In a randomized control trial testing FMT in men with T2DM, A. Vrieze et al. (2012) found that when subjects received duodenal tube-facilitated fecal transplants from lean individuals (allogenic transplantation) their insulin sensitivity improved in concordance with increased microbial diversity compared to individuals who received autologous transplantation (stool from self) after a 6 week period. This evidence concerns the gene INS and type 2 diabetes mellitus.