ABSTRACT
Neonatal intestinal microecology is unstable and susceptible to various factors such as bacterial exposure, conditions that promote and inhibit bacterial growth, and host factors.These factors affect the initial development of the immune system during a critical period known as the "neonatal window of opportunity" . Epidemiological investigations have found a link between the development of the immune system during the "neonatal window of opportunity" and immune-mediated diseases.Recent studies have found that the principal mechanism may be promoting the development and maturation of the intestinal mucosal barrier, influencing the maturation of lymphocytes, and establishing immune tolerance.This review summarizes the effects of neonatal intestinal microecology on immune development during the "neonatal window of opportunity" .