For decades, excitement and interest in the gut microbiome has come from a growing understanding that its trillions of organisms have the power to transform both your physical and mental health. Here, discover the role that food plays in shaping the microbiome and transforming your health.
—By Deborah Kesten
A life-changing, groundbreaking, national research project about your gut microbiome, done in the 21st century, has given us pioneering, quantum-leap, newly discovered insights into what may be the underlying causes of many chronic physical and mental conditions with which millions of us struggle.
These can range from overweight, obesity, heart disease, diabetes, and some cancers, to a plethora of negative emotions, such as anxiety, depression, and food cravings. (A brief aside… Based on research on my science-backed Whole Person Integrative Eating program, I’m defining ‘food cravings’ as a negative feeling.)
Meet your gut microbiome!
Meet Your Microbiome
The science that is verifying the profound influence of gut health on your body and mind evolved from the Human Microbiome Project (HMP). Launched in 2007, the 10-year project received $170 million in funding from the National Institutes of Health Common Fund. Its purpose was twofold: (1) to identify and define the human microbial flora in the gut, (2) then, to illuminate the role of these microbes in health and disease.
What exactly is the microbiome, and why is it pivotal to both your physical and mental health?
Simply put, the microbiome is the genetic material of all the trillions of microbes—bacteria, fungi, protozoa, and viruses—that live on and inside the human body. Micro in the word microbiome means “small”; biome means “a habitat of living things.”
Our gut microbiome is made up of between ten to one hundred trillion bacteria, fungi, and viruses: it is a complex ecosystem of microorganisms that live in our digestive systems. And these trillions of organisms play a powerful role in up to 90 percent of your physical and mental health.
I’m going to repeat that: The trillions of organisms in your gut play a powerful role in up to 90 percent of your physical and mental health.
Here’s how it works.
The Bad, Good, and Your Microbiome
I’m starting with the bad news (sorry!). Get ready.
Poor gut health, meaning too much “bad” bacteria—or, put another way, a decrease in “good” gastrointestinal bacteria—increases odds of dozens of physical health problems and mental disorders. For instance, it can lead to a weakened immune system—did you know that 70% of your immune system, which fights disease, is in your gut? Too much bad bacteria is also linked with inflammation and increased odds of overweight and obesity, heart disease, diabetes, arthritis and other autoimmune disease, some cancers, cognitive decline (think Alzheimer’s), and more.
And a proliferation of bad bacteria is also linked to mood disorders. How so? Your gut microbiota influence the way your brain functions by communicating with your nervous system through neurotransmitters, naturally occurring chemical messengers that transmit signals throughout your mind-body. And high levels of bad bacteria send messages to your brain that could lead to mood and stress-related disorders, such as anxiety and depression.
The good news is this: You may recall that I mentioned the second half of the National Institutes of Health study on the microbiome focused on illuminating the role of gut microbes not only on disease, but also on health. Because of this, we now know about the powerful influence that food, especially, has on your microbiome and in turn, on your weight and physical and mental health. And we also know more about the influence that other lifestyle elements—such as stress and sleep and exercise and social support—have on your gut bacteria, and in turn your mental and physical health.
The bottom line: State-of-the-art, 21st century science is now verifying that the gut plays a pivotal role in almost all aspects of our physical and mental health.
A Gut-Obesity Story:
Can Gut Microorganisms from Fast Food Make You Fat?
A new gut-obesity story is emerging in the world of microbiome research: decades of studies have revealed a strong association—meaning, some kind of connection—between the gut microbiome and obesity in humans, but a cause-and-effect, direct relationship between the quality of the microbes in your gut and obesity has been elusive—until now.
In other words, rapid developments in the field are showing that the gut microbiome responds quickly and precisely to diet, antibiotics, and other external input in ways that impact a variety of conditions, including obesity and weight management. And the key seems to be the roles of specific sets and types of gut microbes. I, personally, use the idea of the “quality of gut microbes” to describe their influence on weight and physical and mental health.
The researchers who discovered the gut-microbes-obesity, cause-and-effect relationship, began by conducting what’s called a transplant experiment: they transplanted various gut microorganisms harbored in the gastrointestinal tract from both lean and obese mice into germ-free mice, meaning mice with organism-free guts. No good or bad gut microbes. None.
After only two weeks, the germ-free mice who were given the microbiota from obese mice gained more body fat compared to the mice injected with the gut microbiota from lean mice. Clearly, certain gut bacteria were involved in the development of obesity!
