Proton pump inhibitors increase the risk of which infection?

• A. Pneumonia
• B. UTI
• C. MRSA
• D. C-diff

Answer: (D)

When stomach acid is suppressed by a proton pump inhibitor, the normal barrier that helps kill ingested bacteria is weakened. This allows Clostridioides difficile spores to survive the journey to the colon and more easily establish an infection, especially in people whose gut microbiota has already been disturbed by antibiotics. The result is a higher risk of C. difficile infection, which can range from mild diarrhea to severe colitis. While other infections can be seen with acid suppression, the association with C. difficile is the most well-established and clinically important reason to monitor PPI use carefully, particularly in patients with recent antibiotic exposure or hospitalization. If diarrhea develops in someone on a PPI, evaluating for C. difficile is key, and limiting unnecessary PPI therapy can help reduce risk.