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Dietary Bioactive Components (Poster Session)

(P04-054-24) Effects of Blueberry Consumption and Exercise on Gut Microbiome Composition in a Randomized Controlled Trial of Sedentary Older Adults With Overweight or Obesity

Sunday, June 30, 2024
11:45 AM – 12:45 PM CT
Location: Poster Board 127
Disclosure(s):
Kathryn Porter Starr, PhD, RD: No relevant financial relationship(s) with ineligible companies to disclose.


Objectives: Increased consumption of phytonutrient-rich foods, including blueberries, provides benefits to multiple physiologic and metabolic systems; this study explored the potential that regular, generous blueberry intake could directly modulate the gut microbiome in sedentary older (≥60 years) men and women with overweight or obesity (BMI) ≥25 to 32 kg/m2.

Methods: Participants (n=55) were randomized to either lyophilized blueberry powder (equivalent to ¾ cup blueberries) (BB-EX; n=27), or an indistinguishable placebo powder (P-EX; n=28); both groups participated in weekly supervised exercise class and were asked to increase baseline daily step counts using a Garmin® device for tracking. Exclusions relevant to microbiome included recent antibiotic use or colonoscopy. Fecal samples were collected at 0 and 12 weeks (n=17 BB-EX; 21 P-EX) and frozen. The 16S rRNA gene V3–V4 hypervariable region was used to profile participant gut microbiomes. The standard DADA2 process was used to generate amplicon sequence variants (ASVs) and the resulting ASVs were taxonomically classified using the SILVA v138 database and DADA2 implemented RDP classifier with a bootstrap confidence threshold of 80.

Results: Comparing the pre-post results for BB-EX versus P-EX, there were no compositional differences (principal component analysis) or differences in alpha diversity of the microbiome. However, there was a significant enrichment at 12 weeks in the relative abundance of Coriobacteriales Incertae Sedis (a taxon that activates dietary polyphenols) in BB-EX versus P-EX, with enrichment in 70.6% (12 of 17), depletion in 11.8% (2 of 17), and retained non-detected in 17.6% (3 of 17) BB-EX participants.

Conclusions: Regular, generous blueberry consumption may help up-regulate the ability of the older human gut to utilize dietary polyphenols.

Funding Sources: U.S. Highbush Blueberry Council