Some bats in Latin America are eating nothing but sugar

Amazing stuff! How sweet!

"... So the authors of a new study were shocked to discover that some species of leaf-nosed bat, which inhabit jungles in Central America, South America, and the Caribbean, are surviving—and thriving—on nothing but sugar. ...
Hoping to discover how these bats diversified their diets, scientists spent several years catching them and measuring their blood glucose. Those tests revealed that the bats’ “blood sugar levels … are the highest we have ever seen in nature—what would be lethal, coma-inducing levels for [other] mammals,” ... “We are seeing a new trait we didn’t know was possible.” ..."

"... “Fruit bats have honed their insulin signaling pathway to lower blood sugar,” said Camacho. “On the other extreme, nectar bats can tolerate high blood glucose levels, similar to what is observed in people with unregulated diabetes. They have evolved a different mechanism, and it does not seem to depend on insulin.” ..."

From the abstract:

"Dietary specializations in animals lead to adaptations in morphology, anatomy and physiology. Neotropical bats, with their high taxonomic and trophic diversity, offer a unique perspective on diet-driven evolutionary adaptations. Here we assess the metabolic response to different dietary sugars among wild-caught bats. ... bats with nectar and fruit-based diets showed significantly higher blood glucose levels in response to glucose and sucrose, reaching levels over 750 mg dl−1. The genomic analysis of 22 focal species and two outgroup species identified positive selection for the digestive enzyme trehalase in insect eaters, while sucrase–isomaltase showed selection in lineages with omnivorous and nectar diets. By examining anatomical and cellular features of the small intestine, we discovered that dietary sugar proportion strongly impacted numerous digestive traits, providing valuable insight into the physiological implications of molecular adaptations. Using hybridization chain reaction (HCR) RNA fluorescence in situ hybridization, we observed unusually high expression in the glucose transporter gene Slc2a2 in nectar bats, while fruit bats increased levels of Slc5a1 and Slc2a5. Overall, this study highlights the intricate interplay between molecular, morphological and physiological aspects of diet evolution, offering new insights into the mechanisms of dietary diversification and sugar assimilation in mammals."

ScienceAdvisor

Bats are surviving and thriving on nothing but sugar (original news release) "The team of researchers recorded the highest natural blood sugar levels ever observed in a mammal, now they hope it could help them better understand diabetes."

Sugar assimilation underlying dietary evolution of Neotropical bats (open access)

Fig. 2: Molecular basis of sugar assimilation.