Our Science

We’re AnimalBiome—a team of pet parents, scientists, and veterinarians committed to using science to improve pet health. As the world’s leading pet microbiome research company, we’ve developed award-winning innovative solutions, including the first-ever at-home gut microbiome test for cats and dogs. Health and happiness for your pet—backed by science.

The Microbiome

Your pet’s gastrointestinal (GI) tract hosts a unique community of hundreds of different types of bacteria and other microbes (such as viruses and fungi), referred to collectively as the gut microbiome (pronounced: mī-krō-ˈbī-ˌōm). A diverse, well-balanced gut microbiome is essential for digestion and nutrient absorption. Each bacterial group in the gut plays an important role in your pet’s body, so a healthy gut microbiome is also crucial for overall well-being and longevity.

When some key beneficial bacteria are missing from the microbiome, or the different bacterial groups aren’t present in the right amounts, the resulting imbalance can trigger inflammation. And constant inflammation can lead to chronic illnesses, such as inflammatory bowel disease (IBD), skin issues, immune system reactions, diabetes, and even depression.

Our Process

AnimalBiome’s scientists have studied the microbiomes of more than 15,000 cats and dogs, and have developed science-backed solutions for pets suffering from a range of symptoms. If your pet suffers from health problems like diarrhea, vomiting, or itchy skin, the cause could be a microbiome imbalance. Our microbiome testing and supplement products provide a scientific, comprehensive roadmap to achieving a healthy gut microbiome through our 3-Step Process: Assess | Restore | Maintain.

Assess your pet’s gut health to understand what’s really going on inside your cat or dog.

Restore balance to the gut’s microbial populations to relieve your pet’s uncomfortable symptoms.

Maintain a healthy, well-balanced microbiome to help your pet live a longer, happier life.


A small stool sample can reveal a lot about your pet’s health. Using genetic sequencing, we identify all the resident bacteria groups in your pet’s microbiome. Then we compare the results to our healthy pet reference set. Finally, we provide you with a comprehensive report that includes personalized diet and lifestyle recommendations to improve your pet’s health and happiness.

How Microbiome Testing Works

Our Gut Health Test kits for cats and dogs contain everything you need to collect a small sample of your pet’s stool and send it to our laboratory.

When we receive your pet’s sample, we first extract DNA from all bacteria. A fecal sample about the size of a pea contains roughly one billion bacterial cells. Using DNA sequencing and powerful analytic software, we identify all the types of bacteria living in your pet’s gut.

Then, we compare your cat’s or dog’s results to our large and growing database of healthy pets to determine how closely the types and amounts of bacteria in your pet’s gut match that healthy reference set. We can detect any bacterial imbalances, identify any key groups that are missing, and flag any harmful bacteria that may be causing troublesome symptoms, like diarrhea or itchy skin.

Our Healthy Reference Set

AnimalBiome has built the world’s largest database of cat and dog microbiome samples. So far, we have collected and analyzed more than 15,000 fecal samples from domestic cats and dogs. Out of those, we’ve assembled a group of samples that meet our criteria for healthy pets.

By studying those healthy samples, we were able to build a profile of the specific bacterial taxa (groups) we could expect to find in the gut microbiome of a healthy cat or dog. We identified a “healthy reference set” consisting of 22 taxa that make up the core microbiome of cats and 17 taxa that make up the core microbiome of dogs.

What's in the Test Report?

In addition to a detailed explanation of your pet’s microbiome test results, the report you receive also includes personalized recommendations—such as dietary adjustments, supplements, and lifestyle changes—to improve your pet’s health and relieve symptoms. If your pet has been diagnosed with a chronic digestive or skin issue, the test report will provide actionable information for you and your veterinarian.


If your cat or dog suffers from diarrhea, vomiting, or itchy skin, their symptoms may be related to an imbalance in the gut microbiome. Approaches to balance, support, and strengthen the gut microbiome of pets include diet, prebiotics, probiotics, and fecal microbiota transplantation (FMT). Your pet’s Gut Health Test report will tell you whether you need to add key bacteria that are missing, remove harmful bacteria (pathogens) from the mix, or rebalance the existing populations to achieve better proportions.

Adding Key Bacteria

Many cats and dogs with digestive problems, skin issues, or other symptoms turn out to be missing certain important gut bacteria. In these cases, we need to add those missing bacteria to the microbiome and help those new populations grow and thrive.

Probiotic products contain beneficial microorganisms, but even the leading probiotics can’t restore an imbalanced microbiome. Fortunately, there’s a better option. A growing body of research has found that fecal transplants can help improve several different gastrointestinal disorders (as well as many other conditions) by changing the gut microbiome.

So What Exactly Is a Fecal Transplant?

Also called fecal microbiota transplantation (FMT), a fecal transplant is the process by which stool from a healthy donor is transferred to the intestines of a sick recipient. The stool from the donor contains a healthy community of bacteria that can take up residence in the sick recipient’s gut. In human medicine, for example, FMT is used to treat C. difficile (aka C. diff) infections.

