A health-promoting role of exclusive breastfeeding on infants through restoring delivery mode-induced gut microbiota perturbations.

The establishment of human gut microbiota in early life is closely associated with both short- and long-term infant health. Delivery mode and feeding pattern are two important determinants of infant gut microbiota. In this longitudinal cohort study, we examined the interplay between the delivery mode and feeding pattern on the dynamics of infant gut microbiota from 6 weeks to 6 months post-delivery in 139 infants. We also assessed the relationship between infant respiratory infection susceptibility and gut microbial changes associated with delivery mode and feeding pattern. At 6 weeks postpartum, the composition and structure of gut microbiota of cesarean section-delivered (CSD) infants differed from those of vaginally delivered (VD) infants, with decreased Bacteroides and Escherichia-Shigella and increased Klebsiella, Veillonella, and Enterococcus. At 6 months postpartum, these delivery mode-induced microbial shifts were restored by exclusive breastfeeding, resulting in similar gut microbial profiles between VD and CSD infants who were exclusively breastfed (P = 0.57) and more variable gut microbial profiles between VD and CSD infants who were mixed fed (P < 0.001). We identified that the VD-associated genera were enriched in healthy infants, while the CSD-associated genera were enriched in infants who suffered from respiratory infections. Our findings indicate that exclusive breastfeeding may play a health-promoting role by reducing infant respiratory infection susceptibility through the restoration of gut microbiota perturbations caused by cesarean section.

Overexpression of IGF2 affects mouse weight and glycolipid metabolism and IGF2 is positively related to macrosomia.

Objective: To investigate the effects of insulin-like growth factor 2 (IGF2) on growth and glycolipid metabolism, as well as the underlying mechanism. Methods: A mouse model of IGF2 overexpression was constructed to measure weight gain before adulthood, to obtain the values of adult glycolipid metabolism indicators in the peripheral blood and to detect the expression of genes in the IGF2 signaling pathway in different mouse tissues. The present study also explored the independent association between the IGF2 gene and macrosomia by detecting and comparing the expression levels of IGF2 mRNA/H19 RNA in maternal peripheral blood and fetal cord blood of 26 human pregnancies. Results: In the mouse model, weights of the IGF2-overexpressing mice were significantly higher than those of the control mice at the age of 5-10 weeks. The glucose concentration, total cholesterol and high-density lipoprotein cholesterol (HDL-C) levels of IGF2-overexpressing mice were significantly lower than those of wild-type (WT) mice. Compared with the WT mice, the expression of H19 was significantly decreased in the pancreas and IGF1R was significantly decreased in the muscle of mice with IGF2 overexpression. The expression levels of STAT3 and AKT2 showed significant decrease in liver, muscle and increase in muscle of IGF2-overexpressing mice, respectively. GLUT2 expression showed significant increase in liver, kidney, muscle and decrease in pancreas of mice with IGF2 overexpression. This study also found that in normal mothers with the similar clinical characteristics, IGF2 expression in the maternal peripheral blood and fetal cord blood is an independent factor influencing macrosomia. Conclusion: IGF2 expression was independently correlated with the occurrence of macrosomia, and overexpression of IGF2 significantly increased the weights of mice at the age of 5-10 weeks and significantly affected the values of adult glycolipid metabolism indicators, which might be the result of changes in the IGF2-IGF1R-STAT3/AKT2-GLUT2/GLUT4 pathway. These findings might suggest that IGF2 plays an important role in growth and glycolipid metabolism during both pregnancy and postnatal development.

Composition of Maternal Circulating Short-Chain Fatty Acids in Gestational Diabetes Mellitus and Their Associations with Placental Metabolism.

