Estudio de los mecanismos fisiopatológicos del consumo sostenido de fructosa y del efecto protector de un extracto de granada en ratas wistar mediante el uso de técnicas ómicas

Resum

Some of the compounds we commonly ingest, such as reducing sugars, promote the onset of oxidative stress in the lumen of the gastrointestinal tract (GIT). The role of the in vivo-promoted oxidative stress in several pathologies within the GIT, including gastrointestinal cancers, ulcerative colitis, Crohn’s disease, or other inflammatory bowel diseases, is well known. The consumption of reducing sugars, such as fructose, promotes the increase of luminal oxidative stress. The association between increased reducing sugars consumption among the population and the high prevalence of metabolic diseases such as obesity, hypertriglyceridemia, non-alcoholic fatty liver disease (NAFLD), insulin resistance, or diabetes is a matter of great concern for health authorities. Therefore, understanding the mechanisms that promote the onset and/or development of the pathologies related to high sugars consumption is essential for improving nutritional strategies to reduce the harmful effects. On the other hand, the food proteins we ingest are targets of the luminal oxidative stress, and their interaction with free radicals could lead to the formation of undesired compounds whose consequences for consumers remain unclear. The formation of these compounds in any phase of the digestion exposes the GIT and other organs to the potential toxic and mutagenic effects of some of these species. In this doctoral thesis, we assessed how the presence of glucose and fructose affects protein digestibility during digestion, using an in vitro digestion model and an in vivo assay in which the gastrointestinal contents of Wistar rats exposed to high fructose consumption in drinking water for 10 weeks were analyzed. Likewise, in the in vivo experiment, the gastrointestinal and hepatic tissues, as well as the serum and the urine from animals exposed to both fructose supplementation and supplementation with a punicalagin-rich pomegranate extract, were analyzed. The advanced techniques employed in this doctoral thesis have allowed for an analysis of the physiopathological mechanisms involving fructose and the beneficial effects of the polyphenol-rich supplement on the physiopathology of the animals.