Qualitative and quantitative changes in fecal microbiota of cats fed high‐ or moderate‐protein diets

Abstract

The objective of this study was to identify changes in the fecal microbiota of cats fed high- or moderate-protein diets. Eight healthy female adult domestic shorthair cats (1 yr old) were acclimated to a control diet (38% protein) for 4 wk. After acclimation, fresh fecal samples were collected and stored at −80°C. Cats were then randomly allotted to a moderate-protein (MP; 34% protein; n=4) or high-protein (HP; 53% protein; n=4) diet and fed for 8 wk. Fresh fecal samples were again collected and stored at −80°C. Following DNA extraction, denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction (qPCR) were performed to identify qualitative and quantitative changes in microbiota, respectively. Dice’s similarity index was calculated as a measure of microbial diversity. qPCR data were analyzed using the mixed repeated measures method of SAS. Compared to baseline, cats fed HP had a similarity index of 40.6% compared to 66.7% for those fed MP. These data exhibit marked changes in intestinal microbiota, especially in cats fed HP. Bifidobacterium were drastically decreased (P < 0.05; 10.53 vs. 5.59 cfu/g), while C. perfringens were increased (P < 0.05; 8.96 vs. 12.36 cfu/g) in cats fed HP. Thus, consumption of high protein diets results in vast changes in the intestinal microbiota. Further research is required to determine what implications these changes have on intestinal health.