Short-chain fatty acids (SCFAs), which are produced by gut microbiota from dietary fiber, have become candidates for gestational diabetes mellitus (GDM) treatment. However, the associations of circulating SCFAs with maternal-neonatal clinical parameters in GDM and further influences on placental immune-metabolic responses are unclear. Acetate, propionate, and butyrate were decreased in GDM during the second and third trimesters, especially in those with abnormal glucose tolerance at three "oral glucose tolerance test" time points. Butyrate was closely associated with acetate and propionate in correlation and dynamic trajectory analysis. Moreover, butyrate was negatively correlated with white blood cell counts, neutrophil counts, prepregnancy BMI, gestational weight gain per week before GDM diagnosis, and ponderal index but positively correlated with total cholesterol and low-density lipoprotein levels in all pregnancies. On the premise of reduced SCFA contents in GDM, the placental G-protein-coupled receptors 41 and 43 (GPR41/43) were decreased, and histone deacetylases (HDACs) were increased, accompanied by enhanced inflammatory responses. The metabolic status was disturbed, as evidenced by activated glycolysis in GDM. Maternal circulating acetate, propionate, and butyrate levels were associated with demographic factors in normal and GDM women. They influenced placental function and fetal development at birth through GPRs or HDACs, providing more evidence of their therapeutic capacity for GDM pregnancies.

Gut microbiota in women with gestational diabetes mellitus has potential impact on metabolism in pregnant mice and their offspring.

Studies have shown that gestational diabetes mellitus (GDM) is closely related to abnormalities in the gut microbiota, and the offspring of these women have an increased risk of diabetes. There is no direct evidence of whether bacteria in women with GDM colonize the intestinal tract of offspring and cause hyperglycemia. In this fecal microbiota transplantation (FMT), pregnant mouse model study, two groups of germ-free (GF) mice after FMT showed different colonization patterns of gut microbiota and phenotype. Compared with the control group (healthy-FMT), we found in the GDM-FMT group as a lower relative abundance of Akkermansia and Faecalibacterium; a lower content of short-chain fatty acids and naringenin in feces; an elevated blood glucose; an inflammatory factor expression (TNF-α, CXCL-15, and IL-6), and a hepatic fat deposition. In addition, the influence of the gut microbiota continued in offspring. The gut microbiota of the offspring of GDM-FMT mice was still different from that of the control group as a lower relative abundance of Akkermansia and Parvibacter; and a higher relative abundance of bacteria such as Oscillibacter, Romboutsia, and Harryflintia. In addition, the offspring of GDM-FMT mice had higher body weight and blood glucose levels than the control offspring.

High glucose increases IGF-2/H19 expression by changing DNA methylation in HTR8/SVneo trophoblast cells.

INTRODUCTION: Gestational diabetes mellitus (GDM) is associated with many adverse outcomes of pregnancy, especially macrosomia. The aim of our study was to verify whether high glucose concentrations change the methylation levels of the insulin-like growth factor-2 (IGF-2)/H19 gene promoters to increase the expression of IGF-2, a key gene in fetal growth regulation. METHODS: HTR8/SVneo cells were used to establish a cell model of intrauterine hyperglycemia in pregnant women with GDM. The RNA expression levels of the IGF-2/H19 genes and the methylation levels of the IGF-2/H19 gene promoter regions were measured. Methylated and unmethylated IGF-2/H19 gene promoter plasmids were transfected into HTR8/SVneo cells. RESULTS: Among the five groups of cells, the RNA levels of IGF-2 and H19 were lowest in the 5-mM (physiological blood glucose level) group, which was statistically significant (all P < 0.05). Compared with those in the 5-mM group, two cytosine-phosphate-guanine (CpG) sites in the promoter region of the IGF-2 gene and twelve CpG sites in the promoter region of the H19 gene had statistically significant changes in methylation levels (all P < 0.05). Additionally, luciferase activity was significantly higher in cells transfected with the methylated H19 gene promoter plasmid than in control cells transfected with the unmethylated plasmid (P < 0.01), while the methylated IGF-2 gene promoter plasmid produced lower luciferase activity than the unmethylated plasmid (P < 0.01). DISCUSSION: High glucose concentrations may increase IGF-2/H19 expression by changing the methylation levels of the IGF-2 and H19 gene promoters.

