Carried out by researchers from the Department of Twin Research & Genetic Epidemiology at King's College London, the new study looked at 916 female twins in the UK to investigate the effect of different alcoholic drinks -- beer, cider, red wine, white wine and spirits -- on the gut microbiome. The microbiome is the communities of microorganisms, including bacteria, viruses and fungi, which live in our bodies, mainly in the small and large intestines. An imbalance of 'good' microbes compared to 'bad' in the gut has been linked to a range of negative health outcomes including a reduced immune system, weight gain and high cholesterol.
The findings, published today in the journal Gastroenterology, showed that the gut microbiome of participants who drank red wine was more diverse and contained a greater number of different bacterial species, which is a sign of gut health, compared to non-red wine drinkers. However, there was no difference in the gut microbiome of white wine, beer or spirits drinkers compared to non-drinkers.
Drinking red wine was also associated with lower levels of obesity and LDL cholesterol, also known as the 'bad' cholesterol, which the researchers say was in part due to the gut microbiota. The findings held true even after taking into account factors such as participants' age, weight, diet and socioeconomic status. The same results were also found when researchers also looked at three different cohort groups in the UK, the US and the Netherlands.
The authors explained that the positive association between red wine drinking and gut health appears to be due to the many polyphenols in red wine. Polyphenols, chemicals naturally present in many fruits and vegetables, have beneficial properties for health and serve as fuel for the microbes present in our system. Lead author Professor Tim Spector said, "This is one of the largest ever studies to explore the effects of red wine in the guts of nearly three thousand people in three different countries and provides insights that the high levels of polyphenols in the grape skin could be responsible for much of the controversial health benefits when used in moderation."
"Although we observed an association between red wine consumption and the gut microbiota diversity, drinking red wine rarely, such as once every two weeks, seems to be enough to observe an effect. If you must choose one alcoholic drink today, red wine is the one to pick as it seems to potentially exert a beneficial effect on you and your gut microbes, which in turn may also help weight and risk of heart disease. However, it is still advised to consume alcohol with moderation," added first author Dr. Caroline Le Roy.