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Prebiotic dietary fibres and the immune system

  • Sensus B.V.

Abstract and Figures

This paper describes the effect of prebiotic fibres, especially of inulin and oligofructose, on the immune system. A brief introduction of the immune system is followed by an overview of results from experimental animal trials on the relation of inulin consumption and immune parameters. Then data from human volunteer studies in healthy and diseased people are presented, followed by an overview of the data for inulin consumption and resistance to gastrointestinal infections. After a discussion about the potential mechanisms that are based on the effects of inulin in the composition and activity of the colonic microbkna, it is concluded that prebbtic fibres as inulin can affect the immune system in various ways. The results obtained so far underline the view that inulin may support the immune system in a positive way which for instance may lead to increased resistance to infections, or less incidence of atopic dermatitis. In people with colon diseases consumption of inulin (alone or in combination with probiotic bacteria) could lead to less disease symptoms. It is also clear that more research will be required to fully substantiate these positive findings.
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GALT and its functions. Non-fermentable fibres such as cellulose
seem to have fewer effects (4). These effects of inulins and
oligofructose/fructooligosacchrides (FOS) and other prebiotics are
described below. These serve as an example showing how the
immune system can be modulated by such dietary components.
Animal model studies
In a series of publications by Bruggencate et al. (5) it was shown that
oligofructose consumption in rats has a negative effect on the barrier
function of the intestine, as measured by the lowered resistance to
Salmonella translocation. With higher fermentation rates the effect
became more pronounced, and the effect could be abolished to a
large extent with dietary calcium.
Another effect on the innate immune system comes from the data by
Roller et al. (2004). They showed that inulin supplementation of rat
feed leads to increased production of interleukin (IL)-10 and
interferon-γfrom PP cells (6).
Model studies with chemically induced colitis in animals generally
show a beneficial effect of inulin consumption. E.g. Videla et al. (7)
found that with 10 percent inulin in the diet the inflammatory response
to dextran sulphate sodium was much less, and similar data were
The immune system is the host's defence both against attacks from
the outside, such as by viruses or bacteria and from the inside (e.g.
malignant cells). It consists of an innate part and the acquired or
adaptive part. The innate immune system is non-specific and
provides the early response to invasion and includes physical barriers
(e.g. mucous membranes), cell-mediated barriers for instance from
phagocytes and natural killer cells, and soluble factors such as
cytokines. The adaptive response of the immune system is specific
and occurs after the response by the innate part and involves the
activity of B- and T-lymphocytes. They modulate the function of other
immune cells or destroy cells infected with pathogens.
The immune activities in the gastrointestinal tract that protect the
intestine are located in a variety of tissues together called the gut-
associated lymphoid tissue (GALT). This system consists of the
following components (see Figure 1 and 2):
1. Peyer's patches (PP) found throughout the mucosa of the small
intestine. They are covered by special cells (M-cells), which can
take up (phagocytosis) soluble antigens and microorganisms and
release them into the PP. There these antigens are presented to T
and B lymphocytes.
2. Isolated lymphoid follicles are the functional equivalent of PP
present throughout the intestine, but especially in the colon and
3. Non-aggregated cells in the lamina propria consisting of T and B
cells, where the majority of the B cells secrete soluble IgA into the
gut lumen. This IgA is an important component of the
gastrointestinal defence.
4. Intraepithelial lymphocytes are located in the interstitial spaces of
the mucosal epithelium, and they can be found in small and large
5. Mesenteric lymph nodes although not located in the intestine are
considered part of the GALT as they have strong interactions with
other parts of this system. The GALT is also the site where immune
system and components of the diet interact.
Dietary fibres defined shortly as nondigestible dietary carbohydrates
have various physiological effects that include a positive effect on
defecation, on serum lipids, on feelings of satiety (see for instance 3).
Insoluble fibres such as wheat bran are well known for their stool
bulking effect; in contrast, soluble fibres have less stool bulking
properties but exert their physiological effects after being fermented
by the resident colonic microbiota.
More and more evidence shows that fermentable fibres can affect the
vol 19 n 3 May/Jun 2008 Ag roFOOD industry hi-tech
Prebiotic dietary fibres and the
immune system
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Immune system
ABSTRACT: This paper describes the effect of prebiotic fibres, especially of inulin and oligofructose, on the immune system. A brief
introduction of the immune system is followed by an overview of results from experimental animal trials on the relation of inulin
consumption and immune parameters. Then data from human volunteer studies in healthy and diseased people are presented,
followed by an overview of the data for inulin consumption and resistance to gastrointestinal infections. After a discussion about the
potential mechanisms that are based on the effects of inulin in the composition and activity of the colonic microbiota, it is concluded that
prebiotic fibres as inulin can affect the immune system in various ways. The results obtained so far underline the view that inulin may
support the immune system in a positive way which for instance may lead to increased resistance to infections, or less incidence of
atopic dermatitis. In people with colon diseases consumption of inulin (alone or in combination with probiotic bacteria) could lead to less
disease symptoms. It is also clear that more research will be required to fully substantiate these positive findings.
Figure 1. Schematic overview of the lymphoid elements of the gut-
associated lymphatic system. Peyer's patches (PP) and mesenteric
lymph nodes (MLN) are organised intestinal lymphoid follicles. (A-C)
Pathways of intestinal antigen uptake: luminal antigen can be taken up
by (A) intestinal epithelial cells, (B) interdigitating lamina propria
dendritic cells, and by (C) M cells. The lymphatic drainage of PP and
villus lamina propria goes to the MLN (direction of lymph flow indicated
by arrows). (Taken from 1)
Prebiotic consumption can have an effect on atopy and allergy as
shown in animal models. Fujitani et al. (19) suggested on the basis of
their mouse model studies with FOS from sucrose that these fructans
may have antiallergic activity.
Human studies in healthy volunteers
The effect of oligofructose consumption on barrier function as found
in rats (see above) could not be reproduced in humans even at high
consumption rates. In humans consuming oligofructose at 20 g/d (20)
or more (up to 30 g/d; 21) markers for barrier function were not
affected. These data show (again) the difficulties of translating data
from animal trials to a human situation.
Two studies with elderly people show that inulin consumption affects
their immune system. Guigoz et al. (22) noted that with the
consumption of 8 g/d of FOS from sucrose some inflammatory
response markers decreased. They showed in healthy elderly people
a decreased phagocytic activity of granulocytes and monocytes, as
well as a decreased expression of IL-6 mRNA in peripheral blood
monocytes after 3 weeks of FOS consumption. Bunout et al. (23)
investigated the effect of prebiotics on the response to vaccination in
elderly. A mixture of inulin and oligofructose (6 g/d) did not lead to a
changes immunological response on the volunteers with age > 70 y.
