A plant in a pot on the sidewalk outside of a health food store, it’s tag reads “Kombucha Inside”.

Welcome to our probiotic blog series! After realizing that we’ve only scratched the surface on the diverse world of probiotics, you may find yourself with even more questions than you originally had, including “how many strains of probiotics are there?” or even “what are the top 3 probiotic strains?”. Luckily we are going to answer some of these burning questions for you, letting you in on the secret benefits that lie within these tiny helpful bacteria species and dive deeper into probiotic specifics, including names of probiotic strains and what they do. We’ll also touch on the meaning behind some confusing words commonly found on probiotic bottles, such as CFU or multi-strain probiotics. Our hope is that this article serves as a more in depth “FAQ” for any question you might have had or even will have in the future regarding the diverse world of probiotics!

Meet the Main Characters

Let’s start with who’s who in the probiotic world. While there are a number of species, some of the most common ones found in probiotic rich foods and supplements include: Lactobacillus, Bifidobacterium, Bacillus, Saccharomyces, Streptococcus, and Enterococcus. Lactobacillus may be one of the most popularly known probiotics, found in many fermented dairy foods such as yogurt and kefir. One lactobacillus strain in particular, Lactobacillus plantarum(L. plantarum) has been found to have its own unique set of benefits, including supporting the body’s immune system and supporting the gut-bacterial balance in our digestive tract.* Surprisingly enough, L. plantarum already naturally lives in our GI tracts, saliva, vaginal and urogenital tracts. It is also extremely acid-tolerant, which helps allow it to be particularly tolerant to extreme conditions of our bodies and even helps it have a very wide range of application in the probiotic food and beverage industry.

While Lactobacillus may win “most popular” in the probiotic superlative competition, there are so many other beneficial strains that stand out on their own. One of these include probiota bifido, or more specifically, Bifidobacterium longum (B. longum), which have shown to potentially have many promising benefits in recent studies, including supporting the immune system and supporting healthy gastrointestinal health.* B. longum doesn’t just help support adult digestive health, but can also help babies’ gut health as well! One specific B. longum strain, B. longum KABP-042, has been clinically-tested to reduce fussiness and crying associated with an occasional upset tummy in both breast and formula fed babies.* As far as food sources for adults go,B. longum is easy to find in several different foods including cow and goat dairy products (such as yogurt and kefir), miso soup and is even found in seaweed.

Our third hero-probiotic is called Bacillus coagulans (B. coagulans) and may tout many of the same potential benefits as our probiotics discussed above such as helping to support the immune system, and studies have shown it may support gastrointestinal bacterial balance.* B. coagulans also assists in aiding healthy digestion.Bacillusand Bacillus coagulans is found in various fermented foods such as kimchi, yogurt, and sauerkraut, but is also available in supplement form, including SmartyPants probiotic supplements for adults and kids.

Black cat licking yogurt from spoon his pet owner at home kitchen.

Choosing Your Probiotic

Now that we’ve learned a little bit about specific types and benefits of some of the most commonly known probiotic strains, let’s try and answer the age-old question of “how do I choose?” The answer may be simpler than you thought, because for general gut health and overall wellness, it may be most advantageous to receive benefits from all of the different types of probiotics out there. Ensuring diversity and variety in your probiotic and prebiotic sources can be helpful in unlocking the benefits from these friendly helper organisms—and can even help ensure you are getting benefits that scientists aren’t even aware of yet! Many supplement companies are now offering multi strain probiotic options to ensure you are getting a greater variety of potential probiotic benefits.

And finally, to cap off our probiotics deep dive, let’s discuss one of the most confusing words that is found on a probiotic bottle—CFU, which stands for “colony forming units” or the number of live probiotic strains in each serving listed on the back of the bottle. Now the actual “ideal” number of CFU per serving to look for is a little more complicated, and although many probiotic supplements claim, “the more the better”, that may not always be the case as their benefits can vary based on survival rates of the probiotics and the type of strain or strains. Probiotic servings may also be different for adults, children, and infants. In fact, both the National Institutes of Health and the World Gastroenterology Organisation do not state a general “recommended amount” for probiotics, but rather encourage speaking to your physician regarding specific serving amounts and strain recommendations. Lastly, a final tip to ensure you are getting the most out of your probiotic supplement is to make sure that the supplement company lists the total CFU number accompanied by an expiration date or “use by” date, rather than listing the CFU number “at time of manufacture.” This ensures the total number of CFU listed will still be alive and active up until the expiration date, by taking into account the natural lifespan of the active bacteria in the product.

A Happy and Healthy Gut

All in all, probiotics are slowly but surely becoming more and more widely viewed and accepted as a powerful component in supporting our overall health and wellness. More evidence based studies are being done to confirm other probiotic benefits, but until then, my suggestions as a Registered Dietitian to get the most out of potential probiotic benefits are to always eat a variety of fermented, naturally prebiotic and probiotic-rich foods (see part 1 of our probiotic series for a full list) and also take advantage of probiotic supplements from trusted companies to even further support your health and wellness. In addition, make sure your research is science-based, comes from reputable sources such as peer-reviewed journal articles, and is backed by clinical studies or testing. With all of this in mind, optimizing your gut-health is perfectly achievable with so many different probiotic options now--the sky is truly the limit for a happy and healthy gut.



Kristen Espinosa MS, RD is a Registered Dietitian with a Master of Science degree in Nutrition. She works with nutrition clients virtually and in the Los Angeles area, and has also worked as a Clinical Dietitian for UCLA Medical Center, Cedars-Sinai Medical Center, and Children’s Hospital Los Angeles.
*This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.