Walk into any grocery or health food store, and chances are you’ll see a section dedicated to probiotic supplements. In the past few years, they’ve become popular health aids that promise to improve digestion, mood, energy—and the list continues.
It’s thought that these supplements, which are industrial-made groupings of different strains of bacteria, can enhance the bacteria living in our digestive systems. Our bodies are filled with several thousand species of beneficial bacteria living on us and inside of us, called the human microbiome. Each species plays a different role in protecting our health and supporting our immunity. The bacteria living in our large intestine (gut microbiome) help break down food and keep the digestive system running smoothly.
"Many of us, however, have a lower diversity of beneficial bacteria than we should," says M. Elizabeth Swenor, D.O., a functional lifestyle medicine physician with Henry Ford Health. "Overuse of antibiotics, which kills the good bacteria along with the bad, is one reason for this. A societal emphasis on being germ-free may also contribute to a lower diversity of beneficial bacteria. Processed diets filled with refined sugars and oils, saturated fats, preservatives and artificial sweeteners can also lower bacteria diversity, as it makes it difficult for the good gut bacteria to thrive.
While probiotic supplements can be helpful, they should be used under a doctor’s supervision—not self-prescribed. Here, what you should know before taking a probiotic supplement.
There’s not a lot of data for or against probiotics.
“We only discovered the human microbiome in 2008, so there’s a huge gap in what unregulated free marketing promotes and what science has actually proven,” says Dr. Swenor. “Medically, evidence has shown that probiotic supplements may prevent antibiotic-associated diarrhea (AAD). In premature infants, probiotics may prevent sepsis and an intestinal disease called necrotizing enterocolitis, and in babies, it may treat infant colic. In adults, probiotics may treat periodontal disease and ulcerative colitis."
Off label, however, probiotics are used by the general public for prevention and treatment of illnesses and diseases, but in most cases, we still do not know which bacterial species are helpful and which are not.
Probiotic supplements are not regulated by the Food and Drug Administration (FDA).
“All supplements fall under the category of food, and food doesn’t have to meet the stringent criteria that prescriptions do,” says Dr. Swenor. “Probiotics are listed with the FDA as a food ingredient, a dietary supplement, or a drug. Most probiotics are listed as a dietary supplement and do not require FDA approval before they are released to the public.”
General probiotic supplements may or may not have research backing their use, their outcome, or their function. Companies don’t have to put risks on the label. They’re not obligated to follow science. Some companies take it upon themselves to get a pharmaceutical-grade certification, which is the highest quality category of over-the-counter supplements, but it’s not required. If a probiotic is going to be marketed as a drug for prevention or treatment of a disease, it must be proven through clinical trials as being safe, effective and approved by the FDA.
“Unless you take a probiotic supplement with a pharmaceutical-grade certification, or one that’s recommended by your doctor, you cannot be sure that what’s on the bottle matches what’s inside the bottle,” says Radhika Aggarwal, M.D., a gastroenterologist with Henry Ford Health.
It’s important to choose the right supplement.
If you have a gut bacteria imbalance, chances are it’s a specific strain you’re lacking and you need a supplement to fill in those gaps—a one-size-fits-all probiotic probably won’t work.
“I don’t prescribe a probiotic supplement without evaluating the patient with a comprehensive stool analysis,” says Dr. Swenor. “And I often don’t prescribe a probiotic supplement at all, but instead advise patients to eat a predominately plant-based diet.”
Fiber from fruits and vegetables are prebiotics, or food for probiotics that help them grow and proliferate. Most of the time you just need to eat more plant-based foods like fruits and veggies.
Probiotic supplements may cause bacterial imbalances.
Generally speaking, the higher diversity of bacteria that lives in your gut, the healthier you’ll be, says Dr. Swenor. If you keep taking one probiotic supplement over long periods of time, the species of bacteria in the supplement could crowd out the other species in your gut and create a low diversity of bacteria.
“It’s like a garden—if you continue to seed your garden with one certain flower, that one will grow and potentially overpopulate and push out the other flowers,” says Dr. Swenor.
Probiotic supplements may be harmful for people who are immunocompromised.
Whether from a digestive condition like short bowel syndrome, an organ transplant, an autoimmune disease or cancer, anyone with a compromised immune system may react poorly to probiotic supplements. “There’s evidence that these bacteria can be dumped into the bloodstream and create an immune response,” says Dr. Swenor.
There are, however, situations where probiotics have been beneficial using strain-specific supplements. “Studies have shown that immunocompromised patients who are in remission with illnesses such as ulcerative colitis have been prescribed strain-specific probiotics under medically monitored treatment plans,” says Dr. Swenor
The takeaway? It’s important to work with your doctor and not just take a supplement of your own choosing.
In some people, probiotic supplements could cause brain fog, dizziness or headaches.
There are several theories as to why probiotic supplements can cause neurological difficulties like brain fog, dizziness and headaches, but one theory is that they may create intestinal inflammation that affects the neuroendocrine system, says Dr. Swenor. (This is part of the mind-gut connection.)
“And not everyone responds the same way to certain pills and medications,” says Dr. Swenor. “We know that, for example, I could take an antibiotic and have no side effects, but you could take it and have nausea. A probiotic should be used like a prescription because not everyone will respond the same way. They should be used with caution.”
When in doubt, it’s probably better to eat probiotics than to swallow them from a pill.
“Any time you can get a nutrient or probiotic from food in its natural state, it’s better than getting it from a supplement,” says Dr. Aggarwal. Try yogurt, kefir, kimchi and sauerkraut, which go through a natural fermentation process and contain naturally occurring probiotic bacteria.
But before trying anything new, if you have digestive issues and you think probiotics would help, it’s best to see your doctor for advice.
To find a doctor at Henry Ford, visit henryford.com or call 1-800-HENRYFORD (436-7936).
Dr. M. Elizabeth Swenor leads the functional and lifestyle medicine team and sees patients at Henry Ford Medical Center in Bloomfield Township. Learn more about Dr. Swenor and read her articles.
Dr. Radhika Aggarwal is a gastroenterologist specializing in digestive disorders. She sees patients at Henry Ford Hospital in Detroit and Henry Ford Medical Center -- Fairlane in Dearborn.
