Rutin supplementation did not yield significant changes in the response of pancreatic ß-cells to an oral glucose tolerance test or in the gut microbial composition in a randomized controlled trial.
Prebiotic polyphenol rutin is a potential dietary supplement for the prevention of type 2 diabetes in obese adults, as indicated by glycemic improvements observed in previous mouse model studies. This study, published in the journal Nutrients, investigated the effects of polyphenol rutin supplementation on gut microbiota profiles and pancreatic ß-cell function in overweight individuals who were either prediabetic or normoglycemic.
A total of 87 individuals were enrolled in this study, of whom microbiota data were obtained from 73 participants due to low DNA yields from two samples. Of the total, 47 were normoglycemic and 40 were prediabetic, as indicated by elevated fasting plasma glucose (FPG).
Rutin Supplementation and Metabolic Health Parameters
There were no significant changes in study participants’ body weight during the 12 weeks of the study across the three treatment groups, which included a rutin capsule group, a rutin yogurt group, and a normoglycemic placebo control group. There were no significant changes in the oral glucose tolerance test glycemic endpoints or ß-cell secretion of insulin across the treatment and control groups.
Microbiota Composition Unaffected by Treatment or Glycemic Status
Utilizing permutational analysis of variation, this study analyzed sources of variation in the microbiota, accounting for repeated measures due to multiple time points. Neither treatment nor participant glycemic status significantly affected microbiota composition. Similarly, bacterial alpha diversity metrics (zOTU richness and Shannon diversity) showed no significant impact from treatment or glycemic status.
Rutin Supplementation and Gut Microbiota Composition
The predominant bacterial phylum observed in the fecal samples of all patients was Firmicutes, followed by Bacteroidetes. Contrary to the predictable change, there were no changes in the microbiota composition between clinical intervention (CID) 1 and CID 4. Spearman correlation analysis demonstrated a negative association between Ruminococcus torques abundance and significantly elevated fasting insulin in normoglycemic participants in the control group. Conversely, there was a negative association between Roseburia inulinivorans, a butyrate-producing bacterium with anti-inflammatory capacity, and FPG in prediabetic participants in the control group.
Mathrani, A., Yip, W., Sequeira-Bisson, I. R., Barnett, D., Stevenson, O., Taylor, M. W., & Poppitt, S. D. (2023). Effect of a 12-Week Polyphenol Rutin Intervention on Markers of Pancreatic β-Cell Function and Gut Microbiota in Adults with Overweight without Diabetes. Nutrients, 15(15), 3360. https://doi.org/10.3390/nu15153360