The Interplay Between Fiber and the Intestinal Microbiome in the Inflammatory Response

Abstract

Fiber intake is critical for optimal health. This review covers the anti-inflammatory roles of fibers using results from human epidemiological observations, clinical trials, and animal studies. Fiber has body weight-related anti-inflammatory activity. With its lower energy density, a diet high in fiber has been linked to lower body weight, alleviating obesity-induced chronic inflammation evidenced by reduced amounts of inflammatory markers in human and animal studies. Body weight-unrelated anti-inflammatory activity of fiber has also been extensively studied in animal models in which the type and amount of fiber intake can be closely monitored. Fermentable fructose-, glucose-, and galactose-based fibers as well as mixed fibers have shown systemic and local intestinal anti-inflammatory activities when plasma inflammatory markers and tissue inflammation were examined. Similar anti-inflammatory activities have also been demonstrated in some human studies that controlled total fiber intake. The anti-inflammatory activities of synbiotics (probiotics plus fiber) were reviewed as well, but there was no convincing evidence indicating higher efficacy of synbiotics compared with that of fiber alone. Adverse effects have not been observed with the amount of fiber intake or supplementation used in studies, although patients with Crohn's disease may be more sensitive to inulin intake. Several possible mechanisms that may mediate the body weight-unrelated anti-inflammatory activity of fibers are discussed based on the in vitro and in vivo evidence. Fermentable fibers are known to affect the intestinal microbiome. The immunomodulatory role of the intestinal microbiome and/or microbial metabolites could contribute to the systemic and local anti-inflammatory activities of fibers.

An LPS based method to stimulate the inflammatory response in growing rabbits

“…Likewise, an increase in the dietary ratio of digestible fibres to starch decreases the incidence of digestive disorders in weanling rabbits (Perez et al, 2000). These beneficial effects upon health could be associated with a decreased inflammatory response, as previously demonstrated in other species submitted to feed restriction (Matsuzaki et al, 2001;MacDonald et al, 2011a) or fed fibrous diets (Kuo, 2013). Thus, the second aim of our study was to determine whether the beneficial effects of feed restriction and a dietary increase in digestible fibre to starch ratio upon health were associated with a decreased inflammatory response to an LPS injection.…”

Probiotics, prebiotics and synbiotics- a review

“…3) Be easily fermentable by the beneficial intestinal microflora (Kuo 2013). FAO/WHO defines prebiotics as a non-viable food component that confer health benefit(s) on the host associated with modulation of the microbiota.…”

Dietary intake of soluble fiber and risk of islet autoimmunity by 5 y of age: results from the TEDDY study

“…1 Ancillary Studies, 2 Diet, 3 Genetics, 4 Human Subjects/Publicity/Publications, 5 Immune Markers, 6 Infectious Agents, 7 Laboratory Implementation, 8 Maternal Studies, 9 Psychosocial, 10 Quality Assurance, 11 Steering, 12 Study Coordinators, 13 Celiac Disease, 14 Clinical Implementation, and 15 Quality Assurance Subcommittee on Data Quality. Colorado Clinical Center: Marian Rewers (principal investigator), 1,4,5,6,10,11 Kimberly Bautista, 12 Judith Baxter, …”

“…Colorado Clinical Center: Marian Rewers (principal investigator), 1,4,5,6,10,11 Kimberly Bautista, 12 Judith Baxter, …”

“…Besides a direct effect on immune regulation, soluble fiber intake may also modulate the immune response through alterations of the microbial composition in the gut (10). There is growing evidence that dietary fiber intake directly affects the gut microbiome (11,12), which may, in turn, interact with the immune system (13).…”