Effects of prebiotic and probiotics on intestinal permeability in endotoxemic rats

Microbiota is an important factor in the continuation of vital functions, also initiation and development of diseases. The body's largest microbiota located in the intestinal colon. Recently, it has been shown that critical changes in microbiota composition are associated with many diseases such as endotoxemia, diabetes, obesity, neurodegenerative and cardiovascular diseases. Endotoxemia is a pathophysiological condition that strong stimulation of the immune system against endotoxins such as lipopolysaccharide (LPS) causes systemic inflammation and can result in death. With the increase of intestinal permeability during endotoxemia, gram-negative bacteria with LPS found on their cell walls move to the systemic circulation and move forward this condition. Changes in microbiota composition can cause changes in intestinal permeability, endotoxin production and transport. Therefore, prebiotics and probiotics that are effective in microbiota composition are used in many studies. Inulin is a dietary fiber that acts as a prebiotic. Humans cannot digest inulin, but inulin is fermented by the gut microbiota. Recently, it has been shown that inulin reduces intestinal permeability caused by the increase of LPS, selectively changes the microbiota composition and has anti-inflammatory properties. The discovery of the antimicrobial and immunomodulatory effects of Bacillus clausii, one of the probiotic bacteria species, and its versatile intestinal regulatory properties such as cell adhesion and vitamin production has increased the interest in this probiotic strain. Therefore, this study was carried out in order to determine the changes in the structure of the intestine, to understand the destructive effects of endotoxemia in the intestine or the endotoxemia triggering effects of intestinal changes. Also, we want to show the usage areas of inulin and Bacillus clausii in pathological cases. In our study, 3 months old 39 male Wistar Albino rats were used. After twenty-one days of prebiotic and probiotic application, LPS was applied intraperitoneally 24 hours before the taking of the tissues. Subsequently, small and large intestine tissues of the experimental animals were prepared for histological and immunohistochemical methods. After tissue preparation, histological methods were used to determine the intestinal structure. As an immunohistochemical methods, occludin antibody to show intestinal permeability and myeloperoxidase (MPO) antibody to show leukocyte infiltration were applied. As a result, our study showed that prebiotics and probiotics can protect the tight junctions in the small intestine and prevent the intestinal permeability to pathogens. It has been observed that prebiotic and probiotic feeding of healthy individuals may partially reduce the intestinal permeability but not fully protect the intestinal structure against endotoxemia that may occur in many pathological conditions.