Tuoli Xiaodu powder ameliorated 5-fluorouracil-induced intestinal injury by reducing intestinal inflammation, oxidative stress, and intestinal flora imbalance.

Chemotherapy-induced diarrhea (CID) is a common adverse event in cancer patients treated with 5-fluorouracil (5-FU). This study aimed to investigate the potential protective effects of Tuoli Xiaodu (TLXD) powder on CID and to explore its possible mechanisms. Mice with CID induced by 5-FU were randomly divided into seven groups: Blank group, CID group, positive drug (loperamide) group, and TLXD powder low, medium, and high groups. The degree of diarrhea, tumor growth, intestinal barrier damage, intestinal inflammation, oxidative stress, and gut microbiota diversity were assessed. The study showed that TLXD powder significantly inhibited diarrhea and tumor growth in 5-FU-induced CID mice. H&E staining and western blot showed that TLXD powder improved the intestinal mucosa and intestinal permeability of 5-FU-induced CID mice. Furthermore, TLXD powder elicited a reduction in the expres-sion of inflammatory factors within the intestinal tract of mice with CID while simultaneously augment-ing the expression of anti-inflammatory factors and maintaining a balanced Th17/Treg ratio. TLXD pow-der decreased intestinal oxidative stress and intestinal epithelial cell ferroptosis and activated the Nrf2/HO-1 signaling axis in CID mice. The results of the gut flora analysis showed that TLXD powder improved the intestinal flora structure of CID mice. TLXD powder significantly reduced the proportion of Proteobacteria, Actinobacteria, Deferribacteres, and TM7 at the phylum level and Desulfovibrio, Mucis-pirillum, Adlercreutzia, and Odoribacter at the genus level. These findings provide a new therapeutic approach for the management of CID in cancer patients treated with 5-FU.