No changes in secretory IgA could be found, neither an effect on the
antibody titre after vaccination with influenza or pneumococcal
In another vaccination study with 8-months old infants that received 1
g of a 30/70 mixture of native inulin and oligofructose in 25 g cereal
for 10 weeks, Haschke et al. (24) showed that after vaccination with
measles vaccine IgG antibody titres were higher in the group
receiving the prebiotic mixture.
Roller et al. (25) investigated the effects of a synbiotic preparation on
the systemic immune system in colon cancer and polypectomised
patients. They concluded that there were only minor immune
reported by others (8) for the response to trintrobenzene sulphonate
in rats. In this latter model system it was shown that FOS
consumption reduced disease scores and lowered several
inflammatory markers and cytokines (9). In another mouse model
similar effects were found with an inulin/FOS mixture as well as an
upregulation of transforming growth factor-β(10). Another stimulatory
effect was reported in rats where FOS enhanced TNF-αand
prostaglandin E2 levels in serum after a lipopolysaccharide challenge
(11). These studies show that inulin/oligofructose can suppress
inflammatory symptoms by mechanisms that are microbiota related.
The work of Pierre and others in Min mice with fructo-
oligosaccharides in their feed shows that the GALT was modulated in
such a way that antitumoral activity was stimulated (12) and they
suggested that this might be due to the activation of an
immunosurveillance mechanism by inulin related to the suppression
of colon tumours (13). Other model studies with chemically induced
colon cancers showed similar data, but it remains to be elucidated
whether such effects are mediated through immune modulation as
suggested by Pierre et al. (12, 13).
γ-Inulin is a dahlia-derived inulin in a crystallised form with a high
molecular weight (14). This special type of inulin activates the
alternative complement pathway (part of the adaptive immune
response) and shows adjuvant activity when injected intraperitoneally
in mice (15). It was shown to enhance the function of murine antigen-
presenting cells and it enhanced production of complement factor C3
by macrophages (16).
Inulins with a different chain length exist which may have different
effects; it is well known that different ratios of fermentation products,
short chain fatty acids (SCFA) and lactate will arise from different
inulins (17). A recent report shows that this may also be the case for
the immune effects as in rats IgA production increases with
fermentation rate in the cecum, i.e. increases with decreasing chain
length (18).
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Immune system
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Surprisingly, only the group that consumed 3.2 percent FOS in food
showed fewer episodes of diarrhoea; whilst with 4 percent no effect
was found. Looking at diarrhoeal episodes of less than 2 days, both
FOS percentages were effective. The effects became evident after 4
months of consumption. Juffrie et al. (39) used FOS from sucrose to
explore the effect in diarrhoeal diseases in children aged 1-14 years.
They could show that prebiotic consumption (2.5 - 5 g/d) shortened
the duration of diarrhoea, and that stools had a lower pH with FOS
consumption, indicative for increased fermentation and formation of
SCFA. Agustina et al. (40) reported comparable data for a synbiotic
preparation consisting of inulin, soy polysaccharides and L.
rhamnosus. Duration of diarrhoea was shortened in children suffering
from acute diarrhoea, but it remains difficult to decide whether this
was caused by the prebiotic, probiotic or both.
The extra consumption of iron and zinc also complicates drawing
unequivocal conclusions. Other investigators showed that
oligofructose consumption at 2 g/d led to less episodes with diarrhoea
or fever in children aged 7 - 19 months (41) with a concomitant trend
for an increased content of faecal bifidobacteria and a significant
decrease in potential pathogens, such as clostridia.
Arslanoglu et al. (42) showed similar data with a 9/1 GOS/FOS
mixture in children during the first 6 months of life. The prebiotic
mixture reduced the number of infectious periods and especially the
incidence of respiratory infections.
The immune alterations as described above can be brought about by
various mechanisms, as schematically shown in Figure 2.
The increase in bifidobacteria and lactobacilli due to prebiotic
consumption means that there is a change in the pattern of immune
effecting molecules from the lumen. More bifidobacterial cell wall
components, such as peptidoglycan or lipoteichoc acids, can have an
effect on the mucosal immune system (43). It has also been reported
that consumption of probiotic bifidobacteria leads to increased IgA
levels in small intestine and faeces (44) again indicating the effect of
these bacteria on the immune system. As pointed out before inulin
consumption leads to increased production of SCFA which may lead
to physiological effects of the mucosa, as it has been reported that
butyrate suppresses lymphocyte proliferation, reduces cytokine
expression and enhances IL-10 production in rats. Furthermore, as
modulating effects of the synbiotic that consisted of 10 g/d of
FOS/inulin and Bifidobacterium lactis and Lactobacillus rhamnosus in
the two patient groups. Other data for healthy humans are based on
the application of a 9:1 GOS/FOS mixture in infant foods. Moro et al.
(26) reported that the same mixture reduces the incidence of atopic
dermatitis during the first 6 months of their life. These investigators
also showed that the number of bifidobacteria in the GOS/FOS group
increased significantly suggesting that the change in faecal flora has
a positive role in the development of the immune system.
Human studies in patients
Whereas it is difficult if not impossible to show improved immune
functions in healthy people, studies with patients with colonic
disorders offer an attractive way of investigating the effects of
prebiotics on the immune status.
Studies in patients with inflammatory bowel disease (Crohn's disease,
CD or ulcerative colitis, UC) show encouraging, but not totally
unequivocal results. Casella et al. (27) found a significant reduction of
faecal calprotectin (a marker for mucosal inflammation) in UC patients
consuming 12 g/d of an inulin/oligofructose mixture, but no difference
in disease activity versus placebo. With CD patients it was shown that
15 g/d of FOS decreased disease scores together with an increase of
faecal bifidobacteria (28).
It may be that synbiotic treatment (using the combination of a
prebiotic with a probiotic bacterium) is also effective. E.g. in a case
study with inulin (15 g/d) in combination with B. longum a paediatric
UC patient remained in remission and could stop medical treatment at
least for a year (29, see also 30).
A possible complication of a colectomy is an inflammation of the ileal
reservoir (pouchitis). A study by Welters et al. (31) indicates that inulin
may be beneficial under these conditions. These investigators gave
24 g/d of inulin to potential pouchitis patients. This treatment not only
decreased histological inflammation scores but it also increased
butyrate concentrations and induced a lowering of the pH, as well as
less secondary bile acids and a lower number of Bacteroides fragilis.
