Changes in oral microbes may lead to gum disease, heart problems, and cancer, study says.

Heavy drinkers in the study had higher levels of harmful bacteria and lower levels of bacteria thought to prevent sickness.

Drinking alcohol can throw off the balance of good and bacteria in the mouth and raise your risk for a variety of diseases, according to new research.

Good Versus Bad Bacteria

More than 700 different species of bacteria and some species of fungi live in the mouth. Many of these microorganisms can play an important role in factors that help maintain wellness, including immune response, nutrient digestion, and possible cancer prevention. The heavy drinkers in the study had higher levels of harmful Bacteroidales, Actinomyces, and Neisseria bacteria; and they had lower levels of Lactobacillales, commonly found in probiotic food supplements and thought to prevent sickness.

Oral bacteria composition can influence the development of oral and upper digestive tract cancers, including cancers of the oral cavity, oesophagus, and pancreas. Changes to bacterial composition from heavy drinking potentially contribute to periodontal disease, heart disease, and head and neck cancer as well.