Alcohol as a gastric disinfectant? The complex relationship between alcohol consumption and current Helicobacter pylori infection.

Alcoholic beverages have antimicrobial effects against Helicobacter pylori in vitro. To elucidate the relation between alcohol consumption and current infection with H. pylori in vivo, we carried out a pooled analysis of three recent studies from Southern Germany, comprising 1410 adults age 15 to 69. Detailed information on consumption of various alcoholic beverages was collected through standardized questionnaires. Helicobacter pylori infection was measured by 15C-urea breath test. Overall, prevalence of current H. pylori infection was lower among subjects who consumed alcohol (34.9%) than among nondrinkers (38.0%). The adjusted odds ratio was 0.79, with a 95% confidence interval of 0.58-1.08. Furthermore, alcohol consumption showed a strong inverse relation to the result of the 13C-urea breath test, a semiquantitative measure of the bacterial load, among infected subjects. The inverse association between alcohol consumption and H. pylori infection was not monotonic, however. Odds of infection were lowest at moderate levels of alcohol consumption and increased at higher levels of alcohol consumption, regardless of the type of alcoholic beverages consumed. These results support the hypothesis that moderate alcohol consumption may favor suppression and eventual elimination of H. pylori infection. At higher levels of alcohol consumption, the antimicrobial effects of alcoholic beverages may be opposed by adverse systemic effects of drinking, such as adverse effects on the immune defense.