Temporal shifts and cross-site relationships of oral, gut, and vaginal microbiota during the third trimester of pregnancy.

Composition of the microbial communities at different body sites in women with preterm birth and their newborns

Defining the relationship between vaginal and urinary microbiomes

Background Women at high risk of prenatal depressive symptomology have higher rates of adverse obstetric outcomes (1) and altered infant development (2). The mechanisms underpinning this may be linked to inappropriate remodelling of the microbiome during pregnancy and subsequent vertical transmission of a suboptimal microbiome at birth. Aim This cross-sectional study aimed to assess the association between the maternal microbiome and depressive symptoms. Method Women enrolled in the IMPROvED study at Cork University Maternity Hospital (3) completed the Edinburgh Postnatal Depression Scale (EPDS) and provided faecal samples during the second (n=46) and third trimester (n=33) of pregnancy. Vaginal swabs were collected prior to delivery (n=60). EPDS ≤8 and EPDS ≥9 were used to indicate low and high depressive symptoms respectively. Microbial community structure analysed by 16S rRNA gene sequencing. Results Women reporting higher depressive symptoms in second trimester had reduced phylogenetic diversity (p=0.024) and species richness (chao1; p=0.040) of the gut microbiota. There were significant alterations observed at Phyla, Family and Genus level including an increase in the dominant Faecalibacterium (p=0.029) among the higher depressive group. The magnitude of the depression-associated gut alterations was greatly reduced in the third trimester. The vaginal microbiome remained largely unchanged by prenatal depressive symptoms. Conclusions The experience of depressive symptoms in mid pregnancy is associated with marked alterations in the maternal gut microbiome that do not persist into late pregnancy. Further studies are planned to clarify the implications of these depression-associated maternal microbiome alterations during pregnancy for obstetric outcomes and infant development.

In healthy women at reproductive age, the vaginal microbiota is mainly dominated by Lactobacillus bacteria during pregnancy and non-pregnancy stages. However, little is known about longitudinal changes within the vaginal microbiota composition from the third trimester of pregnancy to childbirth in healthy women. Thus, we conducted an exploratory longitudinal study of vaginal microbiota composition of 10 Mexican pregnant women, sampling from the same volunteer at two-time points: third trimester of pregnancy and active childbirth. Vaginal bacterial microbiota was characterized by V3-16S rDNA libraries by high-throughput sequencing and bioinformatics methods. Out of ten, vaginal microbiota from eight women was dominated by the Lactobacillus genus at both time points, whereas the other two women showed vaginal microbiota composition with high abundance of genera Gardnerella, Prevotella, and members of the Atopobiaceae family, without any preterm birth correlation. Importantly, we found no statistically significant differences in relative abundances, absolute reads count, alpha and beta diversity between the third trimester of pregnancy, and active childbirth time points. However, compared to the third trimester of pregnancy, we observed a trend with higher absolute reads counts for Gardnerella, Faecalibaculum, Ileibacterium, and Lactococcus genus at active childbirth and lower absolute reads count of Lactobacillus genus. Our results suggest that the vaginal microbiota composition is stable, and Lactobacillus genus is the dominant taxa in Mexican women's vagina at the third trimester of pregnancy and childbirth.

