Alterations in the gut mycobiome with coronary artery disease severity.

BACKGROUND: Coronary artery disease (CAD) is a prevalent cardiovascular condition, and numerous studies have linked gut bacterial imbalance to CAD. However, the relationship of gut fungi, another essential component of the intestinal microbiota, with CAD remains poorly understood. METHODS: In this cross-sectional study, we analyzed fecal samples from 132 participants, split into 31 healthy controls and 101 CAD patients, further categorized into stable CAD (38), unstable angina (41), and acute myocardial infarction (22) groups. We conducted internal transcribed spacer 1 (ITS1) and 16S sequencing to examine gut fungal and bacterial communities. FINDINGS: Based on ITS1 analyses, Ascomycota and Basidiomycota were the dominant fungal phyla in all the groups. The α diversity of gut mycobiome remained unaltered among the control group and CAD subgroups; however, the structure and composition of the mycobiota differed significantly with the progression of CAD. The abundances of 15 taxa gradually changed with the occurrence and progression of the disease and were significantly correlated with major CAD risk factor indicators. The mycobiome changes were closely linked to gut microbiome dysbiosis in patients with CAD. Furthermore, disease classifiers based on gut fungi effectively identified subgroups with different degrees of CAD. Finally, the FUNGuild analysis further categorized these fungi into distinct ecological guilds. INTERPRETATION: In conclusion, the structure and composition of the gut fungal community differed from healthy controls to various subtypes of CAD, revealing key fungi taxa alterations linked to the onset and progression of CAD. Our study highlights the potential role of gut fungi in CAD and may facilitate the development of novel biomarkers and therapeutic targets for CAD. FUNDING: This work was supported by the grants from the National Natural Science Foundation of China (No. 82170302, 92168117, 82370432), National clinical key specialty construction project- Cardiovascular Surgery, the Reform and Development Program of Beijing Institute of Respiratory Medicine (No. Ggyfz202417, Ggyfz202308), the Beijing Natural Science Foundation (No. 7222068); and the Clinical Research Incubation Program of Beijing Chaoyang Hospital Affiliated to Capital Medical University (No. CYFH202209).

Gut microbiota combined with metabolites reveals unique features of acute myocardial infarction patients different from stable coronary artery disease.

INTRODUCTION: Acute myocardial infarction (AMI) accounts for the majority of deaths caused by coronary artery disease (CAD). Early warning of AMI, especially for patients with stable coronary artery disease (sCAD), is urgently needed. Our previous study showed that alterations in the gut microbiota were correlated with CAD severity. OBJECTIVES: Herein, we tried to discover accurate and convenient biomarkers for AMI by combination of gut microbiota and fecal/blood/urinary metabolomics. METHODS: We recruited 190 volunteers including 93 sCAD patients, 49 AMI patients, and 48 subjects with normal coronary artery (NCA), and measured their blood biochemical parameters, 16S rRNA-based gut microbiota and NMR-based fecal/blood/urinary metabolites. We further selected 20 subjects from each group and analyzed their gut microbiota by whole-metagenome shotgun sequencing. RESULTS: Multi-omic analyses revealed that AMI patients exhibited specific changes in gut microbiota and serum/urinary/fecal metabolites as compared to subjects with sCAD or NCA. Fourteen bacterial genera and 30 metabolites (11 in feces, 10 in blood, 9 in urine) were closely related to AMI phenotypes and could accurately distinguish AMI patients from sCAD patients. Some species belonging to Alistipes, Streptococcus, Ruminococcus, Lactobacillus and Faecalibacterium were effective to distinguish AMI from sCAD and their predictive ability was confirmed in an independent cohort of CAD patients. We further selected nine indicators including 4 bacterial genera, 3 fecal and 2 urinary metabolites as a noninvasive biomarker set which can distinguish AMI from sCAD with an AUC of 0.932. CONCLUSION: Combination of gut microbiota and fecal/urinary metabolites provided a set of potential useful and noninvasive predictive biomarker for AMI from sCAD.

