P1345 Human milk-derived Bifidobacterium breve SHMB 8001 alleviates DSS-induced colitis by restoring intestinal barrier and modulating gut microbiota

Background Human milk contains a diverse microbial community that is important for the infant microbiome and immunity. Here, we isolated a novel Bifidobacterium breve strain named Bifidobacterium breve (B. breve) SHMB 8001 from human milk and aimed to investigate its ameliorative effect on DSS-induced colitis in mice. Methods The efficacy of B. breve SHMB 8001 (1 × 109 CFU/g/day) on C57BL/6 mice with DSS-induced colitis was examined by weight, disease activity index (DAI) score, colon length, and histopathological alterations. Western blot was applied to examine the expression of colonic occludin and claudin-1. 16S rRNA gene sequencing was utilized to investigate the microbiota composition and diversity. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Cluster of Orthologous Groups of proteins (COG) pathway analysis were employed to explore the microbial functional profiles. Results The administration of B. breve SHMB 8001 demonstrated a protective effect against DSS-induced colitis in mice, as evidenced by the reduction of weight loss, disease activity index (DAI) score, colon length shortening, and histological damage. B. breve SHMB 8001 enhanced the expression of colonic occludin and claudin-1 while diminishing the levels of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). 16S rRNA gene sequencing revealed that B. breve SHMB 8001 could modulate the composition and diversity of the gut microbiota community and improve the structural integrity of the microbial ecosystem. The KEGG and COG pathway analysis indicated that B. breve SHMB 8001 could partially restore the metabolic pathways altered by DSS. Conclusion The human milk–derived B. breve SHMB 8001 exhibits promising probiotic characteristics and relieves DSS-induced colitis in mice. Therefore, B. breve SHMB 8001 may serve as a prophylactic and adjunctive treatment for alleviating intestinal inflammation. Conflict of interest: Liu, Gaojie: No conflict of interest Wang, Xufei: No conflict of interest Xiao, Fangfei: No conflict of interest Xu, Qiao: No conflict of interest Li, Xiaolu: No conflict of interest Ye, Lin: No conflict of interest Li, Dan: No conflict of interest Prof. Dr. Zhang, Ting: No conflict of interest Wang, Yizhong: No conflict of interest