Suboptimal gut flora opens the door for unfriendly microbes to step in and disrupt balance. Think of probiotics as little helpers that restore order and help maintain harmony in the gut ecosystem.* You want them to outnumber and antagonize the unwelcome bugs, including unfavorable bacteria, yeast, and parasites.* Probiotic bacteria actually compete against unfriendly flora for bacterial binding sites on the inside lining of your intestines, further protecting you.* One way to populate your gut with probiotics, to promote or restore harmony and get all their many benefits, is with the right foods, which support the growth and proliferation of the good bacteria that crowd out the bad ones. These include cultured foods (such as yogurts or kefir); fermented foods like sauerkraut, miso, pickled vegetables, and kimchi; and cultured beverages, like kombucha—that all contain favorable live bacteria. During my recent trip to Japan, one thing I noticed was the inclusion of pickled vegetables in almost every traditional Japanese meal. Unfortunately, most Americans don’t consume enough of these probiotic-rich foods and drinks. Even when they do, restoring equilibrium oftentimes requires higher doses of these microorganisms. That’s where a probiotic supplement comes in.* While there are virtually endless species of beneficial bacteria, the ones you’ll most commonly find in probiotic supplements are Lactobacillus, Bifidobacterium, and Saccharomyces boulardii5 (which is actually a favorable, noncolonizing yeast, not a bacteria). Among these three genera (or families) are specific species6. Lactobacillus, for instance, includes the individual species L. acidophilus, L. rhamnosus, L. bulgaricus, L. reuteri, and L. casei. The most common Bifidobacterium species include B. animalis, B. infantis, B. lactis, and B. longum. And at an ever more granular level, there are unique strains (e.g., L. acidophilus NCFM, B. lactis Bi-07, etc.) Let’s look at the benefits of these three families—Lactobacillus, Bifidobacterium, and Saccharomyces—more closely:* The most beneficial species are L. acidophilus, L. plantarum, and L. paracasei.* A preclinical study found Lactobacillus acidophilus supported the inflammatory response in the gut7.* L. rhamnosus helps increase GABA expression8 (an inhibitory neurotransmitter that helps you feel relaxed) in the brain, resulting in lower stress-related behavior.* Another found that a combination of Lactobacillus 4and 4Bifidobacteria 4(which we’ll talk about next) improved bloating4, and yet another found that when individuals took the Lactobacillus rhamnosus GG strain, it helps protect normal bowel movement function and buffer from loose stools associated with antibiotic use.* But butyrate is also absorbed by the body, where it regulates a variety of metabolic processes, including your sensitivity to the hormone insulin (which regulates your blood sugar) and even memory formation in the brain.* The most beneficial of the Bifidobacteria are B. lactis and B. longum. Research shows the benefits for Bifidobacteria in maintaining a healthy bowel9.* Another study showed that a specific strain (B420) of Bifidobacterium lactis 3helped control body fat mass3, waist circumference, and food intake.* This yeast promotes the health of the intestinal lining, helping support healthy tight junctions and protect from gut microbial imbalance.* S. boulardii can also outcompete other unfriendly yeast that is cohabitating in the gut.* If that sounds confusing, don’t worry. With the following three strategies, you don’t need to remember those names to choose the right probiotic supplement Quality matters for any supplement, and that goes triple for probiotics. Many commercial brands lack the technology to identify specific strains and how much of that strain each dose contains. That could mean you get an ineffective or potentially harmful dose. It’s a great sign if the company is using probiotic strains that have been used specifically in clinical trials at a dose similar to or the same as that used in the study. This is one of the only ways to guarantee a probiotic’s effectiveness.* And even then, with probiotics, it’s all about survival. These delicate microorganisms must survive several obstacles—the manufacturing process, packaging, shelf life, and (once you take them) the acid in your stomach environment—to reach your intestines, where they do their job. Keep in mind that when supplements contain a specific number of organisms, this number has an expiry eventually. Probiotics are living organisms and can die, especially if that supplement sits on your drugstore or warehouse shelf or a shipping truck for a long time or at elevated temperatures. Companies have to produce probiotics with a higher CFU (colony-forming unit; see below) count in each capsule in order to guarantee the label potency through the expiration date, or in the case of probiotics with a manufacturing date, for two years from that. Unfortunately, many commercial brands don’t measure up. They are unstable in stomach acid. Quality control measures aren’t intact, including ensuring supplements have been handled correctly to maintain their freshness. Moisture slipping into probiotic supplements can reduce their efficacy. Higher-quality probiotic supplements are able to endure stomach acid, releasing their contents within the small intestine, where a more alkaline environment ensures the survival of the bacteria. To avoid those and other problems, I strongly recommend buying a professional brand from a reputable health care professional or another vendor who stands by their products and submits their products for multiple rounds of quality testing, from raw ingredients to finished product. Plus, some of these brands have created advanced technology that preserves a probiotic supplement’s survival on the shelf and in your gut. Inferior brands might contain only one probiotic species such as Lactobacillus acidophilus. Look for the beneficial strains of Lactobacillus and Bifidobacterium, and you may also see species like Streptococcus thermophilus and Saccharomyces boulardii, among others. Many high-quality shelf-stable probiotics exist. These do not require refrigeration. Other formulations do. The label should tell you specifically whether or not to refrigerate. If you have chronic GI concerns, I strongly suggest working with a functional medicine doctor or other qualified health care professional to partner with you and personalize your probiotic approach. Remember, if you think a probiotic is not helping, then seek the advice of a functional medicine provider to help you navigate the choices out there.
