Sigma BioVet Sciences

Your animal's gut is trying
to tell you something.
Are you listening?

Real animal microbiome science, made readable. For owners who want to understand what is actually going on inside their animals.

Explore by species Consult with Dr. Nihan

Last updated: March 2026

The basics

Your animal's gut is home to trillions of microorganisms. Bacteria, fungi, viruses, tiny organisms you will never see. Together they form the gut microbiome, and it does a lot more than digest food.

Think of it as a living ecosystem inside your animal. When it is healthy and diverse, your animal thrives. When it goes out of balance, from stress, antibiotics, a sudden diet change, or illness, you see it. Digestive upset, skin issues, behavior changes, low energy. The gut talks. This page helps you understand what it is saying.

The short version

A healthy gut microbiome means better digestion, stronger immunity, calmer behavior, and healthier skin. This is not a wellness trend. It is core biology, and it applies to every species on this page.

What the microbiome does for your animal

1
Digestion

Gut microbes break down food, produce essential vitamins, and absorb nutrients your animal cannot process alone. Without them, even a good diet falls short.

2
Immunity

70 to 80% of the immune system lives in the gut. The microbiome trains immune cells from the first days of life and keeps training them throughout adulthood.

3
Behavior

The gut and brain communicate constantly. A disrupted microbiome has been linked to anxiety and behavioral changes across multiple species, in well-documented research.

4
Skin and coat

Gut health shows up on the outside. Itching, flaking, and dull coat are often gut issues in disguise, not just allergies or diet problems.

What disrupts it?

Antibiotics are the biggest disruptor. Even a single course can cause significant, lasting damage to the microbial community. Other common culprits include sudden diet changes, chronic stress, parasites, low-quality processed food, and aging. The good news is the microbiome is resilient. You can actively support it, and that is what this page is about.

ISAPP on probiotics PubMed animal microbiome research One Health Initiative

By species

Every animal has a unique gut ecosystem. The microbes that keep your rabbit healthy look very different from those in your horse's hindgut. What disrupts one species may do almost nothing to another. Select your animal below.

Species-specific questions?

Dr. Nihan has worked across all of these.

She consults with animal owners, veterinary professionals, and animal health companies across the US, EU, Asia, and beyond. If you found this page looking for a microbiome science resource, her main site is the right next step.

Reach out at sigmabiovet.com

Signs your animal's gut may be out of balance

Dysbiosis, the scientific term for a disrupted microbiome, does not always look like obvious sickness. The signs are often subtle and easy to blame on something else entirely. Here is what to watch for.

1
Loose stools or on-and-off diarrhea

Digestive upset with no clear cause is the gut's loudest signal. If it keeps coming back, something is off in the microbial balance.

2
Excessive gas or bloating

Some gas is normal. Frequent discomfort and bloating point to fermentation going wrong inside the gut.

3
Skin issues that keep coming back

Itching, hot spots, and flaking without an obvious allergy cause. The gut-skin connection is real and well-documented in veterinary science.

4
Dull coat

Nutrient absorption happens in the gut. Poor coat quality often reflects poor gut function, not just what you are feeding.

5
Unexplained weight changes

Losing or gaining weight without a diet change can trace back to shifts in the gut microbial community affecting metabolism and absorption.

6
Anxiety or behavior shifts

The gut-brain axis is bidirectional. Gut dysbiosis has been linked to increased anxiety and reactivity, especially in dogs and cats.

7
Slow recovery or frequent infections

If your animal seems to catch everything, or takes longer than expected to bounce back, gut-based immune function is worth examining closely.

8
After a course of antibiotics

Antibiotics save lives. They also wipe out beneficial bacteria. Microbiome support after antibiotics is not optional. It is essential.

Keep this in mind

Seeing one or more of these signs does not mean your animal has a serious illness. It means the gut is sending a message. The right first step is a conversation with your veterinarian. This page helps you understand the science so you can ask better questions when you get there.

PubMed on dysbiosis in companion animals PubMed on gut-brain axis in animals

When to see your vet

This page gives you the science. Your veterinarian gives your animal the care. Here is how to know when it is time to pick up the phone, and what to bring up when you do.

Go now. Do not wait.

