Investigating the crucial role of selected Bifidobacterium probiotic strains in preventing or reducing inflammation by affecting the autophagy pathway

Several studies have shown that probiotics can prevent and reduce inflammation in inflammation-related diseases. However, few studies have focused on the interaction between host and probiotics in modulating the immune system through autophagy. Therefore, we aimed to investigate the preventive and/or therapeutic effects of native potential probiotic breast milk-isolated Bifidobacterium spp. (i.e. B. bifidum, B. longum, and B. infantis) on the inflammatory cascade by affecting autophagy gene expression 24 and 48 hours after treatment. Autophagy genes involved in different stages of the autophagy process were selected by qPCR. Gene expression investigation was accomplished by exposing the human colorectal adenocarcinoma cell line (HT-29) to sonicated pathogens (1.5 × 108 bacterial CFU ml-1) and adding Bifidobacterium spp. (MOI10) before, after, and simultaneously with induction of inflammation. An equal volume of RPMI medium was used as a control. Generally, our native potential probiotic Bifidobacterium spp. can increase the autophagy gene expression in comparison with pathogen. Moreover, the increase in gene expression was observed with our probiotic strains' consumption in all stages of autophagy. Totally, our selected Bifidobacterium spp. can increase autophagy gene expression before, simultaneously, and after the inflammation induction, so they can prevent and reduce inflammation in an in-vitro model of inflammation.