Presence of periodontal pathogenic bacteria in blood of patients with coronary artery disease.

It has been hypothesised that oral bacteria can migrate, through the blood, from the mouth to the arterial plaques, thus exacerbating atherosclerosis. This study compared bacteria present in the peripheral blood of individuals with and without coronary artery disease (CAD). RNA sequences obtained from blood were downloaded from GEO (GSE58150). Eight patients with coronary artery calcification (CAC) scoring > 500 and eight healthy individuals were analysed. After conducting quality control, the sequences were aligned to the hg38 reference genome using Hisat2. Bacterial taxa were analysed by inputting the unmapped sequences into Kraken. Ecological indices were calculated using Vegan. The package DESeq2 was used to compare the counts of bacteria per standard rank between groups. A total of 51 species were found only in patients with CAD and 41 were exclusively present in healthy individuals. The counts of one phylum, one class, three orders, two families and one genus were significantly different between the analysed groups (p < 0.00032, FDR < 10%), including the orders Cardiobacteriales, Corynebacteriales and Fusobacteriales. Twenty-three bacterial species belonging to the subgingival plaque bacterial complexes were also identified in the blood of individuals from both the groups; Fusobacterium nucleatum was significantly less frequent in patients with CAD (p = 0.0012, FDR = 4.8%). Furthermore, the frequency of another 11 bacteria differed significantly among patients with CAD than that among healthy individuals (p < 0.0030, FDR < 10%). These bacteria have not been previously reported in patients with atherosclerosis and periodontitis. The presence of members of the subgingival plaque bacterial complexes in the blood of patients with CAC supports the hypothesis that the periodontopathogens can be disseminated through the blood flow to other body parts where they may enhance inflammatory processes that can lead to the development or exacerbation of atherosclerosis.

Distinguishing feature of gut microbiota in Tibetan highland coronary artery disease patients and its link with diet.

The prevalence of coronary artery disease (CAD) in Tibetan Highlanders is lower than that in plain-living individuals, but the mechanism still unclear. Gut microbiota (GM) disorder is considered one of the potential factors involved in the pathogenesis of CAD, but the GM characteristics of Tibetan Highlanders suffering from CAD are unknown. We sequenced the V3-V4 region of the 16S ribosomal RNA of gut bacteria from fecal samples from Tibetan and Han CAD patients and healthy individuals inhabiting the Qinghai-Tibet Plateau, as well as from Han CAD patients and healthy individuals living at sea level, and we analyzed the GM characteristics of these subjects by bioinformatics analysis. The results showed that Tibetan Highlanders suffering from CAD had higher GM α-diversity, with differently distributed cluster compared with healthy Tibetan Highlanders and Han CAD patients living at high and low altitudes. Genera Catenibacterium, Clostridium_sensu_stricto, Holdemanella, and Ruminococcus 2 were enriched in Tibetan Highlanders suffering from CAD compared with healthy Tibetan Highlanders and Han CAD patients living at high- and low-altitudes. Prevotella was enriched in Tibetan Highlanders suffering from CAD compared with Han CAD patients living at high- and low-altitudes. Moreover, Catenibacterium was positively correlated with Prevotella. Additionally, Catenibacterium, Holdemanella, and Prevotella were positively correlated with fermented dairy product, carbohydrate and fiber intake by the subjects, while Clostridium_sensu_stricto was negatively correlated with protein intake by the subjects. In conclusion, our study indicated that Tibetan Highlanders suffering from CAD showed distinct GM, which was linked to their unique dietary characteristics and might associated with CAD.

Helicobacter pylori increases the risk of carotid plaque formation: a clinical evidence.

