An exercise intervention alters stool microbiota and metabolites among older, sedentary adults

Abstract

Background: Physiologic aging has been associated with gut dysbiosis. Although short exercise interventions have been linked to beneficial changes in gut microbiota in younger adults, limited data are available from older populations. We hypothesized that exercise would produce beneficial shifts in microbiota and short-chain fatty acid (SCFA) levels in older persons. Methods: Stool samples were collected before and at completion of a supervised 24-week cardiovascular and resistance exercise intervention among 50–75-year-old participants. SCFA levels were analyzed by gas chromatography and microbiome by 16S rRNA gene sequencing. Negative binomial regression models compared pre- and post-differences using false discovery rates for multiple comparison. Results: A total of 22 participants provided pre-intervention samples; 15 provided samples at study completion. At baseline, the majority of participants were men (95%), mean age 58.0 (8.8) years, mean body mass index 27.4 (6.4) kg/m2. After 24 weeks of exercise, at the genus level, exercise was associated with significant increases in Bifidobacterium (and other unidentified genera within Bifidobacteriaceae), Oscillospira, Anaerostipes, and decreased Prevotella and Oribacterium ( p < 0.001). Stool butyrate increased with exercise [5.44 (95% confidence interval 1.54, 9.24) mmol/g, p = 0.02], though no significant differences in acetate or propionate ( p ⩾ 0.09) were seen. Conclusion: Our pilot study suggested that an exercise intervention is associated with changes in the microbiome of older adults and a key bacterial metabolite, butyrate. Although some of these changes could potentially reverse age-related dysbiosis, future studies are required to determine the contribution of changes to the microbiome in the beneficial effect of exercise on overall health of older adults. Clinical Trials NCT02404792

Systematic Review of the Effects of Exercise and Physical Activity on the Gut Microbiome of Older Adults

“…The age for inclusion differed between studies, ranging from 50 to 98 years old. Two studies included Body Mass Index (BMI) ranges in their inclusion criteria (between 18.5–25 kg/m 2 and 20–40 kg/m 2 [ 61 , 68 ]), one only accepted subjects who had maintained a consistent lifestyle, diet, and body weight in the most recent decade [ 63 ], and two studies only included subjects with HbA1C < 6.5% and 7.5% [ 61 , 64 ], respectively. Additionally, fasting blood glucose < 7mmol·l −1 , ability to live independently in the community and no diagnosis of type I or II diabetes were the inclusion criteria for the study performed by Zhong and colleagues [ 64 ].…”

“…Regarding cardiovascular diseases (CVDs), only one study excluded subjects with different types of CVD and diagnosed with diabetes [ 64 ]. Moreover, Erlandson et al [ 61 ] excluded participants who had taken sex hormone supplementation for the previous 3 months and intramuscular testosterone.…”

“…Three of the seven studies employed an exercise intervention [ 61 , 63 , 64 ]. Taniguchi et al [ 63 ] ran a randomised crossover trial with 33 older adult men aged between 67–72 years old and employed a 5-week exercise intervention.…”

“…Previous studies have shown that PA/exercise have several benefits during the ageing process such as improvements in cognitive function [ 55 , 56 ], promotion of cardiovascular health [ 57 ] and improvements in the musculoskeletal system [ 58 , 59 , 60 ], making it a precious tool to counteract the age-associated changes that occur in those systems. Besides the benefits mentioned previously, recent studies [ 61 , 62 , 63 , 64 ] on the effects of exercise on the gut microbiome of older people have suggested that exercise might beneficially affect its composition and even reverse some age-associated taxonomical changes, ultimately leading towards healthy ageing. This is a relatively new topic of research.…”

“…This is a relatively new topic of research. As such, human intervention studies are limited and there are only a few observational studies that have assessed this research question [ 61 , 63 , 64 , 65 , 66 , 67 , 68 ]. This systematic review aims to summarise results of human studies that assess the effects/associations of PA/exercise on the gut microbiome of older adults, to better understand whether physical activity can positively influence the gut microbiome of older adults and whether it can help promote healthy ageing.…”