Nutritional consequences of intestinal bacterial overgrowth.

The bacterial overgrowth syndrome occurs when there are alterations in intestinal anatomy, gastrointestinal motility, or a lack of gastric acid secretion. Clinically, patients present with nonspecific gastrointestinal symptoms that include abdominal pain, bloating, excessive gas production, diarrhea, weight loss, and malabsorption. The nutritional consequences of intestinal bacterial overgrowth include vitamin deficiencies, fat malabsorption, and malnutrition. The diagnosis requires a high index of clinical suspicion and can be established by specialized testing, such as the 1-gram 14C-xylose breath test. The goal of treatment is eradication of the bacterial overgrowth (usually with antibiotics) and the correction of nutritional deficiencies.