler (proteinler, peptidler, karbonhidratlar, vitaminler) ve bunların türevleri (ikincil metabolitler) vücut bağışık sistemini dengelediğinden, viral enfeksiyonları ve viral enfenksiyonlardan kaynaklanan (COVID-19) bozulmaları da baskılamaktadır (Reham, Ashwag, Mohamed, Zakiah, Afrah, & Mashael, 2021). ...
Full-text available
Nowadays, the consumption of probiotic foods for customers has increased due to awareness of healthy life and protection from Coronavirus disease 2019 (COVID-19). In this review, the importance of kefir, a fermented and probiotic dairy is emphasized on the healthy diets. The intestinal flora is favourably influenced by the various metabolites and vitamins produced during fermentation. The flora as a whole influences in their turn the digestibility and bioavailability of many nutritive constituents of milk, stimulate the immune systems and suppress infections from viruses (COVID-19). It also has numerous antioxidants and therapeutic properties from illnesses particularly bowel syndrome, hypertension, chronic diseases, metabolic disorders, yeast infections, cholesterol, wound, weight control, diabetic, cancer and Crohn's disease. Consequently, kefir, accepted as a food product, improves health benefits of human body to long human life according to previous literatures. However, it is thought that this study will partially shed light on the next studies because of some missing studies to be done in future.
... The nutritional profile of M. nigeriensis makes it suitable as an interesting assortment for local food enrichment. Fermentation is a food preparation method that improves the bioavailability of nutrients in source foods, increase the shelf-life and promote general health through fermenting bacteria that serves as probiotics ( Gupta, Gangoliya & Singh, 2015 ;Anyiam, Onwuegbuchu & Ekemezie, 2020 ). ...
The high prevalence of undernutrition among children in developing countries has necessitated the present study which was aimed at evaluating the contribution of Microtermes nigeriensis-improved cassava mahewu (TECM) to nutrient intake (RNI) of children. Cassava flour was replaced with M. nigeriensis (MN) powder at 30% and fermented to obtain cassava mahewu. Standard cassava mahewu (SCM) was used as control. The samples were analysed for proximate and micronutrients after freeze drying using standard methods. Nutrient intakes were computed and percentage contributions to RNI were calculated. Data were analyzed using descriptive statistics. Results indicate that contribution of SCM to RNI were protein (5.8, 4.6%), iron (8.6, 7.5%), Zinc (4.5, 2.9%), calcium (2.5, 1.4%) and Vitamin C (34.9, 30.5%) for 6-9 and 10-15 years old respectively, which is extremely low compared to reference RNI. However, the inclusion of MN improved (P<0.05) contribution to protein (46.4 and 36.8%), Zinc (45.4 and 29.5%), Iron (72.7 and 63.6%) and Ascorbate (87.1 and 76.3%) respectively, but did not meet the requirement for calcium (1.98 and 1.06%). This finding indicates that MN-improved cassava mahewu can be used as a food-based strategy to reduce the wide spread child's malnutrition in developing countries if adequately promoted.
... Their reports are in reasonable agreement with the mechanisms of action of probiotic bacteria earlier mentioned. Bacteriocins produced by Lactobacillus can also find useful application in storage and food preservation; other probiotic and functional attributes of Bacillus sp. for local fermented foods like ugba are well documented (Ajanaku et al., 2022;Amin et al., 2020 ;Anukam et al., 2009 ;Anyiam et al., 2020 ;Fouad et al., 2017 ;Maganha et al., 2014 ;Obafemi et al., 2022 ;Nwagu et al., 2020 ;Parvez et al., 2006 ;Ranjana and Nivedita, 2017 ;Wang et al., 2010 ) ...
