The gastrointestinal tract of human and animals is colonized by numerous and diverse microorganisms. Gut microbiota influences human health by modulating the nutrition, metabolism and immunity of host. Lactobacillus spp. and Bifidobacterium spp. are the representative beneficial species, which exhibit multiply important physiological functions. Gut microbiota plays a pivotal role in the development of diet-induced obesity. However, the relationship between gut microbiota and human genetic obesity is still u...