Anti-inflammatory and gut microbiota modulatory effects of polysaccharides from Fuzhuan brick tea on colitis in mice induced by dextran sulfate sodium

In this study, the effects of crude Fuzhuan brick tea polysaccharides (CFBTPS) and their purified fraction (FBTPS-3) on colitis induced by dextran sulfate sodium (DSS) in mice were investigated. Both CFBTPS and FBTPS-3 exhibited intestinal anti-inflammatory activities, including restoring body weight, colon length and solid fecal weight, and decreasing the disease activity index score in mice. Moreover, the expression of lipocalin-2 in colitis could be significantly reduced. The inflammatory cytokines (IL-6, IL-1β, IFN-γ and TNF-α) and lipopolysaccharides in the serum and the expression of inflammation-related mRNA in the colon tissue were decreased. Both CFBTPS and FBTPS-3 could increase tight junction proteins (Occludin, Claudin-1 and ZO-1), promoting the intestinal barrier function. For gut microbiota, DSS treatment resulted in abnormal proliferation of Bifidobacteria, while FBTPS-3 could restore this disorder to a certain extent. In addition, FBPTS-3 promoted the growth of probiotics such as Bacteroides, Parasutterella and Collinsella. Both CFBTPS and FBTPS-3 could attenuate colitis; what's more, FBTPS-3 exhibited a better anti-inflammatory effect than CFBTPS.