Liupao tea aqueous extract alleviates dextran sulfate sodium-induced ulcerative colitis in rats by modulating the gut microbiota

Liupao tea is known for its anti-inflammatory antioxidant and regulation of gut microecological balance properties. This study aims to investigate the therapeutic effects of Liupao tea aqueous extract (LPTAE) on ulcerative colitis (UC) induced by dextran sulfate sodium (DSS) in rats. The rats were randomly divided into five groups: the Normal group, the DSS group, the LPTL group, the LPTM group, and the LPTH group. Throughout the experiment, the rats' activity levels, stool consistency, and body weights were observed and recorded daily. After the experiment, colon length was measured, and colon tissues were collected for pathological analysis. Additionally, the colon contents were analyzed for gut microbiota composition and short-chain fatty acid (SCFA) level, while serum samples were collected to determine inflammatory and oxidative factors. The results indicated that treatment with low, medium, and high doses of LPTAE significantly inhibited weight loss, alleviated rectal bleeding, and reduced colon shortening compared to the DSS group. It also decreased the disease activity index and histopathological activity index scores in the rats. Furthermore, LPTAE reduced the levels of inflammatory cytokines such as IL-1<i>β</i>, IL-6, TNF-<i>α</i>, and malondialdehyde, while simultaneously increasing the levels of superoxide dismutase and SCFAs, including acetic acid, propionic acid, and butyric acid. 16S rDNA gene sequencing of the gut microbiota revealed that all doses of LPTAE reversed the decrease in both <i>α</i> and <i>β</i> diversities caused by UC, increased the relative abundance of beneficial bacteria such as <i>Lactobacillus</i>, Muribaculaceae, <i>Alloprevotella</i>, and <i>Blautia</i>, and decreased the levels of harmful bacteria such as <i>Prevotella</i>, <i>Romboutsia</i>, and <i>Bacteroides</i>. In summary, within the tested doses (100, 150, 250 mg/kg), LPTAE alleviated DSS-induced colitis by modulating the gut microbiota and correcting the metabolic imbalance of SCFAs.