Probiotics are live microorganisms that are thought to have health benefits, as the National Institutes of Health (NIH) reports. These bacteria and yeast are believed to help populate our guts with beneficial microbes, according to Mayo Clinic, and can be found in fermented or unpasteurized foods including yogurt, kefir, sauerkraut, and kimchi, as well as, yes, supplements.
Dr. Michelle Schoffro Cook says there’s no single best strain of bacteria, though some strains, like L. Acidophilus or B. Bacterium, have wide-reaching effects. They often act as a starting point from which to add other strains with more specific impacts. Already have probiotics on hand or want to arm yourself with raw knowledge before you shop? The table below shows the research- and expert-backed strains we looked for in each use case:
Jo A. Panyko is a Master Nutrition Therapist and author of two books about probiotics. She is a professional member of the National Association of Nutrition Professionals (NANP) and works as a functional medicine nutrition therapist (nutritionist) at her company, Chrysalis Nutrition and Health. She writes about how to be healthy with probiotics on her website, powerofprobiotics.com.
The high quality supplement comes in veggie capsule form, and no refrigeration is necessary. This probiotic is made in an FDA registered facility (in the US), and it meets GMP standards. It’s an all natural supplement, that’s free of lactose, soy and gluten. It also contains no artificial coloring. DNA Shift probiotic also offers prebiotic fiber for an extra healthy brain and gut.
What's more, people who have serious heart issues commonly have S. mutans in their heart valves—this is an undesirable type of bacteria that’s actually more often found in the mouth. If your oral microbiome is in balance, S. mutans are normally kept in control by more beneficial species, but if things get out of balance, they can reproduce and make their way into your bloodstream via openings in your gums, compromising your cardiovascular function.3
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.
As you progress with increasing dosages of probiotics internally, you may experience increased abdominal gas, upset digestion with diarrhea, headache, fever, muscle pain, brain fog, and/or anxiety. If the symptoms become too uncomfortable, decrease the dosage for a few days and try again. These symptoms are your body’s way of telling you that things—such as a die-off of pathogens or an awakened intestinal reflex—are changing.
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.
Given that you can get probiotics from the food you eat, you don't necessarily need to take a supplement, and Keatley says she prefers food sources of probiotics to supplements. However, she adds that "There are times when you really need a boost." One example might be during or after a course of antibiotics, as long as you have your doctor's OK, since antibiotics kill both good and bad bacteria: "Seeding your gut with good bacteria can lay the groundwork for a faster recovery and less constipation and diarrhea," Keatley points out. Angelone echoes Keatley's emphasis on food sources of probiotics, but also says that supplements can also play a useful role in "maintaining a healthy gut bacteria colony."
Probiotics are generally considered safe8 for most healthy people, but may cause gastrointestinal discomfort (abdominal tenderness, pain, gas, and/or diarrhea) if intake exceeds individual needs. People with certain health conditions like suppressed immunity or sensitivity to probiotics may experience more severe side effects9. Probiotics can also interact with some medications. Please consult your doctor before starting any new supplement.
B. Longum is one of the first types of bacteria to colonize our bodies at birth. These important microorganisms ferment sugars into lactic acid, helping to stabilize the acidity of the GI tract and inhibit growth of harmful bacteria. For a group of adults prone to constipation, taking a mix of B. Longum BB536 with milk or yogurt for 2 weeks increased bowel movements [1].

The side effects of antibiotic use are often not trivial. Many people experience discomfort and a change in bowel habits, but some experience more severe infections, such as opportunistic colonization of the gut with bacteria such as Clostridium difficile (C.diff), which affected half a million Americans in 2015 and was directly responsible for at least 15,000 deaths.


Though rates of serious lung issues have been dropping among men in the Western world, they're still a major concern, with over three million men affected by ongoing respiratory conditions.1 While steroids and antibiotics are the go-to treatments for these conditions, they often fail to address the underlying issue, and they destroy bacteria indiscriminately, creating conditions in which undesirable bacteria can thrive.
Caution needs to be taken by everyone who chooses to take these supplements, but this is especially true for children, pregnant women, elderly people, and people with compromised immune systems. For people with compromised immune systems due to disease or treatment for a disease (such as cancer chemotherapy), taking probiotics may actually increase one's chances of getting sick. It has been shown that the use of various probiotics for immunocompromised patients or patients with a leaky gut has resulted in infections and sepsis (infection of the bloodstream). One case of bacteremia (bacteria in the bloodstream) was recently found when someone with active severe inflammatory bowel diseases with mucosal disruption was given Lactobacillus GG. Always speak with a doctor before taking any supplement under these circumstances.
EDITOR’S CHOICE: As the only probiotic formula we reviewed backed by a New York Times Bestselling author and expert in the human biome, the Garden of Life Dr. Formulated Once Daily Women’s Probiotic is our top choice for overall digestive and women’s health. With 50 billion cultures and 16 probiotic strains, this probiotic helps to promote women’s digestive, immune and vaginal health.

