Probiotics are live bacteria and yeasts that are good for the human digestive system, but experts in the field have been learning they do a lot more than that. In 2016, probiotic sales in the U.S. reached close to $4 billion. Walk into a favorite pharmacy or health food store and it’s a dizzying array of choices are available. I will briefly discuss what they can do and how to purchase high-quality probiotics.

What probiotics can do
Scientists have only recently begun to scratch the surface of what probiotics can do, such as unmasking some of the mechanisms that help with the immune system, prevent and even help with many diseases. Probiotics have been shown to produce small amounts of vitamins K and B along with short-chain fatty acids, which have many health benefits. 

Additionally, they can produce chemicals that inactivate or even kill some pathogens. There’s also evidence that simply ingesting probiotics stimulates the body’s immune system, as it reacts to the yeast or bacteria.

How to include more probiotics in a healthy diet
All fermented foods contain probiotics. Examples include kefir, yogurt, kimchi, sauerkraut, kombucha and miso. Many of these foods also contain “pre-biotics,” which are substances that help beneficial bacteria grow.

Forms of probiotics 
Aside from in food, probiotics can be found in powder, tablet, liquid, suppository or capsule form. The form doesn’t really matter; it’s more of a personal preference.  

Many patients come into our clinic and have questions about probiotics. For example, “Which is the right one for me?” or, “Do I even need them?” Science is just now beginning to elucidate all the various health benefits individuals may obtain from the various genus, species, strain and culture-specific probiotics. Some are good for overall general health, and some are very specific to a health condition; some even prevent disease when taken by a pregnant woman.

On keeping probiotics in the fridge 
Any high-quality probiotic supplement should be shelf-stable for at least six weeks outside the refrigerator, when kept at room temperature. Keeping them in the fridge will keep the microorganisms alive longer.

Furthermore, not all probiotic products and companies are created equal. A recent study showed that approximately 75 percent of the probiotics on the market today are either contaminated with pathogenic bacterial, contain gluten, or don’t even meet the label claim of the organisms listed and their count (6 billion microorganisms).

The versions we use in our practice are gluten, dairy, soy and lactose free, and have third-party testing for potency, purity and contaminants.  

Caveats
People on immunosuppressant drugs, those with autoimmune disease and pre-term parents of infants should consult with their physicians before taking a probiotic supplement.