Table_1_Microbiome alterations in women with gestational diabetes mellitus and their offspring: A systematic review.docx

AimsGestational diabetes mellitus (GDM) is a metabolic disorder that might predispose pregnant women to develop type 2 Diabetes Mellitus or lead to severe adverse outcomes in their offspring. One of the factors that have been thought to be involved in the pathology behind this disorder is the microbiome. In this systematic review, we comprehensively review the documents regarding the microbiota alterations in different tracts of pregnant women with GDM and their offspring.
MethodsA comprehensive search was conducted in major databases including MEDLINE (PubMed), Scopus, and Web of sciences up to August 2021. Data on the demographics, methodology, and microbiome alterations were extracted and classified according to the type of microbiome in pregnant women with GDM and their offspring. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS).
ResultsIn 49 articles which were retrieved, the findings were variable on the level of changes in alpha and beta diversity, enrichment or depletion in phyla, genera, species and OTUs, in each microbiome type. Although there were some inconsistencies among the results, a pattern of significant alterations was seen in the gut, oral, vaginal microbiome of women with GDM and gut, oral, and placental microbiome of their offspring.
ConclusionEven though the alteration of the microbiome of the different tracts was seen in the cases of GDM, the inconsistency among the studies prevents us from identifying unique pattern. However, the results seem promising and further studies that overcome the confounding factors related to the demographics and methodology are needed.

研究目的：妊娠期糖尿病（Gestational diabetes mellitus, GDM）是一种代谢紊乱性疾病，可使孕妇罹患2型糖尿病的风险升高，或对子代造成严重不良结局。既往研究认为，微生物组（microbiome）参与了该疾病的病理生理过程。本系统综述全面梳理了关于妊娠期糖尿病孕妇及其子代不同部位菌群失调的相关文献。
研究方法：本研究检索了截至2021年8月的MEDLINE（PubMed）、Scopus、Web of Science等主流数据库，开展了全面的文献检索工作。研究提取了纳入文献的人口统计学特征、研究方法及菌群变化相关数据，并按照妊娠期糖尿病孕妇及其子代的菌群类型进行分类整理。采用纽卡斯尔-渥太华量表（Newcastle-Ottawa Scale, NOS）对纳入研究的方法学质量进行评估。
研究结果：本次研究共纳入49篇检索到的相关文献，结果显示，不同菌群类型下，α多样性与β多样性的变化幅度、菌群门、属、种及操作分类单元（Operational Taxonomic Unit, OTU）的富集或缺失情况均存在差异。尽管各研究结果间存在一定不一致性，但可观察到妊娠期糖尿病孕妇的肠道、口腔、阴道菌群，以及其子代的肠道、口腔与胎盘菌群均存在显著失调的共性特征。
研究结论：尽管妊娠期糖尿病患者不同部位的菌群均存在失调现象，但各研究结果间的异质性使得目前无法明确具有特异性的统一菌群变化模式。不过现有研究结果已展现出一定前景，未来仍需开展能够控制人口统计学特征与研究方法相关混杂因素的高质量研究，以进一步明确相关机制。