Nutritional and Health Perspective of Natto: A critical review

Abstract

Natto, a traditional soy food fermented by Bacillus subtilis (natto), is made by steaming or cooking soaked soybean seeds, inoculating them with the bacteria, and then letting them sit for an incubation period. Natto soya has grown in popularity because of its nutritional importance and health advantages. As a result, farmers have more opportunities thanks to the natto soybean market. For the natto soybean market to remain stable and grow, improved soybean cultivars with enhanced natto quality traits are essential. Natto's high-quality attributes are influenced by the bacteria strain, processing parameters, and soybean variety. Natto has a specific flavour and aroma with a slimy, sticky consistency. Natto contains a range of essential nutrients and bioactive compounds, i.e. nattokinase, soybean isoflavone, γ-polyglutamic acid, vitamin K2 and biogenic amines. Natto possesses various therapeutics. Bacterial species, processing conditions, and cultivars of soybean determine the quality characteristics of natto. Natto food is higher in menaquinone-7 and contains 100 times more menaquinone-7 than most cheeses. The present review highlights the production technology, microbiology, nutritional composition, and therapeutic potential of natto.

Full text

Review Article
Nutritional Health Perspective of Natto: A Critical Review
Muhammad Afzaal ,
1
Farhan Saeed ,
1
Fakhar Islam ,
1
Huda Ateeq ,
1
Aasma Asghar ,
2
Yasir Abbas Shah ,
1
Chigozie E. Ofoedu ,
3
and James S. Chacha
4
1
Department of Food Science, Government College University, Faisalabad, Pakistan
2
Department of Home Economics, Government College University, Faisalabad, Pakistan
3
Department of Food Science and Technology, School of Engineering and Engineering Technology,
Federal University of Technology, Owerri, Imo State, Nigeria
4
Department of Food Science and Agroprocessing, Sokoine University of Agriculture, P.O. Box 3006, Chuo Kikuu,
Morogoro, Tanzania
Correspondence should be addressed to Muhammad Afzaal; muhammadafzaal@gcuf.edu.pk and James S. Chacha;
chachajs26@gmail.com
Received 1 June 2022; Revised 25 July 2022; Accepted 8 September 2022; Published 21 October 2022
Academic Editor: Saleh Ahmed Mohamed
Copyright ©2022 Muhammad Afzaal et al. is is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
Natto, a traditional soy food fermented by Bacillus subtilis, is made by steaming or cooking soaked soybean seeds, inoculating
them with the bacteria, and then letting them sit for an incubation period. Natto soya has grown popular because of its nutritional
importance and health advantages. As a result, farmers have more opportunities, thanks to the natto soybean market. For the natto
soybean market to remain stable and grow, improved soybean cultivars with enhanced natto quality traits are essential. Natto’s
high-quality attributes are influenced by the bacteria strain, processing parameters, and soybean variety. Natto has a specific flavor
and aroma with a slimy, sticky consistency. Natto possesses various therapeutic potentials and contains a range of essential
nutrients and bioactive compounds, i.e., nattokinase, soybean isoflavone, c-polyglutamic acid, vitamin K
2
, and biogenic amines.
Bacterial species, processing conditions, and cultivars of soybean determine the quality characteristics of natto. Natto food is
higher in menaquinone-7 and contains 100 times more menaquinone-7 than most cheeses. e present review highlights the
production technology, microbiology, nutritional composition, and therapeutic potentials of natto.
1. Introduction
Natto is a fermented soybean food that was introduced
thousands of years ago in North Japan [1]. ere are three
classes of natto, such as hamanatto, itohiki, and daitokuji
natto. Itohiki natto is a kind of natto that has been inoculated
with bacteria and cultured for 24 hours without the addition
of salt. Daitokuji, or hamanatto, is prepared by injecting it
with mold, raising it for 4–6 months, and adding salt to it [2].
