Effects of Sasa veitchii extract on intestinal epithelial cells and gut microbiota

Leaf extract of Sasa veitchii, a traditional Japanese medicinal plant, has numerous biological activities, including anti-ulcer, anti-inflammatory, and anti-bacterial effects, suggesting its usefulness as a functional food. However, not much is known about the effects of S. veitchii extract on the intestine. In this study, we analyzed the effects of S. veitchii extract on intestinal epithelial cells and the gut microbiota. Mice were fed purified water containing S. veitchii extract for 21 days. The expression levels of the tight and adherens junctions in the small and large intestines, as well as the abundance of gut microbiota in the feces, were analyzed. Changes in the differentiation and proliferation potential of the small intestinal epithelial cells were examined using organoid culture. The expression levels of the genes implicated in the tight and adherens junctions, Cldn3, Tjp1, and Cdh1, in the jejunum and colon were significantly increased in S. veitchii extract-treated mice compared to the control animals. In contrast, the expression levels of the genes involved in cell growth, proliferation, and differentiation, Lgr5, Sox9, Klf4, Ngn3, and Hnf1, in the enteroids remained unchanged. Treatment with S. veitchii extract decreased the abundance of Bacillota, resulting in a lower Bacillota/Bacteroidota ratio. In addition, S. veitchii extract treatment reduced the levels of Clostridial cluster ⅩⅣab and cluster Ⅳ, while it increased the levels of Bifidobacterium and Lactobacillus spp. This study suggests that S. veitchii extract may help maintain intestinal health by regulating intestinal barrier function and increasing the abundance of probiotic bacteria.