In support to this hypothesis, Straub et al showed that the sympathetic tone (ie serum levels of neuropeptide Y) and hypothalamus‐pituitary‐adrenal (HPA) axis (ie serum levels of cortisol) were positively correlated in healthy individuals, but this correlation was abrogated in patients suffering from IBD, who instead show high sympathetic tone and low activity of HPA axis.38 Even though the concomitant use of oral steroids may have affected these results, the authors suggested that uncoupling of the sympathetic nervous system and the HPA axis occurs in IBD patients. Here, NPY is linked to inflammatory bowel disease.