Many states in Asia even have an equivalent product to
natto, which includes the Philippines, Korea, ailand, and
China. Natto has 59% moisture, 16% protein, and 10% lipid
in common; natto was produced from bristled soybeans and
infused with Grass bacillus [3]. Soybean fermentation by
Grass bacillus will create a mildewed flavor, an oily
appearance, and a specific odor produced by sticky and
viscous polymers [1]. Several compounds, including gluta-
mic acid, amino acid, and fructan, are present in the sticky
polymer. In Japan, natto was prepared with mustard sea-
weed, finely sliced onion, and a minor quantity of soy, so it
was always presented with steaming rice [3]. Besides being a
low-priced healthy food consumed with a pair of chopsticks,
natto can also find application as a potential food mix in
various food products. ey should be coated with a white-
colored slimy material that has a distinct flavor, a light
yellow hue, and is able to produce a silky and sticky mass
with a palatably soft texture. Furthermore, natto is used to
flavor fish, meat, and vegetables [4]. Denaturation of soy
proteins through heat, trypsin inhibitors, and bacterial-
enzymatic protein degradation into simply digestible
Hindawi
Biochemistry Research International
Volume 2022, Article ID 5863887, 9 pages
https://doi.org/10.1155/2022/5863887

peptides boosts the nutritional value during the production
process. After enough fermentation, the undamaged soy-
beans are covered in a white-colored sticky fluid and have a
softer texture, a slimy apperance, and a distinct flavor [5].
Fermented natto products are also eaten without cooking
and can be stored in cooler places or freezers, even within the
supermarket, for selling and purchasing. Natto can be served
with a couple of other food ingredients; for example, in
Japanese homes, traditional natto is presented with seaweed,
thinly chopped onion, mustard, and a small amount of
condiment, and together with steamed rice, it is served as an
entremet [6]. Natto can also be used for the preparation of
meat, vegetable, and seafood dishes as a flavoring agent as
well as an ingredient for the production of sauce [7]. Soy-
bean fermentation produces proteolysis activity, which
improves the taste and nutritional value by removing un-
wanted flavors [8]. Owing to the increase of isoflavone
aglycone, the fermentation of soybean has an antidiabetic
effect. To check the effects of fermentation time on total
bioactive content and antioxidant activity, different time
practices were made [9]. Additionally, different ratio
practices have been done previosuly by incorporating Sac-
charomyces cerevisiaewhich affected the sensory character-
istics and pH of black soybean natto. However, during the
Taisho Period (1912–1926), scientists developed a method to
synthesize Bacillus natto in the laboratory without the use of
a straw. When placed in pots of cooked soybeans, the new
laboratory-grown bacteria act as a dependable starter cul-
ture, allowing the production of natto [10]. Natto could
subsequently be produced effectively by utilizing industrial-
scale equipment such as big steaming/boiling caldrons. After
adding the appropriate number of bacteria, the steamed
beans might develop in any clean, non-corrosive container.
Several biological events were reported during soybean
fermentation by Hayashi et al. [11]. e amount and rate of
the reactions and material formed are based on the situation
of steaming, soaking, bacteria straining, and fermentation.
Natto has an unusual flavor, smell, consistency, thickness,
and quantity of mucus under different fusions of processing.
Within this study, there are not even any small-level research
laboratory techniques available to assess the soybean cul-
tivar's acceptability for natto processing. Nowadays, black
beans are solely used to make soy sauce, but black soybeans
have been proven to be medicinally useful, with extracts used
as an anti-inflammatory agent [12]. According to the most
recent data, more than 700,000 tons of natto are produced
each year. e present review highlights the therapeutic
potential, production method, nutritional composition, and
microbiology of natto in detail.
2. Production Technology of Natto
Natto is made from soybeans by the action ofBacillus subtilis
var. natto (also known as Bacillus natto). Soybeans are a
catch-all term for both black and green soybeans. Apart from
the main components that separate soy proteins, fats, car-
bohydrates, cellulose, ash content, and moisture, there are
also various trace elements and vitamins. Bacillus natto is a
bacterium separated from traditional Japanese food, and its
first type is similar to Bacillus subtilis, a subspecies of Bacillus
subtilis [13]. Traditionally, it is wrapped in soybeans and
stored in a warm area for 1–2 days. Computer network
control provides a range of effective controls that may in-
crease stable product quality, minimize utility consumption,
and reduce production costs (Figure 1). ey may also be
used to manually participate in and monitor CR production,
reduce quality risk, and reduce production costs.
