Everything You Ever Wanted To Know About Choosing A Good Probiotic

Many patients arrive in my office who want to improve their gut health. When I say gut health, I'm talking about the more than 500 different species—trillions of microorganisms1 altogether—residing in your gut, whose delicate balance influences gut function, metabolism, hormone balance, and overall health.

Suboptimal gut flora opens the door for unfriendly microbes to step in and disrupt balance.

Among probiotics' numerous health benefits, research shows2 these friendly microorganisms support a healthy bowel and immune system; promote a healthy gut and regularity during travel; help you maintain a healthy weight3, support healthy skin, ease bloating4, and help to reduce the effects of stress.* (For a more in depth look at how probiotics can benefit men, check out our men's probiotics story.)

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.

You'll find probiotic supplements that contain freeze-dried bacteria in capsules, tablets, and powders.That's the easy part: Turn the label around and you'll see a list of unpronounceable ingredients. Many of my patients say choosing the right probiotic supplement is baffling.

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.)

Lactobacillus bacteria predominantly live in your small bowel (the portion of your gut that follows the stomach). Probiotics that contain Lactobacillus species help to repopulate the small intestine with these friendly organisms that aid in supporting digestion and immune function.*

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.*

The Bifidobacteria (Bifidus) bacteria predominantly live in your colon or large intestine. They produce the very important short-chain fatty acid butyrate, which supplies energy to your colon cells to keep them functioning optimally.

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.*

Saccharomyces is a friendly yeast that I often consider for people who have been on antibiotics.

I like a bargain as much as anyone, but buying a probiotic supplement is something you don't want to skimp on. Warehouse stores are great to buy paper towels and grass-fed beef in bulk, but those mega-containers of probiotics are hardly the great deal they might seem.

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 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 to three 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.

Your gut is diverse, so your probiotic should be too. Look for a supplement that contains multiple strains. This is sometimes listed as a proprietary blend, although with blends, you lose the transparency of knowing how many CFU each strain contributes.

Always look for the manufacturing date or expiration date, after which the potency on the bottle can no longer be guaranteed. Most probiotics are good for two to three years from the manufacturing date, but ask the manufacturer if that information is not clear on their website.

If you're most interested in taking a probiotic supplement for overall gut health,* I suggest starting with at least 30 billion CFUs. Take your chosen probiotic on an empty stomach once or twice a day for at least three months. After that time, reassess and decide if the benefits you achieved warrant continuing or maintaining over the long-term.

If this happens, then it's time to consider switching to a new probiotic. It's a good idea to work with your doctors if you have specific gastrointestinal concerns, because certain probiotic strains can potentially make your issues worse.