Maternal diet quality and quantity have significant impacts on both maternal and fetal health and development. The composition and function of the maternal gut microbiome is also significantly influenced by diet. However, little is known about the impact of gestational nutrient restriction on the maternal microbiome during early gestation, which is a critical stage for many developmental processes. Here, we evaluated the effects of dietary restriction and one-carbon metabolite (OCM) supplementation on the ruminal and vaginal microbiota of beef heifers during early pregnancy. For this, 32 beef heifers (approximately 14-month-old) were used in a 2 × 2 factorial experiment with main factors including targeted gain (CON; 0.45 kg/d gain vs. RES; -0.23 kg/d gain), and OCM supplementation (OCM vs. noOCM) (n = 8/treatment). OCM heifers received ruminal-protected methionine (20 g/day) and choline (60 g/day) daily via a fine-ground corn carrier, with weekly intramuscular injections of folate (320 mg) and vitamin B12 (20 mg). The noOCM heifers received only corn carrier and saline injections. Heifers were individually fed and began treatment at breeding (d 0) and remained on treatment until d 63 of gestation. Ruminal fluid and vaginal swab samples were collected at d -2, d 35, and d 63 (at necropsy). Microbiota from samples were assessed using 16S rRNA gene (V3-V4) sequencing. Overall community structure of the ruminal microbiota was affected by gain (PERMANOVA: R2 = 0.04, P < 0.0001), OCM (R2 = 0.013, P = 0.03), time (R2 = 0.16, P < 0.0001) and by their interactions (R2 = 0.08, P = 0.004). The greatest difference in ruminal microbial community structure was between RES and CON heifers (R2 ≥ 0.16, P ≤ 0.003) on d 63. Overall microbial richness (total ASVs) was greater in RES (2,900 vs. 2,737; P = 0.005) but was unaffected by OCM (P = 0.25). Analysis via MaAsLin2 revealed that phyla Firmicutes (31% vs. 22%), Actinobacteriota (0.65% vs. 0.36%) and Chloroflexi were enriched (P < 0.05) in RES heifers. Twenty-five of the 34 differentially abundant genera in the rumen microbiota, including Christensellaceae R7 (5.0% vs 2.6%), Lachnobacterium (2.0% vs. 0.46%), and Butyrivibrio were more relatively abundant in RES; whereas 9 genera including Prevotella (16.5% vs. 31.1%), Ruminococcus (1.6% vs. 2.5%) and Saccharofermentans (0.4% vs. 0.5%) were reduced in RES (P < 0.05) on d 63. Overall vaginal microbiota structure was affected by gain (R2 = 0.02, P = 0.023) and time (R2 = 0.34, P < 0.0001) but not OCM (P >0.05). Community structure of RES was distinct from CON (R2 = 0.16, P = 0.032) on d 63, but microbial community richness and diversity were not influenced by OCM (P > 0.05). On d 63, RES heifers had increased Actinobacteriota (30.5% vs. 17.7%), but reduced Proteobacteriota (6.2% vs. 9.4%) and Fusobacteriota (0.02% vs. 0.94%; P < 0.05). In summary, restricted dietary intake during early gestation induced significant alterations in the ruminal microbiota and its impact also extended to the vaginal microbiota. The composition of these two microbial communities remained largely unaffected by OCM supplement.

Changes within the maternal microbiome during the last trimester of pregnancy and the determinants of the subsequent neonatal microbiome establishment after delivery by elective cesarean section are described. Maternal vaginal and rectal microbiome samples were collected in the last trimester and before cesarean section; intrauterine cavity, placenta, neonatal buccal mucosa, skin, and meconium samples were obtained at birth; neonatal sample collection was repeated 2-3 days postnatally. Microbial community composition was analyzed by 16S rRNA gene amplicon sequencing. Relative abundance measurements of amplicon sequencing variants and sum counts at higher taxonomic levels were compared to test for significant overlap or differences in microbial community compositions. gov ID: NCT04489056. A total of 30 mothers and their neonates were included with available microbiome samples for all maternal, intrauterine cavity and placenta samples, as well as for 18 of 30 neonates. The composition of maternal vaginal and rectal microbiomes during the last trimester of healthy pregnancies did not significantly change (permutational multivariate analysis of variance [PERMANOVA], p > 0.05). No robust microbial signature was detected in the intrauterine cavity, placenta, neonatal buccal mucosa, skin swabs, or meconium samples collected at birth. After birth, the neonatal microbiome was rapidly established, and significantly different microbial communities were detectable2-3 days postnatally in neonate buccal mucosa and stool samples (PERMANOVA, p < 0.01). Maternal vaginal and rectal microbiomes in healthy pregnancies remain stable during the third trimester. No microbial colonization of the neonate was observed before birth in healthy pregnancies. Neonatal microbiomes in infants delivered by cesarean section displayed a taxonomic composition distinct from maternal vaginal and rectal microbiomes at birth, indicating that postnatal exposure to the extrauterine environment is the driving source of initial neonatal microbiome development in this cohort.