3. Microflora and Microbiology
Natto production includes the following steps: washing and
soaking whole grain soybeans overnight in hot water. e
seeds are then cooked for 20–30 minutes at 0.98–1.47 Bar
vapor pressure. Cooked beans are refrigerated to 45°C before
being innoculated with a probiotic bacterial strain, and then
natto is fermented for 18–20 hours at 40–45°C [15].
B. subtilis is a Gram-positive, fast-growing, aerobic bacte-
rium with rod-shaped cells usually 2–6 μm long and im-
partial below 1 μm wide. e optimal temperature is at
30–35°C, which allows for twice as much time as 20 minutes.
Under certain growth conditions, the cells form long chains
that connect to unspecified septal wall components. Under
starving conditions, cells can undergo a complicated two-cell
division that results in endospore creation; this formation is
discharged by lysis of the covering mother cell [16]. In other
words, they can produce biofilms and “fruit bodies” con-
taining grains. Isolated in the 1950s, tryptophan auxotroph
was the most popular and studied type of B. subtilis 168. It
was the first known gene to complete a genetic sequence,
displaying a 4.2 Mbp chromosome containing 4100 genes.
With a series of updates, the B. subtilis genome still has one
of the best annotations. However, recently, “SubtiWiki” (a
complete database) provides an easy-to-use and authentic
configuration for the latest data (Table 1). Nicolas’ work has
resulted in a comprehensive data set for writing values,
facilitators, and RNA controls on the website [18]. A
complete list of key genes has been found in a number of
global projects, recently identifying genes (the 257 genes)
needed for Lactobacillus growth at 37°C′(total genetics) of
approximately 6250 genes and the “core genome” (genetic
unit) of approximately 2500 genes. Considerable genetics
involves a number of genes, about 300 genes were needed to
build the endospore, as well as many prophages or fossils of
the phage. e conclusions from the appearance of genetic
matter are reconcilable with the idea that B. subtilis is
modified for life in plants and the rhizosphere by Nicolas
et al. [17].
4. Nutritional Composition
Natto provides 211 calories per 100 g. One serving contains
19 g of protein, 11 g of fat, and 13 g of sugar. e leftover
carbohydrate complex contains 5.4 g of fiber and 4.9 g of
sugar. Natto includes 1.6 g of saturated fat and provides
13.0 mg of vitamin C, 8.60 mg of iron, 729 mg of potassium,
and 217 mg of calcium per 100 g. erefore, natto is a food
that falls under the category of “legumes and legume
products.” Natto has a variety of carbohydrates. Each kind
2Biochemistry Research International

has its own range of advantages. One cup of natto contains
around 6 grams of natural sugar. Another type of carbo-
hydrate present in natto is fiber, Anderson et al. [19]. When
you utilize a full cup of cooked food, you will obtain more
than 9 grams of fiber. Adults should ingest 28 g of fiber per
day, according to the USDA. Eating fiber not only helps
digestion and exercise but it also has other health advan-
tages, such as a lower risk of several cancers, obesity, heart
disease, and diabetes [20]. One cup of natto has more than
19 g of fat. e majority of these lipids are polyunsaturated.
Polyunsaturated fats can decrease LDL cholesterol and may
reduce the risk of heart disease and stroke. Natto is a protein-
rich food, so if we increase our plant-based protein intake by
34 grams while utilizing a big cup, natto contains an
abundant source of micronutrients. e natto supplement
gives 2.7 mg of manganese, a total of 130 to 134% of your
recommended daily diet. It provides about 1 mg of copper
(58% of your daily needs), 15 grams of iron (84% of your
daily needs), 1276 mg of potassium (36%), 201mg of
magnesium (50%), 305 mg of phosphorus (30%), 5.3 mg of
zinc (35%), and 15.4 mcg of selenium (22%). Food is high in
ascorbic acid, which provides about 23 mg or about 38% of
your daily requirements. e byproduct of the millet pro-
cessing industry, millet bran, is rich in nutrients, particularly
dietary fiber [21].
