Effect of high-refined carbohydrate diet on intestinal integrity.

Objectives: One of the leading causes of obesity is the consumption of excess nutrients. Obesity is characterized by adipose tissue expansion, chronic low-grade inflammation, and metabolic alterations. Although consumption of a high-fat diet has been demonstrated to be a diet-induced obesity model associated with gut disorders, the same effect is not well explored in a mild-obesity model induced by high-refined carbohydrate (HC) diet intake. The intestinal tract barrier comprises mucus, epithelial cells, tight junctions, immune cells, and gut microbiota. This system is susceptible to dysfunction by excess dietary components that could increase intestinal permeability and bacterial translocation. The aim of this study was to evaluate whether an HC diet and the alterations resulting from its intake are linked to small intestine changes.

Methods: Male BALB/c mice were fed a chow or an HC diet for 8 wk.

Results: Although differences in body weight gain were not observed between the groups, mice fed the HC diet showed increased adiposity associated with metabolic alterations. The interferon-γ expression and myeloperoxidase levels were increased in the small intestine in mice fed an HC diet. However, the intestinal villi length, the expression of tight junctions (zonula occludens-1 and claudin-4) and tumor necrosis factor-α cytokine, and the percentage of intraepithelial lymphocytes did not differ in the jejunum or ileum between the groups. We did not observe differences in intestinal permeability and bacterial translocation.

Conclusion: Metabolic alterations caused by consumption of an HC diet lead to a mild obesity state that does not necessarily involve significant changes in intestinal integrity.