Study question Is there any correlation between the total bacterial load and the lactobacilli quantities in the vaginal and endometrial microbiomes in reproductive-age women? Summary answer There was no correlation between the vaginal and endometrial total bacterial loads and only a weak positive correlation between the quantities of lactobacilli. What is known already The Lactobacilli-dominated microbiota is considered to be the most favorable type of microbiota in the uterine cavity. It is associated with increased reproductive success in women undergoing in vitro fertilization. Whereas the non-Lactobacillus dominated microbial communities are more frequent in women with poor pregnancy outcomes. When analyzing endometrial microbiota, one of the challenges is sampling. Transvaginal sample intake involves the possibility of contaminating the samples with vaginal microbiota. Moreover, it is an invasive procedure leading to the development of infectious inflammatory diseases of the upper genital tract. Thus, researchers are currently searching for predictors of the state of endometrial microbiota. Study design, size, duration It is a cross-sectional study of the vaginal end endometrial micorbiomes from 64 reproductive-age women. Endometrial and vaginal samples were collected simultaneously on days 7–10 of the menstrual cycle. To avoid contamination by vaginal microbiota, Endobrush Standard for Endometrial Cytology (Laboratoire C.C.D.; France) was used for endometrial sampling. Participants/materials, setting, methods The study included women who came to the “Garmonia” Medical Center (Yekaterinburg, Russia) seeking infertility treatment. The average age of the patients was 32.2±5.0. DNA from vaginal and endometrial samples was extracted using PREP-NA-PLUS kit (DNA-Technology, Russia). Vaginal and endometrial microbiota was analyzed using Femoflor real-time PCR kit and DTprime 4M1 thermocycler (DNA-Technology, Russia). Main results and the role of chance Total bacterial load (TBL) in vaginal discharge was 3.8–7.9 lg (median — 7.1, interquartile range — 6.6–7.4). TBL in the endometrial samples was 0–5.1 lg (median — 3.9, interquartile range — 3.6–4.2). There was no correlation between TBL values in vaginal discharge and endometrial samples (Spearman’s rho — 0.247, p = 0.049). Lactobacilli quantities in vaginal discharge were 4.5–8.3 lg (median — 7.2, interquartile range — 6.4–7.6), in endometrial samples — 0–5.1 lg (median — 3.7, interquartile range — 3.1–4.2). There was a weak positive correlation between lactobacilli quantities in vaginal and endometrial samples (Spearman’s rho — 0.362, p = 0.003). The proportion of lactobacilli in vaginal discharge was 1–100% (median — 100%, interquartile range — 95–100%), in the endometrial samples — 0–100% (median — 96%, interquartile range — 25–100%). There was no correlation between lactobacilli proportions in vaginal and endometrial samples (Spearman’s rho — 0.225, p = 0.074). Furthermore, there was no correlation between lactobacilli quantity in the vagina and their proportion in the endometrial microbiota (Spearman’s rho — 0.294, p = 0.018). There was only a weak positive correlation between the quantities of lactobacilli in vaginal and endometrial samples. Vaginal TBL values and lactobacilli proportions did not correlate with lactobacilli quantities and proportions in the endometrial samples. Limitations, reasons for caution The study was conducted on a small sample. Moreover, it is notoriously difficult to interpret the analysis results for endometrial microbiota due to the high risk of contamination and its low microbial biomass. Wider implications of the findxings: Apparently, there is no obvious link between the vaginal and endometrial microbiomes. It is possible that, apart from vaginal microbiota, there are other predictors which could allow us to assume whether lactobacilli are present in the endometrial microbiota. Trial registration number Not applicable

To prospectively analyze the effects of gestational stress around 3 months of conception and stress in the second and third trimesters of pregnancy on the dietary preferences in late pregnancy of women in Shanghai City. From April 2016 to April 2018, pregnant women who registered in 2 delivery hospitals in Shanghai were recruited as participants of Shanghai Maternal-Child Pair Cohort with informed consent. Life Events Scale for Pregnant Women was used to evaluate the gestational stress around 3 months of conception and stress during 32-36 weeks of pregnancy, respectively. Food Frequency Questionnaire and factor analysis were used to evaluate the dietary tendency in late pregnancy. Binary Logistic regression model was used to analyze the relationship between gestational stress and dietary tendency. Among the 2634 pregnant women included in this study, factor analysis revealed six dietary preferences in the third trimester of pregnancy, which were &apos;balanced&apos;, &apos;meat and beans&apos;, &apos;richer in sugar or oil&apos;, &apos;pickled products and giblets&apos;, &apos;nutritional supplement&apos; and &apos;caffeine&apos;, respectively. After controlling for potential confounding factors of age, education, occupation, annual family income, body mass index before pregnancy, parity, anxiety and depression in the second and third trimesters of pregnancy, higher total and subjective gestational stress around conception would make pregnant women less likely to have a "balanced" diet in late pregnancy(OR=0. 76, 95%CI 0. 61-0. 95). The higher level of gestational stress in the second and third trimesters of pregnancy was associated with a greater preference for a "balanced" diet(OR=1. 66, 95%CI 1. 22-2. 25), but it also increased the preference for a "pickled products and giblets" diet(OR=1. 32, 95%CI 0. 98-1. 78)and inhibited a preference for a "meat and beans" diet(OR=0. 72, 95%CI 0. 53-0. 96). Lower level of gestational pressure during pregnancy is beneficial to the balance of diet in late pregnancy. Compared with that in the second and third trimesters of pregnancy, gestational stress around conception is more likely to negatively affect dietary preferences in late pregnancy.

