If you thought your obesity and type 2 diabetes diagnoses were genetic “gifts” from your family, it could be a virus instead.
Researchers at San Diego State University have identified a virus called crAssphage – named for the computer software that discovered it – that infects a common intestinal bacteria associated with both obesity and diabetes. The virus is present in more than half the human population, and researchers say it could play an important role in the development of the two metabolic diseases.
“We’ve basically found it in every population we’ve looked at. As far as we can tell, it’s as old as humans are,” said bioinformatics professor and co-author of the study, Robert A. Edwards. “It’s not unusual to go looking for a novel virus and find one. But it’s very unusual to find one that so many people have in common. The fact that it’s flown under the radar for so long is very strange.”
The virus was discovered during analysis of previous studies screening for new viruses, and infects one of the most-common types of gut bacteria associated with obesity, researchers said.
Scientists have recently begun looking at the relationship between good and bad gut bacteria and how it relates to obesity, and have determined that thin people and overweight people tend to have different bacteria present. In mice studies, transferring “thin” bacteria to obese mice led to significant weight loss.
While there are myriad different kinds of gut bacteria, two groups – Bacteroidetes and Actinobacteria – have been associated with weight. According to previous studies, obese people have fewer bacteria from the Bacteroidetes group than thin people and more from the Actinobacteria group
And according to the San Diego study, the new virus, crAssphage, attaches to the cells of the Bacteroidetes bacteria, hijacking the cells, a move that would further decrease the amount of Bacteroidetes in the gut, elevating the risk of obesity.
The discovery could provide scientists a way to transform the existing virus, manipulating it to target bacteria that are more commonly related to obesity, so the bacteria more common in thin people could thrive.
“This could be a key to personalized phage medicine,” Edwards said. “In individuals, we could isolate your particular strain of the virus, manipulate it to target harmful bacteria, then give it back to you.”
The research appeared in the journal Nature Communications.