DuPont Herbert L, Jiang Zhi-Dong, Alexander Ashley S, DuPont Andrew W, Brown Eric L
Center for Infectious Diseases, Division of Epidemiology, Human Genetics and Environmental Sciences, University of Texas School of Public Health, Houston, TX 77030, USA.
Department of Internal Medicine, University of Texas McGovern Medical School, Houston, TX 77030, USA.
Microorganisms. 2022 Dec 29;11(1):93. doi: 10.3390/microorganisms11010093.
IgA-coated bacteria in the gut (IgA-biome) provide a homeostatic function in healthy people through inhibition of microbial invaders and by protecting the epithelial monolayer of the gut. The laboratory methods used to detect this group of bacteria require flow cytometry and DNA sequencing (IgA-Seq). With dysbiosis (reduced diversity of the microbiome), the IgA-biome also is impaired. In the presence of enteric infection, oral vaccines, or an intestinal inflammatory disorder, the IgA-biome focuses on the pathogenic bacteria or foreign antigens, while in other chronic diseases associated with dysbiosis, the IgA-biome is reduced in capacity. Fecal microbiota transplantation (FMT), the use of fecal product from well-screened, healthy donors administered to patients with dysbiosis, has been successful in engrafting the intestine with healthy microbiota and metabolites leading to improve health. Through FMT, IgA-coated bacteria have been transferred to recipients retaining their immune coating. The IgA-biome should be evaluated in FMT studies as these mucosal-associated bacteria are more likely to be associated with successful transplantation than free luminal organisms. Studies of the microbiome pre- and post-FMT should employ metagenomic methods that identify bacteria at least at the species level to better identify organisms of interest while allowing comparisons of microbiota data between studies.
肠道中被IgA包被的细菌（IgA生物群落）通过抑制微生物入侵者和保护肠道上皮单层，在健康人群中发挥稳态功能。用于检测这类细菌的实验室方法需要流式细胞术和DNA测序（IgA-Seq）。随着微生物群落失调（微生物多样性降低），IgA生物群落也会受损。在肠道感染、口服疫苗或肠道炎症性疾病存在的情况下，IgA生物群落聚焦于病原菌或外来抗原，而在与微生物群落失调相关的其他慢性疾病中，IgA生物群落的功能会降低。粪便微生物群移植（FMT），即将经过充分筛选的健康供体的粪便产物给予微生物群落失调的患者，已成功地使健康的微生物群和代谢产物在肠道中定植，从而改善健康状况。通过FMT，被IgA包被的细菌已被转移到受体体内，并保留其免疫包被。在FMT研究中应评估IgA生物群落，因为这些与黏膜相关的细菌比游离的腔内微生物更有可能与移植成功相关。FMT前后的微生物群落研究应采用宏基因组方法，至少在物种水平上识别细菌，以便更好地识别感兴趣的生物体，同时允许在不同研究之间比较微生物群数据。