To evaluate the effect of probiotic supplementation on the vaginal microbiome and provide the effective evidences for clinical management of pregnant women. A total of 28 healthy pregnant women at 32 weeks of gestation were enrolled. The women were divided randomly to the probiotic group where they were prescribed with 2 g combined probiotics daily (13 cases) during the third trimester of pregnancy or to the control group (15 cases) on a voluntary basis. Their vaginal samples were taken for analyzing microbiome with the 16S rDNA amplicon sequencing of V4 region. There was no significant difference on the clinical characteristics between the probiotic and control groups. The complexity of vaginal microbial network increased from 32 weeks of gestation to antepartum. Lactobacillus was the dominant microbiota. The probiotic supplementation had no obvious influence on the structure of the vaginal microbiome, whereas the relationships of some pivotal vaginal microbiota at the genus level changed in the probiotic group. The vaginal microbiome varied during the third trimester of pregnancy. The features of the vaginal microbiota after probiotic supplementation had shifted and the interaction network had the tendency to be loose. The probiotic supplementation may be useful in regulating the interaction network of vaginal microbiome.

Calcium and vitamin D play major roles in calcium homeostasis and skeletal development, especially during pregnancy. This study was conducted to determine changes in calcium, 25 hydroxy [25(OH)] vitamin D3 and other biochemical factors (PTH, osteocalcin, alkaline phosphatase, magnesium, phosphorus) related to calcium homeostasis and bone turnover during pregnancy and compare the values to those of non-pregnant women. In a cohort study, 48 pregnant women, in their first trimester of pregnancy (12+/-2.7 weeks), from 5 prenatal care centers, and 47 non-pregnant women randomly selected from the Tehran Lipid and Glucose Study (TLGS) population were enrolled. These pregnant women were followed in their second (26+/-1.9 weeks) and third trimesters (37+/-3.2 weeks) of pregnancy. Samples were drawn from June 2002 to March 2003. Including criteria were healthy women with no background of disease. Women using photo protection and calcium and vitamin D supplementation were excluded. A questionnaire was used to obtain demographic information for both groups. Venous blood samples were taken after 12-14 h of overnight fasting to measure serum calcium, phosphorus, magnesium, alkaline phosphatase, PTH, 25 (OH) vitamin D3 and serum osteocalcin levels. The repeated measures analysis of variance and t-test were used for statistical analysis. Data were matched for age and weight in both the case (in the first trimester) and control groups. Significant differences were found in the mean serum levels of osteocalcin and alkaline phosphatase between the three trimesters of pregnancy (p< 0.001). Osteocalcin was significantly higher in the first trimester as compared to second and third trimesters of pregnancy. Alkaline phosphatase was significantly lower in the first trimester as compared to the second and third trimesters of pregnancy and their controls. There was also a significant difference in osteocalcin in the second and third trimesters and alkaline phosphatase in the first and third trimesters of pregnancy in comparison to the control group. The mean values of osteocalcin were 12.7+/-8.5, 8.1+/-6.9, 5.6+/-5.0 and 13.9+/-7.9 ng/ml, respectively, and mean values for alkaline phosphatase were 115+/-38, 125+/-37, 174+/-61 and 134+/-35.0 Iu/l, respectively. In the first trimester, alkaline phosphatase was lower and osteocalcin was higher than in the second and third trimesters. In the first trimester of pregnancy, 20 and 40% of women had 25(OH) vitamin D3 < 10 and < 20 ng/ml, respectively, and 19% of women had serum calcium levels < 8.6 mg/dl. 60% of women in the first trimester, 48% in the second and 47% in the third trimester had either severe or moderate vitamin D deficiency. It is recommended that the importance of calcium supplements with vitamin D in pregnant women be stressed for these individuals.

