The beef industry used that question in a commercial (with a different answer) in a very successful series of advertisements in 1992.  Using a sting of celebrity voice overs, initially featured Robert Mitcham and music from the Rodeo (“Hoe-Down”) ran for 17 months (most recently Sam Elliott replaced Mitcham).  It is reported that over 88 percent of Americans recognize this marketing campaign. 

Beef tastes great and is an excellent source of various vitamins and minerals, including vitamins B12, B6, zinc, and iron but zero fiber.  Food from animals, including meat, dairy, and eggs offer many health benefits to the 10% human cells but diets high in animal calories may cause harmful changes in their gut microbiome.

As we continue our journey of understanding a bit about the microbiome ecosystem, let’s dig into what our microbiome eats (which comprise over 90% of our cells).  It is critically important to understand what to eat to grow our microbiome ecosystem.  As we noted in previous posts, fiber is the choice of “food for our microbes”.

Before we discuss the food let’s quickly discuss probiotics and prebiotics at a high level.  Probiotics are “good” bacteria found in yogurt and other fermented foods and in dietary supplements.  There has been a large movement of people looking to take probiotics to cure various stomach and other ailments.  I want to me clear there is typically no harm in consuming various probiotics but as we have been discussing we have over 90 trillion probiotics (which make up the microbiome) the exact composition is unique to each person but in your colon from over 500 different species.  So, since we have trillions already let’s just feed the ones we have and not be too concerned about adding more (this is not medical advice, please engage your doctor to discuss the benefits of taking certain strains of probiotics). 

Prebiotics are certain types of fibers that feed our good microbes.  Think of probiotics as a tomato plant with prebiotics as water.  So, we plant the tomato plant (probiotic) but don’t water it and as you can imagine the tomato plant dies and you go buy more tomato plants and replace them (think of taking probiotics but not feeding them).  Instead of replacing the tomato plant, let’s take care of them by providing water to them (eat prebiotics) daily and the tomato grows.  This is the same for our microbiome, if we feed them daily, they grow and multiply thereby protecting us from food borne pathogens and improving nearly every system of the body.

Overall, “fiber” refers to a diverse group of carbohydrates that humas cannot digest.  Fiber is mostly found in plant foods, including vegetables, fruits, legumes, whole grains, nuts and seeds.  There are two types of fiber, soluble fiber and insoluble fiber.  Soluble fiber blends with water in the gut, forming a gel-like substance and this substance feeds our good microbiome.  Insoluble fiber does not blend with water and passes through the digestive system mostly intact.  It functions mostly as a “bulking” agent and may help speed the passage of food and waste through your gut.

Let’s focus on fermentable fiber, it’s mostly comprised of soluble fiber which reach the large intestine mostly unchanged.  These fibers allow our friendly microbes to digest (ferment) and use as food.  As we continue to understand how the ecosystem works, a few of the of the most studied probiotics are the Lactobacillus and Bifibacterium (will talk more about that these stains do for us in later posts).  It’s been clinically proven that prebiotic soluble fiber from green banana, chicory roots and artichoke selectively stimulate their growth.

Michael Pollan’s well received book title says it all “Eat Food. Not Too Much. Mostly Plants”.