Impact of sanitary living environment on gut microbiota

The human gut microbiota contributes to human health by aiding functions such as digestion, protection against pathogens, host immunity activation, and central nervous system regulation. Its composition is influenced by many effectors such as diet, genetics, and delivery mode. The hygiene hypothesis suggests that an overly clean living environment increases the incidence of asthma, inflammation, and autism. To test if good hygiene is linked to the composition of the gut microbiota, we raised mice with the same diet in living environments with different levels of hygiene and found that each group had special gut microbiota. Hygiene levels of the living environment influenced early establishment of the human gut microbiota. It is also suspected that a sanitary environment alters the composition of gut microbiota through activating development of the immune system and inoculating the gut with microbial components when some microorganism were killed by oral antibiotics or died due to lack of related nutrition.