Red wine is often brought up as one of those foods that, counter-intuitively, might actually be good for you. Usually, the claims are anecdotal at best. But now researchers have discovered that a compound found in red wine actually does reduce the risk of heart disease.

Cardiovascular disease remains the leading cause of death in industrialized societies including the United States, and the incidence is growing in developing countries. In recent years, researchers have learned that the gut microbiome plays a role in the build up of plaque inside arteries, otherwise known as atherosclerosis. The gut microbiota is a complex community of microorganisms that live in the digestive tract. While roughly two-thirds of the gut microbiome is unique to each person, other gut bacteria evolve over the course of a person's life.

Resveratrol, a polyphenol found in red wine, is thought to have antioxidant properties that protect against conditions such as heart disease. However, just how resveratrol, a plant compound, does this is unclear. In a new study, researchers from China conducted experiments in mice to determine whether the protective effect of resveratrol against atherosclerosis was related to changes in the gut microbiome. They found that resveratrol reduces levels of trimethylamine-N-oxide (TMAO), a known contributor to the development of atherosclerosis. They also found that resveratrol inhibits TMA production by the gut bacteria; TMA is necessary for the production of TMAO.

"In our current study, we found that resveratrol can remodel the gut microbiota including increasing the Bacteroidetes-to-Firmicutes ratios, significantly inhibiting the growth of Prevotella, and increasing the relative abundance of Bacteroides, Lactobacillus, Bifidobacterium, and Akkermansia in mice," said Man-tian Mi, PhD, a researcher at the Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China. “Resveratrol reduces TMAO levels by inhibiting the gut microbial TMA formation via remodeling gut microbiota." The study was published in a recent issue of mBio, an open-access journal published by the American Society for Microbiology.

The researchers say the new findings offer new insight into the mechanisms responsible for resveratrol’s anti-atherosclerosis effects and suggest that gut microbiota may be an interesting target for pharmacological or dietary interventions to decrease the risk of developing cardiovascular diseases. "It is good news for patients with cardiovascular disease that resveratrol, a natural polyphenol without any side effects, might function as a prebiotic and could be widely used as an effective agent clinically in the near future," said Dr. Mi. The researchers foresee a future where after examining the gut microbiota of a patient with cardiovascular disease, clinicians will be able to prescribe a probiotic or a prebiotic to remodel the gut microbiota to protect the heart.

The researchers next steps are to further define the role of resveratrol in cardiovascular disease and replicate their findings in humans. They will work toward providing data about the effect of resveratrol on the abundance of functional genes related to TMA formation and clarify the core microbiota regulated by resveratrol.