26
,
1
Natto contains vitamins and other
important compounds that helps to boost the immune
system [22]. e food industry concentrates on using bio-
active compounds because of the growing interest in doing
so to maintain product quality and safety, as well as the
benefits they have for human health and the environment
[23]. Next, a discussion of applications and functionalization
strategies for the administration of therapeutics via various
delivery methods [24]. Natto has numerous health benefits,
including the ability to control blood cholesterol levels,
Soybean
Selection
Washing
Soaking 10 – 12 h
1.5 kg/cm2, 20 min
103 spores/g soybean
40°C, 16 – 18 h
Below 10°C, 24 h
Steaming
Spore inoculation
Fermentation
Cooling and Aging
Natto
Packaging
Figure 1: e mechanism of natto production is depicted in the flow sheet. Source: [14].
Table 1: Important microorganisms and enzymes used in food fermentation.
Microorganisms Species Active enzymes References
Yeast Saccharomyces cerevisiae Amylase, proteases, maltase, dehydrogenase βglucosidase, and alcohol Nicolas et al. [17]
Bacteria Bacillus subtilis Peptidase, hydrolases, proteases, amylase, and cellulase Nicolas et al. [17]
Biochemistry Research International 3

prevent arterial sclerosis, heart disease, and hypertension,
promote bone growth, control the bacterial balance in the
intestines, prevent diarrhea, enteritis, and constipation,
improve immunity, fat reduction, beauty treatment, eye
relief, and so on[25]. Finally, natto is frequently mentioned
as one of the greatest sources of vitamin K, particularly
vitamin K
2
. Vitamin K is used by the body to create bone and
prevent blood clottingaccording to Anderson et al. [19].
Several studies on the health benefits of natto have been
conducted; furthermore, in vivo and in vitro studies have
demonstrated that serine proteases such as subtilisin and
nattokinase have a profibrinolytic effect [26–28]. Mamiya
and Nishimura [29] found that rats fed with natto had
enhanced locomotor activity. Natto has some amazing
benefits for bone development in menopausal women and
postmenopausal bone loss prevention, which is most likely
due to the presence of menaquinones or non-nato flavones
in natto [30, 31].
5. Therapeutic Potential
5.1. Anticarcinogenic Activity. Natto has anticancer prop-
erties. A good example is miso soup, a well-known tra-
ditional Japanese dish that is prepared with soybeans as a
major ingredient. is soup is basically made from the
paste of soybeans that have been cooked with mold, yeast,
and bacteria before being blended with water and salt. In
order to prepare 200 ml of miso soup, commercially
available natto in a quantity of about 50 g was added and
cooked for 1 minute. All the volunteers ate miso soup daily
at mealtime [32]. Human gastric adenocarcinoma cells
were used to study the anticancer properties of chung-
kukjang (a Korean short-term fermented soy paste), and
Bacillus strains from chungkukjang were isolated and
identified. K-Chungkukjang (87%) demonstrated the
strongest growth inhibitory effect at a concentration of
1 mg/mL, followed by H-chungkukjang (85%) and MC-
chungkukjang (69%) (P<0.05) reported by Seo et al. [33].
As per epidemiological studies, high levels of isoflavonoids
are particularly related to a decreased colon cancer risk,
while miso soup intake is linked to a lower risk of stomach
cancer. Beans have been reported to hold large amounts of
carcino-preventive agents. Bowel cancer was not that
common in Japan, but it has now become more common
among Japanese people due to the high-fat consumption in
modern Japanese food, Adlercreutz [34].
5.2. Antibacterial Spectrum. e microbial cytotoxicity of
polyphenols may result from nonspecific interactions with
polysaccharides, inhibition of proteolytic enzymes (pepti-
dases), as well as other interactions that render bacterial
adhesins deactivated [35]. Natto (B. subtilis) possesses an-
tibacterial properties in terms of Escherichia coli O157.
