Changes in Intestinal Morphology of Rats Fed with Different Levels of Bee Pollen

Context: Bee pollen has been related to therapeutic properties including antibiotic, antineoplasic, antidiarrhoeic and antioxidant activities. However, little is known about the effect of pollen feeding on the intestinal structures and functions. Aims: The objective of this study was to evaluate the small intestine morphology in rats fed with three different pollen levels. Materials and Methods: Forty rats were randomly separated into 4 groups of 10 rats each. Control group (C) was fed with a basic diet, group L received a diet supplemented with 0.2% (w/w), group M with 0.5% (w/w) and group H with 0.75% (w/w) bee pollen for 90 days. The relative volume of intestinal mucosa structures, length of villi and Lieberkühn crypts formation were evaluated. Results: Quantitative morphometry and histology methods revealed significant increase in the relative volume of epithelium (P<0.0001) and decrease in the connective tissue volume (P<0.0001) of jejunum in groups M and H as compared to the control. The intestinal villi length significantly (P<0.0001) increased in all experimental groups. On the other hand, the Lieberkühn crypts depth significantly (P<0.0001) increased only in groups L and M but decreased (P<0.0001) in the highest pollen-exposed group H. Conclusion: The most significant results were recorded in the medium pollen exposed group. We conclude that the bee pollen concentration of 0.5% is the most effective in the increase of relative volume of the intestinal epithelium and villi length. The results demonstrated that bee pollen affects the small intestine development in a concentration-dependent manner and could be beneficial for intestinal function.