Fruit-only diet improves bats

Bats are well-known reservoirs for viruses with pandemic potential. While these viruses typically do not cause disease in bats, they can prove deadly in humans. Spillover events — transmission of a virus from a reservoir population (eg, bats) to a new host population (eg, humans) — have been linked to environmental changes such as food shortages, which may impact immune responses.

While previous studies have demonstrated that bats typically generate weaker antibody responses to viruses than other mammals, these studies used viruses that co-evolved with bats. Understanding the bat immune system, including antibody responses to well-characterized antigens, can lead to better understanding of the circumstances that lead to spillover and inform efforts to prevent future events.

In this study, researchers exposed fruit bats and mice to well-studied antigens. They found that bats generated a weaker, more diverse antibody response than mice. Because the antigens were designed to elicit specific types of immune responses, the results provide some insight on the mechanism behind the immune response, which could be explored in future studies.

The researchers also looked at how changes in diet impacted the bats’ antibody responses to an influenza A-like virus and a pseudotyped Nipah virus. Surprisingly, bats fed a fruit-only diet had a stronger antibody response — demonstrated by higher antibody levels and better binding antibodies — compared to those fed a protein-supplemented diet.

The findings demonstrate that fruit bats generate a less robust antibody response than mice that can be improved by changes in diet. Future studies could inform whether this is generalizable across other bat species.

The authors add, “Bats, known reservoirs of zoonotic viruses, can produce weak antibody responses to infections. Our research shows that changing the dietary protein of Jamaican fruit bats can enhance their antibody response to certain viruses.”