Probiotics are among the most popular of all dietary supplements, and sales continue to skyrocket each year. By 2023, probiotic supplement sales are projected to exceed 64 billion dollars (1Trusted Source).
People may take probiotics because they’ve heard they can help reduce symptoms of certain medical conditions, boost immune health, improve depressive symptoms, and even promote weight loss.
But are probiotics really effective? Should everyone be taking a probiotic?
If you and your healthcare team decide that you may benefit from taking a probiotic supplement, there are many excellent products on the market to choose from.
Depending on your needs, you may want to choose a single or multi-strain probiotic. If you’re unsure about the type of probiotic or dosage that you should be taking, ask your healthcare professional for advice.
This article explains what probiotic supplements are, who may benefit from taking one, how to choose the right kind, and our picks of the 9 best products on the market.
A quick look at the best probiotic supplements
- Best overall probiotic supplement: Culturelle Digestive Daily
- Best overall runner-up probiotic supplement: Align Extra Strength
- Best shelf-stable probiotic supplement: Bio-Kult
- Best affordable probiotic supplement: Jarrow Formulas Jarro-Dophilus EPS
- Best dairy-free probiotic supplement: Garden of Life Dr. Formulated Probiotics Once Daily
- Best allergen-friendly probiotic supplement: NOW Probiotic-10 25 Billion
- Best probiotic supplement for IBS: Klaire Labs Ther-Biotic Pro IBS Relief
- Best probiotic supplement for athletes: Thorne FloraSport 20B
- Best probiotic supplement for diarrhea: Florastor Daily Probiotic for Women and Men
What are probiotics?
Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host” (1Trusted Source).
Probiotics are naturally found in certain foods and your gut. For example, foods like kimchi, fermented yogurt, and sauerkraut can be natural sources of probiotics. Probiotics can also be added to foods during processing.
Beneficial bacteria reside in your intestinal tract and participate in a variety of important bodily processes, such as vitamin production, mood regulation, digestion, immune function, and more (2Trusted Source).
What are probiotic supplements?
Probiotics can also be taken in supplement forms, which contain high doses of a single probiotic strain or multiple probiotic strains.
Among all species of probiotics, Lactobacillus and Bifidobacterium species are by far the most commonly studied and added to probiotic supplements. These species are also the dominant strains in human intestinal tracts (2Trusted Source).
In addition to probiotic bacteria, probiotic yeasts like Saccharomyces cerevisiae (S. cerevisiae) and Saccharomyces boulardii (S. boulardii) can be taken in supplement form.
The seven main groups of probiotics most often used in supplements are Lactobacillus, Enterococcus, Saccharomyces, Bifidobacterium, Streptococcus, Escherichia, and Bacillus (3Trusted Source).
Probiotics are named by their genus, species, and alphanumeric strain designation. They may also have a subspecies. For example, a probiotic may contain a specific strain of Bifidobacterium called Bifidobacterium longum 35624 (B. longum 35624) (3Trusted Source).
Probiotics are measured in colony-forming units (CFUs). These units represent the number of viable bacteria per dose.
Products labeled as 1 x 109 CFU contain 1 billion viable or live bacteria per dose. Most supplements contain 1–10 billion CFUs per dose. However, some supplements contain much higher amounts.
To confer beneficial effects, probiotics must be taken in quite large doses. Researchers suggest that probiotics must contain at least 106 (1,000,000) viable CFUs per gram to be able to survive digestion and exert positive effects in the body (4).
It’s suggested that the minimum recommended effective dose per day is 108–109 cells or 100,000,000–1 billion cells (5Trusted Source).
Interestingly, probiotic manufacturers are only required to list the total weight of the microorganisms in the product on the label, including both live and dead microorganisms.
Because probiotics are quite vulnerable to factors like temperature change and storage time, many may no longer be viable by the time the product is purchased.
For this reason, the National Institutes of Health (NIH) recommends that customers choose products that include CFUs at the end of a product’s shelf life, which indicates that a product contains a therapeutic number of CFUs after the product is purchased (3Trusted Source).
Probiotic supplements have been linked to some health benefits. But while probiotic research has grown exponentially over the past 20 years, researchers are still learning about probiotics and their health effects when taken in supplement form.
How we chose the best probiotic supplements
We selected the best probiotics using the following criteria:
- Vetting. All the products have been vetted to ensure that they meet Healthline’s medical and business standards.
- Effective dose. All of the supplements below contain at least 106 (1 million) CFUs per gram.
- Ingredients. We looked for products that are made from high quality ingredients and free of artificial additives and fillers.
- Personal needs. Whether you need a specific probiotic strain or follow a gluten-free diet, we included options to suit a variety of needs and preferences.