There have been multiple additional studies which link stress to changes in gut bacteria, so there does appear to be some sort of link. But Lebwohl says it’s not enough to recommend widespread use in clinical practice. He referred to these as “hypothesis-generating studies,” which should lead to concrete clinical trials in which the probiotics are tested against a placebo. “These are important studies,” he says. “But it’s premature to call them practice-changing studies.”
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.
The U.S. Clinical Guide to Probiotic Products1, Canadian Guide to Probiotic Supplements2 and the WGO Global Guidelines for Probiotics and Prebiotics3 provide suggested effective amounts of specific strains for treating certain health conditions, such as constipation or IBS. All 37 products listed the species of bacteria they contained, but only 14 listed amounts of individual strains. We found that 9 of those 14 products provided beneficial bacteria at effective levels. The Center for Responsible Nutrition recommends4 the industry move toward specifying strains as a best-practice because whether a product works and for what purpose depends on its strains.
If you’re new to Bio-K+, know that each bottle contains 50 billion live and active probiotic bacteria. Probiotics are good for a wide variety of digestive issues, so it’s best to customize your dosage based on what your specific needs are. If you are looking to take a preventative dosage to support the health of your microbiome, start with a ¼ bottle per day. If you suffer from digestive health issues or regularly take antacids, start with a ½ bottle of Bio-K+ per day. If you have more serious gastrointestinal issues or have had to take antibiotics, Bio-K+ probiotics are great for getting your system back on track. Start with a full bottle per day and see how you feel (we’ve had amazing results from our fans!)

"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.


You experience that afternoon slump and reach for a candy bar or a sugar-laden coffee. Or maybe you go through your day, starting with a breakfast of doughnuts or sugary cereal, and then proceed to sodas for drinks, cookies to snack on, dessert after dinner, and finally to a nighttime snack of ice cream. You know that feeling; it’s that I-have-to-have-something-sweet-and- I-have-to-have-it-NOW feeling.
The takeaway: Certain strains were found useful in preventing diarrhea among children being prescribed antibiotics. A 2013 review showed that after antibiotic use, probiotics help prevent Clostridium difficile-associated diarrhea. A review focused on acute infectious diarrhea found a benefit, again for certain strains of bacteria at controlled doses. There’s also evidence that they may help prevent necrotizing enterocolitis (a serious gastrointestinal condition) and death in preterm infants. 

The current probiotic push lends itself to the question, "If humans got along fine without taking a probiotic supplement for thousands of years, why are they so important now?" Although there is no definitive answer to this question, there have been some significant cultural changes that have had an impact on the gut flora (the population of organisms that populate our intestines). These include the use of antibiotics, diets lacking in gut-healthy plant food, refrigeration and improved sterilization of foods. What we don't yet know is true is if probiotics actually turn around these changes and support the health of your gut flora.
Sugar is so easily accessible in Westernized cultures that it is easy to overindulge in it. But why do you crave it? There are several reasons. One, sugar usually means sucrose, which is composed of glucose and fructose. Glucose is the sugar in your blood, so consumption of sugar results in a temporary boost of energy. However, that blood-sugar spike causes insulin to be released to usher the sugar into cells for energy or fat storage, and shortly afterward your blood sugar drops. So then you feel a slump and reach for something to bring your blood sugar back up: more sugar.
Let’s start at the very beginning: probiotics are bacteria. We know what you’re thinking, bacteria cause infections and are just generally kind of gross. Well, in some aspects, you’re absolutely right. But when it comes to your digestive and feminine health, some bacteria are teeny tiny miracle workers that can make all the difference in the way you feel!
Two large-scale clinical trials recently reported in the New England Journal of Medicine suggest that the situation in infectious diarrhoea might also be more complex than previously believed. Freedman and colleagues did a randomised controlled trial of a probiotic containing Lactobacillus rhamnosus and Lactobacillus helveticus in children presenting to the emergency department with gastroenteritis. Contrary to expectations, they found that the probiotic did not prevent development of moderate-to-severe gastroenteritis within 14 days after enrolment. In a separate study, Schnadower and colleagues found similar results with L rhamnosus GG alone. Both trials used probiotics that are available over the counter in North America and showed no significant difference from placebo in the duration of diarrhoea and vomiting, number of unscheduled health-care visits, or length of absence from day care. These results cannot be generalised to other probiotic strains or preparations, but they do show that we have some way to go in elucidating which probiotics might provide benefits in which clinical settings.
The National Institute of Health (NIH) is sponsoring the Human Microbiome Project (HMP), which is developing research resources to enable the study of the microbial communities that live in and on our bodies and the roles they play in human health and disease. The NIH has funded many more medical studies using HMP data and techniques, including the role of the gut microbiome in Crohn's disease, ulcerative colitis, and esophageal cancer; skin microbiome in psoriasis, atopic dermatitis, and immunodeficiency; urogenital microbiome in reproductive and sexual history and circumcision; and a number of childhood disorders, including pediatric abdominal pain, intestinal inflammation, and necrotizing enterocolitis, a severe condition in premature infants in which the intestine tissue dies due to lack of oxygen.

Probiotics: Health benefits, facts, and research Every human on the planet has microbes living in their body. While bacteria get a bad reputation, many can promote good health. Probiotics are a type of 'good bacteria' that provide health benefits for the host. The health benefits of probiotics include treatment of diarrhea and irritable bowel syndrome. Read now
The bottom line: Stick to trusted whole food sources of probiotics if you don’t know a probiotic supplement brand you trust. “Kimchi, pickled beets, Greek yogurt and sauerkraut are great sources of probiotics. If you don’t like them, throw them into a food you do like, like a smoothie, and add your favorite fruit to help mask the flavor,” Taub-Dix says.
Unless you know that your body is lacking in a particular type of probiotic, you should just look for broad-spectrum probiotics that contain a mix of different strains of bacteria, Warren says: "We have billions of bacteria in our gut, so by taking a supplement with a range of different strains, you will ensure you are not overdoing or missing one type." Keatley also stresses the importance of finding a supplement with a diversity of bacteria strains to keep overgrowth of any one strain in check. "Providing too much of an advantage to one strain of probiotic may push out another strain we didn't know was important until it's too late," she points out.
Women’s health expert Dr. Amy Myers is a goop-trusted authority on subjects from autoimmunity and Candida to thyroid dysfunction; and she’ll be speaking IRL at our first wellness summit on June 10. Here, Myers helps us evaluate the increasing buzz around probiotics, and outlines the ins and outs of selecting a particular supplement (whether hers or other brands). Plus, we’ve rounded up our probiotic essentials, from inner beauty powders to favorite fermentation recipes, in one guide:
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