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

Abstract

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; 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.

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 = 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.

Nucleotide sequence accession numbers: 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).

Keywords: Bifidobacteria; Butyrate; Canadian adults; Elderly gut microbiome; Prebiotic; Resistant starch.

Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.