When I polled friends and family about their personal experiences with probiotics, I got a real mixed bag of responses. Some called them a lifesaver and others felt no effects whatsoever. I put the anecdotes aside and talked to Ben Lebwohl, gastroenterologist and director of clinical research at Columbia University’s Celiac Disease Center, to get the straight poop on whether probiotics are miracle or myth.
The right resident strains - quite a few probiotics on the market contain things like active yeasts or soil based organisms. While these ingredients may be helpful to some, if you want to optimize your gut health, you need to look for strains that are resident to the human gut like those from the Lactobacillus, Bifidobacterium, and Streptococcus families.

As with other types of supplements, scientists are still discovering the full potential of probiotics. However, when taken regularly, it is believed that they help support digestive health by helping maintain the balance of beneficial and non-beneficial bacteria in your digestive tract. Having a natural balance of good bacteria in the digestive tract can help defend against occasional digestive issues. In addition, probiotics play an important role in supporting immune health, since 70% of the body's immune system is found in the digestive tract.∗
A number of probiotic products are on the market, including yogurts containing probiotics, as well as supplements and skin creams, and an estimated 3.9 million Americans use such products. Some studies suggest that probiotics may help with diarrhea or symptoms of irritable bowel syndrome (IBS), but strong evidence to support their use for most health conditions is lacking, according to the National Center for Complementary and Integrative Health.

It seems like one minute you have diarrhea (D) and the next minute you are constipated (C). Abdominal pain, cramping, and bloating come and go. You are tired of running to the bathroom frequently, or spending a long time in the bathroom waiting for something to happen. Irritable bowel syndrome (IBS) is a diagnosis of exclusion. Infections and other causes of your IBS-C dominant or IBS-D dominant symptoms have to be ruled out, but in many cases the diagnosis of IBS doesn’t really provide answers. You may be on a low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet, which helps, but is restrictive.
An imbalance in the gut microbiota is believed to contribute to a number of health problems, particularly gastrointestinal issues, as well as immune dysfunction and infections. The bacterial balance can be disrupted by medical conditions, emotional and physical stress, and, most notably, use of antibiotics, which destroy the good bacteria along with the bad.

We are clearly getting to the strain level by going beyond “Saccharomyces boulardii” and to “Saccharomyces boulardii CNCM I-745”. They did a great job by actually putting it on the label so you don’t even have to contact the company to see exactly what strain you’re getting. (P.S. this is a well-researched strain that I highly recommend, especially for preventing antibiotic-associated diarrhea.)
This is also known as S. boulardii and is the only yeast probiotic. Some studies have shown that it is effective in preventing and treating diarrhea associated with the use of antibiotics and traveler's diarrhea. It has also been reported to prevent the reoccurrence of C. difficile, to treat acne, and to reduce side effects of treatment for H. pylori.
Some companies have been around for years, and you may know their names. Those that have made probiotics for a while likely have tested and studied them over and over. It's smarter to choose a product from them over one from a maker you don't know. Check a third-party certifier (like ConsumerLab or the USP) to see if they have tested the product and found that it’s safe and reliable. If you're in doubt, ask your doctor.
The two main species you want to look for are: Lactobacillus and Bifidobacterium. Within these two species, there are a lot of different strains. The strains we chose for our probiotic—Lactobacillus acidophilus, Lactobacillus plantarum, and Bifidobacterium longum—have been shown to help modulate the immune system, help with autoimmunity conditions (which affect most of my patients), and counter infections in the gut.
Cleaning up your diet to remove things that bother you and to add nutrients you and your microbiota need, physical activity to reduce stress and increase feel-good neurotransmitters, mindfulness to discover how your thoughts affect your feelings, and daily consumption of probiotic pills and foods are easy ways to improve your mental health outlook.
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