What are Probiotics, Exactly? - Wakunaga of America
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What are Probiotics, Exactly?

You’ve heard of them. You know they’re good for you. But do you know why?

For a long time, the word “bacteria” was associated with germs and disease. But the reality is that the body is teeming with healthy bacteria that keep digestion, immunity and a score of other bodily functions in balance. Once people began to understand this, they looked for products and foods to help them maintain this balance. Enter probiotics. Probiotics refer to the specific live strains of “good” bacteria that help the body maintain wellness. They’re found naturally in foods such as yogurt, kefir, sauerkraut, kimchi and pickled vegetables, in supplement form and increasingly as additives in a number of functional food and beverage products.

How do probiotics work?

Once they arrive in an adequate host environment, these microbes can replicate. Generally, a moist environment is necessary for probiotics to stay alive. But in the case of supplements, if the bacteria are stabilized and dried properly, they remain alive and can start to grow and replicate again once they return to a moist environment (in this case, in your body).

When you supplement the body with probiotics, you’re essentially repopulating the gut with the healthy bacteria it needs to maintain a balanced microbiome (the collection of microbes that lives in and on the human body). The microbiome can be thrown off balance by a lack of sleep, antibiotics, stress, travel or a poor diet, so probiotics can play a positive role for many people.

Because the intestines are home to trillions of bacterial cells – not all of them friendly –introducing healthy bacteria into the diet through probiotic-rich foods or supplements can result in better digestive health. Probiotics also benefit immune health because the intestines house about 70 percent of the body’s innate immune function. Increasingly, scientists are also beginning to link microbial balance with body-wide benefits ranging from heart health to mental health.

What’s the difference between probiotics species?

In general, any probiotic supplement will help maintain or restore gut bacteria. But each probiotic genus – and the different species within that genus – performs a different role. Important to remember is that more may not be better when it comes to CFU count. Below are some general guidelines of CFUs to look for based on species, but be wary of claims that exorbitantly high numbers of CFUs are superior.

The microbiome affects almost every part of your body, your digestion, your immune system…even your allergies! One way you can support your microbiome is through a daily probiotic supplement. There are lot’s of top-notch probiotics out on the market, so how do you know which one is best for you? Here are some tips to help you get started.

Finding the right probiotic for your needs means looking a little deeper into the genus, species and strains, [link to blog that explains these- think we have one right?] and really assessing what specific benefits you are looking for. There are dozens of friendly bacterial species found in commercial probiotics, and they all help the body in different ways. It’s important to know what these different bacteria do, so that when you buy a probiotic you’re choosing one that has the specific species that will be most helpful to meet your health needs. Here are some of the most beneficial genus/species below, along with which conditions they may be able to improve.

Bifidobacterium bifidum: This specific species can help reduce allergy symptoms like itchy skin, sinus congestion, headaches, and even diarrhea.* It does this by discouraging the production of histamine, a chemical that is released in the body to trigger allergic reactions during times of stress or allergy.1

Bifidobacterium longum: This species may help improve the immune response and help to prevent gut disorders.* Research suggests it may also suppress allergies and improve skin health.2

Bifidobacterium infantis: This species may improve IBS symptoms and help to eliminate E. coli in the gut.* 3

Lactobacillus gasseri: This species produces vitamin K, lactase, and anti-microbial substances. It may also help people with lactose intolerance to digest dairy foods. L. gasseri also helps prevent indigestion, diarrhea, and yeast infections.*4

Lactobacillus rhamnosus: This species boosts cellular immunity. It also helps reduce IBS symptoms and may help to prevent recurrent bacterial vaginosis.*5

Another strong indicator of a great probiotic supplement is if its species and strains have been clinically researched and even more than that, if they have been clinically researched as the combined blend that is found in the supplement. Many probiotics out there do say “clinically studied” on their packaging, but oftentimes they are referring to clinical studies that have been carried out for each of the species, separately. The best-case scenario is if the probiotic’s combined species have been researched together which adds to the studies’ validity. For example, let’s say your probiotic contains these three species: Lactobacillus gasseri, Bifidobacterium bifidum, and Bifidobacterium longum. A clinical study reflecting the benefits of this blend of bacteria, not just each as a standalone bacterial species, is all the better, because then you have proof that they work well together, and you can see from the clinical study which gut health benefits you can look forward to enjoying.

When looking for a new probiotic to try, here is another helpful tip: more CFUs does not equal a better probiotic! When shopping for a probiotic, many people believe that more is better, when it comes to colony forming units (CFUs) so they grab whatever product boasts the highest number. There is no standard recommended daily dose for probiotics, but research suggests aiming for one to two billion live CFUs to maintain good health. If you are taking antibiotics, have digestive problems, or suffer from Candida or frequent urinary tract infections though, you may want to boost that amount.

Lastly, watch out for binders and fillers. Make sure you read the “other ingredients” listed on the probiotic label. Some commercial probiotic supplements contain binders and fillers, including lactose or cornstarch, and these can cause unwanted side effects like gas and bloating.

So, who should take probiotic supplements? In short, anyone who is interested in supporting and improving their digestive health should consider taking a daily probiotic. And not just adults, children can benefit from taking a probiotic too. A healthy gut is more important than you might think. The state of your gastrointestinal tract can impact much more than your digestive system — it can affect your immune health, brain health, and allergies too!* Considering what your GI tract does for you, it makes sense to give it some extra attention and support with a probiotic.

Generally regarded as safe, probiotic supplements cause no significant side effects apart from the intended improvement in your gut health. But not every probiotic is right for each person. It may take some trial and error to find the probiotic that works best for your body. If you notice no benefits from one probiotic after several weeks, try a different one with a different species of bacteria and see if that works better for you.

Something else to be aware of when starting a probiotic is that it may cause some initial gas and bloating, as well as changes in your stool patterns – which are indications that the probiotic is doing its job. If these unwanted side effects continue to persist for several weeks though, it may not be fully compatible with your body. You may want to try a different combination of probiotic bacteria.




  1.     Ku, S, Park MS, Ji GE, et al. Review on Bifidobacterium Bifidum BGN4: Functionality and Nutraceutical Applications as a Probiotic Microorganism. International Journal of Molecular Sciences. 2016; 17(9): 1544.
  2.     Brenner WB, Chey, DM. Bifidobacterium Infantis 35624: a Novel Probiotic for the Treatment of Irritable Bowel Syndrome. S. National Library of Medicine. 2009.
  3.     Groeger, D. Bifidobacterium Infantis 35624 Modulates Host Inflammatory Processes Beyond the Gut. Taylor & Francis. 2013.
  4.     Selle, K, Todd R.. Genomic and Phenotypic Evidence for Probiotic Influences of Lactobacillus Gasseri on Human Health. Oxford University Press. 2013.
  5.     Segers M, Lebeer, S. Towards a Better Understanding of Lactobacillus Rhamnosus GG–Host Interactions. BioMed Central. 2014.

This article is for informational purposes only. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice.