Feline obesity continues to rise, impacting the wellness, quality of life, and longevity of cats. Understanding the metabolic and gastrointestinal changes that companion animals face with the onset of weight gain and obesity may help with future prevention and treatment plans. The implications of overfeeding and weight gain on gastrointestinal transit time (GTT) and its association with fecal microbiota populations have not been studied. Therefore, the objective of this study was to determine the effects of overfeeding and weight gain on apparent total tract digestibility, GTT, blood hormones, serum metabolites, hematology, fecal microbiota populations, and voluntary physical activity of cats. After a 2-week baseline phase, adult cats were allowed to overeat for 18 weeks. Fecal and blood samples were collected, and voluntary physical activity was measured using accelerometers over time. Dry matter, organic matter, protein, fat, and energy digestibilities and GTT were decreased with overfeeding and weight gain. Fecal bacterial beta diversity was impacted by overfeeding and weight gain, impacting the relative abundances of 1 bacterial phylum and 16 bacterial genera. In conclusion, overfeeding and subsequent weight gain reduced nutrient digestibility, reduced GTT and caused changes to the fecal microbial community of adult cats.

Read the full article in the Journal of Animal Science.