Microbiota composition is moderately associated with greenspace composition in a UK cohort of twins

Exposure to natural environments, known as greenspace, appears to positively influence health, yet the mechanisms are unclear. Given that gut microbiota are associated with inflammatory disorders more prevalent in urban areas and individuals with lower greenspace exposure, microbiota may act as a mediator between greenspace and health. Using 2443 participants of the TwinsUK cohort, microbiota differences were compared in relation to rural/urban living and with quantiles of area-level greenspace at three different neighbourhood distances: 800 m, 3000 m and 5000 m. Using microbiota data captured from faecal samples using 16S rRNA marker gene sequencing, small compositional differences in association with 3000 m greenspace (p = 0.003) in models adjusted for confounders of microbiota variance (sequencing depth, antibiotics use, body mass index, frailty, age, diet, region and socioeconomic variables) were observed. Differences in abundances of genus were observed for all measures of greenspace in adjusted models; a key pathogenic genus was increased in abundance in association with urbanicity (Escherichia/Shigella, logFC = 0.73742, padj <0.001). Further, utilising the twin structure, within-pair differences in microbiota composition were compared and associations with 800 m greenspace observed (factor level significance in association with greatest difference, β = 0.08, p = 0.0162) as were differences in Escherichia/Shigella. The microbiota signature of those with a greater exposure to greenspace, but not necessarily explicitly rural individuals, was distinct from other individuals, suggesting microbiota as a potential mediator for greenspace and health.