Possibly the most popular probiotic food is live cultured yogurt or greek yogurt made from the milk of cows, goats or sheep. Yogurt, in most cases, can rank at the top of probiotic foods if it comes from raw, grass-fed animals. The problem is there is a large variation on the quality of yogurts on the market today. When buying yogurt, look for three things: First, that it comes from goat’s, sheep milk or A2 cows milk; second, that it’s grass-fed; and third, that it’s organic.
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.
There are two main types of probiotics; the first is the live cultures I describe above, like the strains of Lactobacillus and Bifidobacterium. You might have heard some naysaying about this kind of probiotic—the typical argument against them is that the classic form of live cultures is destroyed by the acidic environment in the stomach. To get around this, quality probiotics are made with an acid-resistant capsule so that they don’t get immediately broken down. (Which means you don’t have to take the probiotics with food, although I normally do. I’ll sometimes break the capsule and mix it into a smoothie, or use the powder form. You might lose a bit of potency but it’s not significant.)
Constipation is defined medically as fewer than three stools per week and severe constipation as less than one stool per week. Constipation usually is caused by the slow movement of stool through the colon. There are many causes of constipation including medications, poor bowel habits, low fiber diets, laxative abuse, and hormonal disorders, and diseases primarily of other parts of the body that also affect the colon.
In the gastrointestinal tract L. Plantarum can help regulate immunity and control inflammation. A 2007 study found that the probiotic could suppress an inflammatory response in the gut. Perhaps most significantly, a double blind placebo-controlled study over 4 weeks concluded that L. Plantarum 299v provided effective symptom relief, especially of abdominal pain and bloating, in patients with Irritable Bowel Syndrome [1].
What exactly do probiotics do? They are believed to protect us in two ways. The first is the role that they play in our digestive tract. We know that our digestive tract needs a healthy balance between the good and bad bacteria, so what gets in the way of this? It looks like our lifestyle is both the problem and the solution. Poor food choices, emotional stress, lack of sleep, antibiotic overuse, other drugs, and environmental influences can all shift the balance in favor of the bad bacteria.

Bacillus is an interesting genus because these microbes have the ability to form endospores, tough outer coatings, when conditions are not suitable for them to flourish. There are five species of probiotic Bacillus: clausii, coagulans, indicus, licheniformis, and subtilis. Not every species of Bacillus is probiotic. Some Bacillus species are usually pathogens. Bacillus may normally be found in the GI tract, but they generally do not take up residence for long and will pass through and be eliminated if not replenished. Bacillus are common food spoilage organisms and are also found in probiotic supplements and in soil, air, and water.

Bottom line: Probiotics are a promising field of research and may one day be used to treat or help prevent many disorders. But there’s not enough solid evidence to recommend their widespread use. Vague claims that probiotics "support good digestive health" are meaningless. Larger, longer and better studies are needed to test specific strains for specific conditions and to determine the proper doses and regimens.
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.

Most of the prebiotics identified are oligosaccharides. They are resistant to the human digestive enzymes that work on all other carbohydrates. This means that they pass through the upper GI system without being digested. They then get fermented in the lower colon and produce short-chain fatty acids that will then nourish the beneficial microbiota that live there. Oligosaccharides can be synthesized or obtained from natural sources. These sources include asparagus, artichoke, bamboo shoots, banana, barley, chicory, leeks, garlic, honey, lentils, milk, mustards, onion, rye, soybean, sugar beet, sugarcane juice, tomato, wheat, and yacón. The health benefits from these oligosaccharides is a topic of ongoing research.
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: