Over the past few years, we have become much more aware of the tight connection between our gut and brain functioning, including metabolic health, psychological health, performance, and overall wellness. Recent research shows that the gut microbiome (bacteria, fungi, protozoa, viruses) plays an essential role in the central nervous system via its effects on digestion, immune functioning, inflammation, the hypothalamic-pituitary axis, and neurotransmission.
Most of the research so far has been based on animal models, with a few small human studies. These data appear to demonstrate that an unhealthy gut microbiome is associated with depression, anxiety, and various other mood disorders. Research also suggests that gut microbiota may interact with the reward system of the brain as it relates to the individual pursuit and use of food, drugs, and pleasure.
Our 2020 Study
In 2020 we and our colleagues published a study in the Journal of Affective Disorders with 111 adults who were inpatients in a psychiatric hospital to examine the gut microbiome among people with severe mental illnesses. Patients reported their clinical symptoms via a battery of self-report psychiatric symptom and functioning questionnaires outcome measures, and then provided fecal samples shortly after hospital admission. We worked with a team of microbiologists to sequence the DNA of the bacteria and identify different types of bacteria.
Our analyses indicated that depression and anxiety severity at the time of admission to the hospital was negatively associated with gut bacterial richness and diversity. The group further identified patterns of gut bacteria associated with depression and anxiety treatment resistance by the time of discharge from the hospital.
In other words, we were able to identify patients who did not benefit from treatment, based solely on their fecal sample. Much more research is needed before we will be able to truly understand the gut, its multiple roles within our body, and how to best take care of it – but we know it is critically important for our wellbeing.
Performance and Wellness
Our gut microbiome weighs up to five pounds and has 200 times the number of genes found in the human genome. It is symbiotic, not parasitic, to us. We need our gut microbes and they need us. We survive and thrive together, and therefore it is imperative that we take good care of it.
A healthy gut is an essential component of health, performance, and general wellness. So, how do we take best take care of this mysterious universe of organisms that live within us?
Habits to Promote Gut Health
1. A healthy diet with plenty of fiber, lean protein, and water.
2. Pre-biotics, plant fibers that facilitate the growth of healthy bacteria, such as apples, bananas, barley, berries, cocoa, flaxseed, garlic, oats, onions, tomatoes, soybeans, and wheat.
3. Pro-biotics, such as yogurt, kefir, vinegar with active cultures, fermented pickles and sauerkraut, kimchi, etc. You can even take dietary supplements.
4. Minimal to zero consumption of processed foods, junk food, fast food, and added sugar.
5. Intermittent fasting or time-restricted feeding approaches.
6. Consider whether you have food sensitivities or allergies that might benefit from a special diet (e.g., low FODMAP).
7. Exercise on a regular basis.
8. Good quality sleep, and plenty of it.
9. Minimal to zero alcohol and drug use.
10. Meditation, yoga, prayer, or other relaxing activities.
11. Consider exposures to toxic chemicals, heavy metals, excessive smoke, etc., that may require medical consultation.
12. Spend time outdoors.
Our scientific understanding of gut microbiota is still in the infancy stages, and it is true that most human studies to date only examine the strength of the association between psychological functioning and gut health.
From Psychology 101 we are reminded that “correlation is not causation.”
Nevertheless, knowing what we know now and what we can hypothesize, there is every reason to take good care of your gut health – and absolutely no reason not to. We are reminded that whatever is good for your gut, heart, and lungs is also good for your muscles and skeletal system. As well as your brain, cognitive functioning, and ultimately for your overall quality of life, wellness, and performance – performance in literally every important area of personal and professional life.
Alok Madan, Ph.D., MPH is a clinical health psychologist with over twenty years of experience developing clinical, research, and educational programs to improve the quality of care for individuals with chronic medical conditions and serious mental illness. He is Vice Chairman of the Department of Psychiatry and the John S. Dunn Foundation Distinguished Centennial Clinical Academic Scholar in Behavioral Health at Houston Methodist Hospital. This endowed position focuses on identifying gut-based contributions to psychiatric illness, especially the development of novel preventive and/or therapeutic treatments (e.g., “psychobiotics”) to reduce the global burden of psychiatric illness. He also is a Professor of Psychiatry at the University of Texas Health Science Center at Houston (UTHealth), Baylor College of Medicine, Weill Cornell Medical College, and Houston Methodist Academic Institute. Dr. Madan starts his day with a 2-ounce tincture of fermented vinegar with ginger, cinnamon, cayenne pepper, and local honey mixed in.
Madan A, Thompson D, Fowler JC, Ajami NJ, Salas R, Frueh BC, Bradshaw MR, Weinstein BL, Oldham JM, Petrosino JF. The gut microbiota is associated with psychiatric symptom severity and treatment outcome among individuals with serious mental illness. Journal of Affective Disorders 2020; 264:98-106.