Snakes don't go with their gut, they regenerate it

Humans aren't capable of regrowing limbs like some salamanders or full organs like some snails and zebrafish, but we do renew some of our cells, including the absorptive lining of our intestines. In contrast to the relatively minor turnover of cells seen in human intestines, some snakes, including boas and pythons, undergo extensive regenerative transformation of their intestine upon feeding. New research supported by the U.S. National Science Foundation has found that the method these snakes use to renew their guts, while different from the process humans use for regular cell renewal, is similar to mechanisms observed in mammalian wound healing and to how human intestines respond to a particular form of gastric bypass. This discovery increases researchers' understanding of intestinal physiology and could have applications in treating metabolic and gastrointestinal disorders like diabetes and celiac disease, and possibly even cancer.

Humans regularly renew intestinal cells by activating stem cells found in microscopic caverns in the intestinal wall known as intestinal crypts. Boas and pythons don't have these crypts but regenerate their intestines after feeding in one of the most extreme examples of intestinal regeneration found in the animal kingdom — from shrunken and nearly non-functioning to double the size and with a rebuilt structure capable of digesting and absorbing their meal. The new research solved key elements of the mystery of how these snakes accomplished this feat, finding that it involves the unique coordination of pathways also present in humans. It also involves many of the signaling pathways observed in humans after a Roux-en-Y gastric bypass procedure, which is used to aid in weight loss and treat type 2 diabetes.

"By determining the mechanisms that control this fascinating phenomenon in snakes, we can now work to understand the role those mechanisms play in modulating human intestinal regenerative capacity, metabolic reprogramming and responses to Roux-en-Y gastric bypass, which may direct future targeting of drugs to manipulate these responses," said Todd Castoe, corresponding author and a professor at The University of Texas at Arlington. "This could eventually provide treatments for the millions of people living with diabetes and celiac, Crohn's disease, colitis and other gastrointestinal diseases, and may also provide new perspectives for treatment of gastrointestinal cancers."