Intervention time modified the effect of inulin on high-fat diet-induced obesity and gut microbial disorders

Various epidemiological studies support that inulin improves the intestinal environment and decreases the risk of obesity. The same as host feeding rhythms, gut microbiota itself displays daily fluctuations in composition and function. The purpose of this study was to investigate the influences of intervention time of inulin to alleviate high-fat diet (HFD)-induced obesity based on chrono-nutrition. Male C57BL/6J mice were given HFD and gavaged inulin at light-on time (HFM) or light-off time (HFN) daily. Energy expenditure (EE), 16S rRNA sequencing in colonic contents, and short-chain fatty acids (SCFAs) analysis were carried out after 12 weeks. Both in HFM and HFN group, the HFD-induced weight gain was significantly reduced by 20.91% and 23.32%, and the mice in HFN group showed no significant difference in weight gain with the control group. Besides, mice in HFN group showed a tendency to increase EE and fecal SCFAs contents in addition to the relative content of colonic beneficial bacteria. As the light-off period of mice is their active period, these results suggested that inulin intake at active period exhibited relatively stronger effects on ameliorating obesity and improving the gut microbial environment.