Yes, they may help. Lebwohl says there are reputable studies that show a link between the use of probiotics and the reduction in IBS symptoms, citing this meta-analysis. It's estimated that 11 percent of the world population complains of symptoms like abdominal cramps, diarrhea, constipation, excessive gas and/or mucus in their stools. While for some the condition can be attributed to certain dietary triggers, others appear to be stress-related, which brings us to the heart of where many claims about the effectiveness of probiotics lie—in the gut-brain axis.
Oral health. An increasing number of probiotic lozenges and gums are promoted for oral health—to reduce periodontal disease, throat infections, and bad breath, for example. There’s preliminary evidence that certain strains may have some benefits, but commercial products may not have the same strains and formulations as those tested in published studies.

Most of the high-quality probiotics that are available on the market today share the same annoying pitfall: they need to be refrigerated. If losing your supplements in the abyss of your fridge isn’t exactly your idea of a good time, the Garden of Life Dr. Formulated Once Daily Women’s Probiotic is just for you! This probiotic comes with a Shelf Stable Potency Promise, meaning there is no need for refrigeration.


"This suggests that probiotics should not be universally given as a 'one-size-fits-all' supplement," study co-senior author Eran Elinav, an immunologist at the Weizmann Institute of Science in Israel, said in a statement. However, it may be possible to tailor probiotic treatments to the individual, based on the types of microbes already in his or her gut, as well as other factors, so that he or she gets the most benefit from probiotics, the researchers said.

CFU: This is the number of "colony forming units" present in each dose, which are measured in the billions. And while more isn't always better, "you want at least 20 to 50 billion CFU," says Dr. Nazareth. Just for reference, a very high dose is 400 CFU, which most experts agree is not necessary unless your health care practitioner specifically recommends this for you. It's also important to check for the guaranteed CFU upon expiration, which should be listed clearly. "Some products only guarantee the CFU number at the time of manufacturing, therefore will be less potent by the time the product reaches your home," she says.
While past studies have investigated similar questions, they have all used patients' excrement as a proxy for microbe activity in the GI tract. Instead, Elinav, his colleague Eran Segal, (a computational biologist at the Weizmann Institute), and their teams spearheaded by Niv Zmora, Jotham Suez, Gili Zilberman Schapira, and Uria Mor of the Elinav lab collaborated with Zamir Halpern, Chief of Gastroenterology at the Tel Aviv Medical Center to measure gut colonization directly.
Amy Shapiro, MS, RD, CDN, founder and director of Real Nutrition based in NYC, discusses the effect probiotics have on immune system issues. "Probiotics compete with pathogenic microorganisms and produce chemicals that inactivate or kill pathogens," says Shapiro. "They help prevent immune-mediated diseases by improving the gut mucosal immune system. Overall, probiotics protect the body from infections and allow the body to maintain homeostasis."
"In fact," she continues, "80% of immune system cells are found in the gut. In addition to the well-known GI benefits of minimizing bloat, gas, constipation, and diarrhea, probiotics aid in digestion by extracting nutrients, helping your body absorb minerals, produce vitamins, and make brain chemicals, including over 30 neurotransmitters along with mood-enhancing serotonin. A healthy person has over 100 trillion microbes, generally a five to one ratio of helpful to harmful."
The bad news about constipation is that there can be many causes, from simple causes like dehydration and lack of fiber to complicated structural causes or disease. While constipation may seem to be only a nuisance that causes uncomfortable symptoms such as abdominal bloating or pain, the truth is that constipation increases the risks of several diseases.
"This suggests that probiotics should not be universally given as a 'one-size-fits-all' supplement," study co-senior author Eran Elinav, an immunologist at the Weizmann Institute of Science in Israel, said in a statement. However, it may be possible to tailor probiotic treatments to the individual, based on the types of microbes already in his or her gut, as well as other factors, so that he or she gets the most benefit from probiotics, the researchers said.
"Contrary to the current dogma that probiotics are harmless and benefit everyone, these results reveal a new potential adverse side effect of probiotic use with antibiotics that might even bring long-term consequences," Elinav says. "In contrast, replenishing the gut with one's own microbes is a personalized mother-nature-designed treatment that led to a full reversal of the antibiotics' effects." 

