In terms of maintaining a the most nutritious eating regime, the saying “the more the merrier” can apply to stocking your fridge with a variety of fresh fruits and veggies, refilling your water bottle to meet your daily H2O needs, and feasting on fermented foods to support your gut and greater health. But when it comes to probiotic foods and supplements, does the same adage apply when it comes to colony forming unit (CFU) counts?

To see what the real deal is concerning probiotic CFU counts and how much they really, well, count in the general scheme of things, we reached out to microbiologist Miguel Freitas, PhD, VP of Health and Scientific Affairs at Danone North America.

First, what are CFUs?

CFUs are a unit of measure indicating the amount of live and active organisms in probiotic foods and supplements. “Because probiotics are microorganisms, you will find that values of CFUs are usually in the order of billions per serving or billions per milliliter,” Dr. Freitas says. “The value indicates the quantity of microbes or cultures, but not necessarily whether or not the bacteria provides a gut health benefit.”

Is a higher probiotic CFU count always better?

In one word: nope. This fact might come as a surprise, especially in light of findings from an August 2021 Danone survey of 1,004 adults in which 59 percent of respondents believed that more CFUs in a given product yielded greater efficacy.

“This is a common misconception, but higher CFU counts aren’t necessarily better,” Dr. Freitas clarifies. What *is* better, however, is a product that contains “the specific strain at the same amount as what was shown to be effective in human studies using that product.” In essence, any probiotic foods or supplements worth buying will contain specific strains at precise amounts that demonstrate clinically-proven benefits at those levels.

Similarly, another key factor that far outweighs the actual measure of CFU counts (at face value) is that the probiotics will survive long enough to make it into your system and actually yield a given benefit. “For example, Activia yogurt includes a signature probiotic culture Bifidus (Bifidobacterium lactis DN-173 010/CNCM I-2494), plus four additional live cultures. The Bifidus culture was specifically selected because of its ability to survive passage through the digestive system and reach the large intestine in sufficient amounts,” Dr. Freitas says. Another must-know tip: “You should avoid products stating CFUs at ‘time of manufacture’ because those do not account for declines in probiotic numbers during storage,” he adds.

In other words, consumers need to dig deeper and go beyond merely seeking the highest CFU counts—as well as read the fine print to make sure that the number of CFUs listed will remain intact from product development to delivery and all the way to your digestive system.

Are more probiotic species and strains better?

Sometimes, you’ll see that a probiotic food or supplement contains a blend of species and strains—sometimes across a range of genera (e.g. Lactobacillus, Bifidobacterium, Bifidobacterium)—which may also lead you to default back to that “more the merrier” mentality. After all, diversity is the name of the game when it comes to gut health, right? Well… not so fast. Piggybacking off the mythbuster above, a probiotic that contains a variety of strains (within or across genera or species) also doesn’t inevitably mean that it’s superior.

“Again, specific strains are linked to different benefits,” Dr. Freitas says. “Experts have suggested that most probiotics have strain-specific mechanisms of action, but sometimes the same species and genus can have similar benefits.” For example, some—but not all—Lactobacillus will offer similar benefits, yet “without studying the specific strain there is no way to know which bacteria provide benefits and which do not,” he continues.

Read: Precise and conclusive research, rather than a higher amount of CFUs or strains, is most important. One probiotic strain at a lower CFU count can be just as effective as a dozen strains across genera to yield a given benefit—so long as all the numbers match up to said benefit that has been proven to be effective in a clinical setting.

A smarter way to shop for probiotics

As we can see, navigating the world of probiotics (including all the murky—and sometimes outright misleading—messaging) will take some due diligence. However, it’ll be well worth your efforts if you want to find the best probiotic foods and supplements that will actually yield results for your unique concerns. With that said, heed these final tips before making your next purchase.

1. Know the basics

“Some consumers understand the differences between strains and that not all probiotics are the same, while others believe that all cultures are probiotics that have the same benefit,” says Dr. Freitas. Different strains and probiotic blends should be formulated correctly to yield a certain benefit, which can include anything from helping to clear your skin, support immunity, or promote regular bowel movements. Figure out what benefit you’re seeking most and take things from there.

2. Seek out transparency

“I always say that not all probiotics are created equal,” Dr. Freitas continues. “There are many probiotic products that are dubious in their quality and making various claims, both in food and supplements that are unsubstantiated by neither science nor clinical studies.”

With that in mind, some brands will be more transparent than others. You’ll want to look for those that not only clearly list the strains, but also provide the evidence to back up the benefit(s) their product purportedly offers. “First, I would advise consumers to check the product label to see if the full strain name of the probiotic is listed,” Dr. Freitas says. “Then check on the company’s website to find out if studies were conducted and to learn more about the specific strains in the product.”

3. Get curious and put your detective skills to work

Even better than taking a company’s marketing copy to heart is to do your own research. Sure, you’ll likely have to work your way through some pretty dense terminology and data, but you’ll be all the more educated and empowered from it. Plus, it’s simpler than you may think.

Dr. Freitas suggests doing a quick Google search (tip: copy/paste a strain and add “Pubmed” to the search bar) to get a lay of the land. He mentions a few details worth keeping an eye out for, including but not limited to:

• How many studies have been conducted
• The sample size of the studies
• If the studies were conducted in healthy participants

In addition, it’s ideal if you can find a study that includes participants of a similar demographic and/or with the same concerns for you. “The study participants should mirror who will be actually consuming the probiotic if the benefit is to be expected,” Dr. Freitas concludes.