Resistant starch in a wet diet digestibility, SCFAs, faecal microbial composition in healthy dogs and cats

Resistant starch (RS) is known to exert health benefits through the microbe induced production of short chain fatty acids (SCFAs), such as butyrate in mice, pigs and humans. However, the knowledge of RS use in dogs and cats is limited. The aim of this study was implementing RS in a wet maintenance diet for adult dogs and cats and the effect on apparent digestibility, production of SCFAs and BCFAs, gut microbiota composition, faecal characteristics, and the general acceptance in healthy adult dogs and cats. A double blinded randomized cross-over study with consecutive 14-day periods; control diet with no RS, a 2% RS diet and for the dogs only 5% RS diet. In each period all faeces voided during last four days (dogs) and five days (cats) was collected. Maintenance energy was calculated at inclusion and adjusted to maintain weight. The 2% RS diet was found to decrease fat (only dogs), protein, ash, and gross energy digestibility, increase faecal microbial richness, induce specific changes in faecal microbiome composition, and increase SCFAs and BCFAs, as well as leading to improved faecal consistency compared to the control diet. While the 5% RS diet was only associated with a few differences in faecal microbiome composition and improved faecal consistency. The decreased digestibility of fat could indicate potential in the treatment/prevention of obesity. While the decreased apparent digestibility of ash, could indicate an effect on mineral digestibility as some other RS in previous studies (rodent and pig), and should be further investigated.