How to choose a probiotic: a 7-point checklist

In a check of 13 probiotic products sold in the US in 2009, only 4 matched their label claims (Drago et al., 2010). That one finding explains why choosing a probiotic takes more than grabbing the bottle with the biggest number on the front.

You don't need a microbiology degree to choose well. Run through this checklist before you buy, and you'll sidestep the most common traps.

1. Name your goal first

"Better gut health" is too vague to shop for. A practical guide based on 249 trials concluded that probiotic effects are both strain-specific and disease-specific, and that matching the strain to the condition you're targeting is one of the most important factors in choosing (Sniffen et al., 2018).

So start with the specific thing you'd like to change, such as afternoon bloating, irregular bowel movements or diarrhea while taking antibiotics. Then look for strains that were studied for that.

2. Look for full strain names

Each strain should be listed with its genus, species and strain code, like "Lactiplantibacillus plantarum 299v." Without the code, there's no way to check what that exact strain was tested for.

Clear strain names matter for quality, too. In a study of 16 probiotic products containing bifidobacteria, only 1 matched its bifidobacteria label claims in every sample tested, and contents varied from pill to pill and from one production lot to the next (Lewis et al., 2016).

3. Match the dose to the research

Besides the strain itself, the same guide names the type of formulation, the dose used and the manufacturing quality and shelf life as key factors in choosing a product (Sniffen et al., 2018).

The number that matters most is the dose used in studies of your strain, not the largest number on the shelf. Check the CFU per serving, and per strain if the label breaks it down.

4. Check when the CFU count applies

"25 billion CFU at time of manufacture" and "25 billion CFU through expiration" are different promises. The first describes the product on the day it was made. The second describes the minimum you should still be getting on the last day you use it.

Storage is part of the picture. The researchers behind the US product check called for regular independent screening to monitor how storage affects product quality (Drago et al., 2010). Prefer a count guaranteed through expiry, and make sure you can follow the storage directions.

5. Look for signs of independent quality testing

A panel of probiotic quality experts has recommended that companies undergo third-party evaluations to certify quality and label accuracy. They note that a certification mark on the label helps, though not every manufacturer uses one (Jackson et al., 2019).

If there's no seal, ask the company how it confirms strain identity and CFU counts. A trustworthy brand can explain its testing in plain language.

6. Read the "other ingredients" line

Some probiotics add prebiotic fibers such as inulin, chicory root or FOS. These are fermentable fibers, and if bloating is the problem you're trying to solve, they can work against you. Here's what the research says about inulin and bloating.

While you're there, check for allergens you need to avoid, added sugar and, in gummies, sweeteners you don't tolerate well.

7. Set realistic expectations, and check safety

Even a well-chosen probiotic isn't a sure thing. When the American Gastroenterological Association reviewed probiotics for IBS, it found that 44 different probiotics or combinations had been tested, most of them in a single trial. The panel concluded that no single strain or combination had been studied rigorously enough, and it rated the overall certainty of the evidence as low (Preidis et al., 2020).

That isn't a reason to write probiotics off. It's a reason to approach one as a personal experiment: one product, taken daily, tracked for 8 to 12 weeks. Here's how to run that trial.

Before you buy, run a quick safety check:

• Talk to your doctor first if you're immunocompromised, seriously ill, have a central line, or are pregnant or nursing.
• Don't let a supplement delay a medical check for red flags like blood in your stool, unexplained weight loss, anemia or symptoms that wake you at night.
• New bloating that happens most days, especially with early fullness, pelvic pain or urinary urgency, also deserves a doctor's visit before any supplement.

As an example of what these checks look like on a real label, Daily Biotic lists three strains with full strain codes, a CFU count guaranteed through expiry, and no inulin or chicory root.

Sources

1. Drago L, Rodighiero V, Celeste T, Rovetto L, De Vecchi E. Microbiological evaluation of commercial probiotic products available in the USA in 2009. J Chemother. 2010;22(6):373-7. PMID 21303743
2. Sniffen JC, McFarland LV, Evans CT, Goldstein EJC. Choosing an appropriate probiotic product for your patient: an evidence-based practical guide. PLoS One. 2018;13(12):e0209205. PMID 30586435
3. Lewis ZT, Shani G, Masarweh CF, et al. Validating bifidobacterial species and subspecies identity in commercial probiotic products. Pediatr Res. 2016;79(3):445-52. PMID 26571226
4. Jackson SA, Schoeni JL, Vegge C, et al. Improving end-user trust in the quality of commercial probiotic products. Front Microbiol. 2019;10:739. PMID 31105649
5. Preidis GA, Weizman AV, Kashyap PC, Morgan RL. AGA technical review on the role of probiotics in the management of gastrointestinal disorders. Gastroenterology. 2020;159(2):708-738.e4. PMID 32531292

This article is for general information and isn't medical advice. Talk to your healthcare provider before starting a probiotic, especially if you're pregnant, nursing, immunocompromised or take prescription medication.