Gut bacterial overgrowth linked to heart disease

Posted on Mon, 22 May 17

Bacterial overgrowth in the small intestine could contribute to the development of atherosclerosis, in part due to reduced vitamin K synthesis.  

A remarkable new study has found an association between small intestinal bacterial overgrowth (SIBO), reduced vitamin K synthesis, and subclinical atherosclerosis.

SIBO is defined as an abnormally high number and/ or type of bacteria in the small bowel and is a common cause of irritable bowel syndrome-like symptoms. Because healthy gut bacteria synthesise vitamin K, SIBO can negatively affect vitamin K production. And people with SIBO typically have lower vitamin K blood levels. 

Vitamin K plays crucial roles in maintaining the health of the vascular system, and low vitamin K2 status has been associated with vascular disease and increased risk of cardiovascular events.  

Based on these separate lines of evidence a research team decided to see if there is an association between SIBO, reduced vitamin K synthesis, and subclinical atherosclerosis, for the first time.

In people with SIBO they found higher concentrations of a protein (dephosphorylated-uncarboxylated matrix Gla-protein) that indicates low vitamin K2. Furthermore, arterial stiffness was elevated in the SIBO group and correlated with low vitamin K. 

Vitamin K2 intake from diet did not appear to contribute to subclinical atherosclerosis, suggesting that small intestinal dysbiosis and low bacterial vitamin synthesis were fundamental. 

Commenting on their findings the investigators concluded that “…screening for SIBO, intestinal decontamination and supplementation with vitamin K2 has the potential to be incorporated into clinical practice as additional preventive measures.”

Reference: 

Ponziani FR, Pompili M, Di Stasio E, et al. Subclinical atherosclerosis is linked to small intestinal bacterial overgrowth via vitamin K2-dependent mechanisms. World J Gastroenterol. 2017 Feb 21;23(7):1241-1249.