The role of dietary fibre in companion animal nutrition

Dietary fibre is an often overlooked nutrient when considering the nutrition of companion animals. However, increasing evidence suggests that dietary fibre is important in maintaining the health of pets. Both dogs and cats are capable of significant colonic fibre fermentation, and dietary fibre inclusion in pet foods can impact their nutrition in several ways. Moderate to high concentrations of dietary fibre can decrease food intake and help improve appetite regulation. Depending on the fermentability and viscosity characteristics of a particular dietary fibre source, fibres can slow gastric emptying, decrease intestinal transit time, and decrease total tract nutrient digestibility. However, more recent data indicate that ileal nutrient digestibility is not compromised. Other physiological responses attributed to fibre include faecal bulking, production of short chain fatty acids, enhanced colonic morphology and intestinal function, and a positive influence on the distribution of the colonic microflora. These physiological responses indicate the potential of dietary fibre to be used in clinical nutrition applications. Possible medical nutritional uses of fibre include blunting of postprandial glycaemia, prevention of small intestinal bacterial overgrowth, prevention and treatment of obesity, and improved nitrogen metabolism in pets with renal dysfunction. Although dietary fibre has great potential for improving the health and nutrition of dogs and cats, caution must be exercised in formulating companion animal diets containing fibre. In addition to determining the most appropriate concentration of dietary fibre inclusion, consideration must be given to the specific characteristics of the fibre source(s) employed. An ideal dietary fibre should provide good stool characteristics without significantly decreasing nutrient digestibility. These may be achieved by a single fibre source or a blend of different fibres. Future research in these areas should refine our ability to develop diets for companion animals that can facilitate optimal health and wellbeing of companion animals.