Background and aim: Since the relation between Helicobacter pylori (H. pylori) and atherosclerosis has been evidenced, we aimed to analyze whether there is a relationship between the patient's H. pylori infection and age, gender, BMI, blood lipids, and carotid plaque formation.Methods: 810 patients from January 2016 to December 2019 were enrolled in this study, and divided the subjects into H. pylori (+) group and H. pylori (-) group based on the results of UBT. To analyze whether H. pylori infection is related to gender, age, BMI, blood lipids, and neck vascular plaque formation.Results: The single-factor analysis showed that the BMI ≥ 25kg/m2, triglycerides >1.7 mmol/l, the formation of cervical plaques were significantly higher in patients infected with H. pylori in compared to normal cases. Also, multi-variant logistic regression analysis showed that H. pylori infection affects the BMI ≥ 25kg/m2 and triglycerides >1.7 mmol/l to induce vascular plaque. Also, we showed that patients with H. pylori infection are 1.424 times higher than the non-infected group to have triglycerides more elevated than 1.7mmol/l.Conclusion: In this study, we conclude that H. pylori infection is an independent risk factor for higher BMI (>25), triglyceride (>1.7 mmol/l), and neck vascular plaque formation. The multi-variant analysis showed that patients with H. pylori infection are prone to have higher BMI, triglycerides, and neck vascular plaque formation over 1.4-times higher in non-infected individuals.KEY MESSAGESH. pylori infection is an independent risk factor for higher BMI, triglyceride, and neck vascular plaque formation.H. pylori can accelerate vascular plaque formation through increasing BMI and triglyceride.

Microorganisms and cardiovascular diseases: importance of gut bacteria.

Cardiovascular diseases including myocardial infarctions, myocarditis, strokes, coronary artery disease, chronic granulomatous disease, atherosclerotic cardiovascular disease, etc. can be regarded as the severe health trouble round the globe. The reasons behind the heart related complications have been well chalked our so far. Interestingly, along with the non-infectious reasons, an array of bacteria, fungi, parasites and viruses is known to cause different types of heart complications. Unfortunately, the role of microorganisms in inducing heart diseases is not that much known by the mass community in the underdeveloped and even in the developing countries over the world. However, among the microorganisms causing heart diseases, the multifaceted bionetwork by the gut microorganisms especially drew the interests of microbiologists. The impairment of cardiac membrane, the metabolic malfunction of heart, and imbalance in the functionality of the immune cells by the alternation in the composition of gut microorganisms are currently not unknown. Present review outlined the onset of heart diseases caused by the gut microflora in a simple way which would be important in public health regard.

Gut microbiota dysbiosis in stable coronary artery disease combined with type 2 diabetes mellitus influences cardiovascular prognosis.

BACKGROUND AND AIMS: Host-microbiota interactions involving metabolic pathways have been linked to the pathogenesis of atherosclerotic disease and type 2 diabetes. As stable coronary artery disease (SCAD) patients combined with type 2 diabetes have significantly increased risk for cardiac event, we focused on elucidating the role of microbiota affecting cardiometabolic disease development. METHODS AND RESULTS: We used multi-omics analyses (metagenomics and metabolomics) of fecal and serum samples from a prospective cohort including stable coronary artery disease combined with diabetes mellitus (SCAD + T2DM, n = 38), SCAD (n = 71), and healthy control (HC, n = 55). We linked microbiome features to disease severity in a three-pronged association analysis and identified prognostic bacterial biomarkers. We identified that bacterial and metabolic signatures varied significantly between SCAD and SCAD + T2DM groups. SCAD + T2DM individuals were characterized by increased levels of aromatic amino acids and carbohydrates, which correlate with a gut microbiome with enriched biosynthetic potential. Our study also addressed how metformin may confound gut dysbiosis and increase the potential for nitrogen metabolism. In addition, we found that specific bacterial taxa Ruminococcus torques [HR: 2.363 (08-4.56), P = 0.03] was predictive of cardiac survival outcomes. CONCLUSION: Overall, our study identified relationships between features of the gut microbiota (GM) and circulating metabolites, providing a new direction for future studies aiming to understand the host-GM interplay in atherosclerotic cardiovascular pathogenesis.

Effect of coexistence of Chlamydia pneumoniae and increased epicardial fat thickness on coronary artery disease.

