By Raphael Kellman, MD
Over the years I’ve seen many patients with anxiety, brain fog, and depression. Most had been overmedicating with prescriptions like Prozac, Lexapro, or Zoloft long before they came to me. Generally, these patients had experienced only slight improvements or improvements that did not last.
The aforementioned drugs all fall into a category of commonly prescribed antidepressants known as selective serotonin reuptake inhibitors, or SSRIs. Most SSRIs lose their effectiveness over time, which means psychiatrists add other medications to the mix, including antipsychotics (such as Abilify) or other “cocktail” drugs. These drugs often cause weight gain, low libido, and sluggishness, which make patients feel even worse.
There is a simple, natural, and non-pharmacological solution to these mood and brain conditions, however—and it resides inside the gut. I often surprise my patients by asking them, “How is your digestion? Any gas, bloating, nausea, bowel irregularities?” Their responses range from laughing out loud to curiosity or disbelief.
Problems in the brain often originate in the gut and, particularly, in the microbiome—the community of trillions of bacteria that live in the intestines and elsewhere in the body. Even when there are no digestive symptoms, the microbiome can be out of balance—often leading to disastrous consequences for our physical, mental, and emotional health.
Although we’re used to thinking of bacteria as dangerous, they’re actually just the opposite: Bacteria are essential to our health and, indeed, to our very life. Sure, some bacteria are dangerous, just as some are neutral. But the vast majority are beneficial. And because we co-evolved with them, our bodies are literally unable to function without them. Microbes enable us to digest our food, support our immune system, and process thought and emotion. They are an integral part of our health and well-being. A balanced microbiome means that you can think clearly, remember accurately, and focus intently. It also creates a calm, balanced mood with a lot of emotional reserve for processing stress. An unbalanced microbiome, by contrast, often leads to brain fog, anxiety, and depression—the ailments that so many physicians are treating with pharmaceuticals.
The Gut, Microbiome, and Brain: A Powerful Triangle
Some of the most exciting research from the past few years shows remarkable connections between the gut, microbiome, and brain. The microscopic creatures living in our intestinal lining produce a number of biochemical reactions that have a profound effect on both our brain chemistry and on the brain cells themselves.
An imbalanced microbiome activates the immune system, which is adjacent to the microbiome in the gut wall. Microbial imbalance also frequently erodes the gut wall and leads to poor gut function. The whole process results in intestinal permeability—aka leaky gut—a process by which partially digested food leaks through the gut wall and into the bloodstream. The immune system doesn’t recognize food in this form, so it goes on alert, which creates a constant, low-grade immune response. This is known as chronic inflammation, and it can lead to a number of chronic diseases, including obesity, diabetes, heart disease, autoimmune conditions, and cancer.
Meanwhile, the excessive immune reaction also affects the brain via the microglia—specialized immune cells found in the brain. In a healthy condition, the microglia seek out damaged neurons and infections and clear them from the brain.
But when the microbiome is imbalanced, the microglia produce cytokines, inflammatory messengers that can seriously damage the brain. As a result, brain function is altered. Anxiety, depression, and brain fog are the result.
You can significantly turn this situation around with the use of probiotics—pills, powders, or capsules that contain billions of healthy bacteria. Probiotics help restore balance in your microbiome, while reducing inflammation throughout your body and brain; they are a significant part of my treatment of depressed, anxious, or “foggy” patients. New research shows that probiotics raise your brain’s level of IL-10, an anti-inflammatory cytokine that helps fight off the inflammatory type in order to protect and support your brain.
Another supplement that fights depression is butyrate, a type of acid produced in the gut. A 2013 article in Behavioral Pharmacology found that butyrate can be very helpful in medicating depression—I’ve prescribed butyrate for many of my patients, while simultaneously working to rebalance their microbiome so that, eventually, the healthy and restored microbiome could produce its own butyrate.
In a 2013 placebo-controlled, double-blind study published in the journal Gastroenterology, researchers observed the effect of probiotics on brain function. They gave the female participants a fermented milk drink three times a day; some women were given the drink plain, whereas others had drinks supplemented with extra probiotics. When the women’s brains were examined via MRI, the probiotic group showed changes in the midbrain region—the area involved in emotional processing.
Similar research was published in 2007 in the European Journal of Clinical Nutrition. In that study—also placebo-controlled and double-blind—subjects who were given fermented milk with extra probiotics reported significantly improved mood compared with the people who had just been given the milk. I’ve seen these results in my own patients, who indicate that probiotics and other microbiome supports make them feel better with surprising speed.