Distribution characteristics of intestinal microbiota during pregnancy and postpartum in healthy women.

The characteristics of microbial community changes in pregnant women are still unclear. To investigate the changes in gut microbiota during pregnancy and after delivery in healthy women, we enrolled 47 healthy pregnant women who received obstetric care in our hospital from October 2016 to April 2017 and obtained their fecal samples at different time periods: T1 (11-13 W), T2 (23-28 W), and T3 (33-38 W) during pregnancy, and PP6W (6 weeks postpartum) and PP6M (6 months postpartum). Based on 16S rRNA gene sequencing results, there was no significant difference (p > .05) in the index of alpha-diversity between the pregnancy and postpartum periods. Principal coordinate analysis indicated that gut microbiota clustering during the postpartum period was significantly different from that during pregnancy. Phylum-level comparison of species identified using T1, T2, T3, PP6W, and PP6M samples showed higher abundance of Actinobacteria, Firmicutes, and Proteobacteria, while the abundance of Bacteroidetes decreased. At the genus level, 31 types of bacteria were found to be significantly different among these five groups. Akkermansia, Bacteroides, Subdoligranulum, Oscillospira, Ruminococcacea UCG-004), and Alistipes showed higher abundance during pregnancy, while Bifidobacterium, [Eubacterium] rectale group and Hungatella showed higher abundance after delivery. Therefore, the diversity and function of the gut microbiota in healthy pregnant women remained unchanged during pregnancy; however, the composition of the intestinal microbiota in the postpartum period changed significantly. Our results provide the basis for in-depth studies of the composition of perinatal gut microbial communities in women.

Irisin participates in the beneficial effects of exercise in preventing gestational diabetes mellitus in overweight and obese pregnant women and a mouse model.

Objective: We aimed to explore whether irisin participates in the beneficial effects of exercise in preventing gestational diabetes mellitus (GDM) in overweight and obese pregnant women. Study design: Sixty overweight and obese pregnant women each in the exercise and control groups were randomly selected from our previous randomized controlled trial. Eighteen obese model mice were generated and divided into exercise and control groups in which body weight, abdominal circumference, anal temperature, glucose tolerance test, and insulin tolerance test were recorded. The plasma irisin level, the expression of PGC-1α/FNDC5 and brown (UCP1) and beige adipose (CD137, TMEM26, and TBX-1) marker genes were detected in muscle and adipose tissue. Results: In the human study, women in the exercise group had a significantly higher irisin level and lower insulin resistance level than those in the control group. Enhanced expression of beige adipose tissue marker genes (CD137, TMEM26, and TBX-1) in omental adipose tissue and the CD137 gene in subcutaneous adipose tissue were found in the exercise group compared to the control group. In a mouse model, body weight and abdominal circumference were decreased, while glucose homeostasis and insulin sensitivity were significantly improved, and anal temperature was elevated after exercise intervention. A significantly higher level of irisin was revealed in the exercise group after undergoing exercise treatment. The expression of the beige adipose marker genes CD137 and TBX-1 was significantly higher in the exercise group than in the control group in posterior subcutaneous adipose tissue from the inguinal area and interscapular adipose tissue respectively. Conclusion: Our observations show that regular exercise during pregnancy can increase irisin levels, promote white fat beiging/browning, improve glucose homeostasis and enhance body energy expenditure, which may be one of the mechanisms by which exercise prevents GDM.

Perturbations of gut microbiota in gestational diabetes mellitus patients induce hyperglycemia in germ-free mice.

