Last week in our interview with Jo Ann Hattner, gut health expert and author of Gut Insight: Probiotics and Prebiotics for Digestive Health and Well-Being, we covered basics about the gut microbiome. This week we get down to the application: prebiotics, probiotics, and fermented foods. And, we’ll dispel some myths about pre-and probiotic foods.
Can you describe the difference between a probiotic and a prebiotic?
A formal definition of probiotics is “live microorganisms that, when administered in adequate amounts confer a health benefit on the host.” What that means for us is that when we take in foods with probiotics, either in foods or drinks or supplements, they should have a health benefit for us.
What does confer a health benefit mean?
It means that a particular strain of live bacteria has been studied and demonstrated to have a positive health outcome. “Demonstrated” is an important word because research is required to show it has a health benefit before it can be considered a probiotic. For example, stains of bacteria called Bifidobacteria (pronounced biff-ah-doe bacteria),a group of lactic acid bacteria that live in your gut, confer a health benefit by alleviating constipation and reducing the symptoms associated with irritable bowel syndrome, to name a couple of demonstrated benefits.
One other benefit is worth mentioning. Probiotic has an opposite…antibiotic. When we take an antibiotic for an infection, it can have a side effect of disturbing our healthy gut bacteria. Ingesting probiotic foods or supplements when we take antibiotics can help push out the bad bacteria. Bad bacteria don’t like to live in the same space as healthy bacteria.
Prebiotics and probiotics are easily confused. They both contribute to the population of good bacteria in our gut. Think of prebiotics as foods that feed the good bacteria. In other words, once you have a good population of bacteria, it needs to eat! And, it’s nourishment comes from prebiotics. Another term you might hear is synbiotic. That is a food or combination of foods that contain both pre and probiotics. For example, when you eat yogurt (a probiotic) with fruit (a prebiotic) you are doing something good for your gut bacteria. A recent study demonstrated consuming yogurt and fruit is a good combination for a healthy gut.
How do fermented foods affect the gut microbiome?
Fermented foods were traditionally made by taking a food, for example cabbage, and allowing the naturally occurring microbes on the food to grow. This changes cabbage to sauerkraut, and it was originally done for food preservation. Fermented foods can naturally ferment or be aided by adding probiotics. The big question is how many of these new, trendy fermented foods actually contain probiotics that help your gut microbiome? For a probiotic to survive, it can’t be heat treated or pasteurized and it is hard to tell by looking at a food label if it contains live probiotics. Sauerkraut in a glass jar or pouch found in the refrigerated case is more likely to contain probiotics, than canned sauerkraut which is heat treated when it is canned.
One of my favorite fermented foods, and a good source of live active cultures, some of which are probiotics, is kefir, or fermented cow’s milk. It comes in lots of flavors, but you can try the plain kefir and flavor it with fruit or honey until you get used to the sour taste.
Kombucha, a fermented sweetened tea, is made with bacteria and yeast. It is sour-tasting (some people love it, and some describe it as vinegary-tasting dish water). And while it is popular and seemingly sold everywhere, documentation that is an effective probiotic is lacking.
What are some common pre-and probiotic foods that you recommend?
Yogurt is probably the most commonly consumed probiotic food. With so many choices on the market, look for a yogurt that contains the seal “live and active cultures” to make sure you are getting the right strains of bacteria. I prefer yogurt that doesn’t have a lot of added sugar; I would rather eat plain yogurt or Greek yogurt and add my own fruit or toppings, like granola.
Many fruits and vegetables contain fibers that are prebiotics. Inulin is a prebiotic fiber found in banana and is one of the first foods we feed infants. Inulin can also be extracted from chicory root fiber and is well documented to be an effective prebiotic. Many foods, including yogurts and energy bars are adding inulin for its prebiotic fiber. Fiber-rich foods, like whole grains, contain prebiotics, as do some nuts, like walnuts.
The most important thing to remember is to include probiotic foods every few days (every day is ideal) to replenish your healthy gut bacteria. Include prebiotics at every meal; fresh fruit smoothies, veggies and salads, and whole grains all contain fibers which are good for your gut.
What do you think is the biggest misconception about the gut microbiome?
The biggest misconception is that we have a profile of what the gut microbiome should be; we know there are healthy bacteria, but how many bacteria and how much diversity do we need? As we get older the number of good bacteria decrease. Without good bacteria, we are more susceptible to illness.
We are still in the infancy of understanding the gut microbiome and the relationship to human health, but by eating pre- and probiotic foods every day, we can get on the right path to a healthy gut.
Where can people find more information on prebiotics, probiotics, and fermented foods?
There is helpful information on the International Scientific Association of Probiotics and Prebiotics (ISAPP) website.
On my website, Gut Insight, there are resources such as frequently asked questions and a shopping list of probiotic and prebiotic foods.
For those looking for a cookbook, check out The Well-Fed Microbiome Cookbook.
Learn more on a healthy gut, eating well, moving well, and being well, Food & Fitness After 50.