Few supplement categories are as popular these days as probiotics. Twenty years ago, probiotics were relatively obscure and found only in health food stores, but now you can find them at your local big-box store or supermarket.
Popular as probiotics have become, most people (even those who take them daily) probably can’t tell you what they are or how they work. “There has been a slight evolution of the definition,” explains Matthew Ciorba, M.D., a gastroenterologist and professor of medicine at Washington University in Saint Louis. “Essentially, probiotics are living microorganisms — typically bacteria, but some yeasts — that confer a health benefit when taken in adequate amounts.”
Probiotics use increased 66% in the first five months of 2020.
According to the International Scientific Association for Probiotics and Prebiotics (ISAPP), these beneficial bugs help support our natural microbiota — a complex system of trillions of microorganisms that live in and on us and help to keep us healthy. Though probiotics are often associated with improved gut health, they don’t typically take up residence in the gut; rather, they confer benefits on their way through the microbiome and help our natural ecosystem thrive. Some can even alleviate a number of digestion-related symptoms, including gas, bloating, occasional constipation, or diarrhea, but no one probiotic does it all. So if you’ve been lurking around the supplement aisle eyeing the probiotics and unsure which to try, here’s a guide to help you choose one.
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Know Your Strains
If you’re starting a probiotic regimen, the first thing you need to think about is strains. “Strains are the subtype of specific bacteria types,” Dr. Ciorba explains. “For example, Lactobacillus is a common genus of bacteria that includes probiotics. However, there are several species [types] of Lactobacillus (e.g., acidophilus), and then strains would be a specific genetic subtype of L. acidophilus.”
Not all strains are created equal, says registered dietitian Desiree Nielsen, author of Eat More Plants. “There are many individual strains of acidophilus with different genetics, and therefore, different potential effects on human health,” she explains. “Some have no effect. Others are probiotics. Because every single strain of bacteria is unique, you can’t really extrapolate the research on one strain to another.”
Dr. Ciorba agrees. “When one sees a general claim that ‘Lactobacillus acidophilus is good for this or that,’ the study was conducted on a specific strain with unique attributes that may not be generalizable to all L. acidophilus.”
“What’s most important if you’re going to spend your money on a probiotic supplement,” says Nielsen, “is to use a probiotic strain—or combination of strains—that has been researched in human clinical trials.”
For example, Bifidobacterium longum 35624™ (which can be found in Align Probiotic 24/7 Digestive Support*§) helps relieve occasional symptoms like bloating, gas, and abdominal discomfort and is the #1 recommended strain by doctors and gastroenterologists.*‡ Bifidobacterium lactis, BB-12® has been shown to help with digestive health while also helping to boost immune health.
Not all probiotics are the same — different strains have different effects.
Luckily, you don’t have to memorize all these hard-to-pronounce names or wade through reams of scientific studies to find the strain you need. “There’s a really easy-to-use tool called Probiotic Chart,” says Nielsen. Each year, this independent list of Canadian and American probiotics|| is updated, clearly reporting which ones have been researched for which conditions. “It’s a game changer,” she says. Included in the chart are common conditions that may be helped by probiotic use. All you have to do is search for the problem that troubles you, see which strain of probiotics has been shown to help ease it, and find a product that contains that strain.
Count Your CFUs
Once you’ve identified the specific strain you want, all three of our experts recommend paying attention to the number of CFUs in any product you consider buying. Short for “colony forming units,” CFUs are “essentially the [number] of bacteria that can be isolated from a sample,” Dr. Ciorba says.
In this case, more isn’t always better. “A 100 billion CFU product is not automatically better than a 50 billion CFU product,” Nielsen says. “What matters is that the dose of the probiotic matches the dose that was effective in clinical trials. Some probiotics are highly effective at one billion CFU. Others are only effective at 50 billion CFU.” Proper doses can be found in the aforementioned Probiotic Chart and confirmed on labels of quality probiotics.
Know the Possible Side Effects
While rare, side effects occasionally occur from probiotic supplementation. “In the beginning, some people may notice more gas or bloating after starting a probiotic,” Collins says. “It can take time for the gut to adjust to the shifting microbiota. Starting with the lowest recommended dose, drinking plenty of fluids, and consuming adequate fiber can help reduce symptoms in the gut.”
“Probiotics are generally very safe,” Nielsen says. “But in our practice, some people have reported nausea or constipation from a probiotic. If that’s the case, and [it lasts longer than] a day or two, stop taking it.”
The bottom line? You should discuss probiotics, and any other supplements, with your health care provider before taking them to confirm what is right for you. According to Collins, people with significantly compromised immune systems could be susceptible to infections. “And anyone on immunosuppressive drugs should never take a probiotic without the express recommendation of their medical team,” adds Nielsen.
Evaluate Whether Your Probiotic is Working
The person most qualified to determine the effectiveness of your probiotic may not be your doctor or dietician — it could be you. Pay close attention to how you’re feeling while also tracking how long you’ve been taking a given product. If you’re not noticing any effects after giving it at least a month, that could be a sign it’s not the right strain for your specific needs.
Give your probiotic at least a few weeks to see if it’s having an effect.
Some benefits take longer than others to notice. “The amount of time it takes to see benefits with probiotic supplements depends on a lot of factors,” says Collins. “For general gut health, benefits may not be noticeable at all,” but those good probiotic bugs can still be busy helping to promote your digestive health.
For occasional digestive issues, probiotic effects should be evaluated over the course of a few weeks to a month, says Dr. Ciorba. “It’s up to [you] to determine whether it’s really leading to a benefit — less G.I. distress, for instance.”
It can take some trial and error to find the right product; programs such as the Align Healthy Gut Team Up can be a great place to start. Align is bringing together medical professionals and real probiotics users to help educate people on the benefits of probiotics and how to use them. Plus, you’ll get $2 off your first month of Align Probiotics for joining. Shop wisely and keep these basics in mind, and you should get the most out of any probiotic regimen.
§Fortifies your digestive system with good bacteria 24/7 with continued daily use.*
‡Among Doctors and Gastroenterologists who recommended a brand of probiotic in a ProVoice 2022 survey.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
||Procter & Gamble is a member of the alliance for education on probiotics that provides an unrestricted educational grant to support the creation of the probiotic guide.