Medicine in Microecology最新文献

Currently, the etiology of preeclampsia (PE) has not been comprehensively clarified. Accumulating evidence indicated that gut microbiota is associated with the onset of PE. Herein, a systematic review was conducted to explore the dysbiosis of gut microbiota in PE patients compared with healthy controls (HCs). Publications were retrieved from Medline, EMBASE, Web of Science and Scopus. Studies comparing the gut microbiota in PE patients to HCs using culture-independent methods were included. Independent quality assessment and data extraction was performed according to PRISMA statement and Newcastle-Ottawa Scale (NOS). In total, six studies with an overall sample size of 416 ​PE patients and 704 ​HCs were included. In terms of alpha- and beta-diversity, consistent results reflecting the alteration of gut microbiota in PE patients. Furthermore, Fusobacterium and Ruminococcus enriched, while Lachnospira, Akkermansia, Faecalibacterium, Bifidobacterium and Alistipes were depleted in PE. This systematic review demonstrates significant dysbiosis of gut microbiota in PE patients and confirms that that the possible correlations between gut microbiota dysbiosis and PE onset. However, heterogeneity in results was also identified, alluding more well-designed studies are warranted. Above all, these evidence demonstrates that the gut microbiota may be a potential treatment and prevention target for PE.

Most of the disease studies for the gut microbiome have collected cases and control samples from the elderly or the middle-aged. Despite general interest in microbiome health, it is not known how microbial biomarkers from metagenome-wide association studies (MWAS) would perform in a cohort of young individuals, who would be largely free of chronic diseases, as well as medication. Here we analyze high-depth fecal metagenomic shotgun sequencing for 2183 healthy adults with clinical parameters, diet, lifestyle, and metabolite measurements. We provide the first set of large-scale evidence for gut microbiome dysbiosis in hyperuricemia, which relates to meat intake. We build a cardiometabolic disease risk model based on gut microbes for initial screening in a young population and confirm the validity using external cohorts. Fecal bacteria that have been reported to be enriched in colorectal cancer (CRC) are found to correlate with methylhistidines, branched-chain amino acids (BCAA), aromatic amino acids and glutamic acid in these young individuals, which were validated by an additional cohort of 1404 individuals. Our comprehensive data suggest that the gut microbiome could show trends towards diseases years before onset, and the results lay the foundation for the design of larger screens for cardiometabolic diseases and CRC with clinically meaningful cutoffs.

Pregnancy is a complex and continuously changing physiological process. With the increase in gestational age, a series of physiological changes, including hormone, metabolism, and immune, lead to the shift of microbiota of pregnant women. Growing studies have shown that the dysbiosis of microorganisms residing in multiple body sites is closely related to adverse pregnancy outcomes, especially preeclampsia, gestational diabetes mellitus, and preterm birth. In this review, we discussed the adaptations and alternations of the maternal microbiome in different sites (gut, vagina, and oral cavity) during normal and pathological pregnancies. Through the similarities and differences in microbial changes across different gestational diseases, we found three shared microbes (Bifidobacterium, Bacteroides, Dialister). In conclusion, we provide a comprehensive understanding of maternal microbial adaptions and changes, which brings insights into the association between maternal microbial dysbiosis and pregnancy complications and promotes the development of microbiota-specific approaches in the diagnosis and intervention of perinatal diseases.

Gut microbiome influenced many aspects of host physiology and psychology. Vice versa, lifestyles factors such as exercise and healthy diet are ways to shape the gut microbiota towards balance. We observed two distinct microbe groups characterized by physical fitness in a multi-omic cohort of 2183 young subjects with metagenomics, national physique comprehensive test, lifestyle and metabolome data. The panel of bacterial taxa including Clostridium bolteae, Escherichia coli, Ruminococcus gnavus, Clostridium clostridioforme, Clostridium innocuum, Bacteroides cellulosilyticus and Oscillospiraceae, were consistently associated with most of the physical fitness. Clostridium species and trace element both increased in the individuals those tend to stay up late. Yogurt consumption was associated with Streptococcus thermophilus and Bifidobacterium animalis subsp. lactis in feces, which differed from potentially endogenous Bifidobacterium species that was associated with milk intake. Our large-scale analyses were poised to advise for a healthy gut microbiome through behavioural changes.

Objective

In this study, we aimed to examine the changes in the composition of vaginal and gut microbiota during the third trimester of pregnancy among women who delivered preterm. To further understand the relationship of these changes to preterm birth, we analyzed the microecology of vaginal and gut microbiota in mothers, as well as oral and gut microbiota in their newborns, and then compared the microecological characteristics of the microbiome at different body sites between the mothers and their newborns, as well as between the mothers and between the newborns from different groups.

