Eating to Improve Gut Health
New research proves it: Not just the source of ill-timed gurgles and groans, your gut may be the unsung hero of head-to-toe health.
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Our Bodies, Ourselves is more than just the title of the classic 1970s women’s health text that has sold millions of copies worldwide. It’s a phrase that reflects how we have been brought up to view who we are – a singular entity that deserves and, in fact, needs protection from the onslaught of disease and germs lurking around every corner. So why is it that though we have embraced antiseptics and antibiotics to control the bacterial population inside and outside of our bodies, we seem to just be getting sicker?
Research is revealing a surprising source for the recent influx of allergies, autoimmune diseases and even mental health issues that plague our population. It turns out that your gastrointestinal system and, by extension, the nearly immeasurable number of bacteria contained within it are in the business of far more than just ensuring your latest meal is properly digested – and our misunderstanding of their role is leading to a lot more than just an upset stomach.
In The Beginning
“This used to be [a topic] just for gastroenterologists, and now everyone is weighing in; even the media is taking an interest,” says Emeran Mayer, MD, PhD, a professor at UCLA’s David Geffen School of Medicine and the Executive Director of the university’s
G. Oppenheimer Center for Neurobiology of Stress and Resilience. He is also the author of The Mind-Gut Connection (Harper Wave, 2016), which explains how the gut-brain axis, or the information superhighway between your head and “the second brain” in your gut, controls everything from your emotions to how your body fends off disease. And it is indeed a fascinating area of study.
You’ve probably heard that of all the cells in your body, those that are foreign (think bacteria) outnumber human cells (i.e., you). Up until recently, your gut – a word that collectively refers to your stomach, intestines and other digestive organs such as the liver, pancreas and even your mouth – was said to be home to 100 trillion bacterial cells, a 10:1 ratio of bacteria to human cells. However, according to researchers at the Weizmann Institute of Science, that ratio was calculated from numbers based on the premise that the average bacterium is about 1,000 times smaller than the average human cell, but, in fact, the size of bacteria cells and human cells widely vary. Taking that information into account, the researchers revisited the scientific literature behind the ratio of 10:1 and published their findings in Cell in 2016. While they still found that bacteria outnumber human cells, the ratio is actually closer to being equal at 1.3:1. Still, the researchers
caution their numbers are only rough estimates and that the numbers can vary slightly from person to person.
“We have to be cognizant that bacteria are our greatest allies. We aren’t living in a cold, hostile world of bacteria that are out to get us. Actually, it’s the opposite.”
The diversity of this cellular population isn’t a product of your genes alone. It is influenced in utero and during the first three years of your life by many internal and external factors, including your mother’s diet, her stress level, your level of stress, the other people you have contact with and genetics, explains Mayer. Plus, since much of the bacteria that “seeds” the gut microbiome – a community of bacteria, fungi and other microscopic organisms – is passed to an infant during childbirth, those who are born via cesarean are often exposed to (and host to) a smaller variety of beneficial bacteria, putting them at a greater risk later for allergies, asthma and autoimmune diseases.
Against Gut Instincts
Though this army of bacteria is meant to work in harmony with the rest of your body, protecting it from unfriendly bacteria, things can sometimes go awry. When there is a defect in the gut-brain axis, the immune system begins to attack your body’s cells, causing your brain to believe that your body is being attacked by foreign intruders when really it’s just some organ or tissue that would have otherwise been harmless if your gut-brain axis was functioning properly. This effect is manifested in autoimmune diseases like celiac, lupus and even diabetes.
But what can cause this exchange of info error? Some speculate that it could be what we are putting into our environment and, by extension, our bodies. A 2014 review in the journal Autoimmune Diseases surmised that the rise in use of chemicals during manufacturing and farming that has taken place since World War II coincides with the surge in autoimmunity conditions. Studies also show that air pollutants affect the circulation of serotonin, an important neurotransmitter that’s found in both the gut and brain, as well as the function of the vagus nerve, the nerve that connects the brain to the heart, lungs and digestive tract. A malfunctioning vagus nerve causes inflammation within the body, which is linked to arthritis and irritable
bowel syndrome (IBS) and has been tied to diseases like Parkinson’s. More study, however, is needed to determine exactly what the effects of pollution are on the microbiome.
