Latest scientific news 30 March 2023

Another piece in the puzzle – gut microbiota can benefit from red wine

Recent studies suggest that the gut microbiota may play a role in the health benefits associated with moderate red wine consumption. The polyphenols in wine, including phenolic flavonoids and anthocyans, such as hydroxycinnamic acids, phenolic alcohols, and stilbenes as well as other beneficial compounds, interact with the microbiota in the gut.

Despite being poorly absorbed in the intestine, these compounds are found in other plant foods and have potential health benefits. Understanding the mechanisms behind these interactions could help shed light on the benefits of moderate red wine consumption.

It is well known that moderate wine consumption is associated with a lower coronary heart disease rate and a lower death/mortality rate. But why is that? When it comes to wine, the polyphenols are in the focus of research. So far, it couldn’t really be explained how the mechanism works. Newer studies indicate that the polyphenols and the microbiota interact.

Microbiota as the key element

The microbiota is a wide variety of microorganisms that live in a certain environment. The total of all bacteria, viruses and other single-celled organisms that live on and in the human body is called “human” microbiota. Those organisms living in the intestine are called the gut microbiota. The composition, variety and function of such microbiota influences the health, the body weight, the mood and the risk for many diseases. In addition, this microbiota can be altered by the individual lifestyle, diet and the beverages consumed.

Since poorly absorbed polyphenols are considered to be responsible for protective effects of moderate wine consumption on the cardiovascular system, Brazilian researchers examined whether these ingredients in wine can influence/modulate the gut mircobiota.

They recruited 42 middle-aged men with well-established coronary artery disease. During 2 randomized, controlled interventions, where the participants consumed 250 ml of red wine on 5 days a week for 3 weeks (It was a Merlot with known alcohol and polyphenol content: 12.75 vol% and approx.. 2 g/l of polyphenols).Then, during the second intervention, the patients abstained from alcoholic beverages for three weeks. All patients participated in both interventions. Each intervention was preceded by a 2- week washout period, without consumption of any alcoholic beverages

Changes of gut microbiota after red wine consumption

During five visits to the clinic, the patients were questioned about their eating habits and blood samples were taken. They received instructions on how keep their eating habits constant during the trial period and how to take stool samples to analyse the microbiota. Because of modern computer-assisted analyses of the gene sequences of the gut microbiota, a better characterisation and distinction between the numerous types of bacteria is possible. With the help of this technique (16S rRNA sequencing), a distinct change in the gut microbiota was shown, depending on whether they consumed wine or they were abstinent.

Based on the known metabolic properties of the gut bacteria, which increased after red wine consumption, the researchers assume that the observed changes in the gut microbiota could have a beneficial effect. The blood analyses confirmed these observations. Some blood parameters with positive effects on the metabolism were increased after red wine consumption. Whether these shifts in blood parameters were actually caused by the observed changes of the gut microbiota, when the red wine was consumed, cannot be proven. However, the study shows that polyphenols – even though they are poorly absorbed by the intestine – can be effective via the interaction with the gut microbiota.

ReferenceAnother piece in the puzzle – gut microbiota can benefit from red wine


Haas, EA et al.: A red wine intervention does not modify plasma trimethylamine N-oxide but is associated with broad shifts in the plasma metabolome and gut microbiota composition. American Journal of Clinical Nutrition 2022;116:1515-1529