Host-Microbiome Interactions in Alcoholic Liver Disease

Alcoholic liver disease is a leading cause of morbidity and liver-related death worldwide. Intestinal bacterial overgrowth and dysbiosis induced by ethanol ingestion play an important role in the pathogenesis of alcoholic liver disease. After exposure to alcohol in the lumen, enteric bacteria alter their metabolism and thereby disturb intestinal homeostasis. Disruption of the mucosal barrier results in the translocation of microbial products that contribute to liver disease by inducing hepatic inflammation. In this review, we will discuss the effects of alcohol on the intestinal microbiome, and in particular, its effects on bacterial metabolism, bacterial translocation and ecological balance. A better understanding of the interactions among alcohol, the host and the microbiome will reveal new targets for therapy and lead to new treatments.

Modification of small bowel microflora in chronic alcoholics with alcoholic liver disease.

The bacterial flora of the gastrointestinal tract plays an essential role in human physiology. Our aim was to study the pattern of change in bacterial microflora in the small intestines of patients with chronic alcoholic liver disease (ALD). Patients of ALD made up the test group and nonalcoholics served as controls. Duodenal (D2) biopsies were obtained by upper gastrointestinal endoscopy and processed immediately for microbiological analysis. Marked qualitative and quantitative alterations of small intestinal microflora was documented in chronic alcoholics. There was increased bacterial growth of both gram-positive cocci and gram-negative bacilli in the ALD group.