If you’re paying attention to popular science, you probably have read about the microbiome and its many health implications. The microbiome is the collection of bacteria, pathogens, viruses, protozoans and fungi that live on and in our bodies, most predominately in our large intestine or colon (although teeming on every surface and orifice of our bodies). We are, in fact, comprised of much more bacteria than human cells. 90% of the cells in the human body are not human, they’re microbial. Mic drop.
When you consider our genetic material, the numbers get even more impressive. Human genes = 23,000 give or take. Our gut microbiome is made up of 3,300,000 genes and counting. That means in our bodies there is a 1:360 ratio of human genes to microbial. Who is actually hosting whom?
The microbial landscape in our bodies changes on a dime. It changes in response to stress, our food, illness, toxic exposure, antibiotics, even birth control pills. On a practical level, this means our microbiome gives us the ability to adapt to our environment much more quickly than our human genome. Although we are genetically similar to people across the globe, the microbiome of people in Zimbabwe, for example, is different from people born and raised in the U.S., having evolved in response to the available food and climate.
Our microbiome, for better or for worse, changes the course of disease, our susceptibility to disease, our appetite, metabolism, our intelligence and our temperament. No matter what the health concern, the environment of our gut is implicated in disease progression. This is not new news. Hippocrates, the father of medicine, stated, “All disease begins in the gut.” Not some or many. All.
To highlight the complex and multiple ways in which the microbiome influences chronic health issues, I want to share with you a tiny glimpse of the microbiome’s impact on our moods.
Microbiome and its influence on Mood and Behavior
How do these critters affect our mood and behavior? Here’s a short list:
- Gut bacteria produce neurotransmitters serotonin, dopamine and GABA, which are chemicals that play a key role in reducing anxiety and increasing happiness. Ever heard of a Selective Serotonin Reuptake Inhibitor (SSRI) used to alleviate symptoms of depression and anxiety? Well our bugs are actually producing serotonin, upwards of 90% of our serotonin is produced in the gut.
- Gut bacteria, as they munch away at the fiber we ingest, produce a chemical called butyrate, which is linked to reduced depression and anxiety.
- Our gut bacteria also stimulates the vagus nerve, which connects the brain with our gut. The healthier the communication between our brain and our guts, the heathier the brain, the healthier our digestion .
- Gut microbes generate B vitamins, particularly B9 (folate), B1 (Thiamine), B6 (pyridoxine), B3 (Niacin), and B12. These nutrients, which are far more accessible to the body when generated in the gut (as opposed to supplementation), are what keep our nervous system and stress response in control. If one is producing these internally, one will experience less anxiety and stress, will have a happier overall mood, and less depression.
In a western medical model, we look to medications to do what a healthy microbiome should be doing for us.
There’s a wiser path to mental health.
For additional fascinating reading on the gut and its influence on mood and behavior, check out this Scientific American article.
The glorious, empowering truth
We can profoundly influence the variety and balance of our microbiome, and therefore our mood and mental health, by the food we eat. Dr. Alessio Fasano, an Italian medical doctor, pediatric gastroenterologist and pioneering researcher on gut health, asserts “Hands down, the most significant factor related to the health and diversity of the microbiome is the food we eat.” This is incredibly good news if you’re willing to take responsibility for your health outcomes.
So, what now?
The first (and most powerful) step in protecting and increasing the diversity of our microbiome is to eat FOOD not products. By doing so, we automatically are reducing harmful inflammatory additives, high fructose corn syrup, GMOs and sugars that wreak havoc on our guts.
Second: by eating a pound of veggies a day, we will dramatically increase our fiber intake which gives the gut bacteria something to munch on. Consider giving yourself a challenge in the next week. Measure out a pound of veggies to give yourself an idea of how many veggies comprises a pound. Then, spread the veggies out over your meals and snacks for the day. Make sure to include leafy greens, which are not heavy, but are nutrient dense. No fair just eating potatoes! Include a variety of crunchy and leafy vegetables along with a starchy veggie as well.
