Because of a loss-of-function mutation in the GGTA1 gene, humans are unable to synthetize α1,3-Galactose (Gal) decorated glycans and develop high levels of circulating anti-α1,3-Galactose antibodies (anti-Gal Abs). Anti-Gal Abs have been identified as a major obstacle of organ xenotransplantation and play a role in several host-pathogen relationships including potential susceptibility to infection. Anti-Gal Abs are supposed to stem from immunization against the gut microbiota, an assumption derived from the observation that some pathogens display α1,3-Gal and that antibiotic treatment decreases the level of anti-Gal. However, there is little information to date concerning the microorganisms producing α1,3-Gal in the human gut microbiome. Here, available α1,3-Galactosyltransferase (GT) gene sequences from gut bacteria were selectively quantified for the first time in the gut microbiome shotgun sequences of 163 adult individuals from three published population-based metagenomics analyses. We showed that most of the gut microbiome of adult individuals contained a small set of bacteria bearing α1,3-GT genes. These bacteria belong mainly to the Enterobacteriaceae family, including Escherichia coli, but also to Pasteurellaceae genera, Haemophilus influenza and Lactobacillus species. α1,3-Gal antigens and α1,3-GT activity were detected in healthy stools of individuals exhibiting α1,3-GT bacterial gene sequences in their shotgun data.

中文翻译：

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人类肠道微生物组中细菌α1,3-半乳糖基转移酶基因的分布。

由于GGTA1基因的功能丧失突变，人类无法合成α1,3-半乳糖（Gal）修饰的聚糖，无法产生高水平的循环抗α1,3-半乳糖抗体（anti-Gal Abs）。抗Gal抗体已被确定为器官异种移植的主要障碍，并在多种宿主与病原体的关系中发挥作用，包括潜在的感染易感性。抗-Gal Abs可能源自针对肠道菌群的免疫接种，这一假设源自以下观察结果：某些病原体显示α1,3-Gal，而抗生素治疗会降低抗-Gal的水平。但是，迄今为止，关于人类肠道微生物组中产生α1,3-Gal的微生物的信息很少。在这里，可用α1，在来自三个已发表的基于人群的宏基因组学分析的163名成年个体的肠道微生物组shot弹枪序列中，首次选择性地量化了来自肠道细菌的3-半乳糖基转移酶（GT）基因序列。我们显示，大多数成年个体的肠道微生物组都包含一小群带有α1,3-GT基因的细菌。这些细菌主要属于肠杆菌科，包括大肠杆菌，但也属于巴斯德杆菌属，流感嗜血杆菌和乳杆菌种。在散弹枪数据中显示α1,3-GT细菌基因序列的个体的健康粪便中检测到α1,3-Gal抗原和α1,3-GT活性。我们显示，大多数成年个体的肠道微生物组都包含一小群带有α1,3-GT基因的细菌。这些细菌主要属于肠杆菌科，包括大肠杆菌，但也属于巴斯德杆菌属，流感嗜血杆菌和乳杆菌种。在散弹枪数据中显示α1,3-GT细菌基因序列的个体的健康粪便中检测到α1,3-Gal抗原和α1,3-GT活性。我们显示，大多数成年个体的肠道微生物组都包含一小群带有α1,3-GT基因的细菌。这些细菌主要属于肠杆菌科，包括大肠杆菌，但也属于巴斯德杆菌属，流感嗜血杆菌和乳杆菌种。在散弹枪数据中显示α1,3-GT细菌基因序列的个体的健康粪便中检测到α1,3-Gal抗原和α1,3-GT活性。