Cognitive Function and Gut-Brain Health Relationship: Research That Cannot Be Ignored

While there has been much attention directed towards the treatment of neurological diseases and disorders through emerging pharmaceutical drugs, such as Aduhelm for Alzheimer’s, many researchers continue to investigate how lifestyle and environmental risk factors relate to cognitive function and overall brain health. Studies suggest that making lifestyle modifications, such as increasing physical activity and eating a healthy diet, controlling cardiovascular risk factors, increasing mental and social engagement, and improving sleep, impact brain health. Current research aims to assess if such changes can improve cognition, help prevent neurological diseases, or even be used as a treatment approach for individuals with neurological diseases.

The complexity of the gut microbiome and its importance to overall health has resulted in increasing research that assesses the connections between gut health and aspects of overall health, such as brain function, the immune system, mental health, and cancer.

Below, we delve deeper into studies that evaluate the relationship between cognitive function and gut-brain health, potential methods to improve brain health through dietary changes, and how to monitor brain health while implementing such changes.

Research Surrounding the Relationship Between Cognitive Function and Gut-Brain Health

Emerging research suggests that the human gut microbiome—the microorganisms living in the digestive tract—may enable a potential avenue to improve or enhance cognition. The first area of research we will review explores this relationship as a whole, while the second aims to investigate whether or not probiotic supplementation improves cognitive function and mood.

The Gut Microbiome and Brain Function Connection

The first study suggests that the gut microbiome and the brain communicate bidirectionally, meaning the gut microbiome may affect brain functions and vice versa. In vitro, in vivo, and human studies revealed associations between changes in the gut microbiome and functional changes in the brain, indicating that the microbiome affects brain function and thus likely impacts cognitive function. 

Additionally, this study indicates that bacteria can create important neurotransmitters which affect neuronal function, such as gamma-aminobutyric acid, serotonin, and acetylcholine. The takeaway from this study is that regulation, or modification, of the gastrointestinal microbiome may provide a means to prevent or treat brain-related disorders, opening a new pathway for potential treatments.

Probiotic Supplementation and Cognitive Function

Another study evaluated probiotics and if they can be used to ameliorate cognitive impairment and depressive disorder by way of the gut-brain connection. To test this proposition, a randomized, double-blind, and placebo-controlled study was conducted over 12 weeks on a group of 63 healthy seniors aged 65 and older. This study revealed that the group who received probiotics showed a higher degree of improvement on a mental flexibility test and stress score compared to those who were in the placebo group. The modulation of cognitive function and mood may be due to the production of neurotransmitters resulting from probiotic supplements. These findings suggest that the incorporation of probiotics as a part of a healthy diet may support improved cognitive function and mood.

Improving Brain Health Through Diet Modifications

More research is required to fully understand how to utilize the cognitive function and gut-brain health relationship to improve brain health and prevent or treat neurological diseases. However, current evidence suggests incorporating elements of a healthy diet, as well as modifying dietary habits to help regulate gut bacteria, can provide positive effects on brain health.

Incorporating a Healthy Diet: To Eat or Not to Eat

Incorporating a heart-healthy and anti-inflammatory diet may support brain health, memory, and cognition. Such diets typically avoid the consumption of sugar, saturated fats, and alcohol while increasing the consumption of unprocessed fiber-rich foods, such as fruits, vegetables, legumes, whole grains, nuts, and seeds, as well as monounsaturated fats and omega-3 fats. Mediterranean diets as well as researched diets, such as the Mediterranean-DASH Intervention for Neurodegenerative Delay, incorporate anti-inflammatory and heart-healthy foods and may also support brain health.

Potential Treatment Through Diet

Diets that incorporate foods or supplements that help regulate bacteria in the gut microbiome may offer a future therapeutic approach to preventing or treating cognitive diseases and disorders. Foods that may benefit brain health through regulation or modification of the microbiome include:

• Omega-3 fats found in oily fish.
• Fermented foods such as yogurt and sauerkraut.
• Fiber-rich foods including whole grains, seeds, nuts, fruits, and vegetables.
• Polyphenol-rich foods such as olive oil, green tea, and cocoa.
• Tryptophan-rich foods such as turkey, eggs, and cheese.