A Pre-market, Two-stages Interventional Clinical Investigation to Evaluate the Safety and the Performance of Fibroin Syrup in Reducing the Gastroesophageal Reflux Disease (GERD) Symptomatology in Nonerosive Reflux Disease (NERD) Patients

Inclusion Criteria * Patient who signed Informed consent form; * Male or Female over 18 years old at the time of the signature of the Informed consent form; * Symptomatic non-erosive reflux disease (heartburn and/or regurgitation) for at least 8 weeks; * RDQ (Reflux Disease Questionnaire) score ≥ 12 at baseline (questionnaire specific for reporting the frequency and severity of upper gastrointestinal symptoms); * Willingness to follow all study procedures, including attending all site visits, tests and examinations. Exclusion Criteria: * Esophagitis according to the Los Angeles classification (grade A to D); * Diagnosis of Helicobacter pylori infection; * Use of proton pump inhibitors or H2 receptor antagonists in the previous 4 weeks; * Uncontrolled cardiac, renal, liver or pulmonary disease; * Diabetes; * Active malignant neoplasia; * Pregnancy or breast-feeding; * Known allergy to device components; * Simultaneous participation in an interventional study or participation in an interventional study in the last 1 month before study inclusion; * Known drug and/or alcohol abuse; * Mental incapacity that precludes adequate understanding or cooperation.