该研究旨在探究膳食纤维复合体（Dietary Fiber Complex，DFC）对代表性人体肠道菌群及其代谢物的调节。采集10位65~75岁老年人的粪便，分性别开展DFC干预的体外发酵实验。结果发现，2%添加量的DFC组干预效果最好，其中女性组大肠杆菌属、拟杆菌属、双歧杆菌属、乳酸杆菌属的相对表达量为对照组的52.76%、43.40%、249.79%和232.99%，男性组大肠杆菌属、拟杆菌属、双歧杆菌属和乳酸杆菌属的相对表达量为对照组的44.02%、53.14%、228.71%和206.11%。显著差异的肠道菌群代谢物中，女性组的异丁酸、丙酸、甲酸相对丰度显著增加（P<0.01），蛋氨酸、组氨酸、β-葡萄糖、苯丙氨酸、苏氨酸、丙三醇、天冬氨酸、精氨酸、1-甲基组氨酸的相对丰度显著减少（P<0.01），男性组的异丁酸、丙酸、丁酸盐、甲酸相对丰度显著增加（P<0.01），组氨酸、β-葡萄糖、苯丙氨酸、苏氨酸和天冬氨酸相对丰度显著减少（P<0.01），二者潜在的代谢途径都为组氨酸代谢与苯丙氨酸、酪氨酸和色氨酸生物合成。研究结果表明DFC对人体肠道菌群及代谢物的调节作用明显，且在不同性别上潜在的代谢途径变化一致。

The regulatory effect of dietary fiber complex (DFC) on the representative human gut microbiota and derived metabolites was explored. Faeces of 10 elderly people aged 65~75 years were collected, and in vitro fermentation of the DFC for intervention was performed according to gender. It was found that the intervention effect of the 2% DFC addition was the best, and the relative expressions of Escherichiacoil, Bacteroides, Bifidobacterium and Lactobacillus for the female group were 52.76%, 43.40%, 249.79% and 232.99%, respectively, of those in the control group. The relative expressions of of Escherichiacoil, Bacteroides, Bifidobacterium and Lactobacillus for the male group were 44.02%, 53.14%, 228.71% and 206.11%, respectively, of those in the control group. Among the significantly different gut flora metabolites, the relative abundances of isobutyrate, propionate and formic acid increased significantly (P<0.01), whilst the relative abundance of methionine, histidine, β-glucose, phenylalanine, threonine, alanine, aspartate, arginine and 1-methylhistidine decreased significantly (P<0.01) in the female group. In the male group, the relative abundance of isobutyrate, propionate, butyrate and formic acid increased significantly (P<0.01), whilst the relative abundance of histidine, β-glucose, phenylalanine, threonine and aspartate decreased significantly (P<0.01). The underlying metabolic pathways for both groups were histidine metabolism, and phenylalanine, tyrosine and tryptophan biosynthesis. The research results showed that DFC has a significant regulatory effect on human gut microbiota and derived metabolites, and the changes in the potential metabolic pathways are consistent across genders.

国家自然科学基金面上项目（31871802）