The gut microbiota has been presumed to have a role in the pathogenesis of type 1 diabetes (T1D). Significant changes in the microbial composition of T1D patients have been reported in several case-control studies. This study is aimed at systematically reviewing the existing literature, which has investigated the alterations of the intestinal microbiome in T1D patients compared with healthy controls (HCs) using 16S ribosomal RNA-targeted sequencing. The databases of MEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched until April 2019 for case-control studies comparing the composition of the intestinal microbiome in T1D patients and HCs based on 16S rRNA gene sequencing techniques. The Newcastle-Ottawa Scale was used to assess the methodological quality. Ten articles involving 260 patients with T1D and 276 HCs were included in this systematic review. The quality scores of all included studies were 6–8 points. In summary, a decreased microbiota diversity and a significantly distinct pattern of clustering with regard to β-diversity were observed in T1D patients when compared with HCs. At the phylum level, T1D was characterised by a reduced ratio of Firmicutes/Bacteroidetes in the structure of the gut community, although no consistent conclusion was reached. At the genus or species level, T1D patients had a reduced abundance of Clostridium and Prevotella compared with HCs, whereas Bacteroides and Ruminococcus were found to be more enriched in T1D patients. This systematic review identified that there is a close association between the gut microbiota and development of T1D. Moreover, gut dysbiosis might be involved in the pathogenesis of T1D, although the causative role of gut microbiota remains to be established. Further well-controlled prospective studies are needed to better understand the role of the intestinal microbiome in the pathogenesis of T1D, which may help explore novel microbiota-based strategies to prevent and treat T1D.

中文翻译：

---

基于16S rRNA基因测序的1型糖尿病患者肠道菌群谱：系统评价。

肠道菌群被认为在1型糖尿病（T1D）的发病机理中起作用。在一些病例对照研究中，已经报告了T1D患者的微生物组成发生了重大变化。这项研究旨在系统地审查现有文献，该文献使用16S核糖体RNA靶向测序研究了T1D患者与健康对照（HCs）相比肠道微生物组的变化。一直搜索到MEDLINE，EMBASE，Web of Science和Cochrane图书馆的数据库，直到2019年4月，以进行病例对照研究，比较基于16S rRNA基因测序技术的T1D患者和HCs肠道微生物组的组成。纽卡斯尔-渥太华量表用于评估方法学质量。该系统评价包括10篇涉及260例T1D和276 HC患者的文章。所有纳入研究的质量得分均为6–8分。总之，就以下方面而言，微生物群落多样性下降和明显不同的集群模式与HCs相比，在T1D患者中观察到了β-多样性。在门上，T1D的特征是肠道群落结构中的纤毛虫/拟杆菌的比例降低，尽管没有得出一致的结论。在属或种水平上，与HCs相比，T1D患者的梭状芽胞杆菌和普氏杆菌的丰度降低，而拟杆菌属和Ruminococcus被发现在T1D患者中更为丰富。这项系统评价确定了肠道菌群与T1D的发展之间存在密切的联系。此外，肠道营养不良可能与T1D的发病机制有关，尽管肠道微生物群的致病作用尚待确定。为了更好地了解肠道微生物组在T1D发病机理中的作用，还需要进行更好地控制的前瞻性研究，这可能有助于探索基于微生物群的新型策略来预防和治疗T1D。