Introduction
Many individuals rapidly regain excess weight once they stop dieting. This phenomenon, which is commonly called yoyo-dieting, is a pattern of losing weight and then regaining it, placing individuals at greater risk for metabolic complications and obesity. There is some evidence that yoyo-dieting-induced obesity causes long-term alterations in the gut microbiome composition. There is also increasing evidence suggesting that diets high in resistant starch (RS) may positively improve gut health and metabolism.
Aims & Methods
This study aimed to investigate how yoyo-dieting affects gut health and whether supplementation with resistant starch could be a promising and effective weight management strategy.
Male and female C57BL/6 mice (n=48/sex, n=8/group) were allocated to six different diets for 20 weeks [control, high-fat (HFD), yoyo-diet (HFD interspaced with control every 5 weeks), control with RS, HFD with RS, and yoyo-diet with RS]. Metabolic measurements were performed, including body weight, glucose and insulin tolerance tests, adipose tissue, and organ weight. Liver and intestines were collected for structural changes assessed by histology. Epithelial barrier integrity was assessed in Ussing chambers. Faecal samples were collected for microbial profiling using 16S ribosomal RNA sequencing.
Results
Male mice fed a HFD with RS had significantly lower weight gain, liver mass, adipose tissue, and insulin tolerance compared to mice fed a HFD alone, while no significant differences were observed in females. No significant differences in glucose tolerance and intestinal permeability were observed across all diets and between sexes. Male mice had significantly higher alpha diversity and a different microbiota profile compared to female mice. Mice fed diets supplemented with RS had significantly lower alpha diversity and a different microbiota profile compared to mice fed without RS. Male and female mice have different microbiota profiles. Mice fed a HFD with RS have a similar microbiota profile to mice fed the control diet with RS. After changing diets (switching from diets high in fat to the control diet – yoyo groups), no change in microbiome profile was observed in female mice previously fed HFD with RS, while male mice previously fed a HFD supplemented with RS had a similar microbiome profile to control mice.
Conclusion
Different microbiome signatures and metabolic measurements were observed in male and female mice. In male mice consuming a HFD, RS lowered weight gain and shifted the microbiota profile to one similar to mice fed a control diet with RS. In males consuming a HFD diet interspaced with the control diet (yoyo-diet), RS shifted the microbiota profile of mice to a similar signature seen in control animals. No significant differences were observed in females.
Disclosure
No conflict of interest