Abstract:Objectives: This study investigated the adverse effects of excessive consumption of garlic on the small intestine (jejunum and ileum) of adult male Wistar rats.Methodology: Sixteen (16) Wistar rats with average weight of 181.5 g were grouped into two: Control Group A which received distilled water, and Treatment Group B which received 1000 mg/kg/ml aqueous extract of garlic, orally for 28 weeks. The aqueous extraction of raw garlic was done to obtain a concentration of 1000 mg/kg/ml. The animals were sacrificed by cervical dislocation after the last day of administration, and tissues for histological studies were fixed in buffered formalin, while those for enzyme studies were homogenised, and appropriate biochemical kits used to study the activities of acid phosphatase (ACP), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Results:The histological sections of the jejunum of animals that received the high dose of aqueous garlic extract revealed the presence of vacuolations, cell death and loss of epithelium, and intact muscle layer; the Periodic-Acid Schiff (PAS) positivity also reduced, while the ileum also showed degeneration of the brush borders, loss of epithelial cells, reduction in the number of goblet cells, vacuolations, and a reduced intensity of PAS positivity. Activities of ACP, ALP and LDH in the jejunum and ileum were increased. Conclusion:Consumption of excessive amount of garlic could cause structural changes to the intestinal tract, which are capable of affecting intestinal functions, such as decrease in glycogen activity in the small intestine, and impairment of the absorptive activities.