Action of dietary fiber on metabolism of obese individuals with BMI greater than 35kg/m²: A Scoping Review Protocol
Creators: name: de Morais, Violeta
name: da Silva, Lucimar
name: Fernandes, Paola
name: Almeida, Paulo Henrique
name: Martino, Hércia
name: de Oliveira Barbosa Rosa, Carla
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Dietetics and Clinical Nutrition
subject: Nutrition
subject: Medicine and Health Sciences
subject: Life Sciences
subject: clinical study
subject: fiber
subject: nutrition
subject: obesity

description: Chronic non-communicable diseases (NCDs) constitute 7 of the 10 leading causes of mortality in the world. Among the NCDs, the prevalence of obesity has increased in the population and is related to the development and progression of several other diseases such as type 2 diabetes mellitus and cardiovascular diseases. In obesity, the gut microbiome undergoes changes influenced by the individual's diet and these changes can lead to dysbiosis and consequently to the activation of lipid and glucose receptors, hormonal modulation related to leptin, peptide YY (GYY) and glucagon-like peptide 1 (GLP-1), and the increase in serum lipopolysaccharides (LPS), resulting in dysfunction of lipoprotein and glucose metabolism, reduced satiety and induction of chronic inflammation. Dietary fiber is considered a part of plant foods resistant to digestion and absorption, and it is of great importance in the functioning of the intestine, as well as a prebiotic effect serving as a substrate for the intestinal microbiota. Metabolites from the fermentation of dietary fiber as the short-chain fatty acids (SCFAs) interact with receptors expressed in the intestinal epithelium and in the immune system, inducing mechanisms directly related to intestinal and other organ homeostasis, as well as suppression of inflammation. Several studies demonstrate beneficial action of dietary fiber intake in reducing the serum concentration of c-reactive protein and ghrelin in overweight and obese patients, as well as improving insulin sensitivity and weight loss. However, there is no consensus on the mechanisms of action of dietary fibers and their metabolites in metabolic regulation. In severely obese individuals (Body Mass Index - BMI ≥ 40) , this effect of dietary fiber and its metabolites on metabolic regulation appears to be reduced when compared to other individuals. This seems to be associated with the fact that severely obese individuals present a profile with low richness of the intestinal microbiota, in addition to a reduction in the capacity to regulate energy and the capacity of microorganisms to ferment fibers. Before starting the research, a preliminary search was performed on the MEDLINE (PubMed) and Cochrane Library databases, OSF registry platform and JBI Database of Systematic Reviews and Implementation Reports, to identify the existence of scope or systematic reviews with a similar objective. The research was conducted in November 2021 and no publication or project similar to this study was found. In this context, the present study aims to review in the literature the actions of dietary fiber metabolites in the intestinal health and inflammatory response of severely obese individuals and to understand which are the main dietary fiber metabolites, the receptors that act in the mechanisms of action in metabolic pathways and their relationship to gut and other organ homeostasis and inflammation in studies with obese animals and in cells from obese individuals