Q&A: Does stomach acid destroy probiotic bacteria?


Q: When you eat yogurt or take a probiotic supplement, why aren’t the probiotic bacteria killed by stomach acids?

A: The point of consuming a probiotic supplement in a food like yogurt, a powder or a capsule is to introduce beneficial bacteria in the gut, said Dr. Christine Frissora, a gastroenterologist at the Center for Advanced Digestive Care at NewYork-Presbyterian/Weill Cornell hospital.

Yogurt provides probiotics. (Shutterstock photo)

Yogurt provides probiotics. (Shutterstock photo)

There are questions about whether these bacteria survive the gastric acid, make it down to the small intestine or colon and live to have any biological effects.

“Certain bacteria have the capability to survive gastric acid, and others do not,” Frissora said.

One public health concern is that patients taking acid-suppressing drugs called proton pump inhibitors (like Prevacid and Prilosec) have a gastric pH level that is often quite high, allowing many more bacteria to survive, Frissora said. This increases the risk of aspiration pneumonia and perhaps even a Clostridium difficile infection, which causes fever, diarrhea and a high white blood cell count, and can be life-threatening.

A more basic question: Is a probiotic supplement actually needed? Not by most people, Frissora said.

“Oftentimes prebiotic foods, like a banana or honey, will do just as well,” she said.

– C. Claiborne Ray, The New York Times


Last modified: April 15, 2014