Researchers hope to determine how often small intestinal bacterial overgrowth occurs after taking proton pump inhibitors.

Inclusion criteria:

• Predominant symptoms of gastroesophageal reflux disease including heartburn, regurgitation
• Subjects must be able to give appropriate informed consent

Exclusion criteria:

• Prior diagnosis of SIBO
• Use of PPIs or H2R-anatagonstists in the prior 3 months
• Major concomitant illness (renal, hepatic, rheumatologic or cardiovascular disease, or malignancy)
• Antibiotic therapy within one month
• Prior gastrointestinal surgery including esophageal, gastric, and small or large bowel surgery
• Previously diagnosed irritable bowel syndrome or inflammatory bowel disease
• Individuals who are pregnant or breast feeding
• Patients with plans to become pregnant
• Inability to take PPIs, including allergy/sensitivity