How does our gut influence our physical and mental health? We spoke with Alicia Romano, MS, RD, LDN, CNSC, Specialized Ambulatory & Nutrition Support Dietitian, to learn more.
Alicia Romano, MS, RD, LDN, CNSC
National Spokesperson, Academy of Nutrition and Dietetics
What is the microbiome, and what exactly is the gut-brain axis?
The microbiome is defined as the material of the microbes (bacteria, fungi, protozoa, and viruses) that live on and inside the body. The gut microbiome is defined as the community of microorganisms including bacteria, viruses, protozoa, and fungi present in the gastrointestinal tract. The gut microbiome can be shaped by numerous factors, both genetic and environmental (diet, medications, antibiotic exposure, sleep habits, smoking, and alcohol consumption).
The gut-brain axis consists of the communication between the central (brain) and enteric (intestinal) nervous systems; essentially, this bi-directional communication links the cognitive centers of the brain with intestinal function. This is set up by a complex network of nerve cells and immune pathways. Bacteria in the gut make neuroactive compounds like serotonin (which regulates our emotions) and in turn, the brain can send signals to the GI tract, such as stimulating digestion. Recent research is investigating the role the gut microbiome plays in these interactions.
How might the microbiome and gut-brain axis impact depression, mental health, and brain health overall?
The role of the microbiome in health and disease is an exciting area of research that is constantly evolving, and not yet fully understood. The role of the microbiome and gut-brain axis in mental health is no exception.
New areas of research are investigating the role of the microbiome in mental health conditions such as anxiety and depression as well as other cognitive diseases, like Alzheimer’s. There is a lot of excitement and optimism in this field, yet we continue to lack well-designed human studies. Why? There is a great deal of complexity in the mechanisms and implications that link the gut microbiome and health – a number of variables has the potential to affect the microbiome itself, including diet, probiotics and prebiotics, and environmental variables (stress, sleep, exposure to antibiotics, etc.).
So what we do know? There is a strong communication between the gastrointestinal tract and the brain, and that changes to the microbiome-gut-brain access could be associated with a number of psychiatric disorders. What do we need? More time. A better understanding of this communication is key to learning how nutritional intake, the central nervous system, and immune function may influence psychological and brain health.
What should teens and adults know about how their diets and supplements can impact long-term physical and mental health?
Outside of genetic factors, environmental variables play a large role in the health of our microbiome. Although we do not fully understand the link between the gut microbiome and mental health, we can continue to optimize diet and lifestyle factors to improve general health and potentially the health of our gut microbiome. This includes:
- A balanced diet including a variety of plant-based foods (vegetables, fruits, legumes, nuts/seeds, whole grains), healthy fats (plant-based oils, avocado, nuts/seeds), lean proteins (fatty fish/seafood, poultry, etc.), and low-fat dairy (yogurt, kefir, hard cheeses, etc.)
- Plenty of sleep (7 to 8 hours of sleep per night)
- Reduction of sugar-sweetened beverages and highly processed foods
- Adequate hydration
- Cessation of smoking and limitation of alcohol consumption
- Stress management
- Exercise
Nutritional supplements should also be used with caution. Vitamin and mineral supplements should be reserved for individuals with known nutritional deficiencies or for those with heightened nutritional needs (pregnant, breastfeeding, etc.). Be sure to speak with your health care team before starting any new vitamin, mineral, or supplement regimen to avoid over supplementation or potential interaction with your current medication therapy.
And if you have more nutrition related questions on your diet or vitamin and mineral intake, I would suggest working with a registered dietitian (RD), your food and nutrition expert. The RD will be able to create individualized nutritional recommendations to fit your unique personal and health-related concerns. You can find an RD at www.eatright.org.