This study aims to determine normal 24-hour pH-impedance monitoring values, including acid exposure time (AET), in healthy Indian adults. It will help improve GERD diagnosis in India by providing population-specific data. The study will also explore how diet, body position, and nighttime reflux affect acid exposure. Healthy volunteers aged 18 and above will be monitored for 24 hours.

This prospective study aims to establish normal 24-hour ambulatory pH-impedance monitoring values, including acid exposure time (AET), in healthy Indian volunteers. With an estimated GERD prevalence of 8-10% in India, current diagnostic criteria, such as the Lyon Consensus cut-off of 6%, may not be suitable for the Indian population due to differences in AET. The study will investigate the normative values of AET in healthy individuals and examine how factors such as diet, body position, and nocturnal reflux influence acid exposure and reflux episodes. By determining these standard values, the study seeks to enhance the accuracy of GERD diagnosis in India and improve understanding of reflux patterns specific to the Indian population. Participants will be healthy adults aged 18 and above, without gastrointestinal symptoms or major systemic diseases. The study will be conducted as a single-centre, 24-hour monitoring protocol.

Inclusion Criteria:

• Adult 18-50 years of age
• No gastro-intestinal symptoms
• No past GI or thoracic or spine surgery
• Not on any medications
• No history of recent alcohol intake (0 drinks in the past 1 month)
• Non smoker
• Normal BMI (18.5-22.9)

Exclusion Criteria:

• Any diagnosed systemic or organ specific disease (liver/kidney/heart/neurological disease, DM/HTN/Thyroid disease/ connective tissue disorder/inflammatory bowel disease/ irritable bowel syndrome)
• GERD symptoms/ functional dyspepsia
• Pregnant women or breast-feeding women
• Helicobacter pylori infection

50 Healthy participants