Evaluate the Intestinal Microbiome in Patients With Erosive Gastroesophageal Reflux Disease and in Asymptomatic Healthy Controls

Inclusion Criteria: * a confirmed diagnosis of erosive GERD through clinical and endoscopic criteria * who have not taken omeprazole or any other drug that changes gastric pH in the thirty days prior to the completion of diagnostic tests for GERD and other tests included in the protocol. Exclusion Criteria: * Use of antimicrobials or probiotics in the last three months * Presence of severe and/or extensive atrophic gastritis confirmed histologically * Comorbidities that could interfere with motility of the gastrointestinal tract (diabetes mellitus, previous stroke, neurological diseases) * Use of drugs that could interfere with motility of the gastrointestinal tract or salivation (calcium channel blockers, nitrates, anticholinergics, estrogens) * Bulky hiatal hernia (greater than or equal to 5 cm) * Los Angeles grade C or D erosive esophagitis * Long-distance travel in the last 3 months (outside the southeastern region of the country) * Pregnant or breastfeeding patients * Previous history of upper digestive tract surgery * Obesity (body mass index equal to or greater than 30 kg / m2) * Patient with a consumptive syndrome or malnutrition * Tobacco use in the last 30 days / Alcohol use (more than 20 g per day, in the last 30 days)