Background With the establishment of the heart-gut axis concept, accumulating studies suggest that the gut microbiome plays an important role in the pathogenesis of cardiovascular diseases. Yet, little evidence has been reported in characterizing the gut microbiota shift in atrial fibrillation. Methods We include the result of the global alterations that occur in the intestinal microbiota in a cohort of 50 patients with atrial fibrillation and 50 matched controls based on a strategy of metagenomic and metabolomic analyses. Results The alterations include a dramatic elevation in microbial diversity and a specific perturbation of gut microbiota composition. Overgrowth of Ruminococcus , Streptococcus , and Enterococcus , as well as reduction of Faecalibacterium , Alistipes , Oscillibacter , and Bilophila were detected in patients with atrial fibrillation. A gut microbial function imbalance and correlated metabolic pattern changes were observed with atrial fibrillation in both fecal and serum samples. The differential gut microbiome signatures could be used to identify patients with atrial fibrillation. Conclusions Our findings characterize the disordered gut microbiota and microbial metabolite profiles in atrial fibrillation. Further research could determine whether intervention strategies targeting intestinal microbiome composition might be useful to counteract the progression of atrial fibrillation.

Background Accumulating studies have suggested that gut microbiota (GM) dysbiosis and vitamin D3 deficiency each play an important role during the progression of hypertension (HTN). However, few studies have characterized the underlying interaction between GM shift and vitamin D3 deficiency in HTN patients. Hypothesis This study aimed to evaluate the possible crosstalk between GM dysbiosis and vitamin D deficiency in the pathogenesis of HTN. Methods In a cohort of 34 HTN patients and 15 healthy controls, we analyzed the fecal microbiota products, GM composition, and the interaction between GM and vitamin D3. Results Vitamin D3 was significantly decreased in feces of HTN patients (P = .006, vs controls) and was correlated with altered GM, including decreased Shannon index (R2 = 0.1296, P = .0111) and Pielou evenness (R2 = 0.1509, P = .0058). Moreover, vitamin D3 positively correlated with HTN‐reduced bacterial genera, including Subdoligranulum (R2 = 0.181, P = .0023), Ruminiclostridium (R2 = 0.1217, P = .014), Intestinimonas (R2 = 0.2036, P = .0011), Pseudoflavonifractor (R2 = 0.1014, P = .0257), Paenibacillus (R2 = 0.089, P = .0373), and Marvinbryantia (R2 = 0.08173, P = .0464). Partial least squares structural equation modeling showed that 27.7% of the total effect of gut microbiome on HTN was mediated by limiting vitamin D production. Finally, receiver operating characteristic curve analysis revealed the predictive capacity of differential gut microbiome signatures and decreased vitamin D3 to distinguish HTN patients (AUC = 0.749, P = .006). Conclusions Our findings suggest that the GM dysbiosis contributing to the development of HTN might be partially mediated by vitamin D3 deficiency. Future studies involving the underlying mechanism and intervention strategies targeting microbiome composition and vitamin D3 to counteract the progression of HTN are warranted.

Alternations of gut microbiota (GM) in atrial fibrillation (AF) with elevated diversity, perturbed composition and function have been described previously. The current work aimed to assess the association of GM composition with AF recurrence (RAF) after ablation based on metagenomic sequencing and metabolomic analyses and to construct a GM‐based predictive model for RAF. Compared with non‐AF controls (50 individuals), GM composition and metabolomic profile were significantly altered between patients with recurrent AF (17 individuals) and non‐RAF group (23 individuals). Notably, discriminative taxa between the non‐RAF and RAF groups, including the families Nitrosomonadaceae and Lentisphaeraceae, the genera Marinitoga and Rufibacter and the species Faecalibacterium spCAG:82, Bacillus gobiensis and Desulfobacterales bacterium PC51MH44, were selected to construct a taxonomic scoring system based on LASSO analysis. After incorporating the clinical factors of RAF, taxonomic score retained a significant association with RAF incidence (HR = 2.647, P = .041). An elevated AUC (0.954) and positive NRI (1.5601) for predicting RAF compared with traditional clinical scoring (AUC = 0.6918) were obtained. The GM‐based taxonomic scoring system theoretically improves the model performance, and the nomogram and decision curve analysis validated the clinical value of the predicting model. These data provide novel possibility that incorporating the GM factor into future recurrent risk stratification.