Bifidobacterium Breve SHMB 8001 Alleviates DSS-Induced Colitis in Mice Via Modulating the Intestinal Barrier and Gut Microbiota.

B. breve SHMB 8001 administration alleviated DSS-induced colitis symptoms including alterations in body mass, disease activity index, colon dimensions, and tissue histology in mice.

• The strain was derived from human breast milk and tested in a DSS-induced colitis mouse model.
• Colon dimensions were significantly improved (p = 0.007).
• Tissue histology improvements were highly significant (p < 0.001).
• Disease activity index (DAI) and body mass changes were also alleviated.

B. breve SHMB 8001 increased colonic levels of critical intestinal barrier proteins MUC2, occludin, and claudin-1.

• MUC2 levels were significantly increased (p < 0.001).
• Occludin levels were significantly increased (p < 0.001).
• Claudin-1 levels were significantly increased (p < 0.001).
• Measurements were performed using both qPCR and western blotting.

B. breve SHMB 8001 significantly elevated fecal short-chain fatty acids (SCFAs) and colonic GPR43 expression.

• Fecal SCFA levels were significantly elevated as measured by gas chromatography-mass spectrometry (GC-MS).
• Colonic G protein-coupled receptor (GPR) 43 expression was significantly upregulated (p = 0.023) as measured by qPCR.
• GPR43 is a receptor known to mediate SCFA signaling in the gut.

B. breve SHMB 8001 increased the percentage of CD4+ CD25+ FOXP3+ regulatory T (Treg) cells in DSS-treated mice.

• The percentage of CD4+ CD25+ FOXP3+ Treg cells was significantly elevated (p = 0.009).
• Treg cell percentages were determined by flow cytometry.
• Colonic IL-10 expression was also upregulated (p = 0.010) as measured by qPCR, consistent with a regulatory immune response.

B. breve SHMB 8001 suppressed the expression of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α in colonic tissue.

• IL-1β expression was significantly suppressed (p = 0.013).
• IL-6 expression was significantly suppressed (p = 0.005).
• TNF-α expression was significantly suppressed (p = 0.021).
• Gene expression was measured by qPCR.

B. breve SHMB 8001 modulated gut microbiota composition by enriching SCFA-producing bacterial genera and partially restoring microbial functional pathways altered by DSS.

• High-throughput 16S rRNA gene sequencing was used to assess microbiota composition.
• SHMB 8001 enriched bacterial genera including Bifidobacterium, norank_f_Muribaculaceae, and Lactobacillus, which are capable of producing SCFAs.
• Microbial functional pathways altered by DSS were partially restored by SHMB 8001 treatment.