Daniel Gonzalez Izundegui

University of Texas Southwestern Medical Center | UT Southwestern

Background Gut L-type enteroendocrine cells (EECs) are intestinal chemosensory cells that secrete satiety hormones GLP-1 and PYY in response to activation of G-protein coupled receptors (GPCRs) by luminal components of nutrient digestion and microbial fermentation. Regulator of G-protein Signaling (RGS) proteins are negative regulators of GPCR sign...

Background: New biomarkers to identify cardiovascular disease (CVD) risk earlier in its course are needed to enable targeted approaches for primordial prevention. We evaluated whether intraindividual changes in blood metabolites in response to an oral glucose tolerance test (OGTT) may provide incremental information regarding the risk of future CV...

Background and Aims Hunger, satiation, postprandial satiety, and hedonic eating constitute key food intake parameters. We aim to study whether these symptoms are associated with gastrointestinal symptoms (GIS) in patients with obesity. Methods This is a cross-sectional study of patients with obesity. Patients completed the following validated biom...

Background Prescription medications such as selective serotonin reuptake inhibitors (SSRIs), commonly used to treat depression, are associated with weight gain. The role of pharmacogenomics in predicting SSRI-induced weight gain is unclear. Methods In this retrospective cohort study from participants in the Mayo Clinic RIGHT study who were prescri...

Obesity is associated with alterations in cholesterol and bile acid (BA) metabolism. However, the interaction between dietary intake, cholesterol absorption, and BA metabolism in patients with obesity remains unclear. We conducted a 4-week nutritional intervention non-randomized clinical trial with three different sequential diets for a week in the...

Background Increased fecal bile acid excretion (IBAX) occurs in a third of patients with functional diarrhea. Aims To assess the prevalence of IBAX in benign inflammatory intestinal and colonic diseases presenting with chronic diarrhea. Methods All patients with known inflammatory diseases or resections who underwent 48 h fecal fat and BA testing...

The heterogeneity of the human intestinal epithelium has hindered the understanding of the pathophysiology of distinct specialized cell types on a single-cell basis in disease states. Described here is a workflow for the cryopreservation of endoscopically obtained human intestinal mucosal biopsies, subsequent preparation of this tissue to yield hig...

Background and Aims Over-the-scope clips (OTSCs; Ovesco Endoscopy) have been used for closure of fistulas, leaks, acute perforations, gastrointestinal tract bleeding, and stent anchoring. Adverse events (AEs) include perforation, migration, and ulceration. Little is known about the natural history of OTSCs, and no data addressing the longevity of O...

Randomized clinical trials have proven the efficacy and safety of Food and Drug Administration (FDA) approved anti-obesity medications (AOMs) for long-term use. It is unclear whether these outcomes can be replicated in real-world clinical practice where clinical complexities arise. The aim of this study was to evaluate the effectiveness and side ef...

Objective: We evaluated whether intra-individual changes in blood metabolites in response to an oral glucose challenge were associated with incident CVD and mortality. Methods: An oral glucose tolerance test (OGTT; 75g glucose) was administered to a subsample of non-diabetic Framingham Heart Study participants (n=361). Metabolite profiling was perf...

Purpose of Review Metabolomics enables rapid interrogation of widespread metabolic processes making it well suited for studying diabetes. Here, we review the current status of metabolomic investigation in diabetes, highlighting its applications for improving risk prediction and mechanistic understanding. Recent findings Findings of metabolite asso...

Objective: Satiety, defined as the duration of the sensation of fullness, is usually measured by validated visual analog scales (VAS) for appetite. Gastric function plays a key role in food intake regulation. However, the association between gastric emptying (GE) and VAS appetite is unknown. Methods: In this cross-sectional study, 134 participan...

Introduction Enteroendocrine cells (EECs) are hormone secretory cells sparsely distributed throughout the GI tract, and implicated in obesity. Intestinal L-type EECs secrete Glucagon-Like peptide 1(GLP-1) in response to a meal to promote satiety and maintain glucose homeostasis. Abnormal post prandial satiety (APS) is a phenotypic subset of obesity...

Introduction Obesity is a major risk factor for severe coronavirus disease, and clinical evidence now supports the GI tract, in addition to the respiratory system, as a potential route for SARS-CoV-2 infection. Expression of viral entry factors ACE2, TMPRSS2, and CTSL have been detected along the human GI tract including gastric, ileal and colonic...

Objective Little is known about the predictors of response to obesity interventions. Methods In 450 participants with obesity, body composition, resting energy expenditure, satiety, satiation, eating behavior, affect, and physical activity were measured by validated studies and questionnaires. These variables were used to classify obesity phenotyp...

Introduction: Bile acid (BA) diarrhea is the cause in ∼26% of chronic unexplained (nonbloody) diarrhea (CUD) based on SeHCAT testing. To assess fecal BA excretion and healthcare utilization in patients with CUD. Methods: In a retrospective review of 1,071 consecutive patients with CUD who completed 48-hour fecal BA testing, we analyzed the sympt...

In this review, we aim to cover the key aspects of food intake regulation in health and obesity as well as the presumed mechanisms of action of bariatric endoscopic procedures for weight loss. Food intake regulation is a tightly controlled homeostatic process. The key stages of food intake regulation are hunger, satiation and satiety. These differe...

INTRODUCTION Over-the-scope clips (OTSC) are used for closure of fistulas, leaks, and acute perforations, and for GI bleeding. Adverse events include perforation, migration, and ulceration. Little is know about the natural history of OTSCs and no data addressing the longevity of clips is available. We present an interim analysis of our center’s exp...