Dietary Carbohydrates and Lipids in the Pathogenesis of Leaky Gut Syndrome: An Overview

This review summarizes the recent knowledge on the effects of dietary carbohydrates and lipids on the pathophysiology of leaky gut syndrome (LGS). Alterations in intestinal barrier permeability may lead to serious gastrointestinal (GI) disorders. LGS is caused by intestinal hyperpermeability due to changes in the expression levels and functioning of tight junctions. The influence of dietary habits on intestinal physiology is clearly visible in incidence rates of intestinal diseases in industrial and developing countries. Diseases which are linked to intestinal hyperpermeability tend to localize to Westernized countries, where a diet rich in fats and refined carbohydrates predominates. Several studies suggest that fructose is one of the key carbohydrates involved in the regulation of the intestinal permeability and its overuse may cause harmful effects, such as tight junction protein dysfunction. On the other hand, short chain fatty acids (mainly butyrate) at appropriate concentrations may lead to the reduction of intestinal permeability, which is beneficial in LGS. However, long chain fatty acids, including n-3 and n-6 polyunsaturated fatty acids have unclear properties. Some of those behave as components untightening and tightening the intestinal membrane.

Enkephalinases as a new pharmacological target in the treatment of gastrointestinal tract disorders

Enkephalinases, which belong to the family of zinc metalloproteases play a crucial role in modulation of the endogenous opioid system (EOS) activity. Enkephalinase inhibitors (EI) allow obtaining therapeutic concentrations of selected endogenous peptides. One of the first EIs, racecadotril possesses antidiarrheal properties. Moreover, there is evidence that racecadotril presents fewer adverse events compared to other medications used for the treatment of diarrhea, such as loperamide. Lower potency for developing serious adverse events may be the key to choosing EIs as the preferred therapy in patients with chronic diseases. Additionally, EOS is involved in pain modulation, hence EIs might also be used as potential medications in treatment of pain. This review discusses the use of EIs in the treatment of gastrointestinal diseases, including irritable bowel syndrome and inflammatory bowel disease.