The strong protective role of Christensenellaceae against visceral fat

Variation in the human fecal microbiota has previously been associated with body mass index (BMI). Although obesity is a global health burden, the accumulation of abdominal visceral fat is the specific cardio-metabolic disease risk factor. Here, the authors explore links between the fecal microbiota and abdominal adiposity using body composition as measured by dual-energy X-ray absorptiometry in a large sample of twins from the TwinsUK cohort, comparing fecal 16S rRNA diversity profiles with six adiposity measures. They confirmed the association of lower diversity of the fecal microbiome with obesity and adiposity measures, and then compare the association between fecal microbial composition and the adiposity phenotypes in a discovery subsample of twins. While OTUs representing Christensenella were not the top ranked in this larger dataset, Christensenella OTU heritability remained high with one OTU, Greengenes OTU 176318, showing a heritability of 0.31 (95 % CI 0.21–0.41). The microbial heritability estimates presented here are overall consistent with the original microbial twin-based heritability findings from Goodrich et al. (2014) and with recent extended heritability estimates from the extended TwinsUK cohort (Goodrich et al. 2016).

The authors extend the findings here, showing strong protective associations between Christensenellaceae and visceral fat, the most significant bacterial-adiposity association was a negative relationship between Christensenellaceae and visceral fat mass (VFM) (P = 1.48 ×10−10), supporting prior findings from Goodrich et al. (2014). These results suggests that individuals with Christensenellaceae have less cardiovascular risk than those without. Further work to elucidate the mechanism of protection is required.