[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.

Cohort profile: the Taicang and Wuqiang mother-child cohort study (TAWS) in China.

PURPOSE: The Taicang and Wuqiang cohort study (TAWS) was established to examine the association between early-life nutrition and children's health, and to explore the potential roles of maternal health, metabolites and microbiota in children's health in two different regions of China. PARTICIPANTS: A total of 7041 mother-child pairs were recruited during early pregnancy (n=4035, 57.3%) or delivery phase (n=3006, 42.7%) from health centres or hospitals in Taicang and Wuqiang. Mother-child pairs were followed up three times during pregnancy, once during delivery, and 7-10 times in the 3 years after delivery. Questionnaires were used to collect data on diet, supplementary intake, physical activity, depression scale, disease occurrence, feeding practice and development quotient of children. Anthropometric measurements of mothers and their children were assessed at each visit. Pregnancy outcomes were extracted from medical records. Biospecimens were collected and stored, including venous blood, cord blood, urine, stool, breast milk, cord and placenta. FINDINGS TO DATE: Data from the TAWS cohort showed different baseline characteristics of participants at the two sites of TAWS. Abnormal metabolism occurred among newborns whose mothers were diagnosed with gestational diabetes mellitus. Maternal serum folic acid above 14.5 ng/mL at early pregnancy was associated with a reduced risk of delivering small-for-gestational-age newborns. FUTURE PLANS: The association between maternal nutrition and the health of offspring will be examined at various follow-up visits. Biomarkers will be analysed to assess the associations between early-life nutrition and child development, immunity and health. Strategic recommendations for optimal infant feeding practices, obesity prevention and routine healthcare items will be developed and proposed based on the findings from the study. Children in this prospective cohort study will be followed up once a year until age 12 years to further examine the relationships between early-life nutrition and children's long-term development and health.

Exploration of the optimal range of urinary iodine concentration in Chinese pregnant women in mildly iodine-deficient and -sufficient areas.

PURPOSE: There is some uncertainty about the optimal ranges for urinary iodine concentration (UIC) during pregnancy. This study aimed to explore associations between maternal UIC and thyroid function in iodine sufficient and mildly iodine deficient areas. METHODS: It was a cross-sectional study in which 1461 healthy pregnant women were enrolled to collect their blood and urine samples during their routine antenatal care in Tianjin and Wuqiang, China. Wuqiang was a mildly iodine-deficient region, while Tianjin was iodine sufficient. UIC, free triiodothyronine (FT3), free thyroid hormone (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), serum iodine concentration (SIC) including total serum iodine concentration (tSIC) and non-protein bound serum iodine concentration (nbSIC) were assessed during the routine antenatal care visits. RESULTS: The median UIC in pregnant women was 174 (113, 249) µg/L in Tianjin and 111 (63, 167) µg/L in Wuqiang, respectively. Compared with Tianjin, UIC, FT3 and TSH were lower, and FT4, tSIC, nbSIC, rates of TPOAb and TgAb positivity and the thyroid dysfunction rate (TDR) were higher in Wuqiang (P < 0.001). FT3, FT4, tSIC and nbSIC increased during pregnancy in Tianjin with increasing UIC, while only FT3 and nbSIC increased in Wuqiang (P < 0.05). In Tianjin, the TDR increased with UIC and peaked at UIC ≥ 500 µg/L (P = 0.002), while in Wuqiang, the TDR showed a weak "U-shaped" relationship with UIC and the rate was lowest with UIC 100-149 µg/L. CONCLUSIONS: In iodine-deficient areas, there was a lower TDR in pregnant women with UIC 100-149 µg/L. We suspected that the optimal UIC criteria recommended by WHO may be a little high for pregnant women in mild-to-moderate iodine-deficient countries.

[Effect of pregnant serum folate concentration on newborn's birth weight].

OBJECTIVE: To study the effect of pregnant serum folate concentrations on the birth weight. METHODS: This study was a prospective cohort study. Pregnant women aged 18-45 who were examined and delivered in a county in Hebei Province from June 2016 to August 2018 and their newborns were included in the study. A total of 490 women were recruited and collected venous blood before the 20 th week of pregnancy. Basic information of women as well as their use of folic acid supplements was collected at the same time. Newborns' basic information, such as sex and birth weight, had been collected after delivery. The chemiluminescence method was used to determine the serum folate concentrations. Folate concentrations quartile were used as the cut-off point to divide subjects into four groups. The general linear model and multivariate unconditional Logistic regression analysis were used to study the effect of different serum folate concentrations on the infant birthweight. RESULTS: The age of 490 pregnant women was(27. 9±4. 1) years. The serum folate value P50(P25, P75) was 12. 3(9. 0, 14. 5) ng/mL and its' detection time was(13. 7±2. 6) weeks. 49. 3%(242/490) newborns were male. The average gestational age of the newborns was(39. 1±1. 0) weeks and the average birth weight was(3403±425) g. The birth weight of four groups' newborns were(3408±456) g, (3405±450) g, (3427±418) g and(3374±378) g, respectively. General linear model analysis showed that there was no significant difference in the effect of serum folate levels before the 20 th week of gestation on the birth weight(serum folate concentration<9. 0 ng/mL(ß=32. 24, P=0. 55), serum folate concentration 9. 0-12. 2(ß=18. 01, P=0. 74), serum folate concentration 12. 3-14. 4(ß=42. 27, P=0. 43)]. Multivariate unconditional Logistic regression analysis showed that the group with folate concentration above 14. 5 ng/mL can reduce the risk of small for gestational age(SGA) [(P=0. 02, OR=0. 08(95% CI 0. 01-0. 61)]. Comparing with ghe pregnant women whose serum folate concentration was in 9. 0-12. 4 ng/mL. Hovever, there was no significant difference between the pregnant serum folate levels and large for gestational age(LGA). CONCLUSION: There was no significant correlation between serum folate concentrations and the birth weight. But higher folate level may reduce the risk of SGA.