Growth of E. coli O157 in culture and natto (B. subtilis)
growth were both reduced. Natto promotes the growth of
Lactobacillus,Bacillus, and Streptococcus while inhibiting the
growth of E. coli in rat caeca reported by Sumi [36]. Natto’s
commercial diet contained a kind of Bacillus that might be
beneficial as a biocontrol agent (Figure 2). Under optimal
circumstances, natto displayed a substantially stronger in-
hibitory activity against S. aureus. erefore, Bacillus subtilis
has antibacterial action. Under well-designed circumstances,
B. subtilis natto had the strongest activity in preventing
S. aureus. Bactericidal action against Helicobacter pylori has
been found in Bacillus subtilis natto. Because of the presence
of dipicolinic acid, a small test of inhibitory concentration
indicated that B. subtilis natto possessed antiplatelet ag-
gregation and anti-H. pylori properties [39].
5.3. Effect on the Immune System. ere has recently been a
lot of excitement concerning the potential of immuno-
therapeutics. Tumor vaccines and immune checkpoint in-
hibitors are two immunotherapy strategies that have
demonstrated a great promise in both clinical and preclinical
trials [40]. Rivera-Patron et al. [41] investigated the effects of
Bacillus subtilis natto on body function in dairy calves during
the feeding period. Bacillus subtilis natto was mixed with
milk and administered orally to calves. When the calves’
initial diet reaches 2% of their body weight, they are fed.
Bacillus subtilis natto enhanced working conditions by
improving daily gain and nutritional efficiency, as well as
increasing the weaning age of calves. In Bacillus subtilis,
there were no increases in serum IgM, IgA, or IgE, but serum
IgG was greater in natto-supplemented calves than in
control calves studied by Rivera-Patron et al. [41].
5.4. Anti-Inflammatory and Hypocholesterolemic Effects.
Soy protein with an eye or an eye alone has been demon-
strated to decrease oxidative stress and have anti-inflam-
matory characteristics by decreasing nuclear factor-kappa B
(NF–B) and preventing the release of chemical cytokines.
e anticancer effect of lunasin (a peptide present in soy-
beans) comes from natto, which has antioxidative and anti-
inflammatory properties. Lunasin, an antioxidant, was
shown to slow down 2,20-azino-bis (3-ethylbenzothiazoline-
6-sulfonic acid) diammonium salts and inhibit inflamma-
tory cytokines (TNF- and IL-6) in RAW mouse 264.7
macrophages, Smithson et al. [42]. In general, soy iso-
flavones inhibit mTORC1 via the AKT pathway, which
causes a decrease in lipogenesis and adipogenesis and an
increase in lipolysis and oxidation in DIO male rats. is
study shows soy isoflavones have amazing impacts on body
weight and adiposity [43].
5.5. B-Galactosidase Activity. Subtilis bacterial cells (con-
taining pNC61AV10 or pNZ2) were deposited in trimeth-
oprim 10 milliliters of LactobacillusLactobacillus medium,
and by the absorption rate of 600 nm, growth was examined.
All the samples were mixed in, and the pellets were im-
mersed in Z buffer (7 ml solution) (pH 7, 40 mM
NaH
2
PO
4
–2H
2
0, 60 mM Na
2
HPO
4
–7H
2
0, 10 mM KCl,
4Biochemistry Research International

1 mM phenyl methyl fluoro sulfate, 1 mM MgSO
4
–7H
2
0,
and 2-mercaptoethanol). e cell suspension of 2.1 millili-
ters has three drops of toluene, and the solution was
forcefully extracted for 9–10s. en, to evaporate the tolu-
ene, the samples were stirred for 1 h at 37°C and collected at
28°C for 5 minutes. e reaction mixture was immediately
stirred for 1 minute at 28°C, after adding 0.6 ml of ortho-
nitrophenyl galactoside solution (pH 7, 4 mg of orthoni-
trophenyl galactoside per ml in 0.1 M sodium phosphate
buffer). e reaction was stopped by adding 1 M Na
2
CO
3
(1.5ml) to the mixture. After the cells were discharged for 2
minutes, the absorption of clear supernatant (at 420 nm) was
observed by Wang and Doi [44].
