Secretion of Gut Hormones and Expression of Sweet Taste Receptors and Glucose Transporters in a Rat Model of Obesity

Gut-brain communication mediates the impact of dietary lipids on cognitive capacity

Cognitive impairment, as a prevalent symptom of nervous system disorders, poses one of the most challenging aspects in the management of brain diseases. Lipids present in the cell membranes of all neurons within the brain and dietary lipids can regulate the cognition and memory function. In recent years, the advancements in gut microbiome research have enabled the exploration of dietary lipids targeting the gut-brain axis as a strategy for regulating cognition. This present review provides an in-depth overview of how lipids modulate cognition via the gut-brain axis depending on metabolic, immune, neural and endocrine pathways. It also comprehensively analyzes the effects of diverse lipids on the gut microbiota and intestinal barrier function, thereby affecting the central nervous system and cognitive capacity. Moreover, comparative analysis of the positive and negative effects is presented between beneficial and detrimental lipids. The former encompass monounsaturated fatty acids, short-chain fatty acids, omega-3 polyunsaturated fatty acids, phospholipids, phytosterols, fungal sterols and bioactive lipid-soluble vitamins, as well as lipid-derived gut metabolites, whereas the latter (detrimental lipids) include medium- or long-chain fatty acids, excessive proportions of n-6 polyunsaturated fatty acids, industrial trans fatty acids, and zoosterols. To sum up, the focus of this review is on how gut-brain communication mediates the impact of dietary lipids on cognitive capacity, providing a novel theoretical foundation for promoting brain cognitive health and scientific lipid consumption patterns.

Impact of TOTUM-63, a fibre and polyphenol rich plant-based composition, on gut and pancreatic hormone secretion in diet-induced obese mice

BACKGROUND AND AIMS

TOTUM-63, a fibre and polyphenol rich plant-based composition, has been demonstrated to significantly improve body weight and glucose homeostasis in animal models of obesity. Our study aimed at exploring whether the mechanisms include modulation of gut (glucose-dependent insulinotropic peptide (GIP), glucagon-like petide-1 (GLP-1), cholecystokinin (CCK), peptide YY (PYY)) and pancreatic (insulin, glucagon) hormones, all important regulators of glucose control, appetite and body weight.

METHODS AND RESULTS

Male C57BL/6JRJ mice were assigned to either standard chow (CON), high fat diet (HF, 60% energy from fat) or HF-TOTUM-63 (HF diet 60% supplemented with TOTUM-63 2.7%) for 10 weeks. In vivo glucose homeostasis (oral glucose tolerance test (OGTT), intraperitoneal pyruvate tolerance test (ipPTT)), glucose-induced portal vein hormone concentration, gut hormone gene expression and protein content as well as enteroendocrine cell contents were assessed at the end of the dietary intervention. The present study evidenced that TOTUM-63 reduced food intake, limited weight gain and improved glucose and pyruvate tolerance of HF-fed animals. This was associated with an increase in PYY content in the colon, an altered pattern of PYY secretion between fasted and glucose-stimulated states, and with a significant improvement in the portal vein concentration of GLP-1, insulin and glucagon, but not GIP and CCK, in response to glucose stimulation.

CONCLUSION

Overall, these data suggest that TOTUM-63 might have a specific impact on gut L-cells and on the expression and secretion of GLP-1 and PYY incretins, potentially contributing to the reduced food intake, body weight gain and improved glucose homeostasis.

Luminal Chemosensory Cells in the Small Intestine

In addition to the small intestine's well-known function of nutrient absorption, the small intestine also plays a major role in nutrient sensing. Similar to taste sensors seen on the tongue, GPCR-coupled nutrient sensors are expressed throughout the intestinal epithelium and respond to nutrients found in the lumen. These taste receptors respond to specific ligands, such as digested carbohydrates, fats, and proteins. The activation of nutrient sensors in the intestine allows for the induction of signaling pathways needed for the digestive system to process an influx of nutrients. Such processes include those related to glucose homeostasis and satiety. Defects in intestinal nutrient sensing have been linked to a variety of metabolic disorders, such as type 2 diabetes and obesity. Here, we review recent updates in the mechanisms related to intestinal nutrient sensors, particularly in enteroendocrine cells, and their pathological roles in disease. Additionally, we highlight the emerging nutrient sensing role of tuft cells and recent work using enteroids as a sensory organ model.

Peptides from Natural or Rationally Designed Sources Can Be Used in Overweight, Obesity, and Type 2 Diabetes Therapies

Overweight and obesity are among the most prominent health problems in the modern world, mostly because they are either associated with or increase the risk of other diseases such as type 2 diabetes, hypertension, and/or cancer. Most professional organizations define overweight and obesity according to individual body-mass index (BMI, weight in kilograms divided by height squared in meters). Overweight is defined as individuals with BMI from 25 to 29, and obesity as individuals with BMI ≥30. Obesity is the result of genetic, behavioral, environmental, physiological, social, and cultural factors that result in energy imbalance and promote excessive fat deposition. Despite all the knowledge concerning the pathophysiology of obesity, which is considered a disease, none of the existing treatments alone or in combination can normalize blood glucose concentration and prevent debilitating complications from obesity. This review discusses some new perspectives for overweight and obesity treatments, including the use of the new orally active cannabinoid peptide Pep19, the advantage of which is the absence of undesired central nervous system effects usually experienced with other cannabinoids.