Small bowel bacterial overgrowth. An underrecognized cause of malnutrition in older adults.

Small bowel bacterial overgrowth (SBBO) is an important and under-recognized clinical syndrome in the elderly. It is the most common cause of malabsorption among older adults. Presentation of SBBO syndrome is often occult, which makes it imperative to maintain a high index of suspicion for this disorder. When symptomatic bacterial overgrowth is appropriately identified and treated there can be positive dramatic results. This article discusses the importance of considering a diagnosis of bacterial overgrowth in those predisposed to its development and the mechanisms by which nutrient malabsorption occurs. Signs and symptoms of bacterial overgrowth, differential diagnosis, investigation, and current treatment options are discussed.