Differential intestinal anti‐inflammatory effects of Lactobacillus fermentum and Lactobacillus salivarius in DSS mouse colitis: impact on microRNAs expression and microbiota composition

Scope To compare the intestinal anti‐inflammatory effects of two probiotics Lactobacillus fermentum and Lactobacillus salivarius in mouse colitis, focusing on their impact on selected miRNAs and microbiota composition. Methods and results Male C57BL/6J mice were randomly assigned to four groups (n = 10): non‐colitic, DSS colitic and two colitic groups treated with probiotics (5 × 108 CFU/mouse/day). Both probiotics ameliorated macroscopic colonic damage. They improved the colonic expression of markers involved in the immune response, and the expression of miR‐155 and miR‐223. L. fermentum also restored miR‐150 and miR‐143 expression, also linked to the preservation of the intestinal barrier function. Besides, these beneficial effects were associated with the amelioration of the microbiota dysbiosis and a recovery of the SCFAs‐ and lactic acid‐producing bacterial populations, although only L. fermentum improved Chao richness, Pielou evenness and Shannon diversity. Moreover, L. fermentum also restored the Treg cell population in MLNs and the Th1/Th2 cytokine balance. Conclusion Both probiotics exerted intestinal anti‐inflammatory effects in DSS‐mouse colitis, maybe due to their ability to restore the intestinal microbiota homeostasis and modulate the immune response. L. fermentum showed a greater beneficial effect compared to L. salivarius, which makes it more interesting for future studies. Lactobacillus fermentum and L. salivarius, exert intestinal anti‐inflammatory effects in mouse DSS colitis, maybe due to their ability to restore intestinal microbiota composition and modulate the immune response. L. fermentum improved more parameters than L. salivarius, which makes it more interesting for future studies.