5.6. Gastrointestinal Proliferation. e use of extracts from
certain Bacillus strains in natto, such as targeted microbial
(direct-fed microbial), has been proven to have the ability to
germinate and enter the digestive systems of diverse animals,
such as poultry [45]. As a result, they are active and give a
variety of nutritional advantages, such as the creation of
exogenous enzymes such as cellulose, protease, phytase,
lipase, keratinase, and xylanase, as well as other chemical
compounds that improve the regulation of the body. In vitro,
Bacillus spp. Xylanase was selected by using the in vitro
digestive model. Cellulase production as DFM was then
tested for digestion viscosity and C. perfringens to increase
the diversity of chicken feed. e results of this study
revealed that the use of less expensive grains (fermented
soybean products) for poultry feed improved the digestion
and activity level of birds found by Hendricks et al. [46].
5.7. Antidiabetic Effect. Hyperlipidemia and obesity are
frequently linked with type II diabetes and insulin resistance,
both of which lead to metabolic illness. Remarkably, fer-
mented soybeans have antidiabetic and hypolipidemic
properties in animals [47]. Soybean products that are
fermented and contain soy protein, such as Bacillus subtilis
natto, have been shown to be particularly helpful in reducing
type 2 diabetes in humans. For six weeks, women aged 19–39
years were given a diet that included soy protein (20–30%
other plant protein, 30–35% animal protein, and 30–35% soy
protein). Jiang et al. [48] did an experiment and fed the rat
soy protein-supplemented sucrose-rich foods. e results
showed that the rat reduced cholesterol and hepatic tri-
glyceride storage, steatosis, normal glucose-6-phosphate,
and glycogen levels, and glucose transporter GLUT4
transplant. When this supplement is given for 4 weeks to
diabetic Wister rats, it increases insulin sensitivity, insulin
signaling, and pancreatic function studied by Kwon et al.
[49].
5.8. Antiallergic Properties. An immune hypersensitivity
disorder called allergy is caused by an allergy that enters the
body through skin contact, injection, ingestion, and/or
smell. ese immune responses can develop into allergies,
including inflammation such as atopic dermatitis, asthma,
anaphylaxis, food allergies, and allergen rhinitis [50]. Lee
et al. [51] found that natto has antiallergic effects on epi-
dermis pigmentation, ear thinning, internal lymph nodes,
and mast cell infiltration, among other things.
5.9. Antioxidative Properties. Many lifestyle-related disor-
ders are induced by free radical oxidative damage to the
living body. Reactive oxygen species and antioxidant
mechanisms are out of balance, which leads to oxidative
stress [52]. e study found that fermented-soy-products
boosted antioxidant profile, total phenolic content, total
flavonoid content, and isoflavones content. e variations in
isoflavones might be attributed to -glycosidase activity [53].
Natto, or cooked beans, is a traditional Japanese meal that
has been consumed for many years. Antioxidant activity has
been demonstrated in the soluble components of natto
Natto food
Polygamma
glutamic acid
Bacteriocins
Vitamin
K2(MK7) Nattokinase
Biosurfactants
Probiotics
B. subtilis
natto
Figure 2: Potential effects of Bacillus subtilis natto. Source: [37, 38].
Biochemistry Research International 5

water. Iwai et al. [54] have also reported that natto fractions
suppress plasma low-density lipoproteins. LDL oxidation is
recognized to play a role in the genesis and progression of
arteriosclerosis. In this study, hypercholesterolemic mice fed
a meal containing one or two natto components, a low
molecular weight viscous or a soybean water extract, were
found to have a considerable effect on LDL oxidation in
vitro. To explore the inhibitory impact of natto fractions on
LDL oxidation in vivo, lipid peroxidation in plasma and LDL
were assessed following natto-treated mouse’s plasma oxi-
dation [54].
5.10. Effect on the Blood Pressure Level. Natto is a soybean
derivative that is a popular traditional meal in Japan and is
also used as a health supplement. Omura et al. [55] dis-
covered that NKCP®, a natto supplement derived from the
enzyme bacillopeptidase F, has antithrombotic, fibrinolytic,
and antihypertensive properties. e utilization of dietary
supplements present in traditional Japanese food provides
further advantages in removing the independent symptoms
of patients getting health treatment who have life-threat-
ening diseases [56].
