Interoception, Trait Anxiety, and the Gut Microbiome: A Cognitive and Physiological Model

Trait anxiety is characterized as a constant and often subliminal state that persists during daily life. Interoception is the perception of internal states and sensations, including from the autonomic nervous system. This review aims to develop a predictive model to explain the emergence, manifestations, and maintenance of trait anxiety. The model begins with the assumption that anxiety states arise from active interoceptive inference. The subsequent activation of autonomic responses results from aversive sensory encounters. A cognitive model is proposed for trait anxiety that includes the aversive sensory components from interoception, exteroception, and proprioception. A further component of the hypothesis is that repeated exposure to subliminal anxiety-evoking sensory elements can lead to an overgeneralization of this response to other inputs that are generally non-aversive. Increased uncertainty may result when predicting the sensory environment, resulting in arbitrary interoceptive anxiety responses that may be due to unjustifiable causes. Arbitrary successful or unsuccessful matching of predictions and responses reduces the individual's confidence to maintain the anxiety trait. In this review, the application of the proposed model is illustrated using gut microbial dysbiosis or imbalance of the gut microbiome.