Probiotics and raw fermented foods and drinks, such as sauerkraut and kefir that contain probiotic-like microbes, are very helpful for digestion. They help to keep your gastrointestinal tract at the proper pH for optimal digestion and help to break down foods. They also regulate the motion of your intestines so that food moves through at the proper pace.
In addition to the prophylactic effect of stocking your gut with good bacteria, there are some probiotic strains that have also shown promise in treating symptoms of autoimmune disorders, including L. Paracasei and L. Acidophilus. Others, like B. Lactis, could help prevent respiratory infections. Renew Life Flora Extra Care has all three targeted bacteria strains at 30 billion CFUs per serving.
Unless you have a perfect gut and are already eating lots of fermented foods—which is rare, although you can work up to this point—it’s difficult to get all the probiotics you need from diet alone. Most of us don’t have perfect guts—everything from antibiotics to high-carbohydrate diets to being born via a C-section can compromise the balance of bacteria in our microbiome. Supplementing with a probiotic can help to restore imbalances, and it’s also just a great preventative health measure, helping to keep your microbiome in balance and your immune system healthy to ward off illnesses.
The second piece of research investigated whether patients should take probiotics to help the recovery of the natural gut bacteria after treatment with antibiotics. The evidence supporting this is not entirely clear and the FDA does not officially recommend it, but there are some reputable sources which discuss their use, such as this blog from Harvard Medical School. Research has suggested that up to 60% of healthcare professionals in the U.S. recommend taking probiotics, but is this justified and could it even be harmful?

Stability and organism types — Some probiotic strains need to be kept cold in order to preserve their potency. This applies to their production, transport, storage and sales. Others are shelf-stable and don’t require refrigeration. Unfortunately, most refrigerated probiotics never make it past the stomach because they aren’t stable. Instead, look for a shelf-stable product that contains soil-based organisms.
There’s preliminary evidence that some probiotics are helpful in preventing diarrhea caused by infections and antibiotics and in improving symptoms of irritable bowel syndrome, but more needs to be learned. We still don’t know which probiotics are helpful and which are not. We also don’t know how much of the probiotic people would have to take or who would most likely benefit from taking probiotics. Even for the conditions that have been studied the most, researchers are still working toward finding the answers to these questions.
Some yogurts contain the aforementioned bacteria; however, because they are sensitive to oxygen, light, and dramatic temperature changes, make sure to look for yogurts with “live and active cultures.” Many commercial yogurts are heat-treated or pasteurized, resulting in the loss of these valuable cultures. Learn more about the smart way to shop for probiotics.
Like other top probiotics available today, LEAN’s 50-Billion Probiotic is packaged in a handy, delayed-release capsule, designed to protect non-acid-resistant bacteria until they reach deep into your GI tract, where they’re most needed. The result is maximum effectiveness – better gut health, an immune boost, and relief of common digestive problems.

We also found strains linked to five other health benefits like weight loss and lowering cholesterol. We feature options for those cases below, but they aren’t top picks because those use cases aren’t as heavily researched as immune health or IBS relief. Still, chances are any probiotic supplement is going to make some improvement to your digestive health, so don’t be afraid to experiment.
Lebwohl says IBS isn’t just about intestinal distress. For many IBS sufferers, it’s about the way our brain receives messages about pain. He describes the human colon as “almost reptilian” in the way that it contracts and relaxes throughout the day, but says these contractions are usually happening way below our threshold of consciousness, so we don’t even notice. In people with IBS, the neurotransmitters in our gut (yes, we have them in there too) may be sending severe distress signals to the brain about benign contractions happening in digestive tract.

Yet that’s how probiotics are often offered. They can be distributed in the United States as food, supplements or drugs. The regulations for each are very different. Most people looking for probiotics don’t see the distinctions. Ideally, the ways in which we use and consume probiotics would conform to the data and evidence that back them up. That rarely happens.


Undaunted, researchers looked into whether probiotics might be beneficial in a host of disorders, even when the connection to gut health and the microbiome was tenuous. Reviews show that there is insufficient evidence to recommend their use to treat or prevent eczema, preterm labor, gestational diabetes, bacterial vaginosis, allergic diseases or urinary tract infections.

Although people often think of bacteria and other microorganisms as harmful “germs,” many microorganisms help our bodies function properly. For example, bacteria that are normally present in our intestines help digest food, destroy disease-causing microorganisms, and produce vitamins. Large numbers of microorganisms live on and in our bodies. Many of the microorganisms in probiotic products are the same as or similar to microorganisms that naturally live in our bodies.
This Korean staple relies on lactic acid fermentation (also called lacto-fermentation) to turn cabbage or other vegetables into a spicy, pungent side dish that's packed with vitamin C. Order it at Korean restaurants or buy it in the refrigerated section of your grocery store (King's Kimchi is widely available at Walmart). For some guidance on making your own, turn to The Art of Fermentation ($23; amazon.com). Then, use it to spike veggie-laden rice bowls, top on soup, or serve alongside meat.
×