Coronary heart disease (CHD) is closely related to gut microbiota, which may be significantly affected by ethnicity and the environment. Knowledge regarding the gut microbiome of Tibetan CHD patients living in the Qinghai–Tibet Plateau is very limited. In this study, we characterized the physiological parameters and gut microbiota from 23 healthy Tibetans (HT), 18 CHD patients, and 12 patients with non-stenosis coronary heart disease (NCHD). We analyzed the alterations of the gut microbiome in CHD patients and investigated the relationship between these alterations and the pathological indicators. We found no changes in trimethylamine N-oxide, however, a significant increase in lipopolysaccharides and white blood cells, and a decrease in high-density lipoprotein were observed in the blood of CHD patients, compared to that in the HT group. The gut microbiota of the NCHD group had a significantly higher Shannon index than that of the HT group. Adonis analysis showed that both microbial compositions and functions of the three groups were significantly separated. The Dialister genus was significantly lower and Blautia, Desulfovibrio, and Succinivibrio were significantly higher in abundance in CHD patients compared with the HT group, and the changes were significantly correlated with physiological indexes, such as increased lipopolysaccharides. Moreover, enrichment of genes decreased in four pathways of amino acid metabolism, such as arginine biosynthesis and histidine metabolism, although two lipid metabolism pathways, including fatty acid degradation and arachidonic acid metabolism, increased in the CHD group. Additionally, occupation and a family history of CHD were shown to be risk factors and affected the gut microbiota in Tibetans. Our study will provide insights into the understanding of CHD, leading to better diagnosis and treatment of Tibetan patients.

冠心病（CHD）与肠道菌群密切相关，肠道菌群可能受种族和环境的影响很大。关于生活在青藏高原的藏族冠心病患者肠道微生物组的知识非常有限。在这项研究中，我们表征了来自23名健康藏人（HT），18名CHD患者和12名非狭窄性冠心病（NCHD）患者的生理参数和肠道菌群。我们分析了冠心病患者肠道微生物组的变化，并研究了这些变化与病理指标之间的关系。我们发现三甲胺N-氧化物没有变化，但是与HT组相比，CHD患者的血液中脂多糖和白细胞显着增加，高密度脂蛋白减少。NCHD组的肠道菌群的香农指数显着高于HT组。Adonis分析表明，三组的微生物组成和功能均明显分离。的拨号器 属明显较低， 脱硫弧菌Blautia和 琥珀弧菌与HT组相比，CHD患者的丰度显着更高，并且变化与生理指标（如脂多糖增加）显着相关。此外，尽管在CHD组中，包括脂肪酸降解和花生四烯酸代谢在内的两个脂质代谢途径有所增加，但在氨基酸代谢的四个途径中，例如精氨酸的生物合成和组氨酸代谢，基因的富集程度有所降低。此外，业已显示冠心病的职业和家族病史是危险因素并影响藏族人的肠道菌群。我们的研究将提供对冠心病的了解，从而更好地诊断和治疗藏族患者。