Living near greenspace may support healthy gut microbiotaContact with nature and exposure to greenspace have been linked to improved physical health, however the mechanisms that underlie this relationship are unclear. This study explored human gut microbiota as a possible mediator between greenspace and health. The study utilized a large registry of adult twin pairs to examine if differences in gut microbiota composition vary in relation to measures of residential greenness.
Data from 2443 adult participants living in the UK was analyzed in this study. Participants were members of TwinsUK, a large registry of twins who volunteered to participate in health research. Profiles of gut microbiota were obtained from fecal samples using 16S rRNA marker gene sequencing. Measurements of greenspace in the residential area of each participant were calculated using the Ordnance Survey Open Roads dataset and satellite data from the Land Cover Map of Great Britain. Buffer distances of 800-meters, 3000-meters and 5000-meters were selected to assess the effect of the immediate home environment as well as wider areas that an individual might regularly encounter. Additionally, to investigate whether urbanicity, rather than greenspace, might be related to microbiota composition, measures of urbanicity were determined using the Rural-Urban 2-fold classification (RUC) for each participant's postcode. Statistical analysis of the data aimed to determine if differences in microbial compositions were related to living in areas of high green space compared to low greenspace. Analysis also addressed other potential factors that might influence this relationship, including age, recent antibiotic use, body mass index (BMI), dietary quality, frailty, educational attainment, and an area-based index of deprivation.
Main findings indicate that “the microbiota signature of those with a greater neighborhood exposure to greenspace was distinct from other individuals.” Analysis revealed small, but significant, differences in the composition of microbiota associated with greenspace at the 3000-meter buffer. At this buffer distance, greenspace was nearly as strongly related to microbiota composition as participants’ eating habits. Differences in microbiota abundance were also detected between participants residing in rural versus urban areas. Additionally, small, significant differences in microbiota comparisons between twins were found when one had low levels of greenspace close to their home and the other had high levels of greenspace close to their home (within 800-meters).
Findings suggest that exposure to greenspace may support healthy gut microbiota. Overall, results indicate that there may be “geographic patterns in the microbiota observable in this dataset which do not seem to be accounted for by diet, BMI and frailty.” Findings also lend support to possible role that gut microbiota may play in mediating the relationship between greenspace and health.
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