Betaine supplementation alleviates dextran sulfate sodium-induced colitis <i>via</i> regulating the inflammatory response, enhancing the intestinal barrier, and altering gut microbiota

Abstract

Inflammatory bowel disease (IBD) is a multifaceted and recurrent immune disorder that occurs in the gastrointestinal tract. Betaine is a natural compound that exerts beneficial anti-inflammatory effects. However, the role of betaine in protecting IBD is still unclear. Therefore, the aim of our study was to investigate the anti-inflammatory effect of betaine in dextran sulfate sodium (DSS)-induced colitis. The results showed that betaine greatly increased the body weight and decreased the disease activity index score of DSS-treated mice. Furthermore, betaine effectively downregulated the protein levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNFα) and upregulated tight junction proteins (occludin and ZO-1) in the mice. Additionally, betaine exposure remarkably restricted the DSS-induced phosphorylation of IκB and NF-κB p65 in mice. Similarly, betaine pretreatment improved the inflammatory response and intestinal barrier of Caco-2 cells. Betaine altered the gut microbiota composition, markedly decreasing the relative abundance of Firmicutes and Proteobacteria and considerably increasing the relative abundance of Bacteroidota and Campylobacterota in DSS-induced mice. In conclusion, betaine could attenuate colitis <i>via</i> regulating the inflammatory response, enhancing the intestinal barrier, and altering gut microbiota and is conducive to developing new drugs for treating human diseases.