Shifts in the maternal gut microbiota have been implicated in the development of gestational diabetes mellitus (GDM). Understanding the interaction between gut microbiota and host glucose metabolism will provide a new target of prediction and treatment. In this nested case-control study, we aimed to investigate the causal effects of gut microbiota from GDM patients on the glucose metabolism of germ-free (GF) mice. Stool and peripheral blood samples, as well as clinical information, were collected from 45 GDM patients and 45 healthy controls (matched by age and prepregnancy body mass index (BMI)) in the first and second trimester. Gut microbiota profiles were explored by next-generation sequencing of the 16S rRNA gene, and inflammatory factors in peripheral blood were analyzed by enzyme-linked immunosorbent assay. Fecal samples from GDM and non-GDM donors were transferred to GF mice. The gut microbiota of women with GDM showed reduced richness, specifically decreased Bacteroides and Akkermansia, as well as increased Faecalibacterium. The relative abundance of Akkermansia was negatively associated with blood glucose levels, and the relative abundance of Faecalibacterium was positively related to inflammatory factor concentrations. The transfer of fecal microbiota from GDM and non-GDM donors to GF mice resulted in different gut microbiota colonization patterns, and hyperglycemia was induced in mice that received GDM donor microbiota. These results suggested that the shifting pattern of gut microbiota in GDM patients contributed to disease pathogenesis.

Midtrimester amniotic fluid from healthy pregnancies has no microorganisms using multiple methods of microbiologic inquiry.

BACKGROUND: There is controversy about whether the amniotic fluid contains bacteria. With the use of sequencing-based methods, recent studies report that the amniotic fluid is colonized by microorganisms. However, background-contaminating DNA might lead to false-positive findings when such a low microbial biomass sample is examined. OBJECTIVE: The purpose of this study was to determine whether the midtrimester amniotic fluid of patients who subsequently had normal pregnancy outcomes contains a microbial signature. STUDY DESIGN: In this prospective cohort study, 42 amniotic fluid samples were collected from 37 pregnancies (5 twin and 32 singletons) during genetic amniocentesis in the midtrimester. The subsequent pregnancy outcomes of all the participants were followed. Multiple methods were used to detect the presence of microorganisms in this study, which included cultivation, quantitative real-time polymerase chain reaction, and 16S ribosomal RNA gene sequencing. Multiple positive control samples (n=16) served as quality control samples and included 3 adult fecal samples, 4 vaginal swabs, and 9 artificial bacterial communities that were run in parallel with negative control samples (n=12) that included 4 samples from the hospital operating room and 8 samples from the laboratory, to account for background-contaminating DNA during each step of the experiments. RESULTS: No bacteria under anaerobic or aerobic conditions or genital mycoplasmas were cultured from any of the amniotic fluid samples. Quantitative polymerase chain reaction did not reveal greater copy numbers of 16S ribosomal RNA gene in amniotic fluid samples than in negative control samples. 16S Ribosomal RNA gene sequencing did not indicate a significant difference in the microbial richness or community structures between amniotic fluid and negative control samples. CONCLUSION: With multiple methods of microbiologic inquiry, no microorganisms were identified in the midtrimester amniotic fluid of healthy pregnancies with a normal pregnancy outcome.

Effects of oligosaccharide-sialic acid (OS) compound on maternal-newborn gut microbiome, glucose metabolism and systematic immunity in pregnancy: protocol for a randomised controlled study.

