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

Background: 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.Objective: The primary objective was to assess if elderly (ELD; !70 years age) had microbiome dysbiosis compared to mid-age (MID; 30e50 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.Design: 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.Results: 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 ¼ 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. Conclusions: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.Clinical Trial Registry Number: NCT01977183 listed on NIH website: ClinicalTrials.gov.The full trial protocol is available on request from the corresponding author.