Fig. 1.

Risk factors for stress-related psychiatric disorders include: (1) genetic predisposition; and (2) environmental influences, including adverse childhood experiences (ACEs), and exposures to diverse microbial inputs. Microbial inputs can be either proinflammatory or anti-inflammatory/immunoregulatory (i.e., resulting in a balanced expression of regulatory T cells (Treg) and effector T cells). A failure of immunoregulation can lead to chronic low-grade inflammation and increased risk of stress-related psychiatric disorders. Figure created with biorender.com