Five years ago, nobody knew they had a microbiome. Today, we’re obsessed with it. That may be a slight exaggeration, but the health of the community of microbes living in and on our bodies—100 trillion single-cell organisms, outnumbering human cells 10 to 1—has become a top priority. With good reason: Our gut bacteria regulate many of our bodily functions, from creating vitamins to controlling our immune system, our brain function and of course, our metabolism and weight. They are critical to our long-term health.
Meanwhile, modern living and our bad lifestyle choices have been hard on those little bugs. The standard western diet is impoverished of the things our beneficial gut bacteria require. All the chemicals from processed foods and the environmental toxins we take in only make the situation worse. Our guts become damaged when we eat a processed diet that’s high in sugar and starch, don’t eat enough of the right fiber and prebiotics, or take too many gut-busting drugs (like antibiotics, acid blockers for reflux, anti-inflammatories, hormones, and more). Think of your gut as an inner garden; just as with any garden—when you let the weeds take over, you get into trouble.
We are home to more than 500 different species of microbes. Some of them help us, but others are harmful. Many of us have too few bacteria in our intestines, where they do us the most good. Others have an overgrowth of the bad kind, which causes its own problems. Not enough of the good bacteria, or too much of the bad, can lead to intestinal disorders like Irritable Bowel Syndrome, Leaky Gut, and SIBO, but also chronic inflammation, depression, even cancer and heart disease.
So, it’s our job to encourage the good microbes by feeding them the things they need and avoiding the things that damage them. Meanwhile, we have to starve the bad bacteria by avoiding the foods and other forces that allow them to thrive.
Not surprisingly, good bacteria love healthy whole, organic, plant-based foods, ones that are high in fiber and nutrients and contain no artificial ingredients. One of the biggest questions I get when I tell people to eat more fiber is, “What are good sources of fiber?” Below, I’ve put together a partial list of foods filled with fiber and foods to feed your gut.
Fiber-rich foods for your gut:
- Brussels sprouts
- Coconut (and foods made from it)
- Dandelion greens
- Nuts and seeds
- Olives and olive oil
- Seeds, especially when sprouted
Good bacteria also benefit from foods that have been fermented or cultured, like these:
- Naturally fermented sauerkraut
- Pickled vegetables (including organic pickles)
- Kimchi (the Korean version of fermented vegetables or fruit)
- Kefir (fermented milk—unsweetened only)
- Tamari (the liquid from miso)
- Tempeh (fermented tofu cake)
- Tofu (which is sometimes fermented)
- Naturally fermented soy sauce
- Unpasteurized apple cider vinegar
- Coconut yogurt (unsweetened)
Even if you’re eating the right things, you may need some outside assistance maintaining plentiful and diverse gut bacteria. That’s what prebiotic and probiotic supplements are for. Prebiotics feed the good microbes, mostly with fiber. Probiotics are the actual bacteria. The best way to determine if probiotics work for you and which ones to choose is to work with a Functional Medicine practitioner. Everyone is different, and for some people, deeper gut healing might be required before you start taking probiotics.
To tend your inner garden, you might need to do some weeding, seeding, and feeding—a process that Functional Medicine doctors follow: First, you weed to get rid of the bad bugs using herbs or medications; then you seed the gut lining with good bugs; and then you feed the good bugs with prebiotic foods and fibers to keep everything healthy.
There are many different varieties of probiotics out there. When shopping for a probiotic, you should look for one with at least 25-50 billion living CFUs (colony-forming units), including the most beneficial strains like:
- Bifidobacterium bifidum
- Bifidobacterium longum
- Bifidobacterium breve
- Lactobacillus acidophilus
- Lactobacillus rhamnosus
- Lactobacillus bulgaricus
Foods made from coconut are good for our gut microbes. One such food—taken as a supplement—is medium-chain triglyceride (MCT) oil derived from coconut oil. This dramatically reduces intestinal inflammation and helps eliminate bad bugs.
Another supplement is glucomannan, a dietary fiber derived from a root. It bulks up the food passing through the digestive tract, thereby aiding people with constipation. It also helps with weight control.
What NOT to feed your microbiome:
You won’t be surprised to know that the foods and other edible substances that damage everything else about our health are also no good for our microbiome. It’s the usual suspects:
- Highly processed or packaged foods
- Refined grains, especially wheat
- Sugars, especially high fructose corn syrup, and artificial sweeteners
- Refined oils and fats, especially soybean and corn oil
- Antibiotic drugs, except when absolutely necessary
- Hormones, including birth control pills
- Anti-inflammatories, including ibuprofen, Advil, and aspirin
- Acid blockers, like those prescribed for acid reflux
Products that damage our guts:
What we put on our bodies also affects our guts. Taking antibiotics can alter our gut health for the worse, and so can using antibiotic-based products. Avoid the following:
- Antibiotic soap
- Alcohol-based hand sanitizers, like Purell
- Even dishwasher use is thought to be bad for our microbiome, because it kills germs too well
Stress, Sleep, Exercise and Your Gut:
Lack of sleep and chronic stress also contribute to gut imbalance. In fact, your gut flora listens to and becomes influenced by your thoughts and feelings. So be sure to get 7 to 8 hours of quality sleep and remember to practice your favorite stress reduction activities daily. This can be deep belly breathing, meditation, therapy, or yoga. Whatever you like to do to relax.
Recent studies have also pointed to the idea that exercise can have powerful impacts on our gut health. One study showed that exercise alone, without dietary intervention, led to an increase in beneficial butyrate-producing bacteria. Butyrate is a fatty acid, which can prevent cancer, speed up your metabolism, and reduce inflammation.
This means that movement matters. You won’t find me at the gym, but I love to play sports, hike swim, and run on the beach. Find what works for you, and do it daily. Your gut will thank you.
All this attention paid to our gut microbes requires an adjustment in our thinking—we grew up believing that bacteria were bad things that should be killed at any cost. We now know that this is not true, and scientific research today is still learning about the ways these single-cell organisms are necessary to a healthy life. I’m excited to see what we’ll find next.
PS: For more information about what the heck to eat (and what to avoid) to feel your best, check out my new book, Food: What the Heck Should I Eat?