Bifidobacterium longum subsp. longum K5 alleviates inflammatory response and prevents intestinal barrier injury induced by LPS in vitro based on comparative genomics. (May 2022)

• Record Type: Journal Article
• Authors: Zhao, Li; Xie, Qinggang; Evivie, Smith Etareri; Yue, Yingxue; Yang, Han; Lv, Xiuli; Liu, Fei; Li, Bailiang; Huo, Guicheng
• Is Part Of: Journal of functional foods. Volume 92(2022)
• Publication Date: 2022-05
• Subjects: B. longum subsp. longum -- Anti-inflammation -- Intestinal barrier -- Comparative genomics; Functional foods -- Analysis -- Periodicals; Food -- Biotechnology -- Periodicals; Nutrition -- Periodicals; 613.2
• DOI: 10.1016/j.jff.2022.105030
• Languages: English
• ISSNs: 1756-4646

Abstract

Graphical abstract: Highlights: K5 inhibited TNF-α, IL-1β, IL-6, ROS and NO level better than K15 in the LPS-induced RAW 264.7 cell model. K5 increased TEER value and decreased paracellular permeability in LPS-induced Caco-2 cell monolayers model. Comparative genomics showed K5 had a specific gene encoding fatty acid synthase associated with the immune system. Comparative genomics showed K5 and K15 had four genes with only an amino acid mutation. Abstract: Excessive immune responses and intestinal barrier injury are leading causes of inflammatory bowel diseases (IBD). Previously, we demonstrated that B. longum subsp . longum K5 alleviated DSS-stimulated colitis in mice, while K15 could not. Here, we investigated both strains' underlying mechanisms regarding their anti-inflammatory and intestinal barrier protective capacities. We assessed the potential characters of two strains, anti-inflammation activities in the LPS-induced RAW 264.7 cell model, and intestinal epithelial barrier functions in the LPS-induced Caco-2 cell monolayers model. Results showed that B. longum subsp . longum K5 exhibited high inhibition against the adhesion of E. coli ATCC 25922 to HT-29 and acetic acid production. B. longum subsp. longum K5 (MOI 1:100) significantly decreased the pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and inflammatory mediator ROS, NO level in LPS (1 μg/mL) -induced RAW 264.7 cells. It also significantly increased TEER value and decreased paracellular permeability of Caco-2 cells stimulated by LPS. B. longum subsp. longum K5 (MOI 1:100) up-regulated ZO-1, occlaudin and claudin-1 mRNA expression, down-regulated the mRNA expression level of TLR4 and pro-inflammatory cytokines ( TNF-α, IL-1β, IL-6 ) in LPS (100 μg/mL) -stimulated Caco-2 cells. While B. longum subsp. longum K15 did not do as well as B. longum subsp. longum K5 on these assays. Furthermore, the whole-genome sequencing results revealed a gene encoding fatty acid synthase associated with the immune system in K5 specific genes, LacI family related with carbohydrate metabolism, and serine/threonine-protein kinase involved in signal transduction with an amino acid mutation. Our findings provided the theoretical basis for B. longum subsp . longum K5 to be used as a candidate for IBD therapy.