Pu’ er raw tea extract alleviates DSS-induced colitis in mice by restoring intestinal barrier function and maintaining gut microbiota homeostasis

Numerous investigations have uncovered the outstanding therapeutic effect of tea extract on ulcerative colitis (UC). However, the therapeutic potential on UC of Pu’ er raw tea extract (PRTE) remains debated and need to be investigated. In our study, PRTE (100 and 300 mg/kg) was applied to the DSS-induced colitis mice via intragastric administration. Results have shown that PRTE treatment significantly ameliorated DSS-induced weight loss, loose stool, hematochezia, colon atrophy, splenomegaly and colon pathological injury. It could also inhibit UC by down-regulating pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and increasing the expression of tight junction protein (zonula occludens-1, ZO-1) to reinforce intestinal barrier. Fecal microbiota transplantation has further confirmed that PRTE could maintain intestinal homeostasis and relieve UC by improve the abundance of beneficial bacteria such as Lactobacillus, Muribaculum, Lachnospiraceae and Rikenellaceae, and reduce the abundance of harmful bacteria such as Turicibacter and Romboutsia. This study suggested that PRTE exhibited a noteworthy therapeutic effect on UC via restoring intestinal barrier function and maintaining gut microbiota homeostasis, which develops a safe and efficient novel strategy for UC prophylaxis and therapy, and provides theoretical support for medical application of Pu’ er raw tea in the future.