Methods

In total, 26 women who delivered at Zhujiang Hospital, Southern Medical University (China) from July 2020 to January 2021 were categorized into the preterm and term groups. A blank swab and laboratory air and water samples were collected as part of the control group. We collected maternal vaginal and rectal samples, as well as neonatal oral and rectal samples. Total DNA from different parts of the swabs was extracted and sequenced using the 16s rRNA technique. Then, the data was analyzed using bioinformatics and statistical analysis.

Results

The abundance and alpha diversity of vaginal microbiota in the preterm group was found to be higher, but the difference was not statistically significant. There were significant differences in beta diversity of vaginal microbiota between the two groups (p ​< ​0.05). The levels of Rothia and Gemella in the gut microbiota of women who had delivered preterm were significantly lower (p ​< ​0.05). The alpha diversity of gut microbiota and neonatal oral and gut microbiota in women who had delivered preterm was lower. No significant differences were observed in alpha and beta diversity between the two groups in maternal gut microbiota and neonatal oral and gut microbiota. In the newborns in both groups, some species of oral microbiota were consistent with their mother's vaginal microbiota, and some species of gut microbiota in the newborns in both groups were consistent with their mother's gut microbiota.

Conclusions

Vaginal and gut microbiota in women who had given birth preterm were noticeably different from the vaginal and gut microbiota of women who had delivered at term, and it was probably related to preterm birth. Oral and gut microbiotas of preterm newborns were also noted to be different from that of the term newborns. It suggests that the changes in the microbiome of the newborns could be related to preterm birth. Some part of the newborns’ microbiota probably originates in the uterus.

Ureaplasma genus (including U. urealyticum and U. parvum) and M. hominis are common opportunistic pathogens in vaginal microenvironments, which would lead to bacterial vaginosis, infertility and adverse pregnancy outcomes. Ascertaining associations between these elements and the vaginal microbiome can help us identify pathogenic mechanisms, and target control measures for different colonization levels. 92 childbearing-age, non-pregnant women were included, with vaginal swabs collected. DNA was extracted and 16S rRNA genes were sequenced using the IlluminaHiseq 2500 platform. A quantitative PCR method quantified bacterial loads. The colonization rates for the Ureaplasma genus and M. hominis were 87.0 ​% (80/92) and 29.3 ​% (27/92), respectively. No M. genitalium was detected. There were no statistical differences for Simpson, Shannon and Chao1 indices between Ureaplasma negative and positive groups (P ​> ​0.05). Based on the quartile classification of relative abundance for Ureaplasma, the third quartile group had the highest relative abundance of Lactobacillus. The Simpson index for the M. hominis positive group was statistically lower than the negative group (P ​= ​0.038). The Lactobacillus abundance appeared to decrease when the M. hominis relative abundance was >0.03 ​%. From a microbiome perspective, Ureaplasma vaginal colonization, at low levels appeared to be harmless, whereas M. hominis colonization was associated with vaginal microbiome changes. Further studies are required to confirm the diagnostic and treatment thresholds for Ureaplasma and M. hominis infections, and to explore in-depth associations between these organisms and the vaginal microbiome.

Whether or not bacteria exist in the placenta is a controversial issue. In the present study, bacteria in the placenta and blood of pregnant mice were evaluated after administration of Enterococcus faecalis, Lactobacillus reuteri, Lactococcus lactis, Lactobacillus johnsonii, Streptococcus thoraltensis, and Staphylococcus epidermidis. Results showed that 57.14–85.71 ​% of the placentas and 71.43%–100 ​% of the blood samples positively existed spherical and/or rod-shaped bacteria. All collected placentas treated with or without propidium monoazide were shown to harbor various bacteria using the denaturing gradient gel electrophoresis (DGGE) method. Moreover, E. faecalis and L. lactis were characterized as the dominant and common bacteria in each group. Our results prove the existence of bacteria in the placenta and blood of pregnant mice, which provides clues for researchers to study the role of these bacteria on host health and the development of the fetus.

In the 21st century, the incidence of preterm birth has continued to increase. According to statistics, preterm birth accounts for 5%–18% of all births worldwide, and 70%–75% of perinatal deaths are related to preterm birth. Preterm birth is not only a cardiopulmonary defect for the baby, but also has a negative impact on the mother's health. Many studies have shown that vaginal microecological dysbiosis-related diseases are the most common causes of preterm birth, such as bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), group B streptococcal (GBS) infections and other infectious diseases. Therefore, we have a review of the deeper understanding of the links and mechanisms between vaginal microecological dysbiosis-related diseases and preterm birth. In addition, timely restoration of vaginal microecology through microbial therapy become the key to prevent and reduce the incidence of preterm birth.