Aim In this study by Foessleitner et al., both the maternal microbiome in the third trimester of pregnancy and the factors that influence the development of the child’s microbiome after cesarean delivery were investigated. Methods Maternal vaginal and rectal swabs were collected at inclusion in the last trimester of pregnancy and on the day of the cesarean section. In addition, placental and intrauterine swabs as well as infant dermal, buccal, and meconium swabs were taken during the cesarean section immediately after birth and subsequently on the second/third day of life. All samples were analyzed for microbial composition using 16s rRNA amplicon sequencing. Results A total of 30 mothers and their newborns were included in the study, with microbiome samples available for all maternal, intrauterine cavity, and placenta samples, as well as for 18 out of the 30 newborns. The vaginal and rectal microbiome was stable over the course of the third trimester and showed no significant changes (permutational multivariate analysis of variance [PERMANOVA]; p &gt; 0.05). Both the intraoperative samples (placental, intrauterine) and the neonatal swabs at the time of birth were consistently sterile. However, rapid infant microbial colonization subsequently occurred, with neonatal buccal mucosa and stool samples showing significantly different microbial colonization from their mothers as early as the second/third day of life (PERMANOVA; p &lt; 0.01). Conclusion The conclusion of the presented study was therefore that the vaginal and rectal microbiome of healthy pregnant women does not change in the last trimester, the infant and the placenta are not microbially colonized at the time of birth, and the development of the newborn’s microbiome after birth appears to be influenced mainly by environmental exposure.

To determine changes in malondialdehyde (product of lipid peroxidation) and antioxidant enzymes (Superoxide Dismutase, Glutathione Per-oxidase) levels in pre-eclamptic Nigerian women A Total of 100 subjects each for pre-eclamptic,apparently normal and non pregnant women were recruited into the study.Venous blood samples were taken from the participants during second and third trimesters of pregnancy and at the point of contact for non pregnant women. Malondialdehyde, glutathione peroxidase and superoxide dismutase were measured accordingly from plasma and haemolysate prepared from whole blood.Variables were analysed using SPSS version 16, taking level of significance to be 0.05 RESULTS: Plasma malondialdehyde in the third trimester (3.13±0.61umol/l) of pre-eclamptic subjects was higher than in the second trimester (3.00±1.21umol/l).Plasma malondialdehyde in the third trimester of normal pregnancy (2.03±0.71umol/l) was also found to be significantly higher than in the second trimester (1.65±0.62umol/ l)(p<0.0001). Glutathione peroxidase in pre-eclamptic subjects was significantly higher in the third trimester (2804.11±1573.00U/L) as compared to the second trimester (2655.00±1751.30U/L), p= 0.0001.Glutathione peroxidase activity in the third trimester of normal pregnancy(3339.50±1733.80U/L) was also found to be higher than in the second trimester(3023.50±1115.90U/L)(p=0.131). Superoxide dismutase activity was significantly lower in the third trimester of pre-eclamptic pregnancy when compared to second trimester (110.40±59.47 Vs 118.01±64.41 U/ ml)(p<0.039) .Similarly,superoxide dismutase activity was significantly lower in the third trimester of normal pregnancy (110.40±59.47U/ml) than in the second trimester(153.01±71.85U/ml)(p<0.0001). There was an increased level of lipid peroxidation products,malondialdehyde in subjects with pre-eclampsia. This was more in the third trimester. There was an increased oxidative stress in pre-eclampsia as evidenced also by low serum level of superoxide dismutase in the third trimester.Diet rich in antioxidant enzyme might be beneficial.

