The investigation of the association of pregnancy weight gain on maternal and neonatal gut microbiota composition and abundance using 16sRNA sequencing

OBJECTIVE: To investigate the association of pregnancy weight gain on gut microbiota in pregnant women and newborns. METHODS: Pregnant women who had regular antenatal check-ups and were hospitalised for delivery at Shanxi Maternal and Child Health Hospital from September 2020 to December 2020 were selected as the study subjects. They were divided into the normal pre-pregnancy weight-normal pregnancy weight gain group (N-NG group), the normal pregnancy weight-excessive pregnancy weight gain group (N-EG group), the pre-pregnancy overweight/obese-normal pregnancy weight gain group (O-NG group) and the pre-pregnancy overweight/obese-excessive pregnancy weight gain group (O-EG group). Faecal samples of the pregnant women before delivery (37–41(+ 6) weeks of gestation) and the first meconium samples of their newborns were collected, sequenced for 16S rRNA gut microbiota and analysed. The results of different gut microbiota were compared separately. χ2 test, a one-way analysis of variance or the rank sum test were performed according to data type and distribution. The differences in the Alpha diversity between the groups were analysed using the Kruskal–Wallis rank sum test. The differences in the Beta diversity between the groups were analysed using the Adonis method. RESULTS: A total of 126 pre-delivery faecal samples from pregnant women and the first faecal samples from their newborns were collected. Seven species with significant abundance differences between the maternal O-NG and N-EG groups and 27 species with significant abundance differences in the newborns were analysed by LEfSe. In the Alpha diversity analysis, the differences in the maternal observed species index and the Chao1 index were statistically significant (p < 0.05) when compared between the groups (O-EG group versus the O-NG group, N-EG group and N-NG group), and the differences in the Shannon index and Simpson index were not statistically significant (p > 0.05) when compared between the groups. The neonatal observed species index, Chao1 index, Shannon index and Simpson index showed statistically significant differences in the comparison between the N-EG and O-EG groups (p < 0.05). In the Beta diversity analysis, the maternal samples did not differ Significantly between the four groups (p > 0.05), while the neonatal samples differed Significantly between the N-EG and N-NG, O-NG, and O-EG groups (p < 0.05). CONCLUSION: Pregnancy weight gain affects the composition and abundance of maternal and neonatal gut microbiota species as well as the diversity of neonatal gut microbiota.