A regular glass of wine helps prevent tooth decay, gum disease and sore throats, say researchers.
Both red and white varieties have powerful germ-killing ingredients, claim the Italian scientists.
Their findings add to a growing body of research that demonstrates the health benefits of wine.
Moderate consumption of red is already known to reduce the risk of heart disease, cancer and Alzheimer's.
However, the drink's antibacterial qualities, although well- known by the ancient Romans, have been little investigated, said Professor Gabriella Gazzani, writing in the American Journal of Agricultural and Food Chemistry.
Professor Gazzani's team used bottles of supermarket Valpolicella and Pinot Nero for their research, pouring the wines into bowls containing bacteria.
"Overall, our findings seem to indicate that wine can act as an effective anti-microbial agent against streptococci bacteria and upper respiratory tract infections," she said.
The professor added, however: "We should still drink wine because it tastes good, goes well with food and is a pleasure to share with company. And we should still brush and floss our teeth the accepted way."