| Abstract : |
The brain-gut axis is increasingly recognized as an important regulator of intestinal physiology. Exposure to psychological stress causes activation of the hypothalamus-pituitary-adrenal (HPA)-axis and is linked to altered gut barrier function, intestinal dysbiosis, and changes in behavior. The primary aim of this study was to determine if the effects of psychological stress on intestinal physiology and behavior, including anxiety and memory, are mediated by the adaptive immune system. Furthermore, we wanted to determine whether treatment with probiotics could normalize these effects. We demonstrated that immunodeficient mice displayed altered baseline behaviors, accompanied by an overactive HPA-axis and increased intestinal secretory state. Both the local (intestinal) and central (behavioral) changes were normalized by treatment with probiotics suggesting an overall benefit in health conferred by changes in the microbiota, independently of lymphocytes. Taken together, these findings indicate a role for immune cells in maintaining intestinal and brain health in mice and show that the adaptive immune system mediates signaling between the gut and the central nervous system. |