No effect on the level of bifidobacteria and lactobacilli was found.
The data described above show effects of inulin on various
parameters of the immune system. This part describes the effects of
inulin as measured by resistance against infections, i.e. whether the
immunemodulation depicted above actually leads to an improved
performance of the immune system. Animal trials showed that with 10
percent inulin and oligofructose in the feed the effects of systemic
infections with Listeria monocytogenes, Salmonella typhimurium and
Candida albicans in rats survival increased (32). Long chain inulin
seemed more effective than oligofructose in these trials, especially
with the Listeria infections. Interestingly also in weanling puppies
inulin supplementation reduced the effects of a Salmonella challenge:
with inulin, body weight changes and body temperature increases
after infection were less (33). And in poultry it was found that inulin
consumption may lower infections with Salmonella (34).
Data for humans are scarce, but Cummings et al. (35) showed that
travellers to high-risk countries had a trend for lowered occurrence of
diarrhoea with oligofructose consumption of 10 g/d. Later analysis of
the data showed that the severity of diarrhoea was significantly lower
with oligofructose consumption. Lewis et al. (36) looked whether
oligofructose (12 g/d) could prevent antibiotic-associated diarrhoea.
Although they found an increase in bifidobacteria in the faeces of the
patients, they did not find any protective effect of oligofructose
consumption in these elderly people. There are some data from
studies in children that also show encouraging results. Whereas
Duggan et al. (37) could not find an effect on diarrhoea prevalence
from oligofructose consumption in Peruvian infants, others (38)
showed that FOS consumption lowered the risk for diarrhoeal
infections in children of about 6 months in Indonesia.
vol 19 n 3 May/Jun 2008 Ag roFOOD industry hi-tech
Immune system
Figure 2. Microbiota-dependent mechanisms of inulin induced immune
modulation (adapted from 50)
fermentable fibres, such as pectins or β-glucans. The review by Vos
et al. (50) provides an excellent overview of the immune modulating
effects of other nondigestible carbohydrates.
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2. P.D. Schley, C.J. Field, Br. J. Nutr., 87 (Suppl. 2), pp. S221-S230
3. B.C. Tungland, D. Meyer, Compr. Rev. Food Sci. Food Safety, 3, pp.
73-92 (2002).
4. K. Yamada et al., Biosci. Biotechnol. Biochem., 67, pp. 429-433
5. S.J. ten Bruggencate et al., Gut, 53, pp. 530-535 (2004).
6. M. Roller et al., J. Nutr., 134, pp. 153-156.
7. S. Videla et al., Am. J. Gastroenterol., 96, pp. 1486-1493 (2001).
8. C. Cherbut et al., J. Nutr., 133, pp. 21-27 (2003).
9. F. Lara-Villoslada et al., Eur. J. Nutr., 45, pp. 418-425 (2006).
10. F. Hoentjen et al., Inflamm. Bowel Dis., 11, pp. 977-985 (2005).
11. A.M. Neyrink et al., J. Nutr., 134, pp. 1124-1129 (2004).
12. F. Pierre et al., Cancer Res., 57, pp. 225-228 (1997).
13. F. Pierre et al., Carcinogenesis, 20, pp. 1953-1956 (1999).
14. P.D. Cooper, M. Carter, Molec. Immunol., 23, pp. 896-901 (1986).
15. P.D. Cooper, E.J. Steele, Immunol. Cell Biol., 66, pp. 345-352 (1988).
16. K. Kerekes et al., J. Leukocyte Biol., 69, pp. 69-74 (2001).
17. M.H.M.C. van Nuenen et al., Microb. Ecol. Health Dis., 15, pp. 137-
144 (2003).
18. H. Ito et al., J. Food Sci., 73, pp. H36-H41 (2008).
19. S. Fujitani et al., Allergol. Int., 56, pp. 131-138 (2007).
20. S.J.M. ten Bruggencate et al., J. Nutr., 136, pp. 70-74 (2006).
21. P.A. Scholtens et al., Br. J. Nutr., 95, pp. 1143-1149 (2006).
22. Y. Guigoz et al., Nutr. Res., 22, pp.13-25 (2002).
23. D. Bunout et al., J. Parenter. Enter. Nutr., 26, pp. 372-376 (2002).
24. F. Haschke et al., Monatsschr. Kinderheilk, 148, pp. S66-70 (2001).
25. M. Roller et al., Br. J. Nutr., 97, pp. 676-84 (2007).
26. G. Moro et al., Arch. Dis. Childh., 91, pp. 814-819 (2006).
27. F. Casellas et al., Aliment. Pharmacol. Ther., 25 pp. 1061-1067 (2007).
28. S. Lewis et al., Aliment. Pharmacol. Ther., 21, pp. 469-477 (2005).
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30. E. Furrie et al., Gut, 54, pp. 242-249 (2005).
Readers interested in a complete list of references are kindly invited to write to the author
these fermentation products will be absorbed in the bloodstream they
will reach and affect other parts of the immune system as well.
Especially butyrate may be important as it affects chromatin structure
through inhibition of histone deacetylation (45), which in turn may
effect gene expression. Activation of immune cells of the GALT could
be mediated through activation of the recently described G-protein-
coupled SCFA receptors (e.g. 46).
Another point of interaction is possibly between prebiotics and
carbohydrate receptors on immune cells. It is known for instance that
soluble β-glucans from yeast cell walls can interact with receptors on
natural killer cells (47) and that certain receptors on neutrophils and
monocytes recognize a variety of β-glucans from fungi and plants
(48). Fructans receptors on immune cells have not yet been
described, but in vitro it has been shown that inulin can affect the
activity and proliferation of macrophages (49).
From the data presented above we can conclude that prebiotic fibres
such as inulin affect the immune system in various ways. It is also
clear however that more work will be required to fully assess the role
of inulin on immune activity. Systematic studies to determine the
effect of inulin on lymphocyte activity or other tests of immune
function are needed. To that end, relevant biomarkers have to be
found and their relationship with the immune status has to be
established. Results from such studies will certainly help to exploit the
potential for the application of inulin in functional foods in general, and
more specifically in functional foods to support the immune system or
to enhance immune function. This may be particularly relevant for
foods for the elderly with their lowered immune activity and for infant
foods in which immune development is of paramount importance.
