Pathologic changes of the small intestinal mucosa of pigs after feeding Phaseolus vulgaris beans.

The jejunal mucosa of pigs fed diets containing Phaseolus vulgaris beans was characterized grossly as mucosal atrophy and microscopically as atrophy and blunting of the villus in association with elongation of crypts with cells with increased mitotic activity. These morphologic findings were most severe in the proximal and middle parts of the jejunum. Compared to controls, goblet cells were significantly decreased in the villus but markedly increased in the crypt region. The activity of aminopeptidase and sucrase-isomaltase in the test animals was also significantly lower than in the controls. The findings in this study suggested that feeding Phaseolus vulgaris beans reduced the digestive and absorptive capacity of the mucosa, resulting in weight loss and diarrhea of affected pigs.