The Truth about Probiotics

The facts on probiotics and how to incorporate them into your diet.

probioticsProbiotics are found in yogurt and other foods listed below. Photo via Shutterstock.

Have you ever taken a round of antibiotics and been left with some unpleasant gastrointestinal side effects? Antibiotics are sort of a necessary evil; they are important and powerful medicines that fight bacterial infections, by killing or preventing the reproduction of harmful bacteria. But unfortunately, they often wipe out the good bacteria with the bad, taking out beneficial probiotics in their wake. It’s the good bacteria that helps keep the digestive tract balanced and healthy, preventing a range of digestive ills including constipation and diarrhea, while also promoting immunity.

Probiotics are everywhere now. You can’t read a magazine or turn on the television with seeing Jamie Lee Curtis peddling yogurt or Erin Andrews promoting a supplement. Grocery stores are filled with items that contain probiotics and supplements are crowding the market. But it is important to know that not all probiotics are created equal.

You may have also heard of the term “prebiotic” alongside probiotics. What is the difference? Together they are “symbiotics” working together to create a healthy intestinal microflora. Separately, they function in different ways. Prebiotics are non-digestible substances like inulin (a natural carbohydrate produced by plants) in food that promote the growth of normal, healthful bacteria, that are already in your colon by acting as their “food”.  Some prebiotics may also enhance calcium and magnesium absorption, and reduce risk factors for some intestinal problems, but others can do quite the opposite.

Inulin, for example, is the food industry’s new favorite ingredient because it has no calories (fiber never has any calories because it is not digested by the body); it has a naturally sweet taste to it, and is a very soft fiber, so it is easily incorporated in bars, yogurt, and a range of other products. The problem is that this type of fiber may not have the same benefits as other types of fiber and can be a nightmare ingredient for those with irritable bowel syndrome due to the fact that it often causes or exacerbates gas, bloating, and diarrhea. To spot inulin in your food products, look to the ingredients list; it may also be listed as “chicory root”, the plant from which it is most often isolated.

In general, beware of products that don’t naturally contain fiber, or large amounts of fiber, like Fiber One bars, or Splenda with fiber. Good choices to boost your prebiotic intake include whole grains, onions, some fruits, garlic, honey, leeks, and bananas.

When it comes to probiotics, you’ve probably heard that good bacteria can be found in aged cheeses, certain yogurts, and other cultured dairy products like kefir. But tempeh, miso, kimchi, and sauerkraut also contain probiotics. Many foods that undergo fermentation to produce the final product often contain probiotics. More research needs to be conducted on specific probiotic strains and species as well as the amount needed to see a health benefit, because some products have significant benefits while others have none.

Look for foods that contain “live active cultures” of either Lactobacilli or Bifidobacteria, which may be the best two strains for both gastrointestinal health and immunity. It is important to note that no health claims for prebiotics or probiotics are approved by the FDA, though a structure-function claim may appear on labels, such as “promotes a healthy digestive system”. Despite there being consumer interest for regulation around labeling, safety, and quality of probiotics, there is an overall lack of oversight. The best way to get prebiotics and probiotics is through food.

Foods that contain prebiotics:

Whole grains (such as oatmeal and barley)




Greens (especially dandelion greens, but also spinach, collard greens, chard, kale, and mustard greens)

Berries, bananas, and other fruit


Legumes (lentils, kidney beans, chickpeas, navy beans, white beans, black beans, etc.)

Foods that contain probiotics:

Yogurt: Try Stonyfield Farm, which comes in a bunch of flavors, is organic, and has six live active probiotics cultures.

Kefir: This is a fermented milk product that is a good choice for adding probiotics to your diet but watch the serving size as most tend to add a lot of added sugar.

Buttermilk: Contrary to popular belief, buttermilk does not contain butter. It is a low-fat choice with a tangy taste and can be incorporated into a variety of recipes.

Sauerkraut: You can pair this with chicken sausage and potato salad for a German-inspired meal.

Tempeh: A fermented soy product that is firmer and has a more “earthy” taste than tofu.

Miso: A seasoning that is made by fermenting rice, barley and/or soy.