Study question Could vaginal and endometrial microbiome by sequencing 16S rRNA be comparable to classic diagnostic methods or immunohistochemistry CD138 for diagnosis of chronic endometritis? Summary answer A characteristic endometrial and vaginal microbiome is present in patients with chronic endometritis. An abnormal vaginal microbiome correlates with the presence of chronic endometritis. What is known already Chronic endometritis is a disease characterized by persistent inflammation of the endometrial lining. Currently, histopathological evaluation by immunohistochemistry CD138 marker is most common diagnostic method for CE. Microbiome analysis based on subunit 16S rRNA sequencing is a fast tool that can enable the identification of pathogenic microorganisms associated with CE. The main bacteria at vaginal and endometrial level belong to genus Lactobacillus, producers of lactic acid that allows maintaining acidic pH of vagina and acts as barrier against pathogens. Investigations on the effect of an abnormal endometrial and vaginal microbiome could improve assisted reproductive technologies. Study design, size, duration This is a observational pilot study (60 patients and 120 samples). The study population consists of patients attending to our fertility clinic for frozen euploid embryo transfer (FET) from May 2017 to May 2019. Preimplantation Genetic Testing of aneuploidy (PGT-A) was performed at blastocyst stage using Veriseq (Illumina). The inclusion criteria to be meet by patients were: age between 18 and 50 years, own or donated oocytes and use of ICSI. Participants/materials, setting, methods Cohort study with sixty patients undergoing assisted reproductive treatment (TRA) with their own or donated gametes and PGT-A Vaginal and endometrial samples were taken in the cycle prior to embryo transfer. The vaginal and endometrial microbiome was analyzed by mass sequencing of the V3V4 region of 16S rRNA. Bioinformatics analysis was performed using QIIME2 and MicrobiomeAnalyst packages. Alpha, beta diversity and taxonomic characterization were compared with positive and negative CD138 groups for chronic endometritis (CE). Main results and the role of chance Different bacterial communities were detected when vaginal and endometrial samples were analyzed in patients with and without endometritis diagnosed with CD138 immunohistochemistry. In patients with endometritis, a higher alpha diversity index tendency was found in vaginal samples (p = 0.15 for the Shannon index) and significant differences in endometrial samples (p = 0.01 for the Shannon index). In the beta diversity analysis, no significant differences were observed between the groups established as per the diagnosis of endometritis. Vaginal and endometrial samples from women with endometritis showed a microbiome pattern not dominated by Lactobacillus spp. Relative abundance analysis identified the genera Ralstonia and Gardnerella in endometrial sample, and the genera Streptoccoccus and Ureaplasma in vaginal sample of patients diagnosed with CD138 for endometritis. Comparing endometrial and vaginal samples CD138 positive diagnosed for endometritis, alpha diversity (p = 0.06 for the Shannon index and p = 0.08 for the Simpson index) and beta diversity (p &amp;lt; 0.001) showed significant differences. Relative abundance identified the genera Lactobacillus (p = 3.76E-4), Ralstonia (p = 8.19E-4), Delftia (p = 0.004) and Anaerobacillus (p = 0.004) in these sample groups. Limitations, reasons for caution The main limitation of this study is the small sample size. Larger studies including a higher number of samples are needed to confirm the different microbiome pattern observed at the vaginal and endometrial levels in correlation with chronic endometritis. The microbiome pattern has not been analyzed after treatment of CE. Wider implications of the findings Our findings suggest the existence of a characteristic vaginal and endometrial microbiota in patients with chronic endometritis. Different genera and species were identified in patients with and without endometritis depending on whether the sample was endometrial or vaginal. An abnormal vaginal microbiome appears to be strongly correlated with chronic endometritis. Trial registration number Not Applicable

Background. The purpose of our study was to investigate the concentrations of markers of bone turnover in normal pregnancy and preeclampsia. Material and Methods. Forty-five pregnant patients with preeclampsia, 78 healthy pregnant women (26 in first, 26 in the second, and 26 in third trimester of pregnancy), and 20 nonpregnant women were included in the study. Serum concentrations of osteoprotegrin (OPG), receptor activator of nuclear factor kappa B ligand (sRANKL), and the markers of bone turnover, osteocalcin and CrossLaps—degradation products of type I collagen, were determined using the ELISA method. Statistical analysis was performed using Mann–Whitney U-test. Results. The concentrations of sRANKL and OPG were significantly higher in the second trimester of normal pregnancy when compared to the first and the third trimesters and to nonpregnant controls. The concentrations of osteocalcin were significantly higher in the first trimester of physiological pregnancy in comparison with nonpregnant women and with second and third trimesters of pregnancy. The concentrations of CrossLaps were significantly higher in the second trimester of normal pregnancy when compared to the first and third trimester. In preeclampsia, the sera concentrations of osteocalcin and CrossLaps were significantly higher when compared to the third trimester of normal pregnancy. Conclusion. The results suggest that the bone formation is increased in the first trimester, whereas the bone resorption is increased in the second trimester of normal pregnancy. Furthermore, the results suggest that the bone turnover is increased in patients with preeclampsia when compared to healthy normotensive pregnant women.

The assembly of microbial communities within the gastrointestinal tract during early life plays a critical role in immune, endocrine, metabolic, and other host developmental pathways. Environmental insults during this period, such as food insecurity and infections, can disrupt this optimal microbial succession, which may contribute to lifelong and intergenerational deficits in growth and development. Here, we review the human microbiome in the first 1000 days - referring to the period from conception to 2 years of age - and using a developmental model, we examine the role of early microbial succession in growth and development. We propose that an 'undernourished' microbiome is intergenerational, thereby perpetuating growth impairments into successive generations. We also identify and discuss the intertwining host-microbe-environment interactions occurring prenatally and during early infancy, which may impair the trajectories of healthy growth and development, and explore their potential as novel microbial targets for intervention.