There has been particular interest in the prebiotic-like effects of commonly consumed polyphenols. This study aimed to evaluate the effects of hesperidin (HD) and its aglycone hesperetin (HT), major flavonoids in citrus fruits, on the structure and activity of gut microbiota in rats. Rats ingested an assigned diet (a control diet, a 0.5% HT diet, or a 1.0% HD diet) for 3 weeks. Terminal restriction fragment length polymorphism analysis revealed that the proportion of Clostridium subcluster XIVa in the feces collected at the third week of feeding was significantly reduced by the HT diet: 19.8 ± 4.3% for the control diet versus 5.3 ± 1.5% for the HT diet (P < 0.01). There was a significant difference in the cecal pool of short-chain fatty acids (SCFA), the sum of acetic, propionic, and butyric acids, between the control diet (212 ± 71 μmol) and the HT diet (310 ± 51 μmol) (P < 0.05), whereas the HD diet exhibited no effects (245 ± 51 μmol). Interestingly, dietary HT resulted in a significant increase in the excretion of starch in the feces. HT, but not HD, might reduce starch digestion, and parts of undigested starch were utilized to produce SCFA by microbial fermentation in the large intestine.
Keywords: Clostridium subcluster XIVa; gut microbiota; hesperetin; hesperidin; short-chain fatty acids; starch digestion.