Researchers at the National Institutes of Health fed antibiotics to fruit flies to better understand the role of bacteria in health and disease. They monitored the lifetime activity of hundreds of genes that scientists have traditionally thought control ageing.
To their surprise, the antibiotics not only extended the lives of the flies but also dramatically changed the activity of many of these genes. Their results published in the Journal Science suggested that only about 30 per cent of the genes traditionally associated with ageing set an animal's internal clock while the rest reflect the body's response to bacteria.
"For decades scientists have been developing a hit list of common ageing genes. These genes are thought to control the ageing process throughout the animal kingdom, from worms to mice to humans," said Edward Giniger, PhD, senior investigator, at the NIH's National Institute of Neurological Disorders and Stroke (NINDS) and the senior author of the study published in iScience.
He added, "We were shocked to find that only about 30 per cent of these genes may be directly involved in the ageing process. We hope that these results will help medical researchers better understand the forces that underlie several age-related disorders."
The results happened by accident. Dr Giniger's team studies the genetics of ageing in a type of fruit fly called Drosophila. Previously, the team showed how a hyperactive immune system may play a critical role in the neural damage that underlies several ageing brain disorders. However, that study did not examine the role that bacteria may have in this process.
To test this idea, they raised newborn male flies on antibiotics to prevent bacteria growth. At first, they thought that the antibiotics would have little or no effect. But, when they looked at the results, they saw something interesting. The antibiotics lengthened the fly's lives by about six days, from 57 days for control flies to 63 for the treated ones.
"This is a big jump in age for flies. In humans, it would be the equivalent of gaining about 20 years of life," said Arvind Kumar Shukla, PhD, a post-doctoral fellow on Dr Giniger's team and the lead author of the study. "We were totally caught off guard and it made us wonder why these flies took so long to die."
(With ANI Inputs)
