How to Find the Best Probiotic for You

Photo: LIgorko / Getty Images

These days, there are a lot of people taking probiotics. And considering they can help with everything from digestion to clear skin and even mental health (yup, your gut and brain are definitely connected), it's easy to understand why they've become so popular.

Because there's a huge variety of probiotic products available on the market, many people struggle to find the right one for them. "There are many different strains of bacteria in different combinations within different probiotic supplements," explains Brooke Scheller, a clinical and functional nutritionist. "For example, a probiotic may contain a single strain of bacteria or many. It may also contain other vitamins, minerals, or other ingredients that may tout health benefits," she says. There are many different dosages, delivery systems (powder, tablets, capsules), and formulations (refrigerated vs. shelf-stable), and some probiotics also contain prebiotics, which basically act as fertilizer for the probiotics. (Related: Why Your Probiotic Needs a Prebiotic Partner)

What's more, there's still a lot more to learn about the microbiome and probiotics, in general. "Truth be told, the research area of probiotics and health is still pretty much in its infancy," says registered dietitian Kate Scarlata. Research is growing in the area of gut microbiome daily-but it is much more complicated than first thought." With all these options and major gaps in the available information, where are you supposed to start? Here, gut experts narrow it down to three simple tips for picking the right probiotic for you.

Step 1: Read the fine print.

Finding the right probiotic for you starts with reading the label. The most important elements, according to Samantha Nazareth, M.D., a double board-certified gastroenterologist:

CFU: This is the number of "colony forming units" present in each dose, which are measured in the billions. And while more isn't always better, "you want at least 20 to 50 billion CFU," says Dr. Nazareth. Just for reference, a very high dose is 400 CFU, which most experts agree is not necessary unless your health care practitioner specifically recommends this for you. It's also important to check for the guaranteed CFU upon expiration, which should be listed clearly. "Some products only guarantee the CFU number at the time of manufacturing, therefore will be less potent by the time the product reaches your home," she says.

Method of delivery: "The probiotic needs to be able to survive the acidic environment of the stomach and reach the intestine," explains Dr. Nazareth. This can be optimized through the way you take the probiotic and what's included in the formula. "Some delivery systems to consider are time-released tablet/caplet, capsules with an enteric coating and/or microcapsules, and ones that contain prebiotics and the optimal combination of probiotics," says Lori Chang, a registered dietitian with Kaiser Permanente in West Los Angeles.

Species of bacteria: You want to look for the proper species for the condition you are treating, says Dr. Nazareth. More on that below.

Third-party testing: Lastly, it's important to remember that probiotics are an unregulated supplement. "Find out whether there is third-party data verifying the potency, purity, and effectiveness of the product," suggests Dena Norton, a registered dietitian and holistic nutrition coach. "Remember that dietary supplements aren't regulated, so you can't necessarily just trust the claims on the label." Check out AEProbio, a site that has compiled research on specific brands of probiotics available in the U.S., recommends Scarlata, and an NSF seal is always a good marker to look for.

Step 2: Be specific.

Experts agree that this is the most important factor to consider in choosing a probiotic. "You should absolutely choose a probiotic based on what you are looking to address," says Chang. "Because strain specificity will impact outcomes, it is important to consider that one strain that works for one condition will not necessarily be effective for other conditions."

And though this may come as a surprise, it's not recommended to take a probiotic *just because.* "Not everyone needs a probiotic," says Dr. Nazareth. (If you're not having symptoms and you just want to improve your gut health overall, try adding some fermented foods to your diet.)

That's because issues that can be treated with probiotics stem from specific imbalances in the amount of certain bacterial strains, according to Elena Ivanina, M.D., a gastroenterologist at Lenox Hill Hospital. "Therefore, if someone decides to supplement a particular strain of Lactobacillus, but they already have enough of that strain in their gut and their disease does not stem from a lack of Lactobacillus, then they will not have a response." Makes sense, right?

While this isn't necessarily an exhaustive list, Drs. Nazareth and Ivanina recommend following this quick research-based guide to which strains to look for to help with various issues:

General Gut Symptoms and Digestive Health: Bifidobacterium species such B. bifidum, B. longum, B. lactis, and Lactobacillus species such as L. casei, L. rhamnosus, L. salivarius, L. plantarum. You'll find both species in Ultimate Flora Extra Care Probiotic 30 Billion.

Lactose Intolerance: Streptococcus thermophilus can help you digest lactose.

Antibiotic-Associated Diarrhea: Saccharomyces boulardii and Lactobacillus acidophilus and Lactobacillus casei.

Ulcerative Colitis: VSL#3 and E. coli Nissle 1917 are good options.

Bacterial Vaginosis and Yeast Overgrowth: Lactobacillus species, such as L. acidophilus and L. rhamnosus.

Eczema: Lactobacillus rhamnosus GG can reduce risk of eczema.

Step 3: Be open to trial and error.

Every person's microbiome is different, which means what worked for others might not work for you. "What you eat, whether you were born by C-section or vaginally, what antibiotics you have been exposed to, and whether or not you have ever developed food-borne illness are just some of the many factors that impact your gut microbiome," explains Scarlata. And while research can help you determine which strains to take at which dosages, there may still be several different formulations to choose from.

Once you've selected a probiotic to try, know that it could take up to 90 days to notice an improvement, according to Dr. Nazareth. It's also important to note that digestive problems could worsen when you first start taking probiotics. "If this occurs, you may need a smaller dosage with a gradual increase," she says.

Plus, lifestyle factors, such as overuse of prescription antibiotics, emotional stress, other prescription medications, alcohol consumption, smoking, and poor sleeping habits, can have an impact on how well your probiotics are working. Chang says that probiotics need the right environment (in this case, a healthy body) to colonize.

If you've tried a probiotic after following these steps and it doesn't seem to be working for you (or you just want some extra guidance in choosing one), head to your doctor (or a dietitian) to get a recommendation. "Have a thorough discussion with your doctor to make sure you are taking the appropriate bacterial strain for the appropriate reason," advises Dr. Ivanina. "Then, follow up after taking the probiotic to make sure it is having the intended effect."