Acute coronary syndrome (ACS): is the gut microbiota at the heart of the matter?

Progress in terms of prevention, diagnosis and treatment has had little actual effect: coronary artery disease remains one of the world’s leading causes of morbidity and mortality. The disease involves a complex physiological process with multiple interacting risk factors. Of these many factors, several circulating metabolites derived from the gut microbiota are now known to be linked to cardiovascular disease. Hence this study of the multifactorial nature of coronary artery disease, specifically investigating the gut microbiota and serum metabolites in 199 Israeli patients with acute coronary syndrome (ACS).

When an absence of metabolites signals the disease

The microbial signatures (around twenty depleted or enriched bacteria) and metabolomic signatures (hundreds of disrupted metabolites) were different in the ACS patients compared to the 970 controls. Some forms of intestinal dysbiosis had already been reported, such as a relative depletion in butyrate-producing bacteria (sidenote: butyrate-producing bacteria Clostridium, Anaerostipes hadrus, Streptococcus thermophilus, and Blautia ) , and an abundance of Odoribacter splanchnicus and Escherichia coli. But the researchers also found a lower quantity of a previously unknown bacterial species of the Clostridiaceae family: SGB 4712. This depletion was also found in a geographically distinct cohort (MetaCardis, Northern Europe), confirming the robustness of their observation. The presence of SGB 4712 is therefore negatively associated with cardiotoxic metabolites and positively linked to other protective ones. This suggests that SGB 4712 could play a protective role in the development of coronary artery disease, via a range of circulating blood metabolites. Or possible new therapeutic targets.

The protective role of the microbiota in coronary artery disease

Second finding: the metabolic signatures of the ACS patients were specific to each patient.

• Among these patients, the depletion of certain bacteria was primarily linked to the microbiome and diet, suggesting their early involvement in coronary artery disease via a deficiency of protective metabolites (metabolic syndrome).
• This is opposed to traditional risk factors (sidenote: Traditional cardiovascular disease risk factors age, sex, anthropometric data, blood pressure, smoking, and diabetes. ) and genetics, which come into play at a later stage in ACS and cardiovascular accidents.

According to the authors, the microbiota could play a protective role in coronary disease, resulting in a different disease experience for patients with similar clinical profiles.