Inflammation in Mental Disorders: Is the Microbiota the Missing Link?
Sophie Ouabbou 1,2,3 • Ying He 1,4 • Keith Butler 4 • Ming Tsuang 4,5
1 Department of Psychiatry, and National Clinical Research Center for Mental Disorders, and Hunan Key Laboratory of Psychiatry and Mental Health, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
2 Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
3 Cellular and Molecular Biology Research Centre, University of Costa Rica, San Jose´ 11501, Costa Rica
4 Center for Behavioral Genomics, Department of Psychiatry, Institute for Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
5 Harvard Institute of Psychiatric Epidemiology and Genetics, Harvard School of Public Health, Boston, MA 02115, USA
Research suggests that inflammation is important in the pathophysiology of mental disorders. In addition, a growing body of evidence has led to the concept of the microbiota-gut-brain axis. To understand the potential interactions, we begin by exploring the liaison between the immune system and mental disorders, then we describe the evidence that the microbiota impact the immune response in the developing brain. Next, we review the literature that has documented microbiome alterations in major mental disorders. We end with a summary of therapeutic applications, ranging from psycho-biotics to immunomodulatory drugs that could affect the microbiota-gut-brain axis, and potential treatments to alleviate the adverse effects of antipsychotics. We conclude that there is promising evidence to support the position that the microbiota plays an important role in the immunological pathophysiology of mental disorders with an emphasis on psychotic disorders and mood disorders. However, more research is needed to elucidate the mechanisms.
Mental disorder; Microbiota; Immunology; Neurodevelopment