Using probiotics while on treatment with antibiotics may prevent diarrhea says a new study published in the Journal of American Medical Association.

The study was based on analysis of previous studies done on probiotics and antibiotic-associated diarrhea. A total of 63 studies were extracted from various sources. The researchers found that people on probiotics had a 42 percent reduced risk of getting diarrhea.

"Antibiotics in doing their work actually kill off a lot of the normal flora that are supposed to exist in our gut, so things kind of go haywire," Sydne Newberry, RAND Corporation in Santa Monica, CA, said to Reuters.

Another study published in 2006 says that probiotics reduce risk of antibiotic-associated diarrhea in children.

According to market analysis, probiotic sales will reach an approximate $31 billion by 2015, reports WebMed.

“You still can't take this information, go to a store, and grab a probiotic off the shelf and say, ‘I know this is going to work,’” said Dr. Shira Doron, who wasn’t involved in the study but has worked on the same subject at Tufts Medical Center in Boston.

Antibiotic-associated diarrhea occurs in a quarter of people on antibiotic treatment says a study published in 2008 in the Journal of Clinical Gastroenterology. 

But the present research does not determine which probiotic is most efficient in preventing diarrhea.

"I'm afraid nothing in this review will help consumers choose which probiotic supplement to choose or which foods to eat," said Dr. David Bernstein of North Shore University Hospital, Manhasset.

Limiting use of antibiotics is a better way to prevent antibiotic associated diarrhea writes Dr. Howard LeWine in a blog commenting on the present study. He further adds that the best way to keep normal microbial flora in balance is to use antibiotics when they are absolutely necessary.