Host-microorganism interactions in early life

In recent years, research on human microbiota has become more and more in-depth. It has been found that microorganisms in human body affect the functions of the host's digestive, nervous, immune and many other systems, imperceptibly changing the growth and development of human beings and disease progression. This review summarized the results of research on intestinal microbiota in early life, suggesting that the period from early pregnancy to two years old is a critical period for the colonization of human gut microbiota. It is vital to understand and investigate the factors influencing bacterial colonization at this time. Key words: Gastrointestinal microbiome; Microbiota; Dysbiosis; Pregnancy trimester, first; Infant