关键词: 冠心病, 生物多样性, 计算生物学, 肠道菌群, 多位点测序分型

Abstract: Background　Coronary heart disease（CHD） is one of the most common causes of deaths in developed and developing countries．The composition of gut microbiota plays an important role in the pathological process of CHD．More and more evidences show that the imbalance of gut microbiota induce lipid metabolism disorder，low-grade inflammation，insulin resistance and elevated blood pressure，increasing the risk of CHD．Objective　To explore the risk factors for CHD by examining the characteristics（including composition and diversities） of gut microbiota in CHD patients，providing a new diagnostic and treatment method for such patients．Methods　This study was conducted in the First Affiliated Hospital of Xinxiang Medical University during July 2016 to June 2017 between 62 cases of CHD from CCU and Cardiovascular Department and 30 health examinees（control group）．CHD patients were divided into mild CHD group（n=27） and moderate-to-severe CHD group（n=35） by Gensini score．Fecal samples were collected，from which DNA was extracted and amplified by polymerase chain reaction in the bacterial 16S rDNA V3 region，and the final PCR amplification products were analyzed by bioinformatics．Results　Mild CHD group，moderate-to-severe CHD group and control group had no significant differences in PE_reads，Nochimera，AvgLen，GC and Effective（P>0.05）．ACE，Chao1，Shannon and Simpson differed significantly among mild and moderate-to-severe CHD groups and control group（P<0.05），and they were much lower in the former two compared with the latter one showed by pairwise comparisons（P<0.05）．The relative abundances of bacteroidetes and proteobacteria differed significantly among control group and mild and moderate-to-severe CHD groups（P<0.05），and the relative abundances of bacteroidetes in the former one were much higher than the latter one，the relative abundances of proteobacteria in the former one were much lower than the latter one （P<0.05）．The relative abundances of bacteroidia and fusobacteria varied significantly among control group and mild and moderate-to-severe CHD groups（P<0.05），and the relative abundances of bacteroidia were much lower in the moderate-to-severe CHD group compared with the mild CHD group，and the relative abundances of fusobacteria were much higher in the moderate-to-severe CHD group compared with the mild CHD group，and and the relative abundances of bacteroidia were much lower in mild CHD group compared with the control group，and the relative abundances of fusobacteria were much higher in mild CHD group compared with the control group（P<0.05）．Mild and moderate-to-severe CHD groups and control group showed significant differences in the relative abundance of bacteroides （P<0.05）．Moderate-to-severe CHD group had much lower relative abundance of bacteroides than the mild CHD group and control group，as did the mild CHD group compared with the control group（P<0.05）．Metastats analysis showed that significant differences were found between the control group and mild CHD group in terms of the relative abundances of bacteroides，Barnesiella，Desulfovibrio，Escherichia Shigella and Phascolarctobacterium（P<0.05），and between the control group and moderate-to-severe CHD group in terms of the relative abundances of Barnesiella，Dialister，Flavonifractor，Parasutterella and Phascolarctobacterium（P<0.05），and between the mild and moderate-to-severe CHD groups in terms of the relative abundances of Desulfovibrio，Dialister，Escherichia-Shigella，Flavonifractor，and Paraprevotella（P<0.05）．Conclusion　Changes in the diversity and structure of gut microbiota are risk factors for CHD．Therefore，regulation of gut microbiota and fecal microbiota transplantation may be used as the new treatments for CHD．

Key words: Coronary disease, Biodiversity, Computational biology, Intestinal flora, Multilocus sequence typing