DISRUPTIONS in gastrointestinal interoception may flag who will relapse in anorexia nervosa, new research suggests. Scientists have identified behavioural and computational biomarkers that may predict recurrence and symptom severity after weight restoration in patients with anorexia nervosa.
Gut Signalling and Relapse Risk in Anorexia Nervosa
Anorexia nervosa is a psychiatric disorder with relapse rates nearing 50% after weight is restored. Researchers suspect disrupted gastrointestinal interoception, the brain’s perception of internal gut signals, may sustain symptoms and drive recurrence, yet objective markers have been lacking.
Study Design and Interoceptive Assessment
The single-blind, within-participant crossover trial randomised testing-block order at a US institute between August 2021 and February 2025. It enrolled 62 weight-restored females with restrictive anorexia nervosa (mean age 18.9 years) and 57 age- and sex-matched healthy comparators (mean age 20.7 years). All ingested a vibrating capsule delivering counterbalanced normal- and enhanced-intensity gut stimulation. Behavioural, electroencephalographic, physiological, and computational measures assessed interoception, capturing accuracy, prior beliefs, precision, learning rates, gastric-evoked potentials, and hunger.
Markers Predicting Relapse and Severity
Compared with healthy comparators, the anorexia nervosa group showed lower perceptual accuracy (Cohen d=-0.98; 95% CI, -1.51 to -0.44; P=.001) and higher miss rates (d=1.02; 95% CI, 0.55 to 1.48; P<.001). Computational modelling revealed stronger prior expectations that vibrations were absent (d=-0.31; P=.05) and greater shifts in interoceptive precision (d=0.38; P=.01). Capsule stimulation drove larger hunger increases (interaction P=.04), while gastric-evoked potential amplitudes did not differ by group. At follow-up, relapse was predicted by initial priors (odds ratio 3.82; 95% CI, 1.02 to 15.91; P=.05), response bias (OR 5.37; 95% CI, 1.15 to 32.04; P=.04), and stomach unpleasantness (OR 5.73; 95% CI, 1.38 to 33.5; P=.03), while symptom severity was predicted by precision shifts (β=5.84; P=.004).
Implications for Relapse Prevention
The authors concluded that gastrointestinal interoception was disrupted across multiple domains in weight-restored anorexia nervosa, spanning poor gut-signal accuracy, maladaptive prior beliefs, rigid learning, and abnormal hunger perception, despite intact neural and physiological responses. Because several markers forecast relapse and symptom severity, they proposed ingestible mechanosensory probes with computational modelling as scalable biomarkers to guide relapse prevention. The sample was modest and exclusively female, so larger studies are needed before clinical use.
Reference
Verdonk C et al. Gastrointestinal interoception and relapse in anorexia nervosa. JAMA Psychiatry. 2026;DOI:10.1001/jamapsychiatry.2026.1301.
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