Although the data presented above were confined to inulin and similar
prebiotics the mechanisms may be equally relevant for other
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Immune system
... Tests involving mucus immune response revealed that fish fed 2 % inulin produced significantly higher skin mucus lysozyme and protease activity, as well as total Ig and ALP levels compared to those of the other treatments and the control groups, although the effect on complement activity (ACH50) was not noticeable. Meyer, 2008; revealed within fish defense mechanisms against pathogens, the innate immune system efficiency is greater than that of the adaptive immune system. Staykov et al., 2007; further noted enhanced antibody titration and lysozyme action in rainbow trout fed a MOS-supplemented diet (0.2 % w/w). ...
... Torrecillas et al., 2007; also demonstrated high levels of macrophage phagocytic activity of the head kidney in European sea bass (Dicentrarchus labrax) fed a MOS-supplemented diet (4 %). In addition to the positive effects of supplements conferred on fish immune systems, they have also been found to prevent nonspecific immunity from definite responses (Meyer, 2008). For example, a feeding trial with MOS supplements in the diet of channel catfish (Ictalurus punctatus) produced no apparent growth improvement or improved immunity function (Welker et al., 2007). ...
... The stimulation of the alternative complement pathway through foreign bacteria was characterized as an important defense mechanism in fish (Holland and Lambris, 2002). Additionally, researchers reported the combination and expansion of specific lectin-like receptors on leucocytes and subsequent macrophage as a consequence of immune system induction with long-chained inulin (Causey et al., 1998;Seifert and Watzl, 2007;Meyer, 2008). Cerezuela et al., 2008; claimed that gilthead sea bream had no receptors on white cells capable of binding to inulin; therefore, inulin is an unsuitable choice as an immuno-stimulant for every fish type. ...
Full-text available
The present study evaluated the effects of dietary inulin on growth performance, body composition, serum, biochemical, and mucus immune factors; as well as innate immune responses of rainbow trout fry challenged with Aeromonas hydrophila. Four diets were prepared using a commercially available fish feed as a basal diet and different levels of prebiotic inulin incorporation; 0 (control), 1, 2, and 3%; referred to as C, T1, T2, and T3, respectively. The findings of the 60-day feeding trial showed that inulin inclusion affected final weight, food conversion rate (FCR), and specific growth rate (SGR) compared to that of the control group (P < 0.05), in which the lowest FCR was observed in T3. Body composition analysis revealed that inulin significantly increased protein content and decreased lipid levels, especially in the T1 and T2 groups. The lowest ash level was noticed in T2 (P < 0.05). Blood total protein, albumin, globulin, cholesterol, and glucose were not affected by inulin supplementation (P > 0.05). Analysis of humoral immune responses showed that the inulin supplements significantly increased lysozyme and complement activities (P < 0.05), as well as higher red blood cell count (RBC) and hemoglobin (Hb) in fish, fed 2% inulin, while no significant differences were observed among other treatments (P > 0.05). The mucosal parameters; including lysozyme, alkaline phosphatase (excluding ACH50); protease activities; and total Immunoglobulin (IgM) improved significantly (P < 0.05), particularly in the T2 group. The T2 group also demonstrated the highest survival rate among all groups. The present findings indicate that dietary administration of inulin promotes growth and biochemical parameters, as well as serum immunity and mucosal immune responses of rainbow trout, in which a 2% inclusion produced the best results.
... The results of this study were consistent with [20] who stated that skim milk fortified with FOS has the ability to increase Bifidobacterium and Lactobacillus numbers compared with control treatment, they mentioned that oligosaccharides have the ability to modify the microbial balance in the intestines, this finding was also consistent with [22]. The significant increase in the number of Bifidobacterium and intestinal improvement in T2, which was fed on skim milk, agreed with [20], which indicated that feeding rats on 1ml of skim milk for 25 days led to an increase in the number of Bifidobacterium bacteria, the synergic action that occurred between the skim milk and XOS resulted in increasingBifidobacteriumnumbers compared with Lactobacillus, this increase coincided with [23] who indicated that the feeding of rats on XOS and FOS led to an increase in Bifidobacteriumnumber compared with Lactobacillus, this may be due to that Bifidobacterium has the necessary enzymes such as fructose 6-phosphate ketolase and xyloulose-5phosphate-phosphoketolase [24][25][26]which distinguish them from the rest of the lactic acid bacteria, this can be attributed to the fact that bacteria have the receptors necessary to stimulate the complement system.In addition to the presence of myosin fibers, which are made up of carbohydrate proteins that will provide false receptors tie with pathogenic bacteria, thus preventing the arrival of harmful bacteria to the receptors of the intestinal cells which will be captured by beneficial bacteria [27]. The "Embden-meyerhof-Parnas Pathway" and "Pentose phosphate pathway" play an important role in determining the numbers of bacteria and increasing one comparing with the other [28]. ...
... The significant increase in propionic and butyric concentrations in successive months was due to increased numbers of LAB, or perhaps the difference is due to the metabolic pathway taken by the bacteria to ferment carbohydrates, Bifidobacteriumand Lactobacillus have an appropriate metabolic pathway, namely Embden-Meyerhof-parnas pathway and Pentosephosphate pathway, or due to turning lactic acid and acetic acidity into propionic and butyric acid [26,34] Or perhaps feeding on prebiotics has resulted in an increase in the amount of acidic myosin fiber characterized by containing charges that make it more effective than equivalent myosin fibers [35]. These fibers represent receptors for bacteria and their ability to bind depends on how well they contain charges capable of forming a strong bond, which in turn builds the structure that is the place of stability of the mucous layer that provides an environment conducive to the presence of microorganisms and thus increases its metabolic products such as SCFA [27].The fluctuation in the concentration of shortchain fatty acids in treatments that fed skim milk with RS was due to fluctuations in the numbers of Bifidobacterium and Lactobacillus [15], the significant increase in the concentration of propionic acid in treatments fed on skim milk fortified with prebiotics give an explanation to the increase of Lactobacillus numbers because it is not common to get two types of fatty acids from the same bacteria and the result obtained in this study corresponds to Ríos- [36] which proved that microorganisms that inhabit the colon have the ability to produce one or two types of fatty acids which change their concentration according tofeeding pattern, and this is what was followed during the months of the experiment in addition to the enhancement of this result with the reduction of pH, which is a direct relationship with the increase of these acids during experiment. The effect of skim milk and skim milk fortified with prebiotics feeding on fecal moisture content The results in table (9) showed no significant differences in the moisture content of the rats' feces before starting the experiment. ...
