1st Story of Day 1 at ENDO2013

Day 1 of ENDO 2013

Well, despite difficult travel, including the dreaded lost bags, I was set up in fine fashion by my sister-in-law, and made it to a full 1^st day at the Moscone Center.  And what a day it was.  So many topics, so little time.  Let me try to break it down just a bit.

Of Mice and Men

The first talk did not actually have to do with either of my topic areas, Hypothalamic/Pituitary/Thyroid (HPT) axis or Pediatric Endocrinology, but was such a great talk, I feel I have to say just a bit about it.  Dr. Randy Seeley of the University of Cincinnati, spoke about the mechanism of weight loss after two different kinds of bariatric surgery.   The Vertical Gastric Sleeve (VSG) creates a smaller stomach, but maintains the other anatomy.  The Roux-en-Y Gastric Bypass (RY) creates not just a smaller pouch, but limits the absorption of the nutrients that are ingested by disconnecting the stomach from the duodenum, then reconnecting it at a later point down the small intestine.  Although it seems obvious the main mechanism by which these procedures work is just by limiting intake, this group has done elegant experiments to prove indeed there is more to this than meets the eye.

After proving the stomach will indeed stretch (a female mouse, after having had the VSG, can double her intake to have adequate calories to sustain a pregnancy and to lactate for her pups), the team observed that the most robust finding after surgery is a change in the composition of the diet.  Post-surgical mice (either VSG or RY) consistently chose a diet of lower fat intake and higher carbohydrate intake, why?

Whether the gastroenterologists want to admit it or not, the gut is actually an endocrine organ.  Signals such as insulin, Glucagon-like peptide (GLP-1), the GLP-1 Receptor, and Ghrelin were each systematically tested with knock-out mice (all very remarkable studies), and found not to be the cause of the decreased intake.  Ultimately, bile acids seem to play an important role.  These compounds indeed help digest fats, but also bind to cell surface and nuclear receptors.  One receptor, FXR, on the cell surface, showed particular promise.   If bile acids play such an important role in decreasing caloric intake, other, less-altering surgeries may be possible, an idea tantalizing for these surgeons.

Another important aspect of health changed about post-surgical mice: the bacteria in the gut (called the microbiome), changed after surgery.  In particular, Roseburia, a genus decreased in Type 2 Diabetes, increased in those after VSG or RY.  This raises even more questions for investigation.

So, despite sounding quite “gee, whiz!” from the get go, I was impressed by this talk, delivered so well, representing the work of so many, and it makes me excited about what else is to come.