Alcohol may adversely affect the oral microbiome—that is, the colonies of bacteria and other microorganisms in the mouth—according to a new study in the journal Microbiome, which included 1,044 people. And this may have both local and systemic health implications.
The oral cavity is host to more than 700 species of bacteria, along with other microorganisms, some protective and some potentially harmful.
Participants provided saliva samples (used to analyze their oral microbiome) and completed questionnaires about their alcohol use. Compared to nondrinkers, moderate drinkers (defined as up to one drink a day, on average, for women; up to two a day for men) had lower levels of Lactobacillales bacteria, which check the growth of other microorganisms and are linked, for example, to reduced dental caries and periodontal disease.
Making matters worse, moderate drinkers also had an overabundance of potentially pathogenic bacteria (including Actinomyces and Neisseria), linked, for example, to endocarditis (inflammation of the heart’s inner lining). Heavier drinking was associated with greater shifts in bacterial populations.
Though alcohol in mouthwash kills “germs” that cause plaque and gum disease, the authors noted that drinking alcohol may have both direct and indirect effects on health and has been associated with poor oral health and other conditions. This study may help explain the connections.
Some caveats: The study was observational and doesn’t prove causation. And most participants were white and older (55 to 87), so it’s unclear if the findings apply to other races and age groups.