The role of acid in destroying hostile pathogens is something that has been mentioned in the alternative medicine circles for a long time.

Anxiety, Stress, lack of sleep and/or proper nutrition also plays a role in decreasing production of gastric juices. Naturally this leads to a downward spiral of compounding issues.

On a related note, there has been some interesting research on how acid reflux and gerd are usually more likely to be caused by too little acid.

http://chriskresser.com/what-everybody-ought-to-know-but-doe...