Probiotics are organisms such as bacteria or yeast that are believed to improve health. They are available in supplements and foods. The idea of taking live bacteria or yeast may seem strange at first. After all, we take antibiotics to fight bacteria. But our bodies naturally teem with such organisms…
The digestive system is home to more than 500 different types of bacteria. They help keep the intestines healthy and assist in digesting food. They are also believed to help the immune system.
How Do Probiotics Work?
Researchers believe that some digestive disorders happen when the balance of friendly bacteria in the intestines becomes disturbed. This can happen after an infection or after taking antibiotics. Intestinal problems can also arise when the lining of the intestines is damaged. Taking probiotics may help.
Probiotics and the Immune System
There’s also evidence that probiotics help maintain a strong immune system. “In societies with very good hygiene, we’ve seen a sharp increase in autoimmune and allergic diseases,” Stefano Guandalini, MD, professor of pediatrics and gastroenterology at the University of Chicago Medical Center. tells WebMD. “That may be because the immune system isn’t being properly challenged by pathogenic organisms. Introducing friendly bacteria in the form of probiotics is believed to challenge the immune system in healthy ways.”
Probiotics May Help Lots of Ailments
Although they are still being studied, probiotics may help several specific illnesses, studies show. In 2011, experts at Yale University reviewed the research. They concluded that probiotics are most effective for:
- Treating childhood diarrhea
- Treating ulcerative colitis
- Treating necrotizing enterocolitis, a type of infection and inflammation of the intestines mostly seen in infants
- Preventing antibiotic-associated diarrhea and infectious diarrhea
- Preventing pouchitis, an inflammation of the intestines that can follow intestinal surgery
- Treating and preventing eczema associated with cow’s milk allergy
- Helping the immune system
- The Yale University panel of experts concluded that probiotics may be helpful in other ways, although the evidence is less convincing. These include:
- Treating symptoms of irritable bowel syndrome
- Treating vaginitis
- Treating diarrhea caused by C. difficile bacteria
- Treating Crohn’s disease
Probiotics may also be useful in unexpected ways. A study published in 2010 suggests that probiotics may lower the risk of common childhood illnesses such as ear infections, strep throat, and colds.
Cautions About Probiotics
For the most part, taking probiotics is safe and causes few side effects. Still, probiotics may be dangerous for people with weakened immune systems or serious illnesses. One study found that patients with severe pancreatitis who were given probiotics had a higher risk of death.
Which Is Better, Probiotic Foods or Supplements?
Probiotics come in many forms, including powders, tablets, capsules, and foods such as yogurts and dairy drinks. The form you take them in doesn’t matter, experts say, as long as it contains enough organisms to grow in the intestines. Experts say the effective dose varies, from as little as 50 million to as many as 1 trillion live cells per dose.
Specific probiotic organisms appear to be useful for particular illnesses, however. The bacteria Lactobacillus reuteri and the yeast Saccharomyces boulardii have been shown to be helpful for infectious diarrhea in children, for example. “But there’s no evidence that Lactobacillus acidophilus, which is used in many commercial yogurts, has any benefits for diarrhea,” says Floch. n
(Reviewed by Laura J. Martin, MD)