Medically reviewed by Onikepe Adegbola, MD, PhD
Several brain disorders are related to brain-gut-microbiome interactions. Several studies have shown that the gut microbiome and brain are connected via channels. Diet affects not just the gut microbiota but also the formation and function of the brain via these communication routes.
This review aims to compile information from preclinical and clinical research on the relationship between dietary habits and treatments and a variety of neurologic and psychiatric disorders. Depression, cognitive decline, Parkinson’s disease, autism spectrum disorder, and epilepsy are among these illnesses.
Diet Can Have Multiple Effects On The Brain
Research from the Human Microbiome Project and early rodent studies have introduced the concept of the brain-gut-microbiome (BGM) axis. Psychosomatic medicine asserts that stress, emotional, and cognitive influences affect body functions.
Nutritional psychiatry has emerged as an exciting area of psychiatry since researchers have concluded that diet significantly influences the composition and function of the gut microbiome. In addition to the direct effect of macro- and micro-nutrients on the brain, research has shown that diet could also influence the gut microbiome, thereby affecting mood and cognitive function.
The brain and gut microbiome are connected by hubs. The hubs are connected with multiple feedback loops to create a nonlinear system. Dietary components influence the brain, the gut, and the gut microbiome in different ways. Several components of the diet can directly affect the gut. They reach the brain after they are absorbed in the small intestine.
Communication Between Neurons And The Endocrine System
Metabolism of dietary components is common among microbes. In preclinical studies, some of these metabolites have been shown to affect brain structure and function.
Enteroendocrine cells contain important signaling molecules, including hormones, which can act as neurotransmitters. This neuroendocrine channeling can influence your appetite and alertness.
An endocrine metabolite called indoxyl sulfate may have a role in the pathogenesis of a variety of diseases, including Alzheimer’s disease and depression.
As part of the immune-regulatory pathways, the gut microbiome is directly able to affect brain neuroinflammation via immune activation.
There is an intricate link between inflammatory signals produced in the gut in response to certain diets and the gut microbiota. Researchers do not completely understand the complex mechanism between diet, the gut microbiome, and brain disease.
Diet And Pathophysiology Of Mental Disorders
Scientists have found evidence for gut-brain interaction in certain neurological and psychiatric diseases. Recent studies have showed that dietary habits and interventions affect certain psychiatric and neurological disorders, such as depression, cognitive decline, Parkinson’s disease, autism spectrum disorder, and epilepsy. Changes in the microbiome caused by diet have been linked to these effects.
What Is The Biggest Challenge?
Several published studies suggest that nutritional interventions may provide therapeutic benefits in chronic brain disorders, a significant advance in an area that has not seen significant progress in the development of novel medications. Most of these findings have been shown in preclinical and cross-sectional epidemiological studies, but there isn’t enough evidence from mechanistic human studies yet to say that a certain diet causes microbially mediated brain function.
There is mounting evidence that a mostly plant-based diet, high in fiber and polyphenols, is beneficial to mental health.
Through multiple mechanisms, diet and microbiota interact to affect brain structure and function throughout the lifespan.
The practical implications of specific dietary interventions remain limited until an objective therapeutic benefit is established.
Horn, J., Mayer, D. E., Chen, S., & Mayer, E. A. (2022, April 20). Role of diet and its effects on the gut microbiome in the pathophysiology of mental disorders. Nature News. Retrieved May 3, 2022, from https://www.nature.com/articles/s41398-022-01922-0