The potential of pet gut microbiota modulation

Products targeting gut microbiota modulation in pets are a growing market, and it’s a sector that is likely to continue to increase its output.

As more studies continue to report on the effects on pet health, it’s essential that guidelines and regulation keep pace.

Microbiota in gastrointestinal health

The so-called ‘trio for gut microbiota’ (prebiotics, probiotics and postbiotics) are being extensively investigated for their potential health benefits in companion animals.

Recently, there has been substantial improvement in the number and quality of studies.

Already this year numerous trials have investigated the trio’s benefits for dogs’ gut health, including a study by a team from Chinese veterinary research institutions published in May in Frontiers in Microbiology, which reported that the yeast probiotic Saccharomyces cerevisiae could be used to help with rapid diet transition.

A further Chinese study published in April in the journal Veterinary Sciences demonstrated that Enterococcus faecium Kimate-X and Lactobacillus plantarum Kimate-F helped in alleviating inflammatory bowel disease (IBD) symptoms in dogs and that Enterococcus faecium Kimate-X helped in reducing transport stress in dogs.

Through their work on Enterococcus and Lactobacillus, the authors of the study propose that the probiotics studied work “synergistically to restore gut homeostasis, reduce intestinal inflammation, and enhance host immunity”, but clearly the benefits of gut microbiota modulation go beyond gut health and digestion.

Further health benefits

Different studies have focused on other potential benefits of microbiota modulation. Probiotics produce short-chain fatty acids (SCFAs), which have anti-inflammatory activity in general and can even reduce cytokine production in organs such as the skin.

A May 2025 study from a research team at the University of Adelaide published in Veterinary Dermatology found that daily oral probiotic and postbiotic supplementation modulated canine skin microbiota, which might have an implication in skin protection from infections.

Other commercial probiotics (Bifidobacterium bifidum, Lactobacillus acidophilus and Enterococcus faecium) helped with canine atopic dermatitis, according to recent research published in the BMC Microbiology journal in April.

The health benefits are not just due to enhanced immunity or gut barrier, but also because of modulation of the brain-gut axis.

Microbiota can affect production of signaling molecules (neurotransmitters) such as serotonin, involved in regulating mood, sleep and cognition, and gamma-aminobutyric acid (GABA), which plays a vital role in regulating brain function.

Thus, probiotics are now being used to improve skin and mental health, reduce anxiety and even help with behavioral problems.

Although it might sound ‘edgy’, the mental benefit of gut microbiota modulation is not such a surprise, as even 10 years ago scientists started to increasingly investigate the potential of probiotics in improving human mental health.

This was followed by studies with pre- and postbiotics, and finally synbiotics. Unsurprisingly, and with the classic decade delay, the growing interest coming from both academia and industry is repeating the microbiota research trend in animal health.

Trusting the science

The abundance of studies showing benefits in dogs should, however, be evaluated cautiously due to recently detected publication bias.

A systematic review published in March 2025 in the Canadian Veterinary Journal concluded that a large number of studies that reported no beneficial clinical outcomes from using probiotics will later not be published as full papers.

Additionally, there remains a clear lack of studies on the benefits of probiotics and similar products for cats. It is known that cats have a microbiota distribution that differs from dogs, highlighting the need for more feline-specific research.

Studies showing benefits of probiotics beyond the gut health via gut-brain axis or gut-brain-skin axis in pet cats remain to be published, but this could be only a matter of time.

The most recent clinical evidence published in March 2025 in the journal Microorganisms shows that in cats, complex probiotics (such as Bifidobacterium animalis subsp. lactis BX-259, Lactiplantibacillus plantarum LP-301, and Lacticaseibacillus rhamnosus) can help with constipation, while a previous study in Animal Microbiome from 2023 showed that probiotics such as complex Bacillus sp., help with diarrhea in cats.

A further 2025 paper published in Animals journal in May used yoghurt with postbiotic in combination with inactivated Pediococcus lactis and found lowered metabolic parameters (e.g. triglycerides, urea etc.), as well as mediators of inflammation.

However, the clinical relevance of this remains to be elucidated as all the animals in study remained healthy regardless.

Regulation and safety

The exploration of gut microbiota modulation and its implications for pet health is expanding. But with potential efficacy, one must have in mind potential obstacles in the shape of regulatory approval and safety evaluation.

For this, publicly available European Food Safety Authority (EFSA) expert evaluations of safety and efficacy of various probiotic formulations for pets can be used for guidance.

Regulatory evaluations can slow development but will ensure that the gut modulation approach in veterinary practice remains scientifically based and sound – for the benefit of companion animals and their owners.