OBJECTIVE: Epicardial fat thickness (EFT) and chlamydia infection are independent cardiovascular risk factors in coronary artery disease (CAD). We aimed to evaluate the effect of coexistence of EFT and chlamydia infection on the presence and severity of CAD in patients with stable angina pectoris (SAP). PATIENTS AND METHODS: The study included 208 patients with SAP, divided into a CAD group (n=112) and a control group (n=96). The presence of Chlamydia pneumoniae-IgG (CP-IgG), EFT, and left ventricular ejection fraction (LVEF) were compared between groups. RESULTS: CP-IgG, LVEF, and EFT were found to be independent predictors of CAD (CP-IgG, OR=1.559, p=0.021; LVEF, OR=0.798, p<0.001; EFT, OR=3.175, p=0.026). Moreover, a statistically significant interaction was detected between CP-IgG and EFT for predicting the presence of CAD (p<0.001). A good positive correlation was found between EFT and Gensini score (r=0.684, p<0.001). CONCLUSIONS: We found that there was an interaction between CP-Ig and EFT for CAD development. This finding suggests that the interaction of CP-IgG and EFT plays a prominent role in the inflammatory process.

Investigation of gastric microbiota in patients with coronary atherosclerosis disease infected by Helicobacter pylori.

Gastric microbiota may be involved in the pathogenicity of Helicobacter pylori(Hp). In the present study, 30 male patients with coronary atherosclerosis disease (CAD) infected with Hp and 30 healthy male volunteers with Hp infection as the control group were detectedby macrogenomic sequencing for gastric microbiota. According to the diversity of gastric microbiota, the CAD group was further divided into two subgroups: CAD treatment (CAD-T) and CAD fellow-up (CAD-F). Shannon index of CAD-T was significantly lower than that of the control group and CAD-F (P<0.05), Simpson index was significantly higher than that of the control group and CAD-F (P<0.05), and there was no statistical difference between CAD-T and the control group and CAD-F patients in Chao1 and ACE index (P>0.05). There is a difference in the dominant flora between the CAD group and the control group. After Hp eradication, Shannon index of gastric microbiota increased, Simpson index decreased, and there was statistical difference before and after Hp eradication in CAD-T group (P<0.05). There was no significant difference in Chao1 and ACE index between before and after Hp eradication (P>0.05). There is a significant difference in the dominant flora before and after eradication in CAD-T group. There were significant differences in clinical manifestations, endoscopic manifestations and pathological results among the three groups (P<0.05). The diversity of gastric microbiota is closely related to the pathogenicity of Hp,, regardless of dominant flora.

Plasma levels of trimethylamine-N-oxide can be increased with 'healthy' and 'unhealthy' diets and do not correlate with the extent of atherosclerosis but with plaque instability.

AIMS: The microbiome-derived metabolite trimethylamine-N-oxide (TMAO) has attracted major interest and controversy both as a diagnostic biomarker and therapeutic target in atherothrombosis. METHODS AND RESULTS: Plasma TMAO increased in mice on 'unhealthy' high-choline diets and notably also on 'healthy' high-fibre diets. Interestingly, TMAO was found to be generated by direct oxidation in the gut in addition to oxidation by hepatic flavin-monooxygenases. Unexpectedly, two well-accepted mouse models of atherosclerosis, ApoE-/- and Ldlr-/- mice, which reflect the development of stable atherosclerosis, showed no association of TMAO with the extent of atherosclerosis. This finding was validated in the Framingham Heart Study showing no correlation between plasma TMAO and coronary artery calcium score or carotid intima-media thickness (IMT), as measures of atherosclerosis in human subjects. However, in the tandem-stenosis mouse model, which reflects plaque instability as typically seen in patients, TMAO levels correlated with several characteristics of plaque instability, such as markers of inflammation, platelet activation, and intraplaque haemorrhage. CONCLUSIONS: Dietary-induced changes in the microbiome, of both 'healthy' and 'unhealthy' diets, can cause an increase in the plasma level of TMAO. The gut itself is a site of significant oxidative production of TMAO. Most importantly, our findings reconcile contradictory data on TMAO. There was no direct association of plasma TMAO and the extent of atherosclerosis, both in mice and humans. However, using a mouse model of plaque instability we demonstrated an association of TMAO plasma levels with atherosclerotic plaque instability. The latter confirms TMAO as being a marker of cardiovascular risk.

