By Charlene Laino
WebMD Health News
Reviewed by Laura J. Martin, MD
Nov. 4, 2011 (Washington, D.C.) -- May I have a probiotic with that antibiotic please?
That's a question that hospitalized patients being started on antibiotics may want to ask their doctors, according to a panel of doctors convened by the American College of Gastroenterology at its annual meeting here.
A review of 22 studies involving 3,096 patients presented at the meeting showed that taking probiotics while on antibiotics may cut the risk of developing antibiotic-associated diarrhea by about 60%.
Patients took any of a variety of probiotics, most commonly S. boulardii, for an average of one-and-one-half weeks. Most were hospitalized during treatment.
A second analysis that pooled the results of 28 studies involving 3,338 patients showed those given probiotics for at least as long as they were on antibiotics were 56% less likely to develop antibiotic-associated diarrhea than those given placebo.
Why? For all the good they can do, antibiotics kill "good" bacteria along with the bacteria that cause illness. A decrease in beneficial bacteria may lead to digestive problems. Taking probiotics may help replace the lost beneficial bacteria and help prevent diarrhea.
Probiotics also appeared to provide protection against potentially deadly bouts of diarrhea caused by the bug Clostridium difficile, or C. diff., says researcher Rabin Rahmani, MD, a gastroenterologist at Maimonides Medical Center in New York City.
Up to 3 in 4 Patients on Antibiotics Get Diarrhea
"By giving probiotics, you reduce the risk of antibiotic-associated diarrhea that occurs in 40% to 75% of hospitalized patients on antibiotics," says Fergus Shanahan, MD, of the Alimentary Pharmabiotic Centre, an industry-funded research center at the National University of Ireland at Cork.
In many cases, the diarrhea is mild and short lived; in others, it is severe and persistent, he says.
"We could debate whether all hospitalized patients on antibiotics need probiotics, but certainly the elderly, who are at high risk," Shanahan tells WebMD.
Brian E. Lacy, MD, PhD, a gastroenterologist at Dartmouth-Hitchcock Medical Center and moderator of the panel, went even further. "In my experience, it is certainly rational to offer probiotics [to hospitalized patients given antibiotics]," he says.
"There's no downside, in our experience," Lacy says.
Still, a better solution would be to be more selective in prescribing antibiotics to begin with, says panel member and probiotic researcher Eamonn M.M. Quigley, MD, professor of medicine at the National University of Ireland at Cork. He is co-founder of Alimentary Health Ltd., a biotechnology company that develops probiotic treatments.
The normal human digestive tract contains about 400 types of beneficial bacteria. Probiotic bacteria can be found in yogurt with live cultures and fermented milk and are available as dietary supplements.
Further study is needed to determine what type and dose of probiotic bacteria best prevent diarrhea, Quigley says.
Probiotics Outside Hospital Setting
Should people prescribed antibiotics outside of the hospital setting be taking a preventive course of probiotics as well?
Not unless they have disorders such as cystic fibrosis or recurrent urinary tract infections that require frequent treatment with antibiotics, Shanahan says.
"In general, only about 20% of people in the community setting get diarrhea that is associated with antibiotic treatment, and it is frequently short-lived," he says. "We need more data before we can make a recommendation."
While the expert panel agrees that probiotics are generally safe, they are dietary supplements that are regulated as foods, not drugs.
"Most [labels] don't say which specific bacteria are in your probiotic supplement or what it is supposed to be doing," says panel member Mark H. Mellow, MD, director of the Integris Digestive Health Center in Oklahoma City.
Look for a brand you trust and whose label offers that information, he advises. Also, tell your doctor if you are taking a probiotic supplement, Mellow says.
Probiotics vs. Gut Disorders
Past studies have shown that Bifidobacterium infantis 35624 (B. infantis 35624) -- a commercially available probiotic -- may help to relieve bloating, gas, abdominal pain, and other symptoms in people with irritable bowel syndrome (IBS), Fink says.
Still other research presented at the meeting showed that probiotics may lower levels of inflammation in the body. That could help to protect against inflammatory disorders such as ulcerative colitis, psoriasis, and chronic fatigue syndrome, says Quigley, who worked on the study.
Blood levels of anti-inflammatory proteins dropped in people with one of these conditions who took B. infantis 35624 for eight weeks, he reports. Levels were unchanged in people who took a placebo.
But whether that translates into fewer symptoms and better health has yet to be proven, he says.
The study was funded by Alimentary Health Ltd.
Probiotic supplements generally cost $15 to $40 for a month supply, according to Quigley.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.