INTRODUCTION: The gut microbiota participates in multiple human biological processes, including metabolism and immune responses. During pregnancy, the dynamics of gut microbiota is involved in physiological adaptation. The disturbed profile of microbiome is associated with maternal complications, such as gestational diabetes mellitus (GDM), which further transfers to the offspring and influence their metabolic and immunological functions in the long term. Prebiotics targeting the gut microbiota and modulating metabolic and immune functions have been shown to be effective in non-pregnant populations with metabolic syndrome. Hence, we propose the use of a prebiotic supplement, oligosaccharide-sialic acid (OS) from the first trimester until delivery in pregnant women, can benefit maternal/new-born gut microbiome, glucose metabolism and innate immunity. METHODS AND ANALYSIS: In this prospective double-blinded randomised clinical trial, recruited singleton pregnancies will be stratified by body mass index (BMI) and randomly assigned to consume the OS preparation or placebo daily from the first trimester. At seven later time points (before and after recruitment in the first trimester, in the middle and third trimesters, before delivery, at birth and 42 days postpartum), compliance will be evaluated and/or biological samples will be collected. Along with maternal clinical information, questionnaires on lifestyle and infant development will be recorded. The primary outcomes are the effect of OS on the maternal-offspring gut microbiome and GDM incidence. The secondary outcomes are maternal glycolipid biochemical parameters, cytokine profiles, weight gain during pregnancy and infant morbidities, growth and development. The study aims to validate the effects of OS on reducing maternal morbidity within different BMI groups. The multiple dimensional dataset generated from the study includes clinical and lifestyle-related information, various biological markers and associated protective or risk factors for morbidity and prognosis. An extended follow-up through 42 days after birth could further explore the intrauterine influence on the long-term health of offspring. ETHICS AND DISSEMINATION: This protocol has been approved by Peking University First Hospital, National Unit of Clinical Trial Ethics Committee (reference number: 164). The results are expected to be published in scientific manuscripts by 2021. TRIAL REGISTRATION NUMBER: ChiCTR1800017192.

The Perturbation of Infant Gut Microbiota Caused by Cesarean Delivery Is Partially Restored by Exclusive Breastfeeding.

Early establishment of the infant gut microbiome has been attributed to various environmental factors that may influence long-term health. The aim of this study was to determine the single and combined impacts of the delivery mode, feeding pattern and postnatal antibiotic exposure on the initial establishment of infant gut microbiome at 6 weeks postpartum. A cross-sectional study was conducted at a single center in China. Fecal samples were collected from 120 infants at 6 weeks postpartum. The V3-V4 regions of 16S rRNA gene were analyzed by Illumina sequencing, and clinical information was obtained from medical records and questionnaire survey. Compared with vaginally delivered infants, the gut microbial community structure of cesarean delivered infants were significantly different (P = 0.044), in parallel with the decreased relative abundance of Bifidobacterium (P = 0.028), which contrasts with the normal gut microbial establishment. Using the vaginally delivered and exclusively breastfed (VB) infants as a reference, the comparative analysis of cesarean delivered and exclusively breastfed (CB) infants with cesarean delivered and mixed-fed (CM) infants showed that both within- and between-group UniFrac distance were significantly smaller in CB infants (P < 0.001, P < 0.001). LEfSe analysis showed that the relative abundances of Enterococcus, Veillonella, and Faecalibacterium were significantly different between CB and CM infants, whereas the relative abundances of those genera in VB infants were close to those of CB infants, and distinct from those of CM infants. Additionally, no significant difference of microbial composition, alpha diversity, or community structure was observed between postnatal antibiotics exposed infants and unexposed infants. In summary, delivery mode had a significant impact on the infant gut microbial community structure and composition, and the gut microbiota was disturbed in infants delivered by cesarean section. However, our study showed that this disturbance of gut microbiota in cesarean delivered infants was partially restored by exclusive breastfeeding in comparison with mixed feeding. No distinct impact of postnatal antibiotic exposure on infant gut microbiome was found at 6 weeks of age.

Structured reports of pelvic magnetic resonance imaging in primary endometrial cancer: Potential benefits for clinical decision-making.

