Changes in the intestinal microbiota of Japanese children during the first 3.5 years of life. human gut metagenome

Human gut microbiota plays a crucial role in health and disease. Infancy is a critical period for gut microbiota maturation and immune system development and has the potential to affect long-term health. Understanding the development of gut microbiota in Japanese children is essential because of regional differences and the long-term health effects of the early gut microbiota. However, no longitudinal study in Japan has tracked this development over several years after birth. In this study, we aimed to analyze the gut microbiota of 106 Japanese mother-child pairs from the Chiba Study of Mother and Child Health, Japan, over 3.5 years. The results showed that the alpha diversity of the gut microbiota in children increased with age, and its composition began to resemble that of adults. We identified four distinct clusters of gut microbiota that reflected different maturation stages. The similarity between the maternal and child gut microbiota showed a bimodal distribution, suggesting that the presence of older siblings may enhance this similarity. This study highlights the dynamic nature of gut microbiota development in Japanese children and deepens our understanding of the similarities between maternal and child gut microbiota.