Do Shelf-Stable Probiotics Still Work in Foods That Aren't Refrigerated?

The probiotics market is expected to be worth $95 billion by 2028, according to projections from Grand View Research, so interest doesn't seem to be waning any time soon.

Despite their acclaim, there's still a lot we don't know about probiotics, and attempting to decode their many labels can be confusing: The various strains, amounts of Colony Forming Units (CFUs) and the beneficial bugs cropping up in foods like nut butter and cereal are all worthy of a critical eye.

As the market grows, and as more shelf-stable food products and supplements come around, one question continues to come up: Do probiotics need to be refrigerated to work? Let's dig in.

Here's some good news: Shelf-stable probiotics — aka the ones that don't require refrigeration — are effective.

Not all probiotics have to be refrigerated, as once believed. It really all comes down to the strain.

Some strains are fragile and require a specific and stable environment because they lose their viability if they're exposed to heat, oxygen, light or humidity, according to the Cleveland Clinic.

Other types of probiotics don't require refrigeration ​and​ they're stable enough that they don't require a coating or encapsulation to remain viable when taken either.

The short answer: not necessarily.

What's most important is understanding what you're taking and why. Specific strains have specific benefits (that have been backed by science), and that's what we should be focused on.

"There is no rule of thumb regarding how many different strains. Go with the product that has evidence," Mary Ellen Sanders, PhD, executive science officer of the International Scientific Association for Probiotics and Prebiotics (ISAPP), tells LIVESTRONG.com.

"If you are just looking for adding live microbes to your diet, then choose as many or as few as you'd like. Regarding CFUs, the argument is the same: Use what the evidence requires."

Simply put, the best dose is the one that has been tested in humans and shown to provide positive outcomes. Most probiotics have been tested at levels between 1 and 10 billion CFUs per day, according to the ISAPP.

Here's a list of specific strains of bacteria backed by a significant amount of research.

"I would look for a product that lists strain designations of all strains in the product and CFU at the end of shelf-life (not at the time of manufacture)," Sanders says.

"There are a few quality seals, such as the USP-verified supplement seal, that are meaningful, but there are also other seemingly quality seals you sometimes see on supplements that have nothing backing them."

The ISAPP shares specifics of to look for on a label, including:

• ​Recommended use:​ This term tells you what benefits you can expect from the product. The claim must be accompanied by a disclaimer stating that the FDA has not reviewed these claims.
• ​Use-by date:​ This date tells you how long the probiotic will have enough levels of the live microbes to deliver the claimed benefits on the label.
• ​Dosage usage:​ The amount that needs to be taken; a serving or dosage.
• ​CFUs:​ The CFU listed is usually a total count, although a specific number for each strain is preferred.
• ​Genus, species and strains:​ You need all three of these to know what probiotic you are getting.
• ​Company name and contact information:​ So you can conduct additional research on your own, if needed.