Some foods are made by adding bacteria — yogurt, pickles, cottage cheese, kombucha, and sauerkraut are good examples. Those foods work to provide the same probiotic benefits as supplements. However, most foods are so processed and pasteurized that it’s unlikely you’ll see the same benefits, let alone the right strains, as you would with a supplement. Regardless, it can’t hurt to get extra probiotics through your diet.
“Microbiome” refers to the trillions of bacteria and microorganisms that live on and in our individual bodies. “There’s increased recognition of the various ways that the microbiome affects our health,” Lebwohl tells me. “And with that recognition comes the true observation that many bacteria are good for us. This goes against the old idea that bacteria equal germs, which equal harm. It turns out that many bacteria keep us healthy and probiotics could potentially support that notion.”
Among their numerous health benefits, research shows these friendly microorganisms help prevent bowel diseases, improve your immune system, reduce traveler’s diarrhea, help you maintain a healthy weight, heal various skin conditions, improve bloating and other uncomfortable GI symptoms, and even boost your mood, helping to reduce the effects of anxiety and depression.
Known as the most clinically proven effective probiotic strain, Lactobacillus rhamnosus GG (otherwise known as “LGG”) has been clinically proven to maintain healthy numbers of bacteria and yeast for optimal digestive health. This powerful probiotic is also paired with some of the best probiotic strains for feminine health, making it an ideal choice for any woman that is looking for complete care from her probiotic.
They can break down substances in foods that keep you from absorbing the micronutrients inside. They not only protect against the consequences of rogue molecules passing through a leaky gut, but they assist your intestinal cells in staying healthy to optimize nutrient absorption. In addition, some of the metabolic by-products of probiotics, such as short-chain fatty acids and vitamin production, are very nourishing to your GI tract.
On my recent trip to Japan, one thing I noticed was the inclusion of pickled vegetables in almost every traditional Japanese meal. Unfortunately, many Americans don’t consume enough of these probiotic-rich foods and drinks. Even when they do, restoring equilibrium oftentimes requires therapeutic doses of these microorganisms, because most everyone has been on several rounds of antimicrobials. That’s where a probiotic supplement comes in.
Another study by Elinav and his colleagues suggests that not everyone’s gut reacts the same way to probiotic pills. They studied samples of microbiomes from antibiotic users before and after they took supplements for four weeks. The good bacteria were found in the digestive tracts of some people. But in others, the bacteria were present only in stool samples, not in their digestive tracts, where they’re thought to be needed to improve health.
We have to give a nod to the most famous probiotic food: yogurt. Whether you love Greek or regular, low-fat or full-fat, look for the phrase "live active cultures" on the label. And although choosing a plain yogurt has less added sugar than the flavored kinds, Tallmadge gives you the okay to choose a fruit-infused flavor if that's the only way you'll eat it. Just be sure to aim for fewer than 15 grams of the sweet stuff per serving; sugar can feed the bad bugs in your gut.
A 2014 review by Cochrane—an independent network of experts who serve as rigorous arbiters of medical research—found that probiotics may be particularly useful in a hospital's neonatal intensive care unit. The addition of beneficial bacteria to a nutritional regimen seems to significantly reduce the likelihood of developing necrotizing enterocolitis, which is a devastating, poorly understood and often fatal gut disease that primarily afflicts preterm infants—especially the smallest and most premature among them. Researchers think that many cases of the disease begin with an opportunistic bacterial infection in the not yet fully developed intestine of an infant. As the illness progresses, gut tissue becomes increasingly inflamed and often starts to die, which can, in turn, rupture the intestine and flood the abdominal cavity with pathogenic microbes that proliferate to dangerous levels. Researchers estimate that 12 percent of preterm infants weighing less than 3.3 pounds will develop necrotizing enterocolitis and that 30 percent of them will not survive. Standard treatment involves a combination of antibiotics, feeding via intravenous tubes, and surgery to remove diseased and dead tissue. Probiotics probably prevent the disorder by boosting the numbers of beneficial bacteria, which may deter the harmful ones.

To factor strain-specific benefits into our efficacy score, we referenced the information in these guides. Products were rewarded for containing strains on these lists. Additionally, measured levels of each strain were compared to what is thought to be effective based on these guides, and scores were scaled accordingly. In cases where products did not list strain-specific amounts, or their listed strains were not included in these guides, total measured CFUs were compared to a general effectiveness threshold of 1 billion CFUs cited by research published in the American Journal of Clinical Nutrition11.

×