Effect of acetic acid and glutamine on the microscopic intestinal appearance. As expected, control rats demonstrate a normal histologic architecture. AA rats show extended subepithelial space and epithelial lifting along villus sides (Park score 3–4). AA-GLN rats exhibited a less marked subepithelial space at villus tip (Park score 1–2). Values are mean ± SEM. CONTR-control; AA- acetic acid; GLN- glutamine. * P < 0.05 vs CONTR rats, † P < 0.05 AA-GLN vs AA rats.