BACKGROUND: Although evidence is increasing that the implementation of structured reports (SRs) may increase the standardization of reports and improve communication between radiologists and end-users, it is unclear whether these alternative formats of Chinese radiological narratives are appealing or even acceptable to radiologists and clinicians. OBJECTIVE: To compare the effect of SRs and non-structured reports (NSRs) of pelvic magnetic resonance imaging (MRI) in patients with primary endometrial cancer on referring gynecologists' satisfaction, further decision-making and efficiency. METHODS: Forty-one patients with histologically proven endometrial cancer were included in this study. SRs and NSRs for local MRI staging of endometrial cancer were generated for all subjects. NSRs were generated during clinical routine practice. The same 41 uterine studies were reviewed by the same radiologist using structured reporting system after a period of time. Two radiologists compared SRs on the number of key features related to cancer staging and writing efficiency with NSRs together. Five gynecologists filled in questionnaires regarding satisfaction with content, clinical usefulness, report' quality and time consumption. Statistical analysis included Kendall's W test, paired-sample t test and Wilcoxon signed rank test. RESULTS: There was no significant difference in the number of key features in NSRs comparison to SRs (p = 0.055). A statistically significant difference was observed in the satisfaction with linguistic quality for NSRs versus SRs by three gynaecologists (reader 1: 4.02 vs. 4.63, p = 0.002; reader 3: 3.86 vs. 4.02, p = 0.035; reader 4: 4.05 vs. 4.27, p = 0.024). The radiologist spent less time finishing SRs compared with NSRs (727.22 ± 38.42 sec vs. 616.44 ± 60.00 sec, p = 0.037). CONCLUSIONS: The application of SRs significantly increased the value of female pelvic MRI reports by increasing radiologists' work efficiency and gynaecologists' satisfaction.

Fatty acid-binding protein 4 predicts gestational hypertension and preeclampsia in women with gestational diabetes mellitus.

OBJECTIVE: Fatty acid-binding protein 4 (FABP4) has been proposed to be a potential predictive factor of gestational hypertension or preeclampsia (GH/PE) because of its integrating metabolic and inflammatory responses. Women with gestational diabetes mellitus (GDM) are more likely to develop both GH/PE, than the normal population. The aim of our study was to examine the relationship between plasma FABP4 in the second trimester of pregnancy and the risk of GH/PE in women with GDM. METHODS: This was a nested case-control study conducted within a large on-going prospective cohort study conducted at Peking University First Hospital. A total of 1344 women, who were diagnosed with GDM, according to a 75 g oral glucose tolerance test, participated in the GDM One-Day Clinic at Peking University First Hospital from February 24, 2016 to February 9, 2017. Of the 748 GDM women who agreed to the blood sample collection, 637 were followed until their delivery. The cases included GDM patients who developed gestational hypertension or preeclampsia (GDM-GH/PE group, n = 41). Another 41 matched GDM women without major complications were selected as the control group (GDM group). RESULTS: The incidence of GH/PE was 6.44% and 3.30% for preeclampsia. The level of the second trimester plasma FABP4 in the GDM-GH/PE group was significantly higher than the GDM group (17.53±11.35 vs. 12.79±6.04 ng/ml, P = 0.020). The AUC ROC for the second trimester plasma FABP4 predicted GH/PE in the GDM patients alone was 0.647 (95%CI 0.529-0.766). Multivariate analysis showed that the elevated second trimester FABP4 level was independently associated with GH/PE in the GDM patients (OR 1.136 [95% CI 1.003-1.286], P = 0.045). CONCLUSIONS: Increased second trimester plasma FABP4 independently predicted GH/PE in GDM patients.

Pkm2 can enhance pluripotency in ESCs and promote somatic cell reprogramming to iPSCs.

Aerobic glycolysis is one of the most important common characteristics in both cancer cells and stem cells. Metabolism switch has been discovered as an important early event in the process of reprogramming somatic cells to induced pluripotent stem cells (iPSCs). As a rate limiting kinase in glycolysis, Pkm2 has been reported playing critical roles in many tumors, yet its role in stem cells and iPSCs induction is poorly defined. In the present study, we showed that Pkm2 is a predominant pyruvate kinase in embryonic stem cells (ESCs), and its expression increases many pluripotent genes. During somatic cell reprogramming, up-regulation of Pkm2 can be observed and over-expression of Pkm2 can facilitate iPSCs induction, while Pkm1 or a mutant form of Pkm2 (Pkm2K422R) showed no enhancement role in iPSCs induction. Therefore, our data demonstrated that Pkm2 enhances the pluripotency maintenance in ESCs and promotes the pluripotency acquisition during somatic cell reprogramming.