Third: adding fermented foods to your diet, just a forkful or two a day, can make a dramatic difference. Foods like sauerkraut, kimchi, and other fermented veggies add both fiber AND probiotics. If you need help getting started with this, see below.
Fourth: add prebiotics. By ingesting foods containing prebiotics, a group of carbohydrates that feed the gut bacteria, we can affect our moods. Oxford University neurobiologist Phil Burnet published a paper in the May 2015 issue of Psychopharmacology. In his experiment, he measured the stress levels of 45 healthy (human) volunteers who were fed a powdered prebiotic. He and his colleagues found that subjects who ingested the prebiotics showed lower cortisol, one of our main stress hormones. The results were on par with subjects taking anti-depressants or anti-anxiety medications. What’s going on here? In mice studies, prebiotics fostered the growth of Lactobacillus and Bifidobacteria. As mentioned above, these bacteria manufacture feel-good (and calming) neurotransmitters, including dopamine, serotonin and GABA. Is that awesome or what?!?
Where do we find prebiotics? So simple! Some common foods containing prebiotics include garlic, onions, leeks, berries, flax, Swiss chard, honey, and cruciferous veggies like cabbage, kale, broccoli, Brussels sprouts, collard. Foods that many of you probably eat (without knowing their many powers).
Tra la la! So awesome to see a major corner of our health within our control. We can do this!
So, what about cortisol?
There are numerous and profound health implications in lowering cortisol, one of our main stress hormones, produced by the adrenal glands. For one, increased cortisol may keep you from sleeping soundly. High cortisol is often the upstream issue causing the thyroid to go out of whack. High cortisol also raises blood glucose, which is a precursor to insulin resistance and Type 2 diabetes. According to Dr. Sara Gottfried, author of Hormone Cure and The Hormone Reset Diet, cortisol “turns your waist into a magnet for fat, and because visceral fat has four times the cortisol receptors of fat elsewhere, you keep taking on more fat.”
Circling back, tending to our gut health can be a missing piece in weight loss resistance, insomnia, thyroid malfunction and a major factor in anxiety and depression. Tending to our gut health makes so much sense. It is, more often than not, the heart of the matter.
Fermented Food Gets to the Heart of the Matter
This past spring, I participated in an intensive fermentation certification program. Instruction included the science behind gut health and the impact of fermented foods. The program also included learning how to make a wide variety of fermented foods. Finally, I learned even more in depth how to use particular ferments to bring balance to various health issues.
Since then, I’ve been teaching both my groups and my one-on-one clients how to make them and use for health purposes. If not interested in making them, we discuss where to buy them, what to look for and how to get them into rotation on their plates.
If you’re interested in learning how to make some easy ferments, I have a workshop coming up where participants will make their own to bring home. Want to come?
Bravo, J.A., Forsythe, P., Chew, M.V., Escaravage, E., Savignac, H. M., Dinan, T.G., Bienenstock, J., Cryan, J.F. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve PNAS 2011 108 (38) 16050–16055.
Gottfried, Sara MD. The Hormone Cure. Scribner. NY, NY. 2013.
Lyte M (2013) Microbial Endocrinology in the Microbiome-Gut-Brain Axis: How Bacterial Production and Utilization of Neurochemicals Influence Behavior. PLoS Pathog 9(11): e1003726. doi:10.1371/journal.ppat.1003726.
Perlmutter, David. Brain Maker. Little, Brown and Company. NY, NY. 2015.
Schmidt, Kristin et al. “Prebiotic Intake Reduces the Waking Cortisol Response and Alters Emotional Bias in Healthy Volunteers.” Psychopharmacology 232.10 (2015): 1793–1801. PMC. Web. 4 Aug. 2016.
Stilling, R. M., Dinan, T. G. and Cryan, J. F. (2014), Microbial genes, brain & behaviour – epigenetic regulation of the gut–brain axis. Genes, Brain and Behavior, 13: 69–86. doi:10.1111/gbb.12109.