Effect of dietary fiber/starch balance on the cecal proteome of growing rabbits

Abstract

Dietary fiber/starch imbalance can lead to diarrhea in rabbits. However, the underlying molecular mechanisms are largely unknown, and this is the first study on the proteome profile of the cecal tissue of diarrheic rabbits. In this study, one group of weanling rabbits was fed a high fiber/starch diet (control group), and another group was fed a low fiber/starch diet (diarrhea group). We applied 2-D gel electrophoresis, coupled with histological and biochemical analyses, to study dynamic changes in the proteome of the cecal tissue from healthy and diarrheic growing rabbits. We identified 29 protein spots showing differential abundance between the two groups. We identified the proteins and found that they participated in key biological processes, including absorption, digestion and transport; cell structure and motility; inflammatory response; glucose and energy metabolism; mineral and vitamin metabolism; stress response and cell redox homeostasis. Moreover, the results of our proteomics analysis revealed continuous impairment and compensatory intestinal repair in the rabbits with diarrhea. Therefore, these findings shed light on the main mechanisms and the main proteins involved in intestinal degradation in diarrhea. These findings have important implications for understanding the mechanism of cecal damage and repair in diarrhea in rabbits caused by dietary factors. The different cecal protein expressions were compared between healthy and diarrhea in growing rabbit model fed different fiber/starch diets. Diarrhea caused by feeding high-starch diet induced mucosal injury and inflammation. In this work we identify protein spots by MALDI-TOF MS and classify by biological function. The finding that the expression of all other proteins belonging to seven functional groups was significantly increased in the diarrheic rabbits, except for CMBL, suggests that many intestinal functional proteins may be related to up-regulation, such as cell absorption, digestion, transport, structure, motility, metabolism (including energy mineral and vitamin), inflammatory response, stress response, and redox homeostasis in diarrhea.