Medicine in Microecology最新文献

The surface of the female lower genital tract is covered with squamous epithelium, and some bacteria and fungi reside in the cavity. Among them, the dominant Lactobacillus maintain the acidic environment of the vagina. The acidic environment, squamous epithelium barrier, mucus and innate immune response together resist the invasion of pathogens and local homeostasis. Bacterial vaginosis (BV) is a disorder of the vaginal microbiota, which is characterized by a shift in the vaginal flora from the dominant Lactobacillus to a polymicrobial anaerobic flora accompanied by an increase in pH ​> ​4.5. Its high recurrence rate, obvious clinical symptoms, and possible adverse pregnancy outcome seriously disturb women's healthy life. However, its pathogenesis is still elusive. The vaginal microenvironment includes not only microbiota, but also microbially and host-produced metabolites, and vaginal local immunity. Given the inseparable relationship between the microbiota and its metabolites and the immune response, it is important to study how these interactions regulate vaginal local immunity to resist pathogens. In this review, we will discuss the main theories of BV etiology, which eventually involves the interaction between BV-related pathogens, small molecular metabolites, and host immune responses in the vagina.

Intrauterine adhesions (IUAs) are important causes of female infertility, mainly but not always caused by iatrogenic endometrial injury. The microbiome of the female reproductive tract, including the vagina and uterine cavity, plays an important role in health and disease. Immune regulation imbalance caused by reproductive tract microecological disorders can act in the formation mechanism of IUAs. Here we collected clinical laboratory indicators, the vaginal secretions and uterine secretions of 6 women with and 8 women without IUAs, with a history of curettage. Vaginal and uterine cavity microbes were detected by high-throughput sequencing technology. Compared with the women without IUAs, the proportion of Lactobacillus in vaginal microbes was decreased and the proportion of Bacteroides was increased in the IUAs. The α-diversity index in the vaginal microbiome was significantly positively correlated with the hematocrit and erythrocyte count (P ＜0.05). These clinical and microbiological indicators could be used to indicate the occurrence of IUAs, so this study has clinical guiding significance for detecting and preventing them.

Microbiome biomarker-based modeling has been widely used in classifying health states. However, many diseases do not have explicit biomarkers, or exhibit shortages in detection accuracy using specific species. Based on microbiome big data and cutting-edge computing engine, here we report the search-based strategy of health status detection for shotgun metagenomes. Comparing the species-level profiles against large-scale metagenomes, outlier samples are screened out as unhealthy, and their detailed disease types can be identified by top matches. Benchmarking on a multi-cohort dataset with over 3,000 metagenomes, the search-based approach achieved a promising overall accuracy that was superior to marker-based models constructed by random forest (RF), supporting vector machine (SVM) and extreme gradient boosting (XGBoost). More importantly, the search-based method also featured a balanced performance on different diseases. Hence, this case study further demonstrates the potential and capability of metagenome big data in human health, as well as moves one-step forward of search-based approach in microbiome research and application.

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.