Mucosal bacterial growth in the upper gastrointestinal tract in alcoholics (heavy drinkers)

Background/Aims: Mucosal adherent bacterial flora in chronic alcoholics was studied and compared to a control group referred for upper endoscopy, mainly for dyspepsia. Methods: 22 alcoholics, admitted to hospital for detoxification, were examined using upper gastrointestinal endoscopy. Gastric and duodenal biopsies were taken for tissue pathology, quantitative and qualitative anaerobic and aerobic bacteriological culture and for culture of Helicobacter pylori (antral biopsies). 12 nonalcoholics, admitted for upper endoscopy mainly for dyspepsia, were chosen as a control group. Seven of these had used gastric acid inhibitors. Results: Gastrointestinal symptoms were common among alcoholics: 20/22 (90%) had diarrhea, nausea and/or abdominal pain. There were signs of gastritis by endoscopy in 64% of the alcoholics and in 58% of the controls. Tissue pathology, however, showed active chronic antral gastritis in 27% of the alcoholics and in 42% of the controls. H. pylori were isolated in 7/22 of the alcoholics and in 4/12 of the controls, which corresponds to the mean prevalence for these age groups in Sweden. Significantly more bacteria, dominated by gram-positive aerobic cocci, were present in the gastric biopsies of alcoholics than in those of controls (mean of 2.9 x 10(6)/g material versus 4.4 x 10(5), p < 0.05). There were 2.6 times more bacteria in the duodenal biopsies of alcoholics than in those of the controls (p > 0.05, NS). Bacterial overgrowth (defined as >2 x 10(3) organisms/g material) was found in the stomach in 20/22 (90%) alcoholics and in 6/12 (50%) controls (p < 0.01). Conclusion: Alcoholics have an increased frequency of bacterial overgrowth in the upper gastrointestinal tract. This may contribute to the common gastrointestinal symptoms.