A 2019 study in the journal Gastroenterology found that people who drank red wine had a greater diversity of good bacteria in their guts compared with people who did not drink red wine. The researchers did not see the same effect with white wine or other types of alcohol, according to the study of more than 900 female twins. Having more diverse bacteria (and a greater proportion of some types rather than others) is thought to help with food digestion, immune function, and weight management.
An unhealthy balance of gut bacteria has been linked to weight gain and susceptibility to several diseases. In the study, the red wine drinkers were also less likely to be obese and had lower levels of LDL cholesterol than those who didn’t drink it. And it didn’t need to be a daily drink. The researchers found that drinking red wine even once every two weeks was enough to see the effect.