Full-text available
Probiotics are live cultures of beneficial microorganisms that confer health benefits to humans and animals when administered in adequate amount contributing to both intestinal microbial balance and maintenance of health. The mechanisms of function is believed to be through modification of gut pH, production of antimicrobial compounds, competing for pathogen binding and receptor sites, stimulating immunomodulatory cells and production of lactase among others. Most probiotic foods are of dairy sources such as acidophilus milk, probiotic yoghurt, chesses and probiotic juices among others. These functional food products are exotic and expensive due to their associated health benefits. Ugba a fermented African oil bean seed is a non –dairy probiotic food product that is inexpensive and usually consumed after alkaline solid state fermentation. Ugba has the ability to deliver the health benefits of functional food products when consumed regularly. However, in order to obtain the health benefits from probiotic microorganisms associated with the fermentation of African oil bean seed, these organisms must be maintained in the most viable form and free from contaminations arising from uncontrolled fermentation after the normal production period, contamination during processing from diverse sources like water, air, handling, leaves used for packaging and unhygienic environment predisposing the product to rapid spoilage and decrease in viability of these organisms. The identified methods for maintenance of viability of probiotics from literature such as encapsulation, use of pure cultures, selection of acid-bile resistant strains and prebiotic addition can also find useful application in fermented foods like ugba. The aim of this work therefore is to review from past literatures the probiotic potential and viability of natural fermented African oil bean seed and on how to maintain the viability and therapeutic activity of these beneficial organisms to ensure improved viable delivery to consumers of African oil bean seeds.
... Fermented foods, which form a considerable part of diet in Nigeria, are products obtained from the enzymatic modification of food by microorganisms to bring about desired biochemical changes, improving the nutritional value of foods, extending shelf-life and serves as potential sources of probiotics (Fadahunsi and Soremekun, 2017;Anyiam et al., 2020). Cassava mahewu is a novel cassava-based non-alcoholic fermented beverage widely used as complementary drink for school children in Mozambique and other parts of Southern African countries (Salvador et al., 2016). ...
Full-text available
Cassava mahewu is a non-alcoholic fermented beverage used by school children, but it has low contents of protein and micronutrients. This study examined the effect of inclusion of African winged-termite (AWT) on the nutritional quality and acceptability of cassava mahewu. Cassava flour was replaced with AWT at varying proportions of 100:0 (as control), 90:10, 80:20, 70:30 and 60:40% and fermented to obtain cassava mahewu. After freeze drying, proximate and micronutrients were determined using standard methods. Sensory attributes were assessed using 9-point Hedonic scale. The proximate compositions showed an improvement (p<0.05) in crude protein (1.35 to 32.65), fibre (1.26 to 4.0), fat (1.56 to 19.15) and ash (1.47 to 4.04 g/100 g) following the addition of AWT at the highest ratio compared with the control. A decrease (P<0.05) in carbohydrate (84.90 to 15.65 g/100 g) was recorded. The iron (1.53-31.65), zinc (0.70-4.60), vitamin C (4.90-13.90) and riboflavin (0.40-2.09 mg/100 g) increased with the addition of AWT. In terms of overall acceptability, inclusion at 70:30 was significantly (P<0.05) rated higher than other ratios. Inclusion of termite flour prior to fermentation, improved the nutritional and sensorial qualities of cassava mahewu and hence could be utilized to manage the widespread nutritional deficiency in developing countries.
Full-text available
The coronavirus-disease 2019 (COVID-19) was announced as a global pandemic by the World Health Organization. Challenges arise concerning how to optimally support the immune system in the general population, especially under self-confinement. An optimal immune response depends on an adequate diet and nutrition in order to keep infection at bay. For example, sufficient protein intake is crucial for optimal antibody production. Low micronutrient status, such as of vitamin A or zinc, has been associated with increased infection risk. Frequently, poor nutrient status is associated with inflammation and oxidative stress, which in turn can impact the immune system. Dietary constituents with especially high anti-inflammatory and antioxidant capacity include vitamin C, vitamin E, and phytochemicals such as carotenoids and polyphenols. Several of these can interact with transcription factors such as NF-kB and Nrf-2, related to anti-inflammatory and antioxidant effects, respectively. Vitamin D in particular may perturb viral cellular infection via interacting with cell entry receptors (angiotensin converting enzyme 2), ACE2. Dietary fiber, fermented by the gut microbiota into short-chain fatty acids, has also been shown to produce anti-inflammatory effects. In this review, we highlight the importance of an optimal status of relevant nutrients to effectively reduce inflammation and oxidative stress, thereby strengthening the immune system during the COVID-19 crisis.
