Background-Lipids may exacerbate symptoms induced by gut stimuli.
Aim-To determine the mechanism whereby fat exerts this effect.
Subjects-Twenty four healthy subjects were studied during fasting.
Methods-We measured perception (0-6 scale) in response to jejunal balloon d
istension and transmucosal electrical nerve stimulation; phasic stimuli ton
e minute) were randomly applied at five minute intervals during intestinal
infusion (2 ml/min) of saline and then Intralipid 2 kcal/min thigh fat; n=8
subjects), Intralipid 0.5 kcal/min (low fat; n=8), or saline (n=8).
Results-Intestinal lipids increased the perception of jejunal distension re
gardless of concentration (by 53% with high fat, 49% with low fat, and 17%
with saline; p<0.05 for both fat loads). This effect could not be attribute
d to changes in intestinal compliance as intraballoon pressures remained un
changed during Lipid infusion (2% change; NS). Sensitisation induced by Lip
ids seemed to be specifically related to intestinal mechanoreceptors becaus
e electrical stimulation, which non-specifically activates gut afferents, w
as perceived equally during saline and lipid administration (10%, 11%, and
15% change during high fat, low fat, and saline, respectively; NS).
Conclusion-Physiological amounts or lipids heighten intestinal sensitivity
by modulating intestinal mechanoreceptor response.