【背景】二氢杨梅素(dihydromyricetin, DMY)是一类存在于藤茶中的主要黄酮类化合物，具有抗氧化、抗炎等功能，其药用价值受到广泛关注，但其在生物体内的生物活性及肠道中的分解代谢机制尚不清楚。【目的】探究二氢杨梅素对抗生素应激下小鼠的血清抗氧化性和肠道微生物多样性的影响。【方法】将小鼠分为对照组、抗生素组、抗生素+二氢杨梅素组，检测各组小鼠血清中的抗氧化指标，利用高通量测序分析组间肠道微生物多样性的差异，通过实时荧光定量PCR (real-time fluorescence quantitative polymerase chain reaction, RT-qPCR)验证特定菌群组间的相对丰度差异。【结果】二氢杨梅素显著提高了抗生素应激小鼠血清中过氧化氢酶(catalase, CAT)、超氧化物歧化酶(superoxide dismutase, SOD)、谷胱甘肽过氧化物酶(glutataione peroxidase, GSH-PX)活性(P<0.05)，显著降低丙二醛(malondialdehyde, MDA)含量(P<0.05)，催化一氧化氮(nitric oxide, NO)的合成显著提高了小鼠的总抗氧化能力。二氢杨梅素处理组相较抗生素应激组组间肠道微生物组成种类与结构有明显差异。二氢杨梅素可通过调节厚壁菌门(Firmicutes)与拟杆菌门(Bacteroidetes)的丰度比例，促进乳杆菌属(Lactobacillus)、梭菌属(Clostridium)等细菌增殖，抑制肠杆菌科(Enterobacteriaceae)细菌的增殖，改善小鼠肠道菌群组成，使小鼠肠道中乳杆菌属、梭菌属等与肠道分解代谢相关的有益菌群相对丰度增加。【结论】二氢杨梅素能够改变肠道菌群结构，一些益生菌大量参与到其代谢过程，产生有益代谢产物，提高机体的抗氧化能力并维持肠道健康，改善抗生素对小鼠肠道产生的负面影响。该结果为二氢杨梅素的功能和分解代谢机制研究提供理论基础。
[Background] Dihydromyricetin (DMY) is a major flavonoid compound in Vine tea (Ampelopsis grossedentata), which has antioxidant, anti-inflammatory, and other effects. Its medicinal value has attracted extensive attention, but its biological activity in vivo and catabolic mechanism in intestine are still unclear. [Objective] To explore the effects of dihydromyricetin on serum antioxidant capacity and intestinal microbial diversity of mice under antibiotic stress. [Methods] The experimental mice were divided into a control group, an antibiotic group, and an antibiotic+dihydromyricetin group. The antioxidant indexes in the serum of mice in each group were detected. The differences of intestinal microbial diversity between groups were analyzed by high-throughput sequencing. The relative abundance differences between specific bacterial groups were verified by real time fluorescence quantitative polymerase chain reaction (RT-qPCR). [Results] Dihydromyricetin significantly increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH) in the serum of antibiotic stressed mice (P<0.05), significantly decreased the content of malondialdehyde (MDA) (P<0.05), catalyzed the synthesis of nitric oxide (NO), and significantly increased the total antioxidant capacity of mice. There were significant differences in the composition and structure of intestinal microorganisms between the antibiotic+dihydromyricetin group and the antibiotic group. Dihydromyricetin improved the composition of intestinal flora in mice by regulating the abundance ratio of Firmicutes and Bacteroidetes, promoting the proliferation of bacteria such as Lactobacillus and Clostridium, and inhibiting the proliferation of Enterobacteriaceae, so as to increase the relative abundance of beneficial bacteria related to intestinal catabolism such as Lactobacillus and Clostridium in the intestinal tract of mice. [Conclusion] Dihydromyricetin can change the structure of intestinal flora. Some probiotics are heavily involved in its metabolic process and produce beneficial metabolites to improve the antioxidant capacity of the body and maintain intestinal health. Negative effects of antibiotics on the intestinal tract of mice are thus reduced. These findings provide a theoretical basis for the study of the function and catabolic mechanism of dihydromyricetin.