Eurotium cristatum Exhibited Anti-Colitis Effects via Modulating Gut Microbiota-Dependent Tryptophan Metabolism

Fu-brick tea (FBT) has attracted the attention of researchers because of its unique nutritional value, but it remains unknown whether Eurotium cristatum, the critical fungus from FBT, is responsible for the observed anti-colitis effects of FBT. Herein, the effects of E. cristatum on dextran sulfate sodium (DSS)-induced ulcerative colitis was first discussed. The results illustrated that the oral administration of E. cristatum inhibited DSS-induced colon damage. Microbiota analysis revealed that E. cristatum improved the intestinal homeostasis of colitis mice, especially increased the proportion of Lactobacillus, followed by an obvious increase in fecal short-chain fatty acids (SCFAs). Besides, E. cristatum markedly promoted tryptophan metabolism and increased the fecal contents of tryptophan metabolites in colitis mice. Furthermore, E. cristatum drastically increased the content of colonic IL-22 and the expression of tight-junction proteins. Conclusively, these results suggest that E. cristatum can resist colon damage and other implications of colitis by regulating the microbiota and enhancing tryptophan metabolism to strengthen intestinal barriers.