Detection of periodontal microorganisms in coronary atheromatous plaque specimens of myocardial infarction patients: A systematic review and meta-analysis.

BACKGROUND: Microbial translocation from inflamed periodontal pockets into coronary atheroma via systemic circulation is one of the proposed pathways that links periodontitis and myocardial infarction (MI). The purpose of this systematic review is to determine the reported prevalence of periodontal microorganisms in coronary atheroma and/or aspirated clot samples collected from MI patients with periodontal disease. METHODOLOGY: The "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) guidelines were followed. Six databases were systematically searched using Medical Subject Headings/Index and Entree terms. After a thorough screening, fourteen publications spanning over ten years (2007-2017) were eligible for this systematic review and meta-analysis. RESULTS: Out of 14 included studies, 12 reported presence of periodontal bacterial DNA in coronary atherosclerotic plaque specimens. Overall, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were the most frequently detected periodontal bacterial species. Meta-analysis revealed that the prevalence of P. gingivalis was significantly higher than A. actinomycetemcomitans in coronary atheromatous plaque samples. Apart from periodontal microbes, DNA from a variety of other microbes e.g. Pseudomonas fluorescens, Streptococcus species, Chlamydia pneumoniae were also recovered from the collected samples. CONCLUSION: Consistent detection of periodontal bacterial DNA in coronary atheroma suggests their systemic dissemination from periodontal sites. It should further be investigated whether they are merely bystanders or induce any structural changes within coronary arterial walls.

The gut microbiota-related metabolite phenylacetylglutamine associates with increased risk of incident coronary artery disease.

OBJECTIVE: The gut microbiota is increasingly being implicated in cardiovascular health. Metabolites produced by bacteria have been suggested to be mediators in the bacterial action on cardiovascular health. We aimed to identify gut microbiota-related plasma metabolites and test whether these metabolites associate with future risk of coronary artery disease (CAD). METHODS: Nontargeted metabolomics was performed using liquid chromatography-mass spectrometry in order to measure 1446 metabolite features in the Malmö Offspring Study (MOS) (N = 776). The gut microbiota was characterized using 16S rRNA sequencing. Gut bacteria-related metabolites were measured in two independent prospective cohorts, the Malmö Diet and Cancer - Cardiovascular Cohort (MDC-CC) (N = 3361) and the Malmö Preventive Project (MPP) (N = 880), in order to investigate the associations between gut bacteria-related metabolites and risk of CAD. RESULTS: In MOS, 33 metabolite features were significantly (P < 4.8e-7) correlated with at least one operational taxonomic unit. Phenylacetylglutamine (PAG) was associated with an increased risk of future CAD, using inverse variance weighted meta-analysis of age and sex-adjusted logistic regression models in MDC-CC and MPP. PAG remained significantly associated with CAD (OR = 1.17, 95% CI = 1.06-1.29, P = 1.9e-3) after adjustments for cardiovascular risk factors. CONCLUSION: The levels of 33 plasma metabolites were correlated with the gut microbiota. Out of these, PAG was associated with an increased risk of future CAD independently of other cardiovascular risk factors. Our results highlight a link between the gut microbiota and CAD risk and should encourage further studies testing if modification of PAG levels inhibits development of CAD.

Gut microbiota in coronary artery disease: a friend or foe?

