Gut bacteria linked to blood clot risk in COVID-19 patients

By Isobel Williams via SWNS

The driving factor behind the higher blood clot risk in COVID-19 patients is in the gut, according to a new study.

Researchers found that people with COVID have an increased risk of thrombosis — the formation of blood clots — due to a gut microbial metabolite called 2-methylbutyrylcarnitine (2MBC).

Thrombosis is the leading cause of death and disability related to major adverse cardiovascular events like heart attacks and stroke.

Numerous conditions such as COVID-19 and metabolic disorders can lead to a heightened thrombotic risk, yet the researchers note the underlying mechanisms remain poorly understood.

The team from Guangzhou Medical University, China, set out to bridge this knowledge gap with their study involving 64 people with COVID-19, 12 healthy patients, and 12 individuals hospitalized without COVID-19.

The results, published in the journal Cell Metabolism, showed that 2MBC is accumulated in patients with COVID-19 and in patients with major adverse cardiovascular events.

The elevated level of 2MBC did not decline even after complete clearance of the virus in patients with COVID-19.

2MBC belongs to a class of compounds known as short-branched chain acylcarnitines, which have been previously associated with numerous metabolic disorders including obesity, diabetes, non-alcoholic steatohepatitis, and hypertension.

Another test with mice found that 2MBC did cause the formation of blood clots, as it bonded to receptors in the platelets – a component of blood involved in the formation of blood clots -- which causes hyperresponsiveness.

The researchers believe that their findings may hint at a previously unknown driving factor for increased thrombotic potential in metabolic disorders, such as obesity and diabetes, above and beyond traditional risk factors.

Study co-author Dr. Sifan Chen, of Sun Yat-Sen University, China, said: “Our study provides mechanistic insight by implicating 2MBC as a metabolite that links gut microbiota dysbiosis to elevated thrombotic risk.

“Even though gut microbiota dysbiosis has been intensively described in patients with COVID-19 and metabolic disorders that are associated with heightened thrombotic risk, their causal link and the mechanisms contributing to thrombotic complications remain poorly understood."

Dr. Chen added: “Our findings revealed a new biological function of 2MBC as a signaling molecule and unveiled a potential mechanism contributing to the increased thrombotic incidence in COVID-19.”