Domestic cats could be excellent animal models for studying the origins and treatment of obesity in humans, a new study of cat gut microbes suggests – and both species would likely become healthier in the research process, scientists say.
Veterinary researchers analyzed fecal samples from fat cats as the animals lost and maintained weight during four dietary changes, including strict calorie reduction. The team found that food-related changes in cats’ gut microbiome – the range of bacteria and molecules those bacteria produce and consume – show striking similarities to the nutritional effects on the gut previously observed in humans.
While there is still much to learn, the findings put domestic cats at the top of the list of animals whose gut bacteria can tell us a lot about ours – and whether gut microbe-based therapy could be a way to combat obesity.
“Animals share our beds. They share our ice cream. There are all these things people do with their pets that highlight that they are a naturally occurring disease model with similar environmental exposures as humans,” said lead study author Jenessa Winston, assistant professor of in veterinary clinical sciences from The Ohio State University.
“Being able to see changes in cats that occur in the context of obesity and type 2 diabetes in humans makes them a very good model to start looking at more microbiome-targeted therapies for obesity in humans if we see a similar shift.” to see. she said. “Microbes we saw in this study also show up again and again in human studies — and obviously humans don’t eat cat food, right?”
The research was recently published in the journal Scientific reports.
According to the Centers for Disease Control and Prevention, an estimated 60% of cats in developed countries are obese or overweight, and more than 2 in 5 adults in the United States are obese.
At Ohio State, Winston is overseeing two large clinical trials investigating the potential for fecal transplants from lean dogs and cats to help their overweight pets lose weight.
“My lab is focused on how we can harness the therapeutic power of microbes,” she said. “To do that, we need to understand how disease states can differ from health so that we can better try to pinpoint and mechanistically target changes that occur in the microbiome.”
In this study, researchers fed seven obese cats a four-phase diet for 16 weeks: free feeding of commercial cat food for two weeks, free feeding of a specially formulated weight-loss diet for one week, and calorie-restricted feeding of the cats. weight loss diet to achieve a 1-2% reduction in body weight per week for 11 weeks, and a return to the original maintenance diet.
The analysis of fecal samples taken during the different diet phases focused on changes in the presence of metabolites of short-chain fatty acids, molecules produced by bacteria during digestion. Fatty acids matter because they mediate specific types of communication between gut microbes and tissues in the rest of the body, including hormonal signals that may be linked to inflammation and insulin resistance.
The team found that the abundance of a short-chain fatty acid called propionic acid – which has been shown in other mammals to regulate appetite, reduce fat accumulation and protect against obesity and diabetes – in the feces increased when the cats lost weight by calorie intake. -restricted diet. Greater propionic acid composition was associated with an increase in bacteria Prevotella 9 kopri. Although direct production of propionic acid by Prevotella Since this could not be determined in this study, the finding that these increases occurred at the same time as cats were losing weight was intriguing. Previous research has made a connection Prevotella 9 kopri in the human intestines to weight loss and better blood sugar control.
“When the cats are on the special diet formulated for weight loss, the propionic acid goes up and stays high, and then goes back down when they are put back on the maintenance diet. So it’s really a dietary change,” Winston said. “This paper highlights that when we restrict calorie restriction in obese cats, we can alter their microbial ecosystem – and the community shifts we see are likely linked to certain metabolic outcomes.
“I think the parallels we see in how the ecosystems change in a similar way are useful,” she said.
The precise role of the gut microbiome in obesity in mammals remains a mystery, but Winston said decades of evidence indicate that these organisms and the molecules they produce are part of the problem behind what is now known as a very complex disease. The findings from this study in felines suggest that the gut profile of domestic cats could provide meaningful answers for both species, she said.
The weight-loss diet in the study was provided by Nestle Purina, which also provided funding for the project. Winston and several co-authors are paid speakers for Nestlé Purina.
Co-authors include John Rowe, Valerie Parker and Adam Rudinsky of Ohio State; Katie McCool of North Carolina State University; Jan Suchodolski, Rosana Lopes and Jörg Steiner from Texas A&M University; and Chen Gilor of the University of Florida.