There is a wealth of additional research that links an imbalance of gut microbiota to serious health issues aside from the autoimmune and inflammatory disease variety. For instance, the health of your brain. A 2017 study from Sweden’s Lund University found that when a group of mice had intestinal bacteria from healthy mice transplanted into their guts, they developed fewer beta-amyloid plaques – lumps that accumulate in the brain and may be a cause of Alzheimer’s – than those that had received a sample from a mouse with the disease.
And an imbalance of gut bacteria has been found to play a role in the development of cancer, not just locally as with colorectal cancer but systemically as
with esophageal cancers, as described in the June 2017 issue of Annals of Gastroenterological Surgery. Clearly, keeping your internal bacterial community happy should be a major health priority – and not just to keep tummy rumblings at bay.
Get Your Flora to Flourish
Even though your gut microbiome may be architected during the very years over which you have the least control – the prenatal period, infancy and the first years of life – there are things you can do right now to affect the quality of the bacteria in your gut and the amount of each type, as well as the general day-to-day abnormal gut reactions that Mayer estimates 15% of people suffer from. (The microorganisms in your gut, he explains, create gas when mowing down on fiber, sometimes causing bloating and distension.) There’s a lot of promise in largely plant-based diets with a focus on whole foods, says Mayer. “There is overwhelming evidence that it is the healthiest for your microbiome,” he shares. “It won’t permanently change it, but it will change the abundance and diversity as long as you are on that diet.” In fact, meat-heavy diets have been linked to an increase in Bilophila wadsworthia, a type of gut bacteria that has been shown to be associated with inflammatory bowel disease, according to a 2013 Harvard University study published in the journal Nature.
But you don’t necessarily have to go meat-free to see benefits. Josh Axe, DNM, CNS, DC, author of The Gut Repair Cookbook (Axe Wellness, LLC, 2016) and the founder of Ancient Nutrition, suggests beginning by removing offenders like refined sugar, gluten, processed dairy products, unsprouted grains, and processed foods, which have been shown to cause digestive upset. Slowly start to add in foods like bone broth, fermented vegetables, steamed non-starchy vegetables, probiotic-rich raw cultured dairy, and healthy fats like avocado and coconut oil. He also recommends taking a high-quality probiotic supplement as well as digestive enzymes.
If you suffer from recognized allergies or suspected food intolerances, removing the foods or food groups that trigger reactions from your diet can help reduce digestive upset. This is especially true for individuals with low levels of the enzyme lactase, which breaks down lactose into simpler sugars in the body; avoiding dairy products will prevent the cramping and diarrhea that are sometimes associated with their intake.
It’s not just your diet that can play an important role in your gut health either. A 2017 review published in Neurobiology of Stress concluded that there is a strong link between stress and the diversity of gut bacteria in animal studies, and the relationship is compelling enough to warrant further research. Even exercise has been shown to have positive effects: Participants in a 2017 University of Illinois at Urbana-Champaign study who followed a six-week exercise program had higher levels of bacteria that produce butyrate, a short-chain fatty acid that reduces inflammation, promotes healthy intestinal cells and provides energy to colon cells.
Just being aware of the fascinating community that lives within you can go a long way in helping create balance, too. “We have to be cognizant that [bacteria] are our greatest allies,” says Raphael Kellman, MD, founder of New York City’s Kellman Center for Integrative and Functional Medicine and author of The Whole Brain (Da Capo Lifelong Books, 2017) and The Microbiome Diet (Da Capo Lifelong Books, 2014). “We aren’t living in a cold, hostile world of bacteria that are out to get us. Actually, it’s the opposite.
”In the end, reframing our understanding of the human body as a vibrant and varied community of interworking life-forms is a necessary step on the road to health and longevity. Shifting away from the segregated and narrow “our bodies, ourselves” mindset can be the first step to achieving the balance we all crave. After all, as Dr. Kellman notes, “If you are thinking of the bacteria inside of you as the bad guy, how are you going to heal the microbiome within you?”
For more information, check out our What About Probiotics? and A Healthy Gut Starts with the Gut Lining articles.
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Learn to cook and eat to nourish a thriving microbiome in our Clean Eating Academy course The Gut-Health Fix with health and wellness expert, author of Real Food Heals and award-winning NYC chef and restauranteur Seamus Mullen. Learn more at cleaneating.com/guthealthfix.