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People around the world eat too much sugar. When the body is unable to process sugar effectively, leading to excess glucose in the blood, this can result in diabetes. According to the World Health Organization, diabetes became the in 2019.

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Fruit bats have honed their sweet tooth through adaptive evolution.

Humans are not the only mammals that love sugar. Fruit bats do, too, eating up to in sugary fruit a day. However, unlike humans, fruit bats thrive on a sugar-rich diet. They can than bats that rely on insects as their main food source.

We are a team of and . Determining how fruit bats evolved to specialize on a high-sugar diet sent us on a quest to approach diabetes therapy from an unusual angle – one that sent us all the way to Lamanai, Belize, for the , an annual gathering where researchers collect and study bats.

Wei Gordon,

Authors Nadav Ahituv, left, and Wei Gordon.

In our in Nature Communications, we and colleagues and used a technology that analyzes the DNA of individual cells to compare the unique metabolic instructions encoded in the genome of the Jamaican fruit bat, Artibeus jamaicensis, with those in the genome of the insect-eating big brown bat, Eptesicus fuscus.

is composed of genes, which are segments of DNA that contain the instructions cells use to create certain traits, such as a . The other 98% are segments of DNA that regulate genes and determine the presence and absence of the traits they encode.

To understand how fruit bats evolved to consume so much sugar, we wanted to identify the genetic and cellular differences between bats that eat fruit and bats that eat insects. Specifically, we looked at the genes, regulatory DNA and cell types in two significant organs involved in metabolic disease: the pancreas and the kidney.

regulates blood sugar and appetite by secreting hormones like insulin, which lowers your blood sugar, and glucagon, which raises your blood sugar. We found Jamaican fruit bats have than big brown bats, along with regulatory DNA that primes fruit bat pancreatic cells to initiate production of insulin and glucagon. Together these two hormones work to keep blood sugar levels balanced even when the fruit bats are eating large amounts of sugar.

filters metabolic waste from the blood, maintains water and salt balance and regulates blood pressure. Fruit bat kidneys need to be equipped to remove from their bloodstreams the large amounts of water that come from fruit while retaining the low amounts of salt in fruit. We found Jamaican fruit bats have adjusted the compositions of their kidney cells in accordance with their diet, so their urine is more diluted with water compared with big brown bats.

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This flowchart outlines the authors’ study methodology.

Why it matters

Diabetes is one of the most expensive chronic conditions in the world. The in 2022 on direct medical costs and indirect costs related to diabetes.

Most approaches to developing new treatments for diabetes are based on traditional laboratory animals such as mice because they are easy to reproduce and study in a lab. But outside the lab, there exist mammals like fruit bats that have actually evolved to withstand high sugar loads. Figuring out how these mammals deal with high sugar loads can help researchers identify new approaches to treat diabetes.

By applying new cell characterization technologies on these , or organisms researchers don’t usually use for research in the lab, we and a growing body of researchers show that nature could be leveraged to develop novel treatment approaches for disease.

What still isn’t known

While our study revealed many potential therapeutic targets for diabetes, more research needs to be done to demonstrate whether our fruit bat DNA sequences can help understand, manage or cure diabetes in humans.

Some of our fruit bat findings may be unrelated to metabolism or are specific only to Jamaican fruit bats. There are of fruit bats. Studying more bats will help researchers clarify which fruit bat DNA sequences are relevant for diabetes treatment.

Our study also focused only on bat pancreases and kidneys. Analyzing other organs involved in metabolism, such as the liver and small intestine, will help researchers more comprehensively understand fruit bat metabolism and design appropriate treatments.

What’s next

Our team is now testing the regulatory DNA sequences that allow fruit bats to eat so much sugar and checking whether we can use them to better regulate how people respond to glucose.

We are doing this by in mice with those of fruit bats and testing their effects on how well these mice manage their glucose levels.

This article is republished from under a Creative Commons license. Read the .