Bats from the family of leaf-nosed bats provide a fascinating example of evolutionary adaptations that enable survival with extreme levels of blood sugar, levels that would be fatal for most mammals. Researchers from the Stowers Institute for Medical Research have discovered that these animals have an incredibly high tolerance threshold for sugar, which opens up new questions about potential therapies for metabolic disorders like diabetes. This adaptation not only allows bats to survive but also enables them to thrive in environments where the diet is rich in sugar, such as nectar and fruit.

Over the past 30 million years, these species have evolved and adapted to various food sources. For example, while their ancestors survived solely on insects, today some bat species feed only on nectar or fruit, while others have developed the ability to consume blood or even meat. This dietary diversification has led to evolutionary changes in the way bats manage glucose levels in their bodies. Scientists believe that understanding these mechanisms could help in developing new methods for treating people with diabetes.

One of the key findings of the researchers is that bats with high blood sugar levels have genetic mutations that allow for the continuous expression of the gene responsible for sugar transport into cells. Unlike humans, where uncontrolled blood sugar levels can lead to diabetes, these bats do not experience harmful effects thanks to specific adaptations in their intestines and cells. Specifically, nectar-feeding bats have significantly longer intestinal walls and larger cell surfaces for nutrient absorption. These physiological changes enable them to process sugar more quickly and efficiently, reducing the risk of toxic glucose levels in the blood.

The research team conducted several years of field expeditions in the tropical forests of Central and South America, as well as the Caribbean, to analyze nearly 200 bats from 29 different species. Each species was tested after consuming one of three types of sugar associated with their specific diet – insects, fruit, or nectar. The results showed that different bat species use different mechanisms for processing sugar, indicating a deep evolutionary adaptation based on their dietary habits.

These differences are particularly evident in species that consume nectar, as these species show resistance to high blood sugar levels similar to those found in humans with uncontrolled diabetes. However, unlike humans, these bats do not need insulin to regulate blood sugar levels but have developed a different, previously unknown mechanism. Scientists are now trying to determine how this alternative sugar regulation mechanism works, which could provide new insights into diabetes treatment in humans.

One of the scientists involved in the research, Nadav Ahituv, highlights that these findings represent an important step towards understanding how diet and evolutionary adaptations impact metabolic processes. This research not only enriches our understanding of bats but also opens up possibilities for further investigations into metabolic diseases in mammals, including humans. These discoveries could one day lead to the development of new therapies that will aid in regulating blood sugar levels in patients with diabetes.

Further analyses of the genes responsible for sugar transport in bats, as well as structural adaptations in their intestines, could provide valuable insights for developing new therapeutic methods. As research progresses, scientists hope that their findings will help create better models for understanding and treating metabolic disorders, thereby significantly improving the quality of life for patients worldwide.

Source: Stowers Institute