A randomized trial to determine the impact of a digestion resistant starch composition on the gut microbiome in older and mid-age adults

Abstract

The elderly often have a diet lacking resistant starch (RS) which is thought to lead to gut microbiome dysbiosis that may result in deterioration of gut colonocytes. The primary objective was to assess if elderly (ELD; ≥ 70 years age) had microbiome dysbiosis compared to mid-age (MID; 30-50 years age) adults and then determine the impact of daily consumption of MSPrebiotic® (a RS) or placebo over 3 months on gut microbiome composition. Secondary objectives included assessment of stool short-chain fatty acids (SCFA) and inflammatory markers in ELD and MID Canadian adults. This was a prospective, placebo controlled, randomized, double-blinded study. Stool was collected at enrollment and 6, 10 and 14 weeks after randomization to placebo or MSPrebiotic®. Microbiome analysis was done using 16S rRNA sequencing of DNA extracted from stool. SCFA analysis of stool was performed using gas chromatography. There were 42 ELD and 42 MID participants randomized to either placebo or MSPrebiotic® who completed the study. There was significantly higher abundance of Proteobacteria (Escherichia coli/Shigella) in ELD compared to MID at enrollment (p<0.001) that was not observed after 12 weeks of MSPrebiotic® consumption. There was a significant increase in Bifidobacterium in both ELD and MID compared to placebo (p=0.047 and 0.006, respectively). There was a small but significant increase in the stool SCFA butyrate levels in the ELD on MSPrebiotic® versus placebo. The study data demonstrated that MSPrebiotic® meets the criteria of a prebiotic and can stimulate an increased abundance of endogenous Bifidobacteria in both ELD and MID without additional probiotic supplementation. MSPrebiotic® consumption also eliminated the dysbiosis of gut Proteobacteria observed in ELD at baseline. NCT01977183 listed on NIH website: ClinicalTrials.gov. The full trial protocol is available on request from the corresponding author. The 16S rRNA sequencing data and metadata generated in this study have been submitted to the NCBI Sequence Read Archive (SRA: http://www.ncbi.nlm.nih.gov/bioproject/381931).