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

•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.