Electrical Stimulation of the Colon Can Suppress AppetiteWednesday, June 15, 2011
Regular Readers may recall that, although two gastric stimulators have now been approved for obesity treatment in Europe, US studies on gastric stimulators for the treatment of obesity, have unfortunately not lived up to expectations.
A study published in OBESITY suggests that perhaps rather than electrical stimulation of the stomach, stimulation of the large intestine (colon) may provide a more promising approach.
This idea is based on the finding that key hormones and neuronal signals that affect gastric motility and satiety (e.g. PYY-36) are in fact released by the colon.
In this pilot study, Hanaa Sallam and Jiande Chen from the University of Texas, Galveston, examined the effect of colonic electrical stimulation (CES) using implanted electrodes in dogs and found (compared to sham-stimulation) that CES delayed gastric emptying of solids by 77%, reduced intestinal contractility, and resulted in a 60% reduction in food intake.
The fact that this response was partially inhibited by guanethidine (an autonomic ganglion blocker) suggests a role for the autonomic nervous system in mediating this effect. In fact, CES decreased vagal activity in both fasting and fed states, increased the sympathovagal balance and marginally increased sympathetic activity in the fasting state.
While these findings do suggest that the colon may prove a novel target for efforts to use electrical stimulation to treat obesity (remember, electronic pacemakers are now routinely used on a number of other organs in medical practice), it will certainly take a lot more research before this may indeed be considered an actual treatment option for obesity.
In particular, one would like to certainly better understand exactly how colonic electrical stimulation produces this profound effect on appetite and food intake and that this acute effect continues to be active with prolonged stimulation.
Nevertheless, the results do point to the fact that the colon can potentially play an important role as a target organ in the treatment of obesity.
Sallam HS, & Chen JD (2011). Colon Electrical Stimulation: Potential Use for Treatment of Obesity. Obesity (Silver Spring, Md.) PMID: 21660079