Inflammation and Immune Markers in Psychological Health

Abstract

There has been a growing emphasis on the relationship between inflammatory responses, gut microbiota and the immune system, and their influence on mental health outcomes. Stress can influence the composition of gut microbiota which, in turn, influences the central nervous systems response to future stressors. C‐Reactive Protein (CRP) is a biomarker for inflammation that has been linked to depression, anxiety disorders and PTSD that is released in response to pro‐inflammatory cytokines. The goal of this study was to test a direct association between behavior profiles such as anxiety and depression, the composition of the gut microbiota, basal levels of CRP and cytokines, cortisol and genetic predisposition. Measures of anxiety, depression, PTSD, substance use and overall health were obtained from adults with no recent illness or surgery, or exposure to antibiotics. Biological measures focused on pro‐ and anti‐inflammatory cytokines from plasma, cortisol levels from hair, and gut microbiome; as well as single nucleotide polymorphisms (SNPs) were assayed. Using factor analysis we determined a shared mental health panel including depression, anxiety and PTSD measures that was negatively correlated to related cytokines. Regression modeling was used to related quantitative traits to demographic and genetic factors, revealing significant relationships between inflammatory markers and mental health. Understanding these relationships will help to determine direct future research in assessing causal direction between all of these factors that can promote mental well‐being, and could in the future be used as biomarkers for vulnerability to mental illness, and even help re‐think how we treat mental health disorders. Support or Funding Information The project described was supported by the National Institute Of General Medical Sciences, 1U54GM115458‐01; The Center for Brain and Behavior Research (CBBRe), USD; Basic Biomedical Sciences, USD; and the South Dakota Governor’s Center for Genetics and Behavioral Health.