There is a growing interest in the role of gut microbiota in the pathophysiology of several diseases, including coronary artery diseases (CAD). Gut microorganisms may produce beneficial effects in myocardial ischemia either directly in the form of exogenous administration or indirectly by acting on fiber-rich food to produce important cardioprotective components. The harmful effects of gut microbiota in CAD are due to alteration in their composition with a significant decrease in Bacteroidetes and an increase in Firmicutes, Escherichia, Shigella, and Enterococcus. The altered microbiota may produce potentially toxic metabolites, including trimethylamine-N-oxide (TMAO). Indeed, the fasting plasma levels of TMAO are directly correlated to increased risk of major cardiovascular events in CAD patients, and it is proposed as a potential biomarker to predict the onset of major cardiovascular events. It is concluded that the change in the composition of gut microbiota in CAD patients may predispose to more harmful effects. However, exogenous delivery of probiotics may overcome the detrimental effects of myocardial ischemia.

Gut microbiota and cardiovascular disease: opportunities and challenges.

Coronary artery disease (CAD) is the most common health problem worldwide and remains the leading cause of morbidity and mortality. Over the past decade, it has become clear that the inhabitants of our gut, the gut microbiota, play a vital role in human metabolism, immunity, and reactions to diseases, including CAD. Although correlations have been shown between CAD and the gut microbiota, demonstration of potential causal relationships is much more complex and challenging. In this review, we will discuss the potential direct and indirect causal roots between gut microbiota and CAD development via microbial metabolites and interaction with the immune system. Uncovering the causal relationship of gut microbiota and CAD development can lead to novel microbiome-based preventative and therapeutic interventions. However, an interdisciplinary approach is required to shed light on gut bacterial-mediated mechanisms (e.g., using advanced nanomedicine technologies and incorporation of demographic factors such as age, sex, and ethnicity) to enable efficacious and high-precision preventative and therapeutic strategies for CAD.

Coronary artery disease is associated with an altered gut microbiome composition.

Alteration of gut microbiome composition has been linked to cardiovascular diseases. To identify specific bacterial communities associated with coronary artery diseases (CAD), we conducted a case-control study with 53 advanced CAD patients and 53 age-, sex-, race-, and BMI-matched controls. V3-V5 regions of the 16S rDNA from the fecal gut material were analyzed to compare the gut microbiome composition between CAD patients and controls. The alpha diversity, including Chao-1, Shannon-index, and the number of observed taxonomy units were significantly decreased in CAD patients indicating, decreased richness and evenness of gut microbiome. Among 23 different abundant taxa at the genus level, 12 taxa belonged to Lachnospiraceae family, which are known to produce butyrate. Further, we identified five taxa which showed more than two log-fold changes with maximum proportion >0.002, including Ruminococcus gnavus, Lachnospiraceae anaerosporobacter, Lachnospiraceae NK4B4 group, Lachnospiraceae UCG-004, and Ruminococcus gauvreauii. After adjustment for coronary risk factors (diabetes mellitus and dyslipidemia), decreased relative abundance of Lachnospiraceae NK4B4 group and Ruminococcus Gauvreauii and increased relative abundance of Ruminococcus gnavus were associated with the presence of advanced CAD. The observed differences in taxa between CAD patients and controls in this study may provide insight into the link between the gut microbiome and CAD.

Proteus mirabilis Targets Atherosclerosis Plaques in Human Coronary Arteries via DC-SIGN (CD209).

Bacterial DNAs are constantly detected in atherosclerotic plaques (APs), suggesting that a combination of chronic infection and inflammation may have roles in AP formation. A series of studies suggested that certain Gram-negative bacteria were able to interact with dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin [DC-SIGN; cluster of differentiation (CD) 209] or langerin (CD207), thereby resulting in deposition of CD209s at infection sites. We wondered if Proteus mirabilis (a member of Proteobacteria family) could interact with APs through CD209/CD207. In this study, we first demonstrated that CD209/CD207 were also receptors for P. mirabilis that mediated adherence and phagocytosis by macrophages. P. mirabilis interacted with fresh and CD209s/CD207-expressing APs cut from human coronary arteries, rather than in healthy and smooth arteries. These interactions were inhibited by addition of a ligand-mimic oligosaccharide and the coverage of the ligand, as well as by anti-CD209 antibody. Finally, the hearts from an atherosclerotic mouse model contained higher numbers of P. mirabilis than that of control mice during infection-challenging. We therefore concluded that the P. mirabilis interacts with APs in human coronary arteries via CD209s/CD207. It may be possible to slow down the progress of atherosclerosis by blocking the interactions between CD209s/CD207 and certain atherosclerosis-involved bacteria with ligand-mimic oligosaccharides.