AnimalBiome’s Gut Restore Supplement (fecal transplant in an oral capsule) provides a whole community of healthy cat- or dog-specific bacteria, sourced directly from carefully screened donor animals. By seeding your pet’s microbiome with all the right microbes in the right proportions, our supplement can help reestablish balance and resolve symptoms.

In a pilot study, AnimalBiome gave 72 cats and 40 dogs with inflammatory bowel disease (IBD) a 25-day course of Gut Restore Supplement. After finishing the course of capsules, 83% of the cats and 80% of the dogs had improved symptoms. Appetite also increased for a quarter of the cats and half of the dogs. Researchers continue to learn about the therapeutic benefits of FMT for many different health issues, and this study showed that even for pets with chronic conditions like IBD, FMT can improve symptoms and increase quality of life.

Removing Pathogens

If your pet’s gut health report shows an overgrowth of harmful bacteria, restoring balance may require reducing or removing those troublemaking bacterial groups.

One way to remove harmful bacteria from the mix is through “competitive exclusion.” When the “good” microbes compete successfully and multiply, they take resources away from the “bad” microbes, which gradually die out. Good microbes can be added to the gut microbiome via FMT. Competitive exclusion is thought to be the primary mechanism at work in the successful use of FMT for recurrent C. diff infections in humans.

Sometimes competitive exclusion on its own can’t win control back from the pathogens causing your pet’s symptoms. In these cases, the introduction of an array of healthy gut microbes will be much more likely to have a positive result if we first knock out particular harmful bacteria with bacteriophages or antibiotics.

Bacteriophages are viruses that attack specific types of bacteria. Some bacteriophages, for example, specifically target E. coli. One of the ingredients in our Gut Maintenance Plus (GMP) product is a prebiotic bacteriophage cocktail called PreforPro, which helps take harmful bacteria out of the mix so that the beneficial bacteria in your pet’s microbiome have more room to grow.

Rebalancing the Populations

If your pet’s Gut Health Test report shows that your cat’s or dog’s microbiome contains all the right players but not in the right proportions, rebalancing those resident bacterial groups can improve your pet’s digestion and overall health.

Simple changes to your pet’s diet may be enough to restore balance. The personalized recommendations in the Gut Health Test report will explain exactly what specific nutritional changes can do for your pet. Adding more protein to the diet, for example, supports the growth of the important Fusobacteria group, which do best in a high-protein environment.

If dietary changes and prebiotic supplements aren’t enough to correct the proportions among your pet’s gut bacteria, a course of Gut Restore Supplement can fill in missing bacterial groups and crowd out harmful ones, allowing the members of the microbiome to reestablish a healthy balance.

Mr. Darcy's Journey to Happy

Bloody diarrhea, weight loss, and lethargy were making Mr. Darcy miserable. A Gut Health Test showed that this little dog’s gut microbiome was badly out of balance. After starting him on a course of Gut Restore (FMT) Supplements, his people reported: “Mr. Darcy’s symptoms quickly improved, and over the course of the treatment, completely disappeared.” Read more


Once your cat’s or dog’s microbiome has been rebalanced and any symptoms have been resolved, you can help your pet stay healthy and happy by feeding a high-quality diet. We also recommend retesting your pet’s gut health at least once a year, especially if signs of chronic digestive or skin issues return.

Ongoing Gut Support

Some pets, especially older animals and those with chronic health conditions, may need daily supplementation with prebiotics or postbiotics to help the microbiome stay in balance. While prebiotics provide food for beneficial gut bacteria, postbiotics—healthy byproducts of those bacteria’s metabolic activity—also benefit the gut, especially by helping to reduce inflammation.

We know that certain health issues can keep a pet’s microbiome permanently out of balance. Many kinds of cancer, for example, disrupt the gut microbiome. Genetic factors may also affect the gut’s microbial balance. Some Boxers, for example, have a genetic predisposition that disrupts the proper functioning of the microbiome. In such cases, Gut Restore Supplements can help minimize symptoms and may be an ongoing element of your pet’s care.

Help for Occasional Flare-ups

Even with the best nutritional support, any cat or dog can suffer occasional diarrhea flare-ups. Our Gut Maintenance Plus product is designed to reduce temporary diarrhea caused by antibiotics, C. difficile, and E. coli.

Gut Maintenance Plus contains three active ingredients that we’ve been recommending to pet parents for years with very positive results: Saccharomyces boulardii (S. boulardii), mannan oligosaccharides (MOS), and PreforPro™. Our proprietary blend makes it easy for pet parents to get all three ingredients in one bottle at doses that are appropriate for cats and dogs.

S. boulardii, a yeast-based probiotic, has been shown to resolve diarrhea caused by antibiotics.

Gut Maintenance Plus also contains the prebiotic FOS. FOS has been shown to work synergistically with S. boulardii to improve intestinal health.

PreforPro is a prebiotic bacteriophage cocktail that helps healthy bacteria flourish in the gut. More than 20 studies have confirmed the safety and efficacy of PreforPro.