Several hundred microbial species inhabit the human gastrointestinal (GI) tract and constitute a complex ecological community that influences the host's physiology and immunity through their metabolism and interactions with the host [1,2].The composition of the GI microbiota varies among individuals.Multiple intrinsic and extrinsic factors,including host genetics and physiology,drug and disease,and diets and some other living environments,affect the structure of GI microbiota [3].Asia largely differs among the regions populated by different ethnic groups,with diverse cultures and dietary habits.