Maternal microbiota is involved in many metabolic diseases. However, its role in the pathophysiology of gestational diabetes mellitus (GDM) remains unclear. In this case-control study, we performed a 16S rRNA sequencing-based microbial survey to compare the intestinal and oral microflora at third trimester during pregnancy between 30 GDM and 31 normal controls. Sequentially, a correlation-based network analysis was further performed to explore the interactions among microbiota, maternal and infant blood sugar, and inflammatory markers. Our results show that, compared with controls, the GDM cases showed significant differences in β-diversity and increased Gammaproteobacteria and Hemophilus in intestinal microbiota. Furthermore, the GDM cases showed lower α-diversity, increased Selenomonas and Bifidobacterium, and decreased Fusobacteria and Leptotrichia in oral microbiota. The ROC curve showed the area under the curve to be equal to 0.70 and 0.66 when using oral Leptotrichia or gut Hemophilus, respectively, to predict GDM status. In addition, the components and topography of microbial cooccurrence and coexclusion network were quite distinct by GDM status. In summary, intestinal and oral microorganisms in pregnant women are closely related to the status of GDM in the third trimester of pregnancy. The changes of intestinal and oral microbial features may be noninvasive biomarkers for monitoring the health management of GDM pregnancy.

RNA methylation is considered a significant epigenetic modification, a process that does not alter gene sequence but may play a necessary role in multiple biological processes, such as gene expression, genome editing, and cellular differentiation. With advances in RNA detection, various forms of RNA methylation can be found, including N6-methyladenosine (m6A), N1-methyladenosine (m1A), and 5-methylcytosine (m5C). Emerging reports confirm that dysregulation of RNA methylation gives rise to a variety of human diseases, particularly hepatocellular carcinoma. We will summarize essential regulators of RNA methylation and biological functions of these modifications in coding and noncoding RNAs. In conclusion, we highlight complex molecular mechanisms of m6A, m5C, and m1A associated with hepatocellular carcinoma and hope this review might provide therapeutic potent of RNA methylation to clinical research.

Objective: To explore the characteristics of oral and intestinal microbiota of pregnant women with hypothyroidism during pregnancy, and to find the correlations between the changes of flora and pregnancy outcome of pregnant women with hypothyroidism during pregnancy.Methods: In this study, oral and intestinal microbial composition was surveyed using 16S rRNA sequencing approach in 61 pregnant women (30 with hypothyroidism and 31 normal controls). Sequentially, we validated the differential microbial features using Quantitative Real-Time PCR (QPCR) approach of 10 randomly selected pregnant women (5 with hypothyroidism and 5 normal controls). Furthermore, general clinical data and serological indices were added to the analysis to examine the links between oral and intestinal microbiota and pregnancy outcomes.Results: The 16S rRNA results showed that the relative abundances of Gammaproteobacteria of pregnant women in the hypothyroidism group were higher than those in the control group, while the levels of Firmicutes in the control group were higher than those in the hypothyroidism group. The serum CRP level, the weight gain during pregnancy and the incidence of fetal distress in the hypothyroidism group were higher than control group. The QPCR results also showed the same changes of the intestinal in the two groups.Conclusion: There were significant differences in the oral and intestinal microbiota between pregnant women with hypothyroidism and normal pregnant women. The changes of microbiota is one of the factors influencing the occurrence and development of hypothyroidism during pregnancy.

ObjectiveTo evaluate the small intestinal bacterial overgrowth (SIBO) of subclinical hypothyroidism of pregnant women, and explore their possible relevance.MethodsIn total, 224 pregnant women with subclinical hypothyroidism during pregnancy (study group) and 196 pregnant women whose thyroid function was normal (control group) were enrolled in this study. Lactulose-based hydrogen and methane breath test was performed to evaluate the growth of intestinal bacteria. The serum-free thyroid hormone (FT4), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), body mass index (BMI) and gastrointestinal symptoms were detected and recorded.ResultsThe positive rates of SIBO were 56.7% and 31.6% in study group and control group, respectively. The levels of C response protein (CRP), abdominal distension and constipation in study group were higher than those in the control group. The risk of abdominal distension and constipation in SIBO-positive pregnant women were higher than that in SIBO-negative pregnant women, and the BMI of SIBO-positive patients in the two groups was lower than that of SIBO-negative patients in each group. In addition, the TPOAb-positive rate and TSH levels were higher but the FT4 level was lower in SIBO-positive patients compared to SIBO-negative patients in study group.ConclusionThe occurrence of subclinical hypothyroidism is related to SIBO, and the excessive growth of small intestinal bacteria may affect gastrointestinal symptoms.Clinical Trialhttp://www.chictr.org.cn/index.aspx, identifier ChiCTR1900026326.

Objective: To investigate the relationship between unexplained recurrent pregnancy loss (URPL) and polymorphisms of folate metabolism-related genes. Design: A case-control study. Setting: Urban university-based hospital. Patient(s): Two-hundred and eighteen women with URPL and 264 healthy controls. Intervention(s): None. Main Outcome Measure(s): Fluorescence quantitative polymerase chain reaction examination of sequences of the C677T and A1298C loci of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. Result(s): The frequency of the T allele at the MTHFR C677T locus in the URPL group was statistically significantly higher compared with the control group (odds ratio [OR] 1.324; 95% confidence interval [CI], 1.014-1.729), and the presence of the CCþCT genotype was statistically significantly reduced in the URPL group (OR 0.678; 95% CI, 0.471-0.974). The frequency of the C allele at the MTHFR A1298C locus in the URPL group was statistically significantly higher than that in the control group (OR 1.557; 95% CI, 1.066-2.275), and the presence of the CCþAC genotype was statistically significantly elevated in the URPL group (OR 1.740; 95% CI, 1.137-2.661). The frequency of MTHFR 677CT/1298AC compound genotypes in the URPL group was 6.589-fold higher compared with the control group. Most patients in the URPL group carried two mutant genes (69.3%), and the percentage of patients with two mutant genes was statistically significantly higher than in the control group (OR 4.996; 95% CI,). Conclusion(s):The MTHFR 1298AC genotype and composite heterozygote genotype (677CT/1298AC) are risk factors for URPL. The risk of URPL is highest in women carrying two mutations of A1298C and C677T locus in MTHFR. (Fertil Steril Ò 2019;111:597-603. Ó2018 by American Society for Reproductive Medicine.) El resumen está disponible en Español al final del artículo.