Little gut helpers and their importance for our animals’ health

03. March 2021 — von Daniela Diepold

You can find microorganisms like bacteria, fungi, viruses and archaea everywhere. They are in nature, on trees, in water, in the earth and both on and in the bodies of humans and animals. These microorganisms colonise the human and animal intestines and form a so-called microbiome. In this article, we will clarify exactly what this is and how you can support the microbiome with pre- and probiotics.

The microbiome – what is it anyway?

The microbiome is all of the microorganisms that colonise an organism, that is bacteria, archaea, viruses and eukaryotic microbes. The number of microbial unicellular organisms has an estimated ratio of approximately 10:1 to the body cells of an adult. These microbial ecosystems, which primarily colonise the gastrointestinal tract as biofilms although they are also found in other parts of the body, in cavities and mucous membranes, and have a lasting effect on bodily functions. Bacterial DNA has now been detected in almost every organ. The effect of bacteria on the immune system, liver and brain function, digestion, inflammation, bone formation and breakdown, muscle regeneration, kidney function and the heart are currently the subject of intensive research.

The gut microbiome

The gut microbiome, which is composed differently depending on the section of the digestive tract, has been the most researched. The gut microbiome of mammals is dominated by five bacterial strains: firmicutes, bacteroidetes, proteobacteria, actinobacteria and fusobacteria. Cats, dogs and humans show a similar distribution of bacterial strains. The functions of these bacteria are extremely diverse: they break down food components, alcohols and endotoxins, and produce vitamins, short-chain fatty acids, amino acids, neurotransmitters, bacteriocins, antimycotics and antiviral substances. A disruption of the microbiome is known as dysbiosis. This is when the diversity and individual groups of bacteria decrease. Other bacteria on the other hand, pathogens for example, can then multiply disproportionately. Dysbiosis leads to a disturbed metabolism of the microbiome and thereby to inflammation, reduced nutrient breakdown and vitamin production.

Changes in the gut microbiome can be related to diseases

In cats and dogs, the research is currently focused on the digestive tract, but some studies have also found changes in the gut microbiome to be connected to chronic kidney failure, gastric torsion, obesity or exocrine pancreatic insufficiency. It has not yet been conclusively clarified whether changes in the microbiome are the cause or the consequence of the diseases. There are many influences that affect the microbiome, above all, the diet. A large number of studies have shown the influence of different diets on cats and dogs. The diets differed in their protein, carbohydrate and fibre content, resulting in a different make-up of the microbiome. A healthy microbiome makes a lasting contribution to a healthy organism. Pre- and probiotics can support the small gut dwellers in their daily work.


Prebiotics are non-digestible food components that are broken down by the gut flora. They selectively promote the growth and activity of certain benign bacteria. Simply put, prebiotics is the food for the microorganisms. Examples of prebiotics are inulin, oligosaccharides and the amino acid glutamine, which is important for the intestinal cells. The combination of pre- and probiotics is called synbiotics.


Probiotics are usually beneficial living bacteria or fungi that multiply in the intestine, but they can also be components of dead microorganisms. Well-known probiotics are lactobacilli, bifidobacteria, enterococci and yeasts. They are used, among other things, for diarrhoeal and gastrointestinal diseases, to stimulate the immune system and against allergies. Probiotics grown and multiply in the gut and have antibacterial properties against pathogens, are anti-mutagenic and also stimulate the immune system. In order for probiotics to get into the gut, they have to be resistant to stomach and bile acids.

At a glance

  • The microbiome is comprised of all of the microorganisms that colonise an organism, including bacteria, archaea, viruses and eukaryotic microbes.
  • Probiotics contain living microorganisms such as lactic acid bacteria and yeasts.
  • Prebiotics are non-digestible food components that promote the growth and activity of bacteria in the large intestine – such as fibre, inulin and oligofructose.

Translated by Maria Kruglyak