The Effects of Six Months Supplementation with Probiotics and Synbiotic on Gut Microbiota in the Adults with Prediabetes: A double blind randomized clinical trial

Abstract Background The evidence of 16S rRNA genes in the gut microbiota distinguished a higher Firmicutes to Bacteroidetes ratio in obese and diabetic individuals compared to healthy ones. So, it seems that the modulation of intestinal microbial ecology by pro/pre/synbiotics may contribute to the progression and prevention of metabolic diseases. Aim To assess the effects of probiotics and synbiotic supplementation on intestinal microbiome modifying in adults with prediabetes. Methods In a randomized, double-blinded, placebo-controlled clinical trial, 120 patients with prediabetes were randomly assigned to consume 6 g/d either a placebo containing maltodextrin (control) or multispecies probiotic or inulin based synbiotic for 6 months. Fecal samples were obtained at baseline and after 6 months of supplementation. Dietary intake was assessed throughout the study (at baseline and after 3 and 6 months). Total energy, macronutrients, and dietary fiber were calculated using a dietary programed Nutritionist 4. DNA was extracted from fecal samples and the numbers of Clostridium perfringens (the represent of phylum Firmicutes), Bacteroides fragilis (the representative of Bacteroidetes) and Escherichia coli (as universal bacteria) were determined by quantitative real-time polymerase chain reactions (qPCR). The changes in the relative abundance of the two fecal bacteria before and after supplementation were analyzed and compared within and between groups. Results There were no significant changes in dietary intake during the study. Six months’ supplementation with probiotics resulted in a statistically significant increase in abundance of Bacteroides fragilis to E.coli ratio (MD±SE:0.47±0.37, p=0.04) and decrease of the relative proportion of Firmicutes to Bacteroidetes representatives (MD±SE:-118.8±114.6, p=0.02). Synbiotic had no significant effect on the changes in the bacteria. There were no significant differences between the three groups. Conclusion The results of this study suggest that manipulation of the human gut microbiome by using probiotics could provide a potential therapeutic approach in the prevention and management of obesity and metabolic disorders like diabetes.