[Effects of gestational diabetes mellitus on gut microbiota of 3-month-old infants: a prospective control study].

Objective: To explore the effect of gestational diabetes mellitus on the gut microbiota of their offsprings, the gut microbiota of 3-month-old infants whose mothers diagnosed with and without gestational diabetes mellitus(GDM) was compared.

Methods: Pregnant women and their 3-month-old infants who were examined, delivered and follow-up visited in a county in Hebei Province from June 2016 to December 2019 were included in our study. The pregnants and their infants with result of fasting venous blood glucose≥5.1 mmol/L in the second or third trimester were included in GDM group. Fecal samples of 3-month-old infants were collected and 16 S rDNA high-throughput sequencing technology was used to explore the change of gut microbiota.

Results: A total of 48 pairs of subjects were included, 16 in GDM group and 32 in control group. Comparison of gut microbiota diversity: analysis of the Alpha diversity index showed that the Observed Species index, margalef index and menhinick index of GDM group were(141.4±17.2), (13.66±1.66) and(0.83±0.10), respectively, which were significantly lower than that of control group(154.9±21.7), (15.00±2.11) and(0.91±0.13), respectively. Sequence analysis: at phylum level, the abundance of the Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria were 54.28(47.84), 23.58(23.48), 11.20(30.99) and 0.12(0.07), respectively, while the control group were 42.05(36.23), 29.64(21.30), 9.31(15.82) and 0.15(10.14), respectively. The two groups were mainly composed of these 4 phyla and Actinobacteria was the most abundant. At genus level, there were mainly Bifidobacteria, lactobacillus, Enterobacteria, Bacteroidales and Clostridiales in both groups. The abundance of Erysipelotrichales in GDM group(0.01(0.01)) was significantly lower than that in control group(0.04(0.06))(P<0.05). The abundance of Micrococcales in GDM group(0.13(0.24) was significantly lower than that in control group(0.29(0.78))(P<0.05). PCoA analysis showed that the gut microbiota structure of GDM group and control group was similar. LEfSe analysis showed Erysipelatoclostridium was significantly increased in control group(P<0.05).

Conclusion: GDM can reduce the diversity and richness of gut microbiota of 3-month-old infants and has no significant effect on the phylum level but has effect on some genus level. It suggests that GDM may still have some potential effect on slightly elder infants.