Full-text available
Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely used in these countries may reduce angiotensin-converting enzyme activity or are anti-oxidants. Among the many possible areas of research, it might be important to understand diet and angiotensin-converting enzyme-2 (ACE2) levels in populations with different COVID-19 death rates since dietary interventions may be of great benefit.
Full-text available
The novel coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has engulfed the world, affecting more than 180 countries. As a result, there has been considerable economic distress globally and a significant loss of life. Sadly, the vulnerable and immunocompromised in our societies seem to be more susceptible to severe COVID-19 complications. Global public health bodies and governments have ignited strategies and issued advisories on various handwashing and hygiene guidelines, social distancing strategies, and, in the most extreme cases, some countries have adopted "stay in place" or lockdown protocols to prevent COVID-19 spread. Notably, there are several significant risk factors for severe COVID-19 infection. These include the presence of poor nutritional status and pre-existing noncommunicable diseases (NCDs) such as diabetes mellitus, chronic lung diseases, cardiovascular diseases (CVD), obesity, and various other diseases that render the patient immunocompromised. These diseases are characterized by systemic inflammation, which may be a common feature of these NCDs, affecting patient outcomes against COVID-19. In this review, we discuss some of the anti-inflammatory therapies that are currently under investigation intended to dampen the cytokine storm of severe COVID-19 infections. Furthermore, nutritional status and the role of diet and lifestyle is considered, as it is known to affect patient outcomes in other severe infections and may play a role in COVID-19 infection. This review speculates the importance of nutrition as a mitigation strategy to support immune function amid the COVID-19 pandemic, identifying food groups and key nutrients of importance that may affect the outcomes of respiratory infections.
Full-text available
Fermented foods have long been produced according to knowledge passed down from generation to generation and with no understanding of the potential role of the microorganism(s) involved in the process. However, the scientific and technological revolution in Western countries made fermentation turn from a household to a controlled process suitable for industrial scale production systems intended for the mass marketplace. The aim of this paper is to provide an up-to-date review of the latest studies which investigated the health-promoting components forming upon fermentation of the main food matrices, in order to contribute to understanding their important role in healthy diets and relevance in national dietary recommendations worldwide. Formation of antioxidant, bioactive, anti-hypertensive, anti-diabetic, and FODMAP-reducing components in fermented foods are mainly presented and discussed. Fermentation was found to increase antioxidant activity of milks, cereals, fruit and vegetables, meat and fish. Anti-hypertensive peptides are detected in fermented milk and cereals. Changes in vitamin content are mainly observed in fermented milk and fruits. Fermented milk and fruit juice were found to have probiotic activity. Other effects such as anti-diabetic properties, FODMAP reduction, and changes in fatty acid profile are peculiar of specific food categories.
Full-text available
The intestinal microbiota, composed of pro- and anti-inflammatory microbes, has an essential role in maintaining gut homeostasis and functionality. An overly hygienic lifestyle, consumption of processed and fiber-poor foods, or antibiotics are major factors modulating the microbiota and possibly leading to longstanding dysbiosis. Dysbiotic microbiota is characterized to have altered composition, reduced diversity and stability, as well as increased levels of lipopolysaccharide-containing, proinflammatory bacteria. Specific commensal species as novel probiotics, so-called next-generation probiotics, could restore the intestinal health by means of attenuating inflammation and strengthening the epithelial barrier. In this review we summarize the latest findings considering the beneficial effects of the promising commensals across all major intestinal phyla. These include the already well-known bifidobacteria, which use extracellular structures or secreted substances to promote intestinal health. Faecalibacterium prausnitzii, Roseburia intestinalis, and Eubacterium hallii metabolize dietary fibers as major short-chain fatty acid producers providing energy sources for enterocytes and achieving anti-inflammatory effects in the gut. Akkermansia muciniphila exerts beneficial action in metabolic diseases and fortifies the barrier function. The health-promoting effects of Bacteroides species are relatively recently discovered with the findings of excreted immunomodulatory molecules. These promising, unconventional probiotics could be a part of biotherapeutic strategies in the future.