5.11. Protection against Apoptosis. Apoptosis is a hereditary
cell death formation that plays an important function in cell
number control. e diminished capacity to trigger apoptosis,
which is coupled with changes in cell growth control systems,
has a significant pathogenic feature in many forms of cancer
[57]. e results from this study showed that L. acidophilus
improved apoptosis in treated mice and reduced the severity
of colorectal carcinogenesis. One of the most dangerous
malignant epidermal cancers is melanoma. e natto, or
soybeans fermented by Bacillus subtilis natto, was used to
isolate natto freeze-drying extract (NFDE) and natto water
extract (NWE), which were evaluated as potential anti-
melanoma agents (Table 2). Cell cytotoxicity tests showed that
NFDE and NWE had significant, dose-dependent anti-
melanoma effects while having little effect on normal skin
cells such as Hs68, HaCaT, and adipose tissue-derived stem
cells (ADSCs) reported by Chou et al. [58].
6. Future Perspective
e development of food science in the near future probably
depends on the continuation of active food science, an idea
that was first introduced in Japan about 15 years ago. Japan,
however, followed a unique path of progress in a product-
driven environment rather than a science-driven science. In
fact, the number of substances and products that have the
potential to decrease the risk of disease rather than simply
for health care has been investigated by their body-changing
functions [59]. Some of them have been used in the man-
ufacture of processed foods in accordance with the “defined
health food use” officially defined by the new law. Probiotics
have GRAS certification and are widely ingested across the
world without any issues with safety. It has been demon-
strated in a number of in vivo and in vitro studies. However,
recent studies have revealed concerns about their safety and
their capacity for immunocompetent individuals, Redman
et al. [60]. However, probiotics are very healthy to promote
health, especially in the prevention and treatment of diar-
rhea as well as H. pylori infection and maintaining intestinal
homeostasis [61]. eir use with certain antibodies, espe-
cially for those who are severely ill, newborns, and the el-
derly, should be carefully monitored since reports of
bacteremia in immune-prone patients treated with spores
and other probiotics [62]. On the other hand, the impor-
tance of identification at the stage of severity is also sig-
nificant to detect and eliminate any fundamental
communication between probiotics and problems separated
by allergies involved in the immune system. erefore, it is
essential to remember that clinical experiments involving
these building materials should include a sufficient number
of targeted individuals, including people with low immune
systems. However, there is a dire need to conduct more
clinical studies to investigate the therapeutic potential of
natto.
7. Conclusion
Natto is a fermented soybean product that has a unique
microbial profile and abundant bioactive compounds. e
results of various studies conducted on natto suggest that
natto has high probiotic potential. Significant research has
been conducted to improve B. subtilis natto strains, with a
focus on boosting the synthesis of useful chemicals such as
nattokinase, PGA, and isoflavones, among others, hence
improving the health benefits of natto soybeans. As a
result, combining breeding soybean varieties with
B. subtilis natto strains will allow for greater natto health
promotion. ere is strong evidence in the literature that
B. subtilis natto has a high potential for producing pro-
biotics for use in human food, and natto intake has been
linked to health advantages such as a decreased incidence
of certain illnesses and a lower risk of death.
Data Availability
e data that support the findings of this study are available
from the corresponding author upon request.
Table 2: Lactic acid bacterial strains and their function.
erapeutic property Bacterial strains Regulatory chemicals References
Antioxidant damage DNA L. acidophilus and L. Casei ↑5-fluorouracil Elmore and Susan, [57].
Immune boosting L. acidophilus ↑DCs cell Elmore and Susan, [57].
↑cytokines IL-12 and IL-10
Epigenetics Lipoteichoic acid and L. acidophilus ↑expression of tumor suppressor genes Elmore and Susan, [57].
6Biochemistry Research International

Conflicts of Interest
e authors declare that they have no conflicts of interest.
Acknowledgments
e authors are thankful to the Government College Uni-
versity, Faisalabad, for the literature collection facilities.
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