The role of the gut microbiota in feline energy metabolism

点击翻译按钮获取中文摘要

With 8.5 million of cats in Canada and an estimated and continuously increasing prevalence of about 50%, 4.3 million of cats are overweight or obese. As in humans, obesity in cats can be associated with a range of complications and obesity represents a tremendous health concern for the pet population. Although the etiology and treatment of obesity may seem simple, weight-loss programs often give disappointing results. Therefore, a more in depth mechanistic approach to this disease is warranted. It is nowadays widely accepted that obesity is associated with low-grade inflammation and that inflammation contributes to obesity-related health consequences. Most studies have focussed on adipose tissue. However, the gastrointestinal tract is another potential source of inflammation associated with diet or obesity that has not been investigated in companion animals. Gut microbiota dysbiosis and gut barrier dysfunction seem to be an important factor in obesity and the onset of inflammatory and metabolic disturbances in other species. Also the obese microbiome has been shown in some species to have an increased capacity to harvest energy from the diet, and alters adipose tissue gene expression in favour of increased fat storage. Still, as cats are strict carnivores consuming a diet with a typically higher protein and fat content compared to omnivores, additional studies are required in the feline to identify the factors that link nutrition, gut microbiota and host metabolism. The proposed research program aims to characterise the feline obese microbiome and determine the link with feline energy metabolism, providing new insights in the perturbed molecular mechanisms underlying feline obesity. It is hypothesised that gut microbiota dysbiosis contributes to feline obesity by increasing extraction and absorption of dietary energy and modulating genes that promote fat storage. To test this hypothesis, following objectives will be pursued: 1) To compare the fecal microbiome, metagenome and adipose tissue function among lean and obese cats living in the same household; 2) To evaluate the effect of energy restriction and weight loss on the fecal microbiome, microbiome and adipose tissue function in feline obesity. This Feline Metabolism Research Program will be the first to combine novel techniques such as dual energy X-ray absorptiometry (DEXA) technology, metagenomics, metabolomics and transcriptomics, which have been minimally used in cats, to uncover the dynamic linkage between adiposity, energy metabolism and gut microbial ecology in domestic cats. The knowledge obtain by the proposed research program will form the foundation for future research towards the development and application of new nutritional strategies, that will make maintaining an ideal body condition much easier. The pet food industry constantly focuses on new product development and more and more preventive pet food diets become available. The new knowledge gained from this study will be implemented in redesigning existing and marketing new revolutionary weight loss and weight maintenance products for pets. The results of this research could have direct impact on pet food industry and veterinary practice in 5-10 years. This project will also provide benefits to Canada by the training of highly qualified personnel, as it will allow training of animal nutritionists and basic and biomedical scientists, suited for future careers in Canada’s advanced health technology sector and nutritional research and manufacturing sector.