Gut microbiota diversity associates with cardiorespiratory fitness in post-primary treatment breast cancer survivors

• Published in: Experimental physiology 2019-02, Vol.104 (4), p.529-539
• Main Authors: Carter, Stephen J., Hunter, Gary R., Blackston, J. Walker, Liu, Nianjun, Lefkowitz, Elliot J., Van Der Pol, William J., Morrow, Casey D., Paulsen, Jesseca A., Rogers, Laura Q.
• Format: Article
• Language: English
• ISSN: 0958-0670; 1469-445X
• DOI: 10.1113/EP087404

Previous studies have not adequately considered the influence of adiposity and activity-related energy expenditure (AEE) on gut microbe diversity. We determined associations of gut microbiota diversity with measures of cardiorespiratory fitness while accounting for the potential effects of %body fat and free-living AEE. Cancer treatment uniquely triggers multiple physiologic shifts detrimental to overall health. Though previous research indicates a link between gut microbiota and cardiorespiratory fitness, it is unclear whether these findings are due to potential underlying effects %body fat or free-living activity energy expenditure (AEE). Microbe composition of fecal specimens from 37 breast cancer survivors were determined using 16S microbiome analyses. Individual-sample microbiota diversity (α - diversity) and between-sample community differences (β-diversity) were examined. Peak oxygen uptake (V̇O 2peak ) was estimated from a graded exercise test (GXT) consistent with the modified-Naughton protocol, in which, exercise terminates at 85% age-predicted heart rate max (HR max ). AEE was measured over 10-days using doubly-labeled water wherein %body fat was calculated from total body water. Pearson correlations revealed α-diversity indices (Chao1, Observed Species, PD Whole Tree, Shannon) positively associated with V̇O 2peak ( r = 0.34 to 0.51; p < 0.05) whereas %HR max during Stages 1–4 of the GXT ( r = −0.34 to −0.50; p < 0.05) and %body fat ( r = −0.32 to −0.41; p < 0.05) were negatively associated with the same α-diversity indices. Multiple linear regression models showed V̇O 2peak accounted for 22% and 26% of the variance in taxonomic richness (Observed Species) and phylogenic diversity after adjustment for %body fat and menopausal status. Unweighted UniFrac (β-diversity) was significant for several outcomes involving cardiorespiratory fitness and significant taxa comparisons were found. Associations between gut microbiota and free-living AEE were not found. Results from the present work suggest cardiorespiratory fitness, not physical activity, is a superior correlate of gut microbiota diversity.