A common topic of debate in the probiotic community is the actual survival rate of the bacteria in over-the-counter supplement products -- namely, do probiotics survive stomach acid? If you are reading this, you may have concerns about how efficacious your probiotic really is, or maybe you are thinking about trying some but have reservations about what's going on in your gut.
Whatever your relationship is with probiotics, our goal today is to provide context on probiotic survivability to help you better evaluate probiotic supplement products.
What's the issue in gut tissue?
Many have argued that the controversy around probiotics surviving the stomach started with a laboratory study from the University College London in 2014. They tested multiple commercial probiotics and found only one survived gut acid and thrived in the intestines. This publication is a fascinating read that brings up several aspects you should be looking at when evaluating probiotics.
Stomach Acid & Bile Salts & Pepsin, Oh My!
When looking at the probiotic strains, think about the conditions where they thrive. The same way a shark can dominate the ocean but be helpless on land—certain strains of bacteria in the body survive in an environment that might not work for others.
Lactobacillus strains, often commonly referred to as lactic acid bacteria because they produce (you guessed it!) lactic acid, have been shown to flourish in acidic conditions similar to that of the upper gastrointestinal tract.
Storage vs. Stomach
So if the bacteria can survive your stomach, why do you have to refrigerate it? This question or variations of it appear among the probiotic discourse. Rightfully so; it's a good question! The simple answer is that what you want your probiotic to do in your fridge is different from what you want it to achieve in your stomach.
The bacteria in encapsulated probiotic supplements, traditionally, could survive years in storage. The optimal way to keep probiotic bacteria in a stable state is to put them in a cool and dry environment. This is not too different from storing fruits and vegetables in the fridge to ensure they stay fresh longer. When you intake the probiotic bacteria, they are in a dynamic state that interacts with their microenvironment.
Clinical Trials are Key!
Researching information can be overwhelming. If you have only time to consider one thing, let it be clinically researched strains and human clinical trials. These are the most reliable ways to understand whether a probiotic survives stomach acid it affects the people taking it. If you are planning on taking a new probiotic or have never taken any before, make sure to talk with your doctor or qualified nutrition professional before starting your new regimen.