Love in the Time of COVID: Psychiatric Lessons from Oxytocin and the “Endocrine Organ”

Oxytocin, known as the “love hormone,” is produced in the posterior hypothalamus and participates in numerous physiological processes, including social intelligence, sexual activity, and metabolism. SARS-CoV-2 virus, the etiologic agent of the COVID-19 pandemic, has been shown to suppress oxytocin release from the intestinal epithelial cells, resulting in microbial migration outside of the gut lumen. Limosilactobacillus reuterii, a commensal known for producing oxytocin, normalizes the gut barrier function and exerts antiviral properties, including against the SARS-CoV-2 virus. This may explain the beneficial effect of oxytocin in schizophrenia, a condition associated with a dysfunctional gut barrier and microbial translocation from the gastrointestinal tract into the systemic circulation. The molecular underpinnings of oxytocin in the central nervous system are not entirely clear. However, as viruses target tight junctions, the molecular Velcro that holds the barrier cells together, oxytocin enhances the barrier function. In this mini-view, we summarize what is known about the role of oxytocin in schizophrenia and discuss natural and synthetic compounds that could optimize gut barrier permeability.