Megaloblastic anemia in blind loop syndrome is due to:

Answer is B (Bacterial overgrowth) Vitamin B12 deficiency in blind loop syndrome is not due to defect in the absorption process of vit B1, hut due to competitive uptake of vii B12 by colonizing bacteria and hence decreased availability of vit 131, for absorption. In Blind loop syndrome, malabsorbtion occurs secondary to bacterial overgrowth. The possible mechanism causing malabsorption are : Bacterial deconjugation of bile salts : In contrast to conjugated bile salts, unconjugated bile salts may be absorbed in the proximal small bowel resulting in decreased intraluminal concentration of bile salts in Jejunum. This leads to impaired micelle formation and hence fat malabsorption. Utilization of vit Bp by bacteria: The impaired absorbtion of vit Bp is not related to above disturbed bile salt metabolism, but appears to be due to uptake of vit Bp by microorganisms i.e. competition for vit B,2 by bacteria. Injury to the mucosal absorptive surface. Remember: Blind loop in the upper intestine :defect is chiefly of Fat malabsorption / SteatorrheaQ Blind loop in the lower intestine :There is Vitamin B12 deficiency / Megaloblastic anemiae