Ileal Transposition in Rats Reduces Energy Intake, Body Weight, and Body Fat Most Efficaciously When Ingesting a High-Protein Diet

Effects of preduodenal ileal surgical transposition on enteroendocrine intestinal cells in wistar rats: Histomorphological and serum changes

In our study, we focused on the role of the distal ileum as a main endocrine actor in relation to the pancreas. We investigated the effects of intestinally released hormones on the pancreas in terms of type 2 diabetes mellitus (T2DM) improvement, as a main effect of bariatric surgeries. To specifically study the importance of the ileum, we used an experimental surgical model performed in healthy Wistar rats. After preduodenal transposition of the ileum, we analyzed the histology and enterohormonal cells of the intestine. We measured the plasma level of several hormones and effectors in this enteropancreatic axis. We used a surgical control (Sham) group and a surgical group, where ileum preduodenal transposition (PDIT) was performed. We measured basal glycemia and serum levels of several incretins, including GLP-1, PYY, and GIP, and we performed a glucose overdose test. After two test periods, the basal glycemia and glucose overdose results were not different between groups, however, the PDIT group had significantly increased expression of GLP-1, with increased cellular release in the ileum and duodenum compared with the Sham group. Both plasma GIP levels and GIP tissue expression were decreased in the PDIT group compared with the sham group. There were no differences in PPY hormone levels. The ileum crypts and villi of the PDIT group showed improvement in histological parameters. We concluded that model animals had an altered transposed ileum related to the enterohormonal adaptation of the ileum. Our results indicated that the ileum is important in the hormonal control of the enteropancreatic axis.

Nutrient-Based Appetite Regulation

Regulation of appetite is dependent on crosstalk between the gut and the brain, which is a pathway described as the gut-brain axis (GBA). Three primary appetite-regulating hormones that are secreted in the gut as a response to eating a meal are glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), and peptide YY (PYY). When these hormones are secreted, the GBA responds to reduce appetite. However, secretion of these hormones and the response of the GBA can vary depending on the types of nutrients consumed. This narrative review describes how the gut secretes GLP-1, CCK, and PYY in response to proteins, carbohydrates, and fats. In addition, the GBA response based on the quality of the meal is described in the context of which meal types produce greater appetite suppression. Last, the beneficiary role of exercise as a mediator of appetite regulation is highlighted.

Reverse Transposition - a New Surgical Model for the Study the Role of Ileum in Glucose Metabolism

We studied the possibility of reverse transposition of the small intestine and its effect on glucose metabolism. The reverse transposition model proposed by us consists in a 180° turn of the small intestine after transection and antiperistaltic transposition of the entire intestinal tube. To this end, outbred white rats underwent reverse transposition of the small intestine, sham-operated rats served as the control. Both groups were monitored for body weight and blood glucose levels at fast and after oral glucose tolerance test. The groups did not differ by the duration of surgery, body weight, and blood glucose levels at fast and after glucose tolerance test. The reverse transposition technique proposed by us is reproducible, the anatomical changes lead to early contact of the chyme with the terminal portion of the small intestine, which can modulate absorption of nutrients and the release of ileal hormones (incretins) affecting glucose metabolism.