Bacteria and Brain Chemistry
The microbiome does affect the brain—but our biochemistry is so complex that we are only just beginning to discover some of the many types of gut-brain interaction. The microbiome can alleviate depression and anxiety in four key ways:
- Healthy bacteria produce key neurotransmitters, the biochemicals that express mood. Serotonin, which creates a sense of optimism, confidence, and well-being, is produced by gut bacteria. So is gamma-aminobutyric acid (GABA), which creates a soothing sense of calm.
- Bacteria produce a number of biochemicals that improve brain function, mood, and mental vitality.
- Microbes send messages to the endocrine system, supporting the HPA axis (hypothalamus, pituitary, and adrenals). This, in turn, modulates the body’s production of cortisol and stress hormones, which prevents anxiety and depression.
- A healthy microbiome triggers the immune system to send messages to the brain, instructing it to decrease anxiety and depression.
Individual studies reveal the powerful connection between mood and microbiome. In 2007, for example, Nature published an article about Lactobacillus acidophilus, a type of bacteria found in yogurt, kefir (fermented milk), and many other fermented foods. This common microbe stimulates the brain’s opioid and cannabinoid receptors—the very same receptors that are stimulated by opiates (painkillers, heroin, and other drugs) and cannabis. So the next time you want a natural high, reach for the yogurt—or better yet, the sauerkraut!
Two other friendly bacteria—Lactobacillus helveticus and Bifidobacterium longum—have been shown to lower the stress hormone cortisol, while also reducing anxiety. In a recent double-blind, placebo-controlled random study, these two bacteria were given to patients for 30 days. Patients reported that their moods had improved by the power of bacteria.
Whereas fermented foods feed your healthy bacteria, a diet high in refined carbs supports the unhealthy kind. This diet has the potential to produce LPS, a compound that inflames the microglia, among other ill effects. And inflamed microglia, as we have seen, create brain fog, anxiety, and depression.
Microbiome Medicine: Psychiatry’s New Frontier
As a physician who has treated many patients struggling with depression, anxiety, and brain fog, I believe that psychotropic drugs and antidepressants are not the answer. Most antidepressants are blunt instruments—we don’t know exactly how they will affect us, and they often produce a number of unwanted side effects.
By contrast, the microbiome is a delicate, complex set of tools that works to produce a range of benefits. It seems to take advantage of its intimate knowledge of our biology, neurology, immunology, and genetics, as well as their staggering interconnections—our own natural antidepressant, if only we nourish and support it.
Probiotics are one way to support the microbiome, and I rely on them heavily. But they are not enough. The Microbiome Diet—a comprehensive approach to eating—is crucial for feeding the friendly bacteria and starving out the unfriendly ones.
Prebiotics are also useful. Whereas probiotics are actual bacteria, prebiotics are the foods and supplements that nourish friendly bacteria. I tell my patients that you can stock a lake with new fish, or you can clean up the lake and feed the existing fish. In most cases, it’s beneficial do both!
Today’s medical environment fails so many people suffering from brain fog, anxiety, and depression. However, microbiome medicine gives us an opportunity to offer hope to millions by opening up a new frontier in treatment—and the result might be a whole new world of brain health.
Eight additional ways to support your microbiome:
- Be as careful as possible about avoiding antibiotics; sometimes they are necessary, but they always disrupt the microbiome. If you must use them, make sure to take probiotics at the same time.
- Ask your doctor about discontinuing your proton pump inhibitor, which reduces microbial diversity; explore natural alternatives instead.
- Ask your doctor about discontinuing nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin or Motrin; explore natural alternatives instead.
- Eat organic as much as possible; industrial chemicals are not good for the microbiome.
- Limit meat consumption, which destroys many healthy bacteria. Instead, eat a lot of high-fiber veggies, which will feed the healthy bacteria.
- Eat healthy fats to support gut and microbial health.
- Avoid concentrated fructose, especially high-fructose corn syrup, which is terrible for your microbiome.
- Get a little dirty! If you play in the dirt or eat unwashed produce—organic only, of course—you expose your gut to some additional friendly microbes that make your microbiome healthier and more diverse.
About the Author:
Raphael Kellman, MD, is a pioneer in functional medicine who has a holistic and visionary approach to healing. He is the author of The Microbiome Diet, Gut Reactions, and Matrix Healing. Learn more at raphaelkellmanmd.com.