Full-text available
Fermented foods represent a significant fraction of human diets. Although their impact on health is positively perceived, an objective evaluation is still missing. We have, therefore, reviewed meta-analyses of randomized controlled trials (RCT) investigating the relationship between fermented foods and non-transmissible chronic diseases. Overall, after summarizing 25 prospective studies on dairy products, the association of fermented dairy with cancer was found to be neutral, whereas it was weakly beneficial, though inconsistent, for specific aspects of cardio-metabolic health, in particular stroke and cheese intake. The strongest evidence for a beneficial effect was for yoghurt on risk factors of type 2 diabetes. Although mechanisms explaining this association have not been validated, an increased bioavailability of insulinotropic amino acids and peptides as well as the bacterial biosynthesis of vitamins, in particular vitamin K2, might contribute to this beneficial effect. However, the heterogeneity in the design of the studies and the investigated foods impedes a definitive assessment of these associations. The literature on fermented plants is characterized by a wealth of in vitro data, whose positive results are not corroborated in humans due to the absence of RCTs. Finally, none of the RCTs were specifically designed to address the impact of food fermentation on health. This question should be addressed in future human studies.
The year 2020 will be remembered by a never before seen, at least by our generation, global pandemic of COVID-19. While a desperate search for effective vaccines or drug therapies is on the run, nutritional strategies to promote immunity against SARS-CoV-2, are being discussed. Certain fermented foods and probiotics may deliver viable microbes with the potential to promote gut immunity. Prebiotics, on their side, may enhance gut immunity by selectively stimulating certain resident microbes in the gut. Different levels of evidence support the use of fermented foods, probiotics and prebiotics to promote gut and lungs immunity. Without being a promise of efficacy against COVID-19, incorporating them into the diet may help to low down gut inflammation and to enhance mucosal immunity, to possibly better face the infection by contributing to diminishing the severity or the duration of infection episodes.
The human microbiota is a key contributor to many aspects of human health and its composition is largely influenced by diet. There is a growing body of scientific evidence to suggest that gut dysbiosis (microbial imbalance of the intestine) is associated with inflammatory and immune-mediated diseases (e.g., inflammatory bowel disease and asthma). Regular consumption of fermented foods (e.g., kimchi, kefir, etc.) may represent a potential avenue to counter the proinflammatory effects of gut dysbiosis. However, an assessment of the available literature in this research area is lacking. Here we provide a critical review of current human intervention studies that analyzed the effect of fermented foods on the composition and/or function of the human gut microbiota. A total of 19 human intervention studies were identified that met this search criteria. In this review, we discuss evidence that consumption of fermented foods may modify the gut microbiota in humans. Further, there is cursory evidence to suggest that gut microbiota compositional changes mediate associations between fermented food consumption and human health outcomes. Although promising, there remains considerable heterogeneity in the human populations targeted in the intervention studies we identified. Larger longitudinal feeding studies with longer follow-up are necessary to confirm and enhance the current data. Further, future studies should consider analyzing microbiota function as a means to elucidate the mechanism linking fermented food consumption with human health. This review highlights methodologic considerations for intervention trials, emphasizing an expanse of research opportunities related to fermented food consumption in humans.
Since the renaissance of microbiome research in the past decade, much insight has accumulated in comprehending forces shaping the architecture and functionality of resident microorganisms in the human gut. Of the multiple host-endogenous and host-exogenous factors involved, diet emerges as a pivotal determinant of gut microbiota community structure and function. By introducing dietary signals into the nexus between the host and its microbiota, nutrition sustains homeostasis or contributes to disease susceptibility. Herein, we summarize major concepts related to the effect of dietary constituents on the gut microbiota, highlighting chief principles in the diet-microbiota crosstalk. We then discuss the health benefits and detrimental consequences that the interactions between dietary and microbial factors elicit in the host. Finally, we present the promises and challenges that arise when seeking to incorporate microbiome data in dietary planning and portray the anticipated revolution that the field of nutrition is facing upon adopting these novel concepts.