[Impact of L-carnitine and phosphatidylcholine containing products on the proatherogenic metabolite TMAO production and gut microbiome changes in patients with coronary artery disease].

The aim of the study was to assess the impact of L-carnitine and phosphatidylcholine containing products on the production of the proatherogenic metabolite TMAO and gut microbiome changes in patients with coronary artery disease (CAD). Material and methods. The study consisted of 2 parts. In the first part, a comparison was made between the diet of patients with CAD (n=29) and healthy volunteers (n=30) over the age of 50 with respect to the frequency of intake of L-carnitine and phosphatidylcholine containing products. All participants underwent blood sampling and stool tests to assess the concentration of TMAO and the composition of fecal microflora. The second part of the study was dedicated to assessing the correlation between TMAO blood concentration in patients with CAD (n=89) and the frequency of intake of L-carnitine and phosphatidylcholine containing products. Results and discussion. Patients with CAD comparing to healthy people among the predecessor products of TMAO consumed red meat, dairy products more often, eggs and fish less often. TMAO concentration in patients with CAD was higher than in healthy volunteers (1036.4±748.2 vs 376.5±147.9 ng/ml, p=0.0001). Analysis of fecal microflora in patients with CAD revealed an increase number of bacteria from Verrucomicrobiaceae family (p<0.05) and Enterobacteriaceae family (p<0.05), of the Escherichia/Shigella genera (p<0.05), there was a trend to increased number of Ruminococcus (р=0.065), Clostridium XlV (b) genera (р=0.10). Correlation between TMAO concentration and frequency of red meat, eggs, and dairy products consumption was estimated in patients with CAD (r>0.525, р<0.05). Conclusion. Patients with CAD consume more precursors of TMAO, have higher blood TMAO concentrations compared to healthy volunteers. Fecal microflora of patients with CAD contains a greater number of gut bacteria related to trimethylamine producers compared to healthy volunteers. Reducing the number of L-carnitine and phosphatidylcholine containing products in the diet of patients with CAD may affect the decrease in the proatherogenic metabolite TMAO concentration.

Age-dependent association of gut bacteria with coronary atherosclerosis: Tampere Sudden Death Study.

BACKGROUND: The gut microbiome is thought to remain stable into old age. Gut bacteria and their translocation may play a role in the development of coronary heart disease (CHD) by modulating cholesterol levels and immune responses, as well as by producing toxic metabolites and bacterial endotoxins. The association of changes in the gut microbiome with the severity of coronary atherosclerosis and the ability of gut bacteria themselves to translocate into coronary plaques has not been studied. MATERIALS AND METHODS: As a part of the Tampere Sudden Death Study, we measured age-dependent changes in the relative ratios of major intestinal bacterial communities (Bacteroides species [spp.], the Clostridium leptum group, the Clostridium coccoides group, Bifidobacterium spp., Enterobactericeae, Lactobacillus spp.) and Streptococcus spp. in both feces and coronary plaques of the same male autopsy cases (n = 67, age range 44-95) using real-time quantitative PCR (qPCR). The area of coronary atherosclerotic lesions were measured by computer-assisted morphometry. Fecal bacterial DNA measurements from healthy volunteers served as a control for gut bacterial analyses of autopsy cases. The relative amount of bacterial DNA in a sample was determined with the comparative Cq method. RESULTS: The relative ratios of fecal Lactobacillus spp., Bifidobacterium spp., the Clostridium coccoides group, and Bacteroides spp. did not differ between controls and autopsy cases and showed no age-dependence. In contrast, the ratios of the Clostridium leptum group, Enterobactericeae, and Streptococcus spp. increased with age. Elevated relative ratios of fecal Enterobactericeae associated with a larger coronary plaque fibrotic area (p = 0.001), and the Clostridium leptum group with a larger calcification area (p = 0.015). Intestinal bacterial DNA could be amplified in 67.6% of the coronary plaques, the most common being Streptococcus spp. (41.0%), followed by Enterobactericeae (12.1%), Clostridium leptum (2.4%), and Lactobacillus spp. (2.4%). The percentages of Streptococcus spp. DNA decreased, and those of Enterobactericeae increased in coronary plaques along with age. CONCLUSIONS: DNA of the Clostridium leptum group and pathogenic Enterobactericeae increase in the gut microbiome with age and can be detected in the same individual's coronary plaques along with pathogenic Streptococcus spp., associating with more severe coronary atherosclerosis.

