A gut feeling

Many treatments for metabolic disorders such as obesity and type 2 diabetes directly target the brain or liver (see "Controlling the liver via the gut" and "Targeting diabetes and obesity").¹ Although neural communication was previously known to exist between the small intestine and the brain to curb food intake,^2,3 and between the brain and the liver to mediate regulation of liver glucose production,^4,5 a new study in Nature now closes the loop to reveal a complete "intestine-brain-liver" neural circuit.

Tony Lam and colleagues propose that disconnects in this circuit could be responsible for the aberrant glucose homeostasis that underlies insulin resistance, obesity and type 2 diabetes. Thus,the authors suggestthat targeting nodes within the circuit could restore insulin sensitivity in people with obesity and type 2 diabetes without directly interfering with liver and brain physiology.⁶...