Feed Your Microbes
By now you might be wondering how to have a healthy gut. The short answer is to support your microbes. And how do we do that? Remember we evolved eating a LOT of plant foods and we evolved along with our bacteria which means whatever you put in your mouth or are exposed to can impact them as well. Fiber gets a lot of notice but there are a number of less obvious players like polyphenols, fermented foods, eating organic produce, sourcing pasture-raised meats, avoiding unnecessary antibiotics, and getting fifteen to thirty minutes of activity a day that play a pivotal role in gut health. The exact picture of what a healthy microbiome looks like is still coming into focus, but we do know that a diverse microbial population is supported by the items above and is linked to better health outcomes and fewer non-communicable diseases. While there are some microbial species that seem to be more beneficial and others that thrive when the hosts’ health isn’t the best, because each person, population, and community is different, we cannot say for certain if a specific species is helpful just yet.
Fiber plays a huge role in keeping your gastrointestinal tract healthy through multiple pathways. Firstly, fiber feeds your gut microbiota in the large intestine. They ferment the otherwise unusable parts of plants for us, and that dearest is where the magic happens. The human body lacks enzymes to break down beta-linked glucose polymers present in resistant starches and plant fibers. We have engineered a few ways around this via processing or cooking but we evolved with our bacteria primarily doing that job for us. It really is the most beautiful and complex symbiosis between us and our microbes. Secondly, fiber helps move things through your body to aid with elimination while binding excess hormones, toxins, and lipids along the way. Not pooping on the regular can be a sign of an eating pattern that lacks fiber (as well as stress, low thyroid, or lack of hydration but we’ll get there another day). This backup can cause our bodies to reabsorb waste products which can throw us out of balance.
Aiming for at least thirty grams of fiber a day from whole food sources not only gives your microbes fuel it also supplies them (and you!) with their other favorite food - antioxidants. Also called polyphenols, these are what give foods their amazing and varied colors. These fiber-encapsulated nutrients increase the health of our microbes which in turn produce short-chain fatty acids (SCFA) which help keep our gut lining and therefore us, healthy.
When you eat a rainbow of plant foods as often as you’re able, you ensure that your microbes are getting the best nutrition possible. Data has shown that while overall eating patterns don't matter - vegan, omnivore, etc - eating at least thirty different types of plant foods a week sustains a vibrant and varied gut microbiome. Each type of plant has its own bacteria in and on it, just like us, and when you combine that microbial diversity with the constituents of the food itself you get a powerhouse of nourishment that helps keep your microbiome happy. When you shift your eating pattern to include many different plant foods you can improve the diversity and health of your microbiome in a matter of days to weeks. How cool is that?!
Prebiotics are the specific type of fiber that healthy gut bacteria prefer. Some of the best sources include legumes, dark leafy greens, brassicas, Jerusalem artichokes, asparagus, and alliums. Other great sources of fiber include whole grains, raspberries, avocados, tempeh, chia, cacao, nuts, and seeds. Flax seeds especially are exceptionally high in fiber, protein, and polyunsaturated fats.1 They are also rich in phytoestrogens and polyphenols which make them a great supportive food for everyone but especially women as they help regulate estrogen balance and improve gut health. The magnesium content in flax seed can help relax smooth muscle which can decrease cramping and keep your bowels moving thereby reducing premenstrual discomfort. Just be sure to grind them fresh and consume raw or at low temperatures as those wonderful fats oxidize easily.
Fermented foods such as kimchi, sauerkraut, full-fat yogurt, kefir, kombucha, miso, and fermented pickles help to fertilize your microbes to keep them growing in a lush, varied jungle. It is believed that the bacteria in these foods support diversity in the gut more effectively than probiotic supplements because they are more likely to survive digestion and thus can produce higher quantities of beneficial SCFA. The ingestion of these living foods exerts a positive influence on the intestinal epithelium, immune system, and enteroendocrine cells and this influence has been shown to support weight maintenance, lower cardiovascular disease risk, decrease diabetes risk, improve irritable bowel diseases, improve rheumatoid arthritis, and improve mood and brain activity.2 If you are unable to tolerate fermented foods on a regular basis or there is a specific health concern that requires it, you may consider taking a probiotic supplement but food sources are a generally inexpensive way to get this powerful medicine while including the polyphenols and fiber that probiotics need to flourish.
In addition to eating fiber and getting some fermented foods on a regular (ideally daily) basis, adding moderate levels of activity seems to rev up the whole system and compound the effects of all that healthy food you’ve been eating. As little as ten to fifteen minutes of walking a day has been shown to improve the gut barrier and increase microbial diversity. This could be part of why we feel better when we’re active! Physical activity also stimulates your body to eliminate waste (it makes you poop) which we absolutely want.
Other than the food we choose, our exposure to chemicals including pesticides, herbicides, medications, diesel exhaust, preservatives, food additives, and antibiotics can have profound effects on our microbes. These substances have been proven to alter our microbial diversity towards dysbiosis and thus impact our gut and whole body health. Eating organic when possible is an important step in caring for your microbiome and for those who raise, grow, and produce our food. This includes choosing organic and pasture-raised animal products like eggs, meat, and dairy. Pesticides, herbicides, and medications that animals in industrial settings are exposed to do show up in their meat, milk, and eggs. Not only do these alter our microbiome, but they also destroy the environment and favor a cruel relationship with those animals whose products we consume.
Cooking your own food is a great way to ensure you get quality ingredients and maximize your fiber potential. It doesn’t have to be fancy - beans and sautéed greens are lovely and full of fiber and protein. If there are a couple of simple recipes you love to cook or eat, think of creative ways to incorporate more fiber into them like having a smaller portion of animal protein filling the plate with veggies or adding some beans or tempeh. There’s plenty of room to be excited and try stuff out.
The final ways to support your microbiome are to manage stress and get enough sleep. This one can be tricky. I get it. I struggle with this more than any of the other steps I’ve mentioned. There is a bidirectional relationship between stress and dysbiosis. Eating a low fiber, low polyphenol diet can push you into dysbiosis which then spreads inflammation in the body which perpetuates more inflammation and more dysbiosis. But being stressed from work, experiencing racism, bigotry, sexism, relationships, the news, the world, noise pollution, and overall busyness can independently challenge your gut and cause dysbiosis so it's important to do something every day to calm down your nervous system. Go for a walk, meditate, jam out to your favorite music, stretch, take a nap, get a few really good hugs, take a shower or a bath. Whatever it is. You need that time for you to have a healthy gut which supports a healthy body and mind.
Action steps to shift your relationship to yourself and your microbes:
Eat 30 grams of fiber a day
Eat 30 types of plants a week
Aim for 30 minutes of activity a day
Avoid antibiotics unless medically necessary
Choose organic produce (or as close as possible, some growers just aren’t certified)
Choose grass-fed and organic animal products
Avoid additives and preservatives in food
Get enough good sleep
Take steps to reduce stress
Poop daily
Resources:
1. Kajla P, Sharma A, Sood DR. Flaxseed-a potential functional food source. J Food Sci Technol. 2015;52(4):1857-1871. doi:10.1007/s13197-014-1293-y
2. Marco ML, Heeney D, Binda S, et al. Health benefits of fermented foods: microbiota and beyond. Curr Opin Biotechnol. 2017;44:94-102. doi:10.1016/j.copbio.2016.11.010