Full-text available
Male rats (Albino rats) from college of veterinary-Basrah University were used in this study, randomly distributed depending on weight into five treatments (six rats per treatment), all treatmentsfed on a standard diet along the experiment period, treatment 2 was dosed skim milk (4 ml), while treatments 3, 4 and 5 were dosed(4 ml) skim milk fortified with 1.5g/kg of rat weightprebiotic (Fructooligosaccharide, Resistant starchand Xylooligosaccharides) respectively.Results at the end of experiment (90 days) showed that treatment 5 (XOS) was significantly higher in fecal content of Lactobacillus (log 9.41)and Bifidobacterium (log 8.48), while the least in coliform (log 5.23) significantly comparing with the other treatments. For Short chain fatty acid,treatment 5 was significantly higher in fecal content of acetic acid, propionic acid and butyric acid (92.97, 16.05 and 15.05) g/µmol comparing with the resttreatments. Treatment 5 was the lowest in pH (5.91), the highest in fecal moisture content (49.00), and the best in Villus length and Crypts depth (290.56 and122.00) µm.
... Prebiotic use in animals includes providing a particular limiting nutrient (food or feed ingredients, often polysaccharides or oligosaccharides) that is nondigestible or unused by the host, but used by indigenous microbiota in the gut, and enhances the role of beneficial bacteria such as Bifidobacterium and Lactobacillus species in the environment (Gaggìa et al. 2010, Gibson et al. 2010, McCabe et al. 2015 (XOS), pyrodextrins, stachyose, raffinose, sucrose, lactulose, and lactitol (Gibson et al. 2017, Uyeno et al. 2015. Prebiotics exert their desirable effects through a variety of proposed potential mechanisms (see Figure 1): (a) providing a competitive advantage to select resident beneficial microbiota to establish their colonization and expand their microbiological niche to exclude pathogens from the gut by competing for nutrients/substrates or binding sites, (b) producing, via select resident beneficial microbiota, antimicrobial agents (e.g., colicins or bacteriocins) that are effective against certain pathogens, (c) providing substrates for microbial fermentation to produce beneficial end-products (e.g., SCFAs, vitamins, and antioxidants) for the host, (d ) improving gut morphology and homeostasis, and (e) stimulating the adaptive immune system of the host (Callaway et al. 2012, Gaggìa et al. 2010, Meyer 2008). ...
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The gastrointestinal tract, or gut, microbiota is a microbial community containing a variety of microorganisms colonizing throughout the gut that plays a crucial role in animal health, growth performance, and welfare. The gut microbiota is closely associated with the quality and microbiological safety of foods and food products originating from animals. The gut microbiota of the host can be modulated and enhanced in ways that improve the quality and safety of foods of animal origin. Probiotics—also known as direct-fed microbials—competitive exclusion cultures, prebiotics, and synbiotics have been utilized to achieve this goal. Reducing foodborne pathogen colonization in the gut prior to slaughter and enhancing the chemical, nutritional, or sensory characteristics of foods (e.g., meat, milk, and eggs) are two of many positive outcomes derived from the use of these competitive enhancement–based treatments in food-producing animals. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see for revised estimates.
... Prebiotics may reduce intestinal concentrations of ammonia, as increased fermentation leads to higher amounts of nitrogen converted into bacterial protein [18], and biogenic amines [19]. Finally, inulin and fructo-oligosaccharides (FOS) may positively modulate activity of the immune system [20]. ...
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The gastrointestinal microbiota is a complex ecosystem made up of a multitude of bacterial species, some of which are potentially pathogenic, while others are considered good for the host. The beneficial microorganisms that live in the hindgut influence gastrointestinal functionality and the host’s health in general. Nowadays, many dietary supplements are available to be fed to young farm animals such as broilers, turkeys, piglets and calves in order to improve their intestinal health and growth performance. Despite the fact that non-pharmacological feed additives in general do not reach the efficacy of antibiotics as growth promoters, the proper choice and use of a dietary supplement may improve livestock productivity. Nevertheless, it has to be considered that dietary supplements usually increase the feed price, which means that the cost-benefit ratio of feed additives should always be determined. Keywords: gastrointestinal microbiota; dietary supplements; livestock productivity
... Several reports have confirmed the effects of fermentable dietary fibres on the immune system in the gut ( Onishi et al., 2005;Oomizu et al., 2006;Suzuki et al., 2010;Tester & Al-Ghazzewi, 2016;Torrecillas et al., 2007). The fibres can modulate various properties of the immune system, including those of the gutassociated lymphoid tissues ( Arrieta, Meddings, & Field, 2011;Meyer, 2008). The mechanisms by which these fermentable fibres work have not yet been explored fully. ...
The roles of native and depolymerised glucomannans in the diet are reviewed together with their impact in health and disease. The structure and properties of the carbohydrates are also considered together with their roles as microbiological substrates and their interactions with non-pathogens and pathogens. Native glucomannans have been consumed for centuries in Asia within food products and are permitted food thickeners through the world. However, their strong gel structures limit applications in the diet. Depolymerised and native glucomannans are considered therefore in this review with relevant dietary applications. These applications include swallowing (dysphagia), nutrient absorption control, satiety, dietary-fibre, inflammatory bowel disease, colonic benefits (such as prebiotic).
... also have this ability (Ringø et al. 2006). Insoluble inulin (γ-inulin), although it does not appear to be fermentable by gut bacteria, can stimulate parts of the immune system of mammals by activating parts of the complement pathway (Silva et al. 2004) and by binding to lectin-like receptors on leucocytes to induce macrophage proliferation (Causey et al. 1998;Sefert and Watzl 2007;Meyer 2008). However, high levels of dietary inulin (15% diet) can cause deformation of hindgut villi, formation of lamellar bodies, and increase vacuolization of the hindgut epithelium of Arctic charr (Olsen et al. 2001). ...
