Lactobacillus paracasei from koumiss ameliorates diarrhea in mice via tight junctions modulation

•Lactobacillus paracasei from koumiss showed good probiotic properties, such as acid, bile salt, artificial gastric fluid, and artificial intestinal fluid tolerance•Lactobacillus paracasei can alleviate the increase in intestinal permeability caused by Escherichia coli O8•Lactobacillus paracasei restores the expression of mucin 2, oligomeric mucus/gel-forming and tight junction protein in mouse models of diarrhea•Lactobacillus paracasei prevents the destruction of tight junction structures by Escherichia coli O8 via the inhibition of the nuclear factor kappa B cells–myosin light-chain kinase signaling pathway