Impact of Nutritional Intervention With Probiotics and Prebiotics on Obesity.

Obesity is one of the most severe and prevalent non-communicable diseases worldwide, affecting an estimated one-third of the population in Spain. It is a multifactorial disease that, in extreme cases such as morbid obesity, can become highly disabling and is associated with significant morbidity and mortality. This is because it serves as a risk factor for numerous chronic diseases, including metabolic conditions (type 2 diabetes mellitus), cardiovascular diseases (hypertension, atherosclerosis, etc.), and even cancer. The exact etiopathogenic mechanisms are not fully understood, but subclinical inflammation is considered to form the basis of the metabolic (diabetes) and cardiovascular (endothelial dysfunction, dyslipidemia, etc.) disturbances that almost invariably accompany obesity. Additionally, alterations in the composition of the gut microbiota, or dysbiosis, are now recognized as playing a key role in the pathogenesis of obesity. This makes the gut microbiota a highly attractive therapeutic target for both the prevention and treatment of obesity, including less severe forms and morbid obesity. In this context, the use of probiotics or extracts with prebiotic properties represents a particularly interesting strategy against obesity, offering a combination of efficacy and safety for treating these patients. Consequently, the general objective is proposed to evaluate the impact of dietary interventions aimed at modulating dysbiosis through the administration of a probiotic (Lactobacillus fermentum CECT5716), a standardized olive leaf extract with prebiotic properties, or a synbiotic (a combination of the olive leaf extract and L. fermentum CECT5716) on the clinical response of patients with moderate or morbid obesity. This will include determining its relationship with the immuno-metabolic system and the characteristic cardiovascular complications of obesity. Furthermore, the evaluation of these treatments in experimental models of obesity, including morbid o