C.minuta is the species related to weight gain

Host genetics and the gut microbiome can both influence metabolic phenotypes. Here, Goodrich et al. compared microbiotas across >1,000 fecal samples obtained from the TwinsUK population, including

416 twin pairs. They identified many microbial taxa whose abundances were influenced by host genetics. The most heritable taxon, the family Christensenellaceae,formed a co-occurrence network with other heritable Bacteria and with methanogenic Archaea. Furthermore, Christensenellaceae and its partners were enriched in individuals with low body mass index (BMI).

The authors have showed that an obese-associated microbiome amended with Christensenella minuta, a cultured member of the Christensenellaceae, and transplanted to germ-free mice, reduced weight gain and altered the microbiome of recipient mice. These findings indicate that host genetics influence the composition of the human gut microbiome and can do so in ways that impact host metabolism.