The demand for attributes beyond quality, such as food safety, respect for the environment and production with social responsibility is increasing in world food trade. In parallel, the fish production chain has been confronted by problems with the lack of quality of their products, many of them related to the quality of the cultivation or capture waters. Nowadays, the water where these organisms are created, presents itself as a critical control point, as well as influencing the quality / safety of the product, the cultivation should be done in an environmentally sustainable manner. In this sense, the fish has been shown to be responsible for public health problems, such as scromboid poisoning, toxicity by mollusks, ciguatera and microbial contamination or through toxic metals such as mercury. Besides the aspects of security and environmental sustainability, the relationship between water quality and the occurrence of compounds capable of negatively alter the taste and smell of fish (off flavoUr) has been evidenced in many studies. For crop species there is the possibility of controlling the quality of the fish through the proper management, which primarily begins with the quality of the cultivation water. However, questions regarding the best handling practices, processing, storage and marketing also have troubled the consumer, who is more attentive to issues of food safety and quality programs, being, in some cases, willing to pay more for a product of best quality, convenience and posing no danger to their health, the environment or society. It is noted that the tilapia is a species that can guarantee the availability of fish in many regions, since its cultivation has been successful. The advantages of tilapia farming, in relation to other species, are in the easy feeding, hardiness, prolificacy and good adaptation. Based on the chain of production of fish, although the meaning of quality is broad, standing out in this concept features that the consumer believes that the product should have, or should approach its intrinsic composition, nutritional value, likely to change during the preparation, storage, distribution, sale and presentation to the consumer. Specific actions of environmental and ecological nature should be proposed, with the aim of contributing to the sustainable and rational exploitation of resources, and minimizing the adverse impact that the waste generated by this activity produces on the environment; seeking responsible and sustainable management of fish agribusiness.
... In cattle, Brashears et al. (2003a, b) demonstrated that a Lactobacillus acidophilus culture reduced E. coli O157:H7 shedding by more than 50% in fi nishing cattle. Other studies found that the use of prebiotics can increase the resistance of animals to infection and the incidence of atopic dermatitis (Meyer, 2008). ...
Animal feed is vulnerable to the introduction of bacteria along the entire production chain. The presence of pathogens in feed can arise due to usage of contaminated raw ingredients, or due to contamination during transportation, at the feed mill, or on-farm. Since bacterial contaminants are not uniformly distributed in feed, bacteria that are present may be damaged or injured and difficulties may arise during microbial analysis; laboratory testing of feed and feed ingredients may produce false negative results. The goal of pathogen control in feed should be to make sure that feed contaminants are below a critical threshold to minimize the risk to human and animal health. Reducing the incidence of pathogens in feed requires both improvement of programs to monitor feed production and the use of sensitive and rapid pathogen detection methods. It also requires intervention strategies including chemical and physical treatments to reduce and/or eliminate multiple and/or specific feedborne pathogens.
Aquatic animals, including fishes, suffer from a range of diseases including bacterial, viral, fungal, and other ectoparasites. Disease is a prime agent affecting fish mortality and primarily a consequence of the host-pathogen-environment interaction. Therefore, disease becomes evident only when the stressful conditions surpass the immune capacity of fish. An array of bacterial pathogens cause major losses to aquaculture, comprising around 34% of total diseases. Antibiotics are frequently used as a control measure against bacterial diseases in fish, but the risk of developing antibiotic-resistant bacteria strains is increasing. Research on various options other than antibiotics is being carried out and therapeutic options are being developed. The development of fish vaccines, antimicrobial peptides, probiotic, prebiotic, and synbiotic concepts, and herbal biomedicines derived from plants are often regarded as good developments to control bacterial disease in aquaculture. In this chapter, the recent updates of the control tools for bacterial diseases are discussed.
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Aquaculture plays an increasingly significant role in improving the sustainability of global fish production. This sector has been intensified with the advent of new husbandry practices and the development of new technology. However, the increasing intensification and indiscriminate commercialized farming has enhanced the vulnerability of cultivated aquatic species to damage from pathogens. In efforts to confront these various diseases, frequent use of drugs, antibiotics, chemotherapeutics, and agents for sterilization have unintentionally added to the risk of transmission of pathogens and harmful chemical compounds to consumers. Some natural dietary supplements are believed to have the potential to offset this setback in aquaculture. Application of bio-friendly feed additives such as probiotics, prebiotics and synbiotics are becoming popular dietary supplements with the potential to not only improve growth performance, but in some cases can also enhance immune competence and the overall well-being of fish and crustaceans. The present review discusses and summarizes the effects of probiotics, prebiotics and synbiotics application on growth, stress mitigation, microbial composition of intestine, immune system and health condition of aquatic animals in association with existing constraints and future perspectives in aquaculture.
Mannan oligosaccharide (MOS) is a complex that is derived from the cell wall of the yeast Saccharomyces cerevisiae. This complex carbohydrate product has been utilized around the world to improve the productivity and wellbeing of poultry, fish and livestock. Questions related to the specific interaction between MOS and the immune cells still remain unclear. The objectives of this study are to investigate if MOS passes through the intestinal epithelium and if it is translocated to the lamina propria of the small intestine. In order to understand the fate of MOS in the gastrointestinal tract and its interaction with the immune related cells, this study compares the translocation of Albumin, the negative control which is known not to be quickly digested and not translocated; that of Dextran, the positive control which is known to be phagocytosed by dendritic cells and that MOS, the experimental group. Pure mannan was obtained from a mannan rich fraction by reacting with 7-methoxycoumarin-3-isocyanate in dimethylsulphoxide. The labeled product was isolated by ethanol precipitation. The MOS was labeled with a flourescent tag. In this study sixteen one-day old broiler chicks (Cobb × Cobb) were used. They were kept in brooder batteries with four chicks per pen. Each group (n=4) was assigned to a different fluorescent-labeled diet. The control group got the basal diet without fluorescent-tagged molecules in order to determine background levels of fluorescence. The ratio of fluorescent labeled MOS, albumin and dextran to the basic diet was 20 mg/kg. The experiment lasted three weeks. At the end of the study chickens were terminated with carbon dioxide. The removed intestinal segments were preserved in 10% formalin and fixed on the slides using the paraffin method. From each segment, 72 glass slides were prepared. Images captured by fluorescent microscopy were used to determine the extent of translocation of MOS into the lamina propria. The data was analyzed by ANOVA. P value <0.05 was considered to be significant. Foci of fluorescence from albumin were not detectable. The albumin was degraded prior to entrance into the lamina propria as expected in the negative control group. Thus it was not included in the statistical analysis. Comparatively, dextran, the positive control group was transported into the lamina propria, most significantly in the ileum. MOS, the experimental group was transported into the lamina propria. In the duodenum and jejunum, our results indicated that larger amounts of MOS were as transported into lamina propria as compared to dextran. In conclusion MOS does not interact specifically with the epithelial cells but it makes its way to the gut associated lymphoid tissue (GALT) of the lamina propria via an independent method, which appears to be mediated by dendritic cells as an immune surveillance mechanism that is vital in the mucosal immunity. MOS has likely a general adjuvant effect on immune system without causing "danger signals" that are inherent in pathogen. Further studies are needed to identify the mechanism of this interaction especially with M-Cells, which are specialized epithelial cells and play a key role in stimulating the immune system.
