Abstract: [Abstract] Objective By examining oral health of mothers with or without caries, and next-generation sequencing analysis of saliva samples taken from one month to six months of their newborns at follow-up, the effects of maternal sputum on oral microbial diversity in infants were observed. Method In this study, saliva samples of one month old and six months old of the same batch of newborns were collected through screening follow-up. At the same time, check and record the mother's oral health. According to the oral condition of the mother, the newborns were divided into mothers with caries group (abbreviated positive group) and mother without caries group (abbreviated negative group), followed up to the baby for six months. The changes in microbial diversity in infants at different months of age were analyzed by high-throughput sequencing Results Ten patients were followed up in this study (six males and four females), including 7 in the positive group and 3 in the negative group. There was no significant difference in the Shannon index between the groups (P>0.05). ). The species composition of microbial communities in the positive group was significantly changed from one month to six months . The species composition of the positive group was significantly different at the age of one month and six months. The microbial communities in the two groups were similar at the age of one month, and the species composition of saliva in the two groups began to change at the age of six months.Conclusion The diversity of bacteria within the infants in the positive group was generally higher than that in the negative group. The diversity and abundance of microbial species in the oral cavity between the ages of one month and six months were increased to varying degrees in the positive group and the negative group.

Key words: [Key words] Caries, Microbial diversity, longitudinal study, saliva bacteria