Research

Mixed

Specific bacterial metabolites, particularly short-chain fatty acids (SCFAs) like butyrate and polysaccharides like PSA, directly modulate adaptive immunity by promoting Treg differentiation and suppressing pro-inflammatory Th17 responses.

To support immune balance, focus on consuming fiber-rich foods that feed your gut bacteria to produce SCFAs like butyrate. These metabolites help expand regulatory T cells (Tregs) which calm inflammation, while suppressing excessive inflammatory Th17 responses. This is a key mechanism for preventing autoimmune and inflammatory conditions.

ModerateSupportsHIGH confidence
Polysaccharide A (PSA) from Bacteroides fragilis promoted Treg cell secretion and then suppressed Th17 activity... Butyrate, a large intestinal bacterial metabolite, drives colonic expansion of Treg cells in mice by reinforcing histone H3 acetylation...
Ning Ma et al. · Frontiers in Immunology · 2018

Why this rating

Review paper citing multiple animal and in vitro studies; strong mechanistic evidence but limited direct human clinical trial data presented.

Source

Nutrients Mediate Intestinal Bacteria–Mucosal Immune Crosstalk

Ning Ma et al. · Frontiers in Immunology · 2018

DOI 10.3389/fimmu.2018.00005

narrative_reviewCited 251×
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DOI resolved against Crossref · corpus check 2026-06-10

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