You’ve heard of probiotics. You know the basics: They aid with digestion and offer a host of other benefits. You want to incorporate them into your diet …but you’re not quite sure where to start. Here’s what you need to know.

How to read the label.

While most supplements are measured in milligrams, probiotics are measured in CFUs, with numbers in the billions. CFU stands for Colony Forming Units and refers to the number of live bacteria cells capable of dividing and forming colonies. You’ll want to look for dosages of at least 1 billion, though products can contain 50 billion or more. If you’re healthy and are looking for maintenance, aim for a dose of 1 billion to 5 billion CFUs per day.

Because probiotics must reach the intestines live and intact in order to produce results, choosing a stable supplement with bacteria count guaranteed through the product’s expiration date is critical. In other words, it’s not enough for a product to list the organism counts at the time of manufacture. Supplements must also be stable at room temperature (for storage purposes) and heat resistant (so they can travel through the body).

How to choose a probiotic.

“Probiotic” is a catch-all term for good bacteria. But there are many, many different kinds of bacteria in the gut – and on the shelves as supplements – and they each provide a different benefit. These different kinds of bacteria are organized into genus and species. For example; in the case of lactobacillus gasseri, “lactobacillus” is the genus, and “gasseri’ identifies the species. Taking this one step further, some (but not all) manufacturers include a strain code, which is a unique identifier of the strain, which can be traced back to its origins.

The type you choose will depend on your health goals. Strains in the Lactobacillus genus, for example, are generally helpful for boosting immunity and fending off allergies. Strains in the Bifidobacteria genus, on the other hand, are linked closely to digestive health and reducing gastrointestinal symptoms. Often, products will provide a combination of probiotics to encourage diversity in the gut for better overall health.

How to make it part of your routine.

It’s common to experience some mild stomach upset, gas or bloating when you first start taking probiotics. Some experts believe these fleeting symptoms are a result of the “bad” bacteria dying off in the new healthier environment. If symptoms are bothersome, try to avoid inflammatory foods (like sugary or processed options) and load up on anti-inflammatory antioxidants instead.

If symptoms persist, it’s possible that you are taking bacteria strains that may not be compatible with your system. You may want to try a different combination of probiotics that are in line with your health goals. While this process could take a little time and trial to find a match, it will be worth it for supporting your overall well-being.