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Background. Statements about the availability of selected foods (“functional foods”) to reduce the risk of diseases still continue to polarise opinions. If functional food is offered to infants and toddlers, its safety and efficacy have to be established. Breast-feeding is the best example for functional nutrition during the 1st year of life. Additions to infant food. Probiotics – health-promoting bacteria – added to formula are effective for the prevention and treatment of diarrhoea. Moreover, they act as an anticonstipation factor and reduce the incidence of diaper rash. Prebiotics – oligosaccharides, which promote growth of health-promoting bacteria in the gut – added to infant cereals are helpful in reducing the incidence of fever, any cold symptoms, runny nose, and severity of diarrhoea. Consumption of prebiotics before, during, and after measles vaccination resulted in a higher IgG measles antibody titre 6 weeks after vaccination. Conclusion. Further studies with pro- and prebiotics in small children in developing and developed countries are necessary to elucidate the influence on health and the cellular and humoral immune status.
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Gamma-inulin (g-IN) is a polymorph identified as the active component of inulin preparations that specifically activates the alternative pathway of complement (APC). The APC is central to many leucocyte functions, including B cell activation. We show here that g-IN, when formulated as a pure, endotoxin-free, fine suspension insoluble at 37 degrees C and given at 50-100 micrograms per mouse, is a potent adjuvant for both humoral and cell-mediated responses to a variety of antigens. g-IN increased secondary IgG responses five- to 28-fold (P less than 0.001), using as antigen phosphorylcholine coupled to keyhole limpet haemocyanin; subclasses IgG 2a, 2b, and 3 were boosted several hundred-fold, IgG 1 10-fold. IgM and IgA were increased four- to six-fold. Delayed hypersensitivity, by footpad swelling after secondary challenge with sheep red blood cells (SRBC), was increased more than two-fold (P less than 0.001) if g-IN was included with the primary SRBC, equivalent to increasing primary doses 10-fold. g-IN was equally active if given 5 days before the primary SRBC. Thus it is an immune stimulant rather than a depot or vehicle for antigen. Mice primed subcutaneously with 30-300 HA units of H2N2 influenza virus (strain A/JAP) and challenged intranasally with a lethal dose of H1N1 virus (strain A/WSN) all died, but if g-IN was given with the primary antigen 50% of the mice survived (P less than 0.001), a deduced but not proven boost to cytotoxic T cell-mediated immunity. Unpublished work has shown that g-IN has no adverse effects at adjuvant-active doses.(ABSTRACT TRUNCATED AT 250 WORDS)
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We have previously shown that addition of short chain fructo-oligosaccharides (indigestible carbohydrates) to food prevented colon tumors in C57BL/6-ApcMin/+ mice, a model for human colon cancer. As gut-associated lymphoid tissue was concomitantly developed, we suggested that the immune response generated by this food may interfere with carcinogenesis due to involvement of mucosal cells in the regulation of tissue homeostasis. In the present experiment, we tested whether T cell status may influence colon tumor formation in Min mice fed a food supplement of short chain fructo-oligosaccharides. Min mice depleted of CD4+ and CD8+ lymphocytes developed twice as many tumors as immunocompetent mice (0.8 as compared with 0.4, the mean number in 7-week-old Min mice when food supplementation began; P = 0.02). It is concluded that food supplementation with a substrate (a known prebiotic) fermented in the colon may stimulate a mechanism of immunosurveillance that would otherwise remain inefficient.
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The adjuvant effect of gamma-inulin, a strong activator of the alternative complement pathway, is well-known, but its exact mechanism is not revealed yet. Here, we show that macrophages, isolated from the peritoneal cavity of gamma-inulin-injected mice and used as antigen-presenting cells, enhance the proliferation of antigen-specific T-cells up to 2.5-fold when compared with macrophages of non-treated animals. This effect is abrogated by the presence of anti-C3 F(ab')2 fragments and by prior decomplementation of the donor animals with CVF. It is demonstrated that treatment of mice with the adjuvant results in deposition of C3-fragments onto the surface of peritoneal macrophages, as does in vitro incubation of the cells with gamma-inulin in the presence of fresh autologous serum. Prior incubation of macrophages with gamma-inulin plus serum in vitro enhances subsequent C3 production. Because it has been shown earlier that CR1/2 expressed on activated T-cells and interacting with covalently bound C3-fragments plays an important role in the augmentation of the adaptive response, our present results reveal a mechanism that contributes to the adjuvant effect of gamma-inulin and point to a further link between innate and adaptive immunity.
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Prebiotics stimulate the growth of bifidogenic bacteria in the gut. The aim of this work was to assess the effects of a prebiotic mixture on the immune response in healthy elderly people. Healthy free-living elderly people (age, > or = 70 years), receiving a nutritional supplement that provided 1.6 MJ, 15 g of protein, and 50% of vitamin daily reference values per day, were randomly assigned to receive a prebiotic mixture (6 g/d of a 70% raftilose and 30% raftiline mixture) or placebo (6 g of maltodextrin powder) for 28 weeks. At week 2 of the study, all subjects were vaccinated with influenza and pneumococcal vaccines. At weeks 0, 2, and 8 of the study, serum total proteins, albumin, immunoglobulins, saliva secretory immunoglobulin A (IgA), and serum titers of influenza A and B and pneumococcal antibodies were measured. At week 8, cultured peripheral monocyte cell secretion of interleukin-4, interferon-gamma, and lymphocyte proliferation, stimulated with phytohemagglutinin and influenza antigen, were measured. Sixty-six subjects were considered eligible for the study, and 43 (20 receiving prebiotics and 23 receiving placebo) were considered for final analyses on a per protocol basis. No changes in serum proteins, albumin, immunoglobulins, and secretory IgA were observed. Antibodies against influenza B and pneumococcus increased significantly from weeks 0 to 8, with no significant differences between groups. Antibodies against influenza A did not increase. No effects of prebiotics on interleukin-4 and interferon-gamma secretion by cultured monocytes were observed. No immunological effects of prebiotics were observed in this study.
