This question arose due to an answer in Cooking Exchange.
It was stated that certain larvae can survive stomach acid and pass thru to the intestine.
When a patient is on PPIs, are there foods to be avoided due to reduced stomach acid production in order to reduce the risk of foodborne illnesses. I have read that immunocompromised individuals may require dietary restrictions, e.g. avoid Alfalfa sprouts or soft cheeses.
There are no dietary restrictions recommended for people taking PPIs (MedlinePlus).
You're correct that there is a theoretical basis suggesting that taking PPIs might increase the risk of food-borne illness, but the research has been inconsistent on whether that holds in the real world. It's possible that the decrease in acidity isn't enough to make a practical difference.
It's widely accepted that taking PPIs increases the risk of Clostridium difficile infections (Systematic Review) - a gastrointestinal illness that isn't food-borne. I mention this because it provides evidence that PPIs could create a gastrointestinal environment that is hospitable to infection.
For common food-borne illnesses like salmonella and campylobacter, some studies have found an association with PPI use, some have not (Review Article - See "Other Enteric Bacterial Infections").
There's some evidence linking listeriosis, a less common but more serious food-borne illness, with PPI use, but the body of research is fairly small (Review Article - See "Other Enteric Bacterial Infections").
For brucellosis, another serious food-borne illness, acid suppressing therapy (which includes PPIs) is often given as a risk factor, but most evidence comes from decades-old theory-based studies (nearly everything cites a classic 1978 BMJ study). It's also worth mentioning that most cases of brucellosis come from eating unpasteurized dairy products, which is broadly discouraged by food safety organizations (FDA) and illegal in some countries (Wikipedia: Raw Milk).
While there's some evidence that taking PPIs might increase the risk of food-borne illness, the evidence isn't strong enough and the risk isn't great enough to merit specific dietary recommendations. Following broad food safety recommendations (like washing produce, avoiding uncooked eggs, avoiding unpasteurized milk and cheese, etc.) is probably sufficient.
