Tropical sprue: a narrative review of a neglected malabsorption syndrome

Tropical sprue, a rare malabsorption syndrome, remains a significant yet underrecognized gastrointestinal disorder endemic to tropical regions, including South and Southeast Asia (e.g., India, Pakistan) and Caribbean islands (e.g., Puerto Rico, the Dominican Republic, Haiti). Its etiology remains uncertain, but mounting evidence supports an infectious origin, with bacterial overgrowth involving pathogens such as Alcaligenes, Klebsiella, and Enterobacter species frequently implicated. The disease causes profound intestinal alterations that impair the absorption of vitamin B12, fat-soluble vitamins (A, D, E, and K), and minerals such as calcium and magnesium, frequently resulting in chronic diarrhea and severe nutritional deficiencies. Histologically, villous atrophy of the jejunal and ileal mucosa is a hallmark feature. This narrative review synthesizes current knowledge on the epidemiology, etiology, intestinal pathophysiology, and histopathology of tropical sprue, while highlighting diagnostic challenges and the urgent need for further research to elucidate its pathogenesis and improve clinical management in endemic settings.