We don't often think of bacteria as a good thing, especially in our bodies. Antibacterial soaps fill drugstore shelves, and antibiotics treat countless diseases.
But now, a new kind of "good" bacteria is taking up shelf space in the same stores as hand sanitizers.
Probiotics run counter to antibiotics, which treat bacterial infections ranging from ear infections to strep throat. They are active cultures of bacteria that can regulate digestion and restore organisms killed by antibiotics.
These tiny microorganisms are often already found in the human gut, and are generally safe for most people to take, according to the National Institutes of Health.
"One of the ways people develop diarrhea diseases, stomach problems and the stomach flu is because we get a disruption in the normal bacteria balance in our digestive tract," said Dr. Stacy Kahn, a pediatric gastroenterologist at the University of Chicago. Probiotics are "good" bacteria, or the bacteria that helps to keep our digestive tracks healthy, she said.
More people are taking pills, eating yogurts and drinking smoothies that advertise their probiotic properties.
"Patients usually seek out additional things that they can use to sort of treat themselves over the counter" said Dr. Matthew Ciorba, an assistant professor of gastroenterology at Washington University in St. Louis. "When they start putting probiotics in pills and marketing them more, then this has really created an alluring menu for patients to self-treat.”
Our digestive system naturally contains both good and bad bacteria, said Dr. Kelly Tappenden, a human nutrition professor at the University of Illinois at Urbana-Champaign. When we take antibiotics, however, this disrupts the natural, healthy bacteria in our gut.
When assessing how much of the good bacteria in the human gut a medication like an antibiotic can kill off, "it depends on antibiotic," Tappenden said. She said most antibiotics will kill most bacteria in our digestive tract. Along with killing off the harmful bacteria that is often the cause of an illness, broad-spectrum antibiotics also eliminate the microorganisms that help to keep us healthy.
This is why probiotics have begun to play a growing role in gastrointestinal health.
“Probiotics have been shown to be useful because they help replace and restore that healthy balance,” said Kahn. “I absolutely think that in most cases individuals who are taking [an antibiotic] especially for a prolonged period of time may find some benefit from taking a probiotic at the same time.”
For other illnesses, such as irritable bowel syndrome and inflammatory bowel syndrome, probiotics can play an active role in restoring patient health, said Ciorba.
“Nearly 100 percent of physicians thought that probiotics did have a role in treating gastrointestinal illnesses,” he added.
But simply going to the drugstore and picking up a bottle is not necessarily a surefire way to healthy digestion.
Some doctors agree that more research needs to be done. Some say that probiotics are helpful only for patients experiencing symptoms such as stomachaches, diarrhea or an intolerance of antibiotics. Others say that they may benefit healthy people without these symptoms to simply maintain a healthy microbiota, the balance of bacteria in the gut.
“Many gastroenterologists or physicians in general are not very familiar with specifics with what probiotics are or how they would be most useful,” Ciorba said.
As a food additive, probiotics are not currently regulated by the Food and Drug Administration. Because pharmaceutical companies do not make probiotics, there are also limited studies testing their efficacy, according to Ciorba.
“Unfortunately it’s true that not all products are the same,” said Kahn. “Just because something says ‘probiotic’ doesn’t mean its tested and high quality.”
But although most doctors think that healthy people will not be harmed when taking a probiotic, they are still divided as to whether or not there are additional health benefits to a person who has no digestive concerns.
“I don’t think that we have evidence in the literature that would support a recommendation that the general population should be buying a probiotic,” said Tappenden, the nutritionist at the University of Illinois at Urbana-Champaign.
Instead, she suggested that consumers focus on a different way to ensure a healthy gut: prebiotics. Prebiotics are not found in pill form, but refers to the practice of fostering a healthy balance of bacteria in your gut by eating a mixture of fruits, vegetables and whole grains.
“The prebiotic is actually the food to feed and foster those bacteria, and so it’s a powerful tool that I think is underutilized,” said Tappenden. The prebiotic is able to “foster the commensal microbes that are already there and helps establish a more robust or lasting type of microbial community.”
To foster a healthy microbiota, Tappenden suggests consuming healthy foods at every meal.
“There’s so much we don’t know about probiotics right now,” she said. “There’s too many unanswered questions right now that I think would justify the recommendation for someone to take something like this on a routine basis when we know we can do this naturally.”
But that doesn’t mean that probiotics won’t play a role in the future of intestinal medicine, especially as more and more patients consume them.
“I think the big thing for the future of probiotics research are, one, understanding the matching of particular probiotics to particular disease entities, two, identifying unique molecules within already known probiotics that can be harnessed for their power to modify physiology,” Ciorba said.
FDA regulation and approval is also something that patients and medical professionals can expect to see in the future, although it will be difficult to regulate the current over-the-counter medications. Regulation might come once the medications are more uniquely targeted to specific medical conditions.
But for people currently hoping to find a probiotic to relieve gastrointestinal pain, it is not difficult to become educated enough to make an informed selection at the drugstore, said Mary Ellen Sanders, the dairy and food culture technologies executive director at the International Scientific Association for Probiotics and Prebiotics.
Her organization has developed consumer guidelines describing different probiotics and are available on its websites.
For those who are already taking a probiotic and happy with their results, Sanders said there’s no reason to stop taking it.
“The way I tend to advise people is if they have a product that they use and that works for them, that’s great,” she said. “Just because a product isn’t tested doesn’t mean it won’t work, it just that you really can’t recommend the product because it’s not tested.”