Blood in stool or vomit. Sudden collapse or severe lethargy. Seizures. Not eating or drinking for more than 24 hours. Visible bloating with pain, especially in horses and large dogs. These are emergencies. Call your vet or an emergency clinic immediately.

Schedule an appointment soon

Digestive upset lasting more than 48 hours

Recurring diarrhea or vomiting is not something to wait out. Get it assessed.

Unexplained weight changes

Losing or gaining weight without a diet change is worth investigating with bloodwork and a gut health assessment.

Recurring skin flare-ups

If the same skin problems keep returning, a gut-focused workup may find what topical treatments keep missing.

Behavior shifts after illness or antibiotics

If your animal's personality changed after a health event, mention it. The gut-brain connection is a legitimate part of the picture.

Questions worth asking your vet

  • "Could this be related to gut dysbiosis?"
  • "Should we consider a probiotic alongside this treatment?"
  • "Is there a microbiome test that would be useful here?"
  • "After these antibiotics, how do we support gut recovery?"
  • "Is my animal's current diet actually supporting a healthy microbiome for their species?"
From Dr. Nihan

The best thing you can do for your animal's gut health is build a relationship with a vet who understands it, and show up to appointments already knowing the right questions. You do not need to be a scientist. You just need to be curious. That is exactly what this page is for.

Veterinary professional reading this?

Dr. Nihan works with vet clinics and animal health teams too.

She offers microbiome science training, consulting, and scientific writing for veterinary professionals and industry. Her main site has the full picture.

Explore sigmabiovet.com

Frequently asked questions

The questions animal owners actually ask. About probiotics, testing, diet, behavior, and gut science. Answered plainly, without the marketing layer.

Do probiotics actually work for animals?
Yes, when the right strain is used for the right species and condition. That word "strain" matters more than most people realize. A probiotic that has solid published evidence in dogs may do nothing in cats, and a strain studied in humans has no guaranteed effect in animals. The gut microbiome is species-specific. Look for products with peer-reviewed animal studies, not just general wellness language on the label. A single strain with real evidence beats a multi-strain blend with none every time.
When should you NOT give a probiotic?
If your animal is immunocompromised, has an active systemic infection, or has a significantly compromised gut barrier, introducing live bacteria without veterinary guidance can cause real harm. Probiotics are not universally safe for every situation. They are live organisms entering a living system, and timing and strain selection matter. Always work with your veterinarian before starting any supplement during a health event.
What should I do after my animal finishes antibiotics?
Start microbiome support as soon as the course ends. Ideally, discuss it with your vet before the course even begins. A species-appropriate probiotic, some dietary fiber, and a few weeks of gut-supportive feeding can significantly speed recovery. The mistake most animal owners make is assuming the microbiome bounces back on its own. It often does not, or it takes much longer than expected. Post-antibiotic gut care is one of the highest-impact things you can do for your animal's long-term health.
Does raw food support a better microbiome than kibble?
Raw diets do tend to produce more diverse microbial communities in dogs, and the microbiome does respond directly to diet. But diversity alone is not the goal. Appropriate composition and stability matter more. Raw feeding also carries real food safety risks for both the animal and the humans in the household. The honest answer is that high-quality, species-appropriate food supports a healthy microbiome regardless of format. What matters most is protein source quality, fiber diversity, and consistency.
Does the gut microbiome affect my animal's behavior?
Yes. The gut-brain axis is a bidirectional communication system. The gut sends signals to the brain and vice versa, partly through microbial metabolites, the vagus nerve, and immune pathways. Dysbiosis has been associated with increased anxiety and reactivity in dogs and cats in particular. This does not mean a probiotic will fix a behavioral problem, but gut health is a legitimate and often overlooked factor in the overall picture. Worth discussing with your vet if behavior changes followed a health event.
Does the early-life microbiome matter long-term?
Enormously. The microbial community an animal acquires in the first weeks of life shapes immune development, metabolic function, and disease susceptibility in ways that persist for a lifetime. Early antibiotic exposure, cesarean birth, formula feeding instead of nursing, and lack of environmental microbial diversity all leave measurable marks on the adult microbiome. This is one of the most underappreciated areas of veterinary microbiome science, and one of the reasons early-life gut care matters far more than most owners realize.
What is FMT and does it work in animals?
Fecal Microbiota Transplantation, or FMT, involves transferring gut microbiota from a healthy donor animal to a recipient with the goal of restoring microbial balance. It has shown genuinely promising results in dogs with recurrent Clostridioides difficile infections and some forms of chronic enteropathy. It is a clinical procedure and should only be performed by a veterinarian using screened donor material. DIY versions you may encounter online are not equivalent, carry real risks, and are not recommended.
Have a question not covered here?

