Prebiotics

Prebiotics are non-digestible food components, typically certain fermentable [fibres](/glossary/fibre), that selectively encourage the growth or activity of beneficial gut bacteria. Unlike [probiotics](/glossary/probiotics), which add live bacteria, prebiotics act as the food that nurtures the good bacteria the animal already has, which gives them a major practical advantage: being non-living, they survive the heat and storage of processing far better than live cultures. The best-known examples in pet food are [FOS](/glossary/fos-fructo-oligosaccharides), [inulin](/glossary/inulin) and the fibre in [beet pulp](/glossary/beet-pulp); the related [MOS](/glossary/mos-mannan-oligosaccharides) are often grouped here too, though they work by binding pathogens rather than feeding good bacteria. When colonic bacteria ferment these fibres, they produce short-chain fatty acids that nourish the cells lining the gut, help maintain a balanced microbiome and support stool quality, the same beneficial compounds described under postbiotics. Both dogs and cats benefit, and prebiotics are a staple of premium digestive-care recipes. The catch is dose: too much fermentable fibre too quickly causes gas and loose stools, so prebiotics are added at modest rates and introduced gradually. On a label they appear as named fibres or fibre sources such as chicory among the ingredients. See the [Petipedia glossary](/glossary) for related gut-health entries.

Petipedia · Editorial team

General documentary information. For an individual animal, a veterinarian's advice takes precedence over any online content.