Alterations in the gut microbiome and metabolism with coronary artery disease severity.

BACKGROUND: Coronary artery disease (CAD) is associated with gut microbiota alterations in different populations. Gut microbe-derived metabolites have been proposed as markers of major adverse cardiac events. However, the relationship between the gut microbiome and the different stages of CAD pathophysiology remains to be established by a systematic study. RESULTS: Based on multi-omic analyses (sequencing of the V3-V4 regions of the 16S rRNA gene and metabolomics) of 161 CAD patients and 40 healthy controls, we found that the composition of both the gut microbiota and metabolites changed significantly with CAD severity. We identified 29 metabolite modules that were separately classified as being positively or negatively correlated with CAD phenotypes, and the bacterial co-abundance group (CAG) with characteristic changes at different stages of CAD was represented by Roseburia, Klebsiella, Clostridium IV and Ruminococcaceae. The result revealed that certain bacteria might affect atherosclerosis by modulating the metabolic pathways of the host, such as taurine, sphingolipid and ceramide, and benzene metabolism. Moreover, a disease classifier based on differential levels of microbes and metabolites was constructed to discriminate cases from controls and was even able to distinguish stable coronary artery disease from acute coronary syndrome accurately. CONCLUSION: Overall, the composition and functions of the gut microbial community differed from healthy controls to diverse coronary artery disease subtypes. Our study identified the relationships between the features of the gut microbiota and circulating metabolites, providing a new direction for future studies aiming to understand the host-gut microbiota interplay in atherosclerotic pathogenesis.

Effect of Resistant Starch on the Gut Microbiota and Its Metabolites in Patients with Coronary Artery Disease.

AIM: Bacteroides vulgatus and B. dorei have a protective effect against atherosclerosis, suggesting that expansion of these species in the gut microbiota could help patients with coronary artery disease (CAD). This study aimed to investigate the effect of resistant starch (RS) on the gut microbiota and its metabolites in fecal sample cultures from patients with CAD and individuals without CAD, using a single-batch fermentation system. METHODS: Fecal samples from 11 patients with CAD and 10 individuals without CAD were fermented for 30 h with or without RS in the Kobe University Human Intestinal Microbiota Model (KUHIMM). Gut microbiota and the abundance of B. vulgatus and B. dorei were analyzed using 16S ribosomal ribonucleic acid (rRNA) gene sequencing and the quantitative polymerase chain reaction. Short-chain fatty acids were analyzed using high-performance liquid chromatography. RESULTS: Gut microbial analysis showed significantly lower levels of B. vulgatus and B. dorei in the original fecal samples from patients with CAD, which was simulated after 30 h of fermentation in the KUHIMM. Although RS significantly increased the absolute numbers of B. vulgatus and B. dorei, and butyrate levels in CAD fecal sample cultures, the numbers varied among each patient. CONCLUSIONS: The effect of RS on gut microbiota and its metabolites in the KUHIMM varied between CAD and non-CAD fecal sample cultures. The KUHIMM may be useful for preclinical evaluations of the effects of RS on the gut microbiota and its metabolites.