Lactobacillus acidophilus alleviates polysorbate-80-induced colitis through regulating intestinal microbiota and...

Polysorbate-80 is a prevalent food additive. However, prolonged administration of polysorbate-80 has been demonstrated to induce intestinal inflammation in animal models, there is no effective measure to deal with this hazard at present. In this study, colitis was induced using 1% of polysorbate-80 for 30 days, treated with (10⁹ cfu) Lactobacillus acidophilus (LA) for 14d. Mesalazine served as the positive control. The HE staining technique was used to detect intestinal pathology, while ELISA and WB assays were utilized for the detection of intestinal TNF-α, IL-6, ZO-1 and Claudin-1 expression. Additionally, 16S sequencing was conducted to investigate intestinal flora, whereas metabonomics analysis was performed to assess changes of metabolites. Results the LA treatment attenuated pathological intestinal injury, ameliorated body weight loss, reduced DAI. Furthermore, LA decreased expression of TNF-α, IL-6, and increased ZO-1, Claudin-1 expression. In addition, LA has the potential to regulate the composition of intestinal microbiota, enhance microbial diversity, promote an increased ratio of Firmicutes/Bacteroidetes, and elevate levels of Lactobacillus. Moreover, LA can regulate the intestinal metabolites. Specifically, we discovered that LA exhibited the ability to down regulate the quinolinic acid levels, which is considered to be an important factor in the development of intestinal inflammation. Additionally, our findings demonstrated that LA could down-regulate indoleamine 2,3-dioxygenase 1 (IOD-1), which is the rate-limiting enzyme involved in quinolinic acid metabolism. Conclusion LA demonstrates the ability to attenuate colitis induced by polysorbate-80, possibly through downregulation of IOD-1 expression, consequently leading to a reduction in quinolinic acid concentration.