They are the second-best selling category of medications worldwide. They reduce acid production in the stomach and are used to treat heartburn, GERD and gastric ulcers.
Scientists say stomach acid acts as a barrier helping to control harmful bacteria and pathogens.
Not enough stomach acid to do the job may allow pathogens to flourish and end up in the lungs.
Study authors say, no one is questioning the importance of these medications, but patients should be cautious regarding the overuse.