Preliminary Study to Understand the Role of Gut Microbiota in Coronary Slow Flow Phenomenon (CSFP)

Abstract

Background/Objectives: Coronary slow flow phenomenon (CSFP) is a cardiovascular condition characterized by delayed passage of contrast medium through the coronary arteries, predominantly affecting young male smokers admitted with acute coronary syndrome. Although over 80% of patients experience recurrent chest pain and more than 20% require readmission, the etiology of CSFP remains poorly understood. Given the emerging role of gut microbiome in cardiovascular diseases, this study investigates the microbial composition associated with CSFP. Methods: Stool samples were collected from patients diagnosed with CSFP and healthy control individuals. Microbiota profiling was performed using 16S rRNA sequencing. Taxonomic differences were evaluated to identify microbial markers potentially associated with CSFP. Results: The analysis revealed a notable enrichment of the genus Gemmiger and the species Anaerobutyricum in CSFP patients, specifically within the selenium metabolism pathway. This is of particular interest given the established link between selenium deficiency and heightened cardiovascular risk, suggesting a possible microbiome-mediated modulation of selenium bioavailability in CSFP pathophysiology. Moreover, a marked increase in taxa associated with the biosynthesis of trimethylamine (TMA), a proatherogenic metabolite implicated in the onset and progression of various cardiovascular disorders, was observed in the CSFP cohort, further supporting a potential mechanistic role of gut microbiota in the disease's underlying etiology. Conclusions: Although statistical significance could not be established due to the limited sample size, the observed trends support the hypothesis that specific gut microbes and metabolic pathways, particularly those linked to selenium metabolism and TMA production, may serve as potential microbial indicators for CSFP. These preliminary findings warrant further investigation in larger cohorts.

Keywords: coronary health; coronary slow flow phenomenon; microbiome.

Figure 1

The total relative abundance of each phylum provides a comprehensive overview of the overall distribution within the dataset.

Figure 2

(A) The stacked bar plot indicates the relative abundance of phyla in the control and patient groups. “Control-AVE” refers to the average of the whole control group phylum, and “Disease-AVE” indicates the average of the whole disease group phylum. (Those that have a relative abundance value less than 1% were classified as others). (B) PCA results present the clustered healthy individuals (Control) and CSFP patient groups (Disease) as well as OTUs that provide the discrimination of both groups in a visual format. The green colors show healthy samples, and the red ones demonstrate the patient.

Figure 3

Boxplots illustrate the relative abundances in the phyla Bacillota and Bacteroidota, with the green plots representing healthy individuals in the control group (Con) and the orange plots depicting patients diagnosed with CSFP disease (Dis) (p > 0.05).

Figure 4

(A) The Venn diagram depicts the distribution of OTUs across the genus level and species level. The green section represents control samples, while the red section corresponds to patient samples. (B) This visualization illustrates the percentile of both group-specific OTUs and those shared between the groups, providing a detailed overview of the dataset’s composition at the species level.

Figure 5

Violin plots illustrate the relative abundance of bacterial species directly involved in TMA production for comparison of control and patient groups, with no statistically significant differences observed (p > 0.05).

Figure 6

The violin plot illustrates population variations in TMA-producing bacteria between control and patient samples at the genus level, with no statistically significant difference (p > 0.05).