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Ulcerative colitis (UC) is an acute and chronic inflammatory disease of the large bowel with unknown aetiology. The immune response against normal commensal microorganisms is believed to drive inflammatory processes associated with UC. Therefore, modulation of bacterial communities on the gut mucosa, through the use of probiotics and prebiotics, may be used to modify the disease state. A synbiotic was developed for use in UC patients combining a probiotic, Bifidobacterium longum, isolated from healthy rectal epithelium, and a prebiotic (Synergy 1), a preferential inulin-oligofructose growth substrate for the probiotic strain. Treatment was employed in a double blinded randomised controlled trial using 18 patients with active UC for a period of one month. Clinical status was scored and rectal biopsies were collected before and after treatment, and transcription levels of epithelium related immune markers were measured. Sigmoidoscopy scores (scale 0-6) were reduced in the test group (start 4.5 (1.4), end 3.1 (2.5)) compared with placebo (start 2.6 (2.1), end 3.2 (2.2)) (p=0.06). mRNA levels for human beta defensins 2, 3, and 4, which are strongly upregulated in active UC, were significantly reduced in the test group after treatment (p=0.016, 0.038, and 0.008, respectively). Tumour necrosis factor alpha and interleukin 1alpha, which are inflammatory cytokines that drive inflammation and induce defensin expression, were also significantly reduced after treatment (p=0.018 and 0.023, respectively). Biopsies in the test group had reduced inflammation and regeneration of epithelial tissue. Short term synbiotic treatment of active UC resulted in improvement of the full clinical appearance of chronic inflammation in patients receiving this therapy.
Aims: The primary objectives was to confirm the bifidogenic effects of fructooligosaccharides in elderly subjects (increase equal or higher than 1 log endogenous bifidobacteria per gram of faeces), and to make an exploratory investigation on non-specific immune defense parameters, such as phagocytosis and changes in lymphocyte subpopulations, in relation to the increase in endogenous bifidobacteria. Methods: The study was a pretest/posttest study of 19 elderly nursing home patients, with one period of 3 weeks of 8 g fructooligosaccharides (FOS) given in portions of 4 g, twice a day. Faecal bacteria composition was investigated using viable counts, lymphocyte subpopulation was analysed using a FACS scan, and relative expression of interleukin-6 (IL-6) by measuring levels of IL-6 mRNA in peripheral blood monocytes. Results: Bacterial counts for bifidobacteria increased by a mean of 2.8 ± 0.57 log10CFU/g faeces after 3 weeks of supplementation, and decreased by a mean of 1.1 log10CFU/g faeces after the period without FOS (post-test). Unexpected changes in non-specific immunity were observed: decreased phagocytic activity of granulocytes and monocytes, as well as a decreased expression of interleukin-6 mRNA in peripheral blood monocytes. These results suggest a possible decrease in inflammatory process in elderly subjects after FOS supplementation. Conclusion: The results confirm the bifidogenic effect of FOS with a 2 log increase in bifidobacteria counts and the frail elderly subjects showed low counts at the beginning of study. A diminution in inflammatory process is suggested by the decreased expression of IL-6 mRNA in peripheral blood monocytes. These results need confirmation in further studies.
Inulin stimulates intracolonic generation of butyrate and growth of lactic acid bacteria. This study investigated whether inulin protects against colitis. Rats with dextran sodium sulfate colitis received inulin either orally (1% in drinking water, or 400 mg/day) or by enema. Matched groups received vehicle. In addition, fecal water obtained from inulin-fed rats was administered by enema to rats with colitis and compared with fecal water from control rats. Finally, rats with colitis received daily enemas of either butyrate (at 40 or 80 mmol/L) or vehicle. Inflammation was assessed by eicosanoid asssay in rectal dialysates and MPO activity in colonic tissue. Mucosal lesions were blindly scored by microscopic examination. Luminal pH was measured from cecum to rectum by a surface microelectrode. Oral inulin prevented inflammation, as evidenced by lower lesion scores (p < 0.05), decreased release of mediators (p < 0.05), and lower tissue MPO (p < 0.05) as compared with controls. Inulin induced acidic environment (pH <7.0) from cecum to left colon and increased counts of lactobacilli. Fecal water from inulin-fed rats also reduced scores (p < 0.05) and inflammation (p < 0.05). However, inulin or butyrate enemas had no effect. Oral inulin reduces the severity of dextran sodium sulfate colitis. The effect seems to be mediated by modification of the intracolonic milieu.
Eight-month-old Sprague-Dawley rats were fed on diets containing dietary fiber at the 5% level for 3 weeks to examine the effect on the lipid metabolism and immune function. Among cellulose, guar gum, partially hydrolyzed guar gum (PHGG), glucomannan and highly methoxylated pectin, guar gum induced a significant decrease in the food intake and weight gain, as well as a significant increase in the liver weight. In addition, the epidydimal adipose tissue weight of the rats fed on PHGG was significantly higher than that of the rats fed on cellulose. There was no significant effect on the serum lipid levels, but the serum IgG level of the rats fed on guar gum was significantly lower than that of the rats fed on cellulose. The IgA and IgG productivity in mesenteric lymph node (MLN) lymphocytes was significantly higher in the rats fed on guar gum, glucomannan and pectin than in those fed on cellulose, while the effect on Ig productivity in spleen lymphocytes was not as marked. In addition, only guar gum induced a significant increase of IgM productivity in MLN lymphocytes when compared to the cellulose group. These results suggest that enhancement of the immune function by dietary fiber is mainly expressed in the gut immune system.
In the present study, we tested the hypothesis that dietary oligofructose (FOS) can modulate both the response to an endotoxic shock induced by lipopolysaccharide (LPS) administration and the activity of resident hepatic macrophages, i.e., Kupffer cells. Male Wistar rats (n = 5-9 per group) were fed a standard diet or a diet supplemented with 10 g/100 g FOS for 3 wk. LPS (10 mg/kg) or saline were injected i.p. after dietary treatment. After LPS injection, serum levels of tumor necrosis factor (TNF)-alpha, a proinflammatory cytokine, and prostaglandin E(2) (PGE(2)), an immunosuppressive mediator, were higher in FOS-treated rats than in control rats. Alanine aminotransferase (ALT) activity was approximately 50% lower than in controls 24 h after LPS administration in FOS-treated rats, suggesting less hepatic injury; this was confirmed through histological analysis. FOS treatment increased the number of large phagocytic Kupffer cells, as assessed by histological examination of the liver after colloidal carbon injection into the portal vein. Precision-cut liver slices (PCLS) from FOS-treated rats released more TNF-alpha and PGE(2) into the incubation medium than PCLS from control rats, independently of LPS challenge in vitro. This would suggest that the higher Kupffer cell phagocytic activity and secretion capacity due to FOS supplementation improve LPS clearance in liver tissue and reduce hepatocyte alterations. This study supports the hypothesis that oligofructose might decrease liver tissue injury after endotoxic shock and sepsis.