Abstract: Acer truncatum is a tree species unique to China. Its seeds contain abundant unsaturated fatty acids and multiple nutritional components. The aim of this study was to explore the effects of Acer truncatum seeds on the composition of the intestinal flora in mice and the inhibition of harmful bacteria. Eight-week-old Kunming mice were selected and fed 1.5 g of Acer truncatum seeds every day. After continuous feeding for two weeks, rectal feces were collected for high-throughput sequencing analysis and body mass recorded every day over the entire period. The α-diversity of the intestinal flora did not significantly differ between the experimental and control groups. In the β-diversity analysis, significant separation was found between the two groups (P < 0.05). Compared with the control group, the relative abundance of Firmicutes in the experimental group was increased whereas the relative abundance of Bacteroidetes was decreased. The relative abundance ratio between Firmicutes and Bacteroides was higher in the experimental group than that in the control group (P = 0.063). By linear discriminant analysis effect size analysis, it was found that the relative abundance of Staphylococcus and Acinetobacter was significantly lower in the experimental group, indicating that Acer truncatum seeds can inhibit the proliferation of harmful bacteria. In summary, Acer truncatum seeds can affect the structure and composition of the mouse intestinal flora and inhibit opportunistic pathogens.

Key words: Acer truncatum seed, intestinal flora, α-diversity, β-diversity, linear discriminant analysis