From a Spanish study appearing in The American Journal of Clinical Nutrition, (May 2012), it would seem that 9 ounces of Merlot (about 2 glasses) helps your beneficial bacteria flourish and controls pathogens in the gut.
The research followed ten healthy middle-aged males who were given merlot, low alcohol red wine or gin for periods of time. The benefits in the gut bacteria occurred with the Merlot and the low alcohol red wine but not with the gin, leading the researchers to conclude that the benefit came from the polyphenol content of the wine, not from the alcohol. Gin contains no polyphenols.
One such polyphenol, resveratrol found in red grape skins, has been the subject of a great number of studies showing its benefits to human health.
Researchers also found that after the regular consumption of red wine the men had lower blood pressure, lower triglyceride levels and lower C-reactive protein levels (CRP causes inflammation in the body). The only slight negative in the measurements was that HDL levels (good cholesterol) fell slightly too.
We have told you the other benefits of red wine and polyphenols before. Red wine is left to ferment keeping both the skins and the seeds in the vat. This imbues it with both resveratrol (a polyphenol) and extracts from the grape seeds (a powerful immune booster and more). White wine is not made this way.
Ref: Am J Clin Nutr. 2012;95:1323-1334