Send it directly to Dr. Nihan.

Selected questions are answered and may be published anonymously on this page as the resource grows.

Ask a question below

Ask Dr. Nihan a gut health question

Got a question about your animal's digestive health, a supplement you have seen advertised, or something your vet mentioned? Send it below. Dr. Nihan reads every submission. Selected questions may be answered on this page, always anonymized.

Educational answers only. This form is not a substitute for veterinary care. Always work with your veterinarian for clinical decisions about your specific animal.

Received
Thank you. Your question is on its way to Dr. Nihan. She will be in touch if you left an email. Selected questions may be answered on this page, always anonymized.

Helpful resources

Curated links for animal owners who want to go further. Microbiome testing, finding the right vet, and science you can actually read. Vetted for credibility, not commercial interest.

Microbiome testing

University Research
Texas A&M GI Lab
Research-based microbiome and dysbiosis testing with strong peer-reviewed foundations. Widely referenced in veterinary clinical practice.

Finding a veterinarian

Find a vet
AVMA — How to find a veterinarian
The American Veterinary Medical Association's guide to finding a vet near you.
Specialist
ACVIM — Internal medicine specialists
For complex or chronic gut health cases, an internal medicine specialist may be the right next step.

Understanding biotics

Science for animal owners
ISAPP — Probiotics, prebiotics and postbiotics explained
The International Scientific Association for Probiotics and Prebiotics. One of the most credible, consumer-friendly sources available.
Clinical Guidelines
AAHA — Nutrition and microbiome guidelines
American Animal Hospital Association summaries on clinical use of biotics and gut-supportive nutrition.

Research and deeper reading

Primary Literature
PubMed — Companion animal microbiome
The primary scientific literature. Dense, but the real thing. Searchable by species or condition.
One Health
One Health Initiative
How human, animal, and environmental health are connected. Essential context for anyone thinking seriously about the animal microbiome.
Media, conferences, or industry inquiry?

This hub is one of Dr. Nihan's public education projects.

She is a veterinary microbiologist, PhD scientist, and university educator available for speaking engagements, expert commentary, and consulting across the US, EU, Asia, and global markets. If you landed here looking for a credible voice in animal microbiome science, her main site is where to start.

Visit sigmabiovet.com

About Dr. Nihan Marun

Dr. Nihan Marun is a veterinary microbiologist and PhD scientist with over 20 years of hands-on experience in animal gut health, biotics R&D, and regulatory science. She has worked across the United States, European Union, Asia, and global markets, bringing scientific rigor to an animal health industry that does not always move at the speed of the science.

Founder, Sigma BioVet Sciences LLC

She holds a DVM and a PhD in veterinary microbiology, and currently teaches General Microbiology and microbiome science at university level. She has guided animal biotics product development and regulatory strategy across multiple species and territories, including regulatory submissions to FDA-CVM, AAFCO, EFSA, and APAC authorities. She is also a published author and an active peer reviewer in the field.

This resource exists because she believes every animal owner deserves access to real science. Not marketing copy. Not oversimplified wellness advice. The kind of science that helps you understand what is going on with your animal and ask better questions when it matters.

A note on this page

Dr. Nihan shares microbiome science here in her role as a PhD scientist and university educator. Everything on this page is educational and based on published research. For clinical care decisions about your specific animal, always work with your veterinarian.

What she does at Sigma BioVet Sciences

Regulatory consulting

FDA-CVM, AAFCO, EFSA, and APAC regulatory strategy for animal biotics and feed additives across global markets.

Scientific writing

Technical dossiers, white papers, and peer-reviewed manuscripts for the animal health industry worldwide.

Education and training

Microbiome science education for veterinary teams, university students, and industry companies globally.

R&D strategy

Product development guidance for probiotic, prebiotic, and postbiotic applications across species and regulatory territories.

Visit sigmabiovet.com