The purpose of this study is to evaluate the effects of a common over-the-counter medication, omeprazole, on the normal gut bacteria and inflammation in the body in healthy older adults.

This study aims to enroll 25 healthy subjects from San Antonio, Texas and the surrounding area. Study participants will be asked to provide a blood and stool sample at baseline, complete a 14-day course of omeprazole (Prilosec®), and then complete a follow-up blood and stool sample.

Inclusion Criteria:

• Age 60 years or older

Exclusion Criteria:

• No prior major gastrointestinal surgery
• No chronic daily use or any use within the past two months of the following medications: antibiotics, proton pump inhibitors, other acid reflux medications, probiotics, anti-inflammatory medications, anti-diarrhea medications, laxatives, anti-depressants, anti-anxiety medications, steroids, metformin, or biologic/immune modulating drugs