Knowing that many obese people have what obesity researchers call Western diet-induced obesity (DIO), the research team now wanted to know if there was a relationship between gut microbiota, and (1) diet—specifically, the fast-food-based standard American diet (2) and energy balance (high-calorie intake from the Western diet). To find out, they transplanted DIO, Western diet-induced obesity gut microbiota due to a fast-food diet into germ-free mice.
Again, the Western diet-induced obesity microbes promoted more fat gain than transplants from lean donors.
Food Quality, Weight, and Health
Because of such state-of-the-art studies on the microbiome, we now know that the quality of the food you eat, and your weight, are strongly and deeply interconnected. And we also know that gut microbiota—influenced by the quality of the food you eat—is the new unifying factor in the study of obesity.
Think of it this way: The foods you choose to eat, which also feed your gut, is like fertilizing soil for healthy plants. Tending to your “gut garden” by feeding it fresh, whole foods will allow it to thrive with “good” bacteria that may help you attain and maintain a healthy weight.
But fill up on fast food replete with processed fats, sugars (such as high-fructose corn syrup), and a motley crew of chemicals that damage your intestinal lining and feed your gut with lots of “bad” bacteria, and you’re setting yourself up not only for weight gain—but ongoing weight gain—plus inflammation, autoimmune conditions, anxiety, depression, emotional-eating episodes. . . and more.
Emotions and the Microbiome: It’s a Two-Way Street
The gut microbiome also has a huge impact on our mental health and emotions. And vice versa: our mental health, thoughts, and emotions also have a huge impact on our gut microbiome, the balance of bacteria, and in turn, mental and physical health. Or illness.
In other words, recent research on the microbiome tells us the gut-mood link is a two-way street: not only do your thoughts and feelings influence the balance of “good” and “bad” gut bacteria, but the balance of microbes in your gut can also modulate your emotions.
Then there’s this encouraging finding: Lots of “good” gut-friendly bacteria can help to manage gut-brain communication in a positive way, meaning, an adequate balance of good gut bacteria can function as natural antidepressants and anti-anxiety organisms.
Here’s the takeaway: When your gut microbiome has a balance (called homeostasis) of bacteria, emotions too are likely balanced, making you less prone to depression and making it easier for you to handle stressful situations and negative emotions.
Food for “Good” Gut Bacteria
These groundbreaking findings beg this question: What to eat to up the odds of lots of “good” gut bacteria, and in turn, mental and physical well-being? The nutrient-dense, health-enhancing foods that lead to gut health include fresh, whole plant-based foods (such as fruit, veggies, whole grains (think quinoa, brown rice, and whole wheat), legumes (meaning beans and peas), and raw—not roasted—nuts and seeds with smaller servings of grass-fed, free-range animal-based foods.
Ultimately, this is the well-known Mediterranean Diet, voted the #1 best diet for health by U.S. New & World Report six years in a row.
Conversely, nutrient-deficient foods (processed, fried, high sugar, etc.) are likely to create an over-abundance of “bad” bacteria that could allow negative emotions an ill-health to bloom.
Speaking of which…
SAD and the Mind-Microbiome Cycle
To begin, here’s a question for you: What do industrial farming, farmed fish, pesticides, herbicides, additives, preservatives, and denatured, processed, junk food—and fast food with low nutrient availability and lots of added sugar, salt, fat, and chemicals have in common? They are all part of Western dietary changes over the last seventy years that threaten the stability of both your microbiome and emotions.
What I mean is this: by contributing to the excess of bad bacteria in your microbiome, today’s standard American diet (with the acronym S.A.D., SAD) has a negative impact on your gut health, which in turn can contribute to mood problems like depression and anxiety, weight gain, and many chronic conditions.
But the processed food-bad bacteria-negative emotions story doesn’t stop here. Why? Because there’s another side to it: Negative emotions, by themselves, can also damage gut microflora and create an excess of “bad” microbes. The end result: the negative emotions-microbiome cycle continues.
The Takeaway
Here’s the bottom line: The good news is that the foods you choose—and that are your most-of-the-time way of eating—can give you a lot of control over the health and balance of your microbiome and in turn your weight, your emotions, and overall well-being. And we know this because state-of-the-art, 21st century science, has discovered that the food you choose has a lot to do with the balance of good and bad bacteria in your microbiome, and in turn your weight and physical and mental well-being.
This means you really can reclaim your health destiny through the foods you choose each day. The choice is yours!