Objective: Many clinical and preclinical studies have implicated an association between atrial fibrillation (AF) and its progression to imbalances in the gut microbiome composition. The gut microbiome is a diverse and complex ecosystem containing billions of microorganisms that produce biologically active metabolites influencing the host disease development.Methods: For this review, a literature search was conducted using digital databases to systematically identify the studies reporting the association of gut microbiota with AF progression.Results: In a total of 14 studies, 2479 patients were recruited for the final analysis.More than half (n = 8) of the studies reported alterations in alpha diversity in atrial fibrillation. As for the beta diversity, 10 studies showed significant alterations. Almost all studies that assessed gut microbiota alterations reported major taxa associated with atrial fibrillation. Most studies focused on short-chain fatty acids (SCFAs), whereas three studies evaluated TMAO levels in the blood, which is the breakdown product of dietary l-carnitine, choline, and lecithin. Moreover, an independent cohort study assessed the relationship between phenylacetylglutamine (PAGIn) and AF. Conclusion:Intestinal dysbiosis is a modifiable risk factor that might provide newer treatment strategies for AF prevention. Well-designed research and prospective randomized interventional studies are required to target the gut dysbiotic mechanisms and determine the gut dysbiotic-AF relationship.

OBJECTIVE. We sought to evaluate any association of periodontitis in patients with angina despite non-obstructive coronary artery disease (CAD). METHODS. Electronic records of all patients (n=103,955) labeled as ACS were screened and the patients diagnosed with myocardial infarction with non-obstructive coronary arteries (MINOCA) were enrolled as group 1 and age-matched controls with no CAD were labeled as group 2. RESULTS. Female gender (OR (95%CI): 1.04 (0.93 – 1.59); p=0.004), diabetes mellitus (OR (95%CI): 0.25 (0.05– 0.63); p=0.02), peripheral arterial disease (OR (95%CI): 0.78 (0.63 – 0.91); p=0.001), dyslipidemia (OR (95%CI): 1.45 (0.47 – 2.93); p=0.015), smoking, moderate (OR (95%CI): 5.42 (1.91 – 22.69); p=0.04) and severe periodontitis (OR (95%CI): 2.58 (1.72 – 3.26); p=0.027) were independent predictors of MINOCA. There was an increased graded risk (relative risk (RR)) of MINOCA with periodontitis + diabetes mellitus (RR (95%CI): 0.91 (0.34 – 1.23); p=0.032), periodontitis + peripheral arterial disease (RR (95%CI): 0.85 (0.47 – 1.46); p=0.025), periodontitis + renal disease (RR (95%CI): 1.04 (0.85 – 1.23); p=0.04), and periodontitis + smoking (RR (95%CI): 0.94 (0.77 – 1.06); p=0.006). CONCLUSION. This study demonstrated that moderate to severe periodontitis might be independently associated with the increased incidence of MINOCA among the general population. Furthermore, it discovered various predictors of MINOCA among the general population.