Key Insight: Individuals with anorexia nervosa do not simply ignore signals from the body. Instead, their nervous system may process gut sensations differently, making those signals harder to detect, trust, and learn from.
Gut-Brain Perception Linked to Relapse Risk in Anorexia Nervosa
A study published in JAMA Psychiatry by researchers at UCLA Health has used an ingestible vibrating capsule to explore the relationship between gut-brain signaling and relapse risk in individuals with anorexia nervosa. The research involved 62 women and girls hospitalized with the disorder who had achieved weight restoration, alongside 57 healthy control participants.
Methodology
Participants swallowed a capsule that delivered vibrations of varying intensity to the stomach. They were instructed to press a button when they detected a vibration. Researchers monitored brain, heart, and stomach activity, and collected self-reported data on hunger and bodily sensations.
Data were analyzed using a computational model to estimate participants' expectations of stomach sensations, their reliance on incoming bodily signals, and the rate at which they updated those expectations.
Key Findings
Compared to healthy controls, participants with anorexia nervosa demonstrated:
- Lower accuracy in detecting subtle stomach sensations.
- A higher likelihood of assuming no sensation occurred, even when vibrations were present.
- Slower revision of expectations when signals were present.
These differences in gut-brain perception were associated with relapse risk during a six-month follow-up period after hospital discharge.
Individuals whose perception was biased toward ignoring gut signals experienced higher relapse rates. The differences persisted after weight restoration, suggesting that underlying brain-body communication problems may remain and contribute to relapse.
Expert Commentary
Dr. Sahib Khalsa, senior author of the study, stated that people with anorexia nervosa do not simply ignore signals from the body. Instead, their nervous system may process gut sensations differently, making those signals harder to detect, trust, and learn from. He added that recovery from the disorder is not solely about restoring body weight, as the underlying brain-body communication problems may persist and contribute to relapse.
Implications and Limitations
The researchers stated that these gut-brain perception measures could serve as biomarkers to identify patients at higher risk of relapse and to track treatment efficacy. However, they noted that the findings require replication in broader and more diverse populations before firm conclusions can be drawn.
Background
Anorexia nervosa is a psychiatric disorder characterized by persistent food restriction, fear of weight gain, and distorted body image, leading to low body weight. Relapse rates are up to 50% within one year of weight restoration, and the disorder has high mortality, with suicide as the leading cause of death. Objective biomarkers for tracking treatment response are currently lacking.