What do probiotics do? Here's what to understand before taking them
Within the world of dietary supplements, vitamins and minerals are king. But just behind vitamins and minerals such as vitamin A, vitamin C, vitamin D, calcium, iron and magnesium, exist a variety of other popular supplements known as probiotics. One 2012 National Health Interview Survey (NHIS) shows 4 million Americans taking them monthly, but more recent data shows that the global probiotic market size has grown considerably since then, reaching close to $60 billion nearly a decade later.
"The probiotic industry has grown over the last several years and multiple probiotic products are available for consumers," explains Jamie Bering, MD, a gastroenterologist at Mayo Clinic in Arizona. Despite the popularity of such products, "more rigorous studies are needed to help us understand which bacterial strains of probiotics are best for which disease state, optimal doses and the ideal way to deliver them," she adds.
What are probiotics?
Probiotics are living microorganisms that are intended to have health benefits when consumed or applied to one's body, according to the National Center for Complementary and Integrative Health. They can be found in food products, dietary supplements and beauty products. Many microorganisms also exist naturally in the body's gut flora − an area where millions of both good and bad bacteria live. "Probiotics are intended to confer health benefits by helping to influence and maintain the number of good bacteria found in the human gut," explains Bering.
Jen Messer, MR, RDN, LD a nutrition consultant and lead registered dietitian at Jen Messer Nutrition, says the best food sources of probiotics "are primarily fermented foods" such as yogurt with live and active cultures, some cottage cheeses, and a fermented milk drink called kefir that's "rich in probiotics and can be a good source of beneficial bacteria." Probiotics can also be found in sauerkraut, kimchi, some versions of soybeans and traditional pickles. In all such cases, "look for unpasteurized varieties," advises Messer.
The unpasteurized, live-culture version of such foods is essential because it's the live nature of probiotics that makes them beneficial. While many people think of living microorganisms and bacteria as unsavory or filled with germs, some bacteria, including the probiotic variety, are actually quite helpful.
What do probiotics do?
Such good bacteria produce vitamins and work against the bad bacteria within one's gut to destroy disease-causing cells. "Probiotics can also help with the movement of food through your digestive tract by affecting the nerves that control all types of movement within the gut," explains Lisa Young, PhD, an adjunct professor of nutrition at New York University and author of "Finally Full, Finally Slim." She adds that probiotics can also be helpful in "restoring good bacteria in your gut if the gut is unbalanced."
Messer says that many purported health benefits "continue to be investigated," but says that other potential health benefits of probiotics include reduced inflammation, a boosted immune system, increased metabolism, reduced appetite by increasing satiety or fullness and improved mental health. "There is evidence to suggest that certain strains of probiotics may have the ability to produce compounds that can influence neurotransmitters and other signaling molecules involved in mood regulation," she says. This gut and brain communication is known as the gut-brain axis.
Bering agrees the many such benefits may exist but echoes Messer in saying that some medical recommendations and guidelines are conflicting, and that "there is still a lot to learn about where and when probiotics are truly effective."
Who benefits most from taking a probiotic?
There is also reason to believe that some people benefit more from taking probiotics than others. For example, Young says that individuals taking antibiotics, those with mood disorders, people with diabetes or blood sugar concerns, cancer patients, babies, allergy sufferers, and people with easily upset stomachs or ones dealing with constipation may benefit especially from taking a probiotic. "These populations should discuss with their healthcare provider about taking probiotics as it can have beneficial effects on their GI tract," she advises.
Messer adds that people experiencing a lot of stress might also benefit from getting more probiotics either through diet or supplementation. "Stress can impact the gut microbiome and probiotics may provide support," she says.
It's also worth noting that some probiotic products are considered safer than others. While the Food and Drug Administration (FDA) does not regulate dietary supplements the same way it regulates food and drugs, how a probiotic is marketed affects how much oversight it has. Dietary supplements, for instance, do not have to get FDA approval to be marketed and sold − though they do need approval to make certain claims. On the other hand, probiotics found in food and drugs, have to meet stricter requirements and must be proven safe before being sold.
Because of this, if one is considering taking a probiotic supplement, "it is recommended to consult a healthcare professional for reputable brands of probiotics and product recommendations," Messer suggests. "Your healthcare provider can also determine the appropriate strain and dose of probiotic for your specific needs as well as consider any potential interactions with medications or existing health conditions."
This article originally appeared on USA TODAY: What do probiotics do? Benefits plus who should take them
