How to Improve Your Pet’s Gut Health—and Why It’s So Important

Editor’s Note: This topic is one that is incredibly important to a pet’s overall health. As such, Mud Bay’s Consulting Veterinarian Dr. Katy Miller has provided a deep dive into the specifics of how gut health in pets works, why it’s so crucial, and what you can do to help improve your pet’s gut health. If you’re pressed for time, the key takeaways are bolded for convenience, and when you want to get the full story—including references—we have included that information as well.

Your pet’s gut does a lot more than digest food. In fact, a healthy gut plays a vital role in your pet’s immune system, nutrient absorption, mood regulation, and even behavior. If your dog or cat has chronic digestive issues, frequent itching, low energy, or even signs of anxiety, their gut health could be to blame.

Fortunately, there are simple, science-backed ways to support a healthy digestive system for your furry friend. Here’s why gut health matters and how you can help.

Why Gut Health Matters in Pets

Just like in humans, your pet’s digestive tract houses trillions of microbes, bacteria, fungi, and other organisms, collectively known as “the gut microbiome.” This microbial community helps break down food, produce vitamins, and defend against harmful pathogens.

A balanced gut microbiome contributes to:

• Stronger immune defenses – About 70% of your pet’s immune system lives in the gut, which means that a balanced gut microbiome plays a vital role in supporting your pet’s immune system.¹ The trillions of beneficial microbes in the digestive tract help “train” the immune system to distinguish between harmful invaders and harmless substances, promoting immune tolerance and reducing the risk of allergic or inflammatory responses.² These microbes also strengthen the gut barrier, preventing harmful bacteria and toxins from leaking into the bloodstream, a condition known as “leaky gut.”³ By competing with pathogens for space and nutrients, the microbiome helps prevent harmful bacteria from taking hold.⁴ In addition, beneficial microbes produce compounds like short-chain fatty acids (such as butyrate), which have anti-inflammatory effects and help regulate immune cells throughout the body.⁵ This means that a healthy gut doesn’t just support digestive health, it also plays a central role in your pet’s ability to fight infection, reduce inflammation, and maintain overall wellness.
• Improved digestion and nutrient absorption – Your pet’s gut microbiome plays a big role in helping them get the most out of their food. These friendly microbes help break down complex ingredients that your pet can’t digest on their own, turning them into smaller, useful pieces like vitamins, amino acids, and fatty acids.⁶ Some of these bacteria can even make important nutrients themselves, like certain B vitamins and vitamin K.⁷ A healthy gut also keeps the lining of the intestines strong, so that nutrients can be properly absorbed into the body while keeping harmful substances out.⁸ When the balance of gut bacteria is off, it can lead to poor digestion, less nutrient absorption, and even upset stomach or inflammation. Keeping your pet’s microbiome balanced helps them digest their food better and stay healthier overall.
• Mental well-being – Your pet’s gut doesn’t just influence their digestion, it also plays a super cool role in animals’ mood and behavior, thanks to what’s called the gut-brain axis. This is the two-way communication system between the digestive tract and the brain. In both dogs and cats, gut bacteria produce important substances, including short-chain fatty acids, neurotransmitters (such as serotonin), and immune messengers, which can affect brain function.

When the gut microbiome is healthy and balanced, these signals help regulate mood, reduce anxiety, and promote emotional stability.⁹ But when the microbiome is imbalanced due to stress, illness, antibiotics, or a poor diet, it can send distress signals to the brain that may contribute to anxiety, fearfulness, or even aggression. A 2020 study found that dogs with behavior issues (like fear and aggression) had different gut microbiomes compared to behaviorally normal dogs, suggesting that the makeup of gut bacteria may influence emotional well-being.¹⁰ Other studies show that probiotics and diet can positively influence behavior in pets, likely by restoring a healthier balance in the gut and calming brain-related inflammation.¹¹ This means that supporting your pet’s gut health doesn’t just help their tummy, it could also help them feel calmer, happier, and more emotionally balanced.

5 Science-Backed Ways to Improve Your Pet’s Gut Health

Feed a High-Quality, Digestible Diet

The foundation of your pet’s gut health starts with the food in their bowl. Just like with people, the types of ingredients and how easily they can be digested play a big role in shaping your pet’s gut microbiome. High-quality, easily digestible proteins like chicken, fish, or eggs break down more efficiently in the stomach and small intestine. This means your pet can absorb essential nutrients like amino acids without leaving too much waste behind in the colon, where it could be fermented by less-friendly bacteria, contributing to gut imbalance, gas, bloating, and soft stools.¹²

Add Prebiotics

Fiber is another key player. Prebiotics are dietary fibers that “feed” beneficial gut bacteria. Ingredients like beet pulp, inulin, and fructooligosaccharides (FOS) support a healthy balance of microbes. Soluble fibers (like beet pulp or inulin) help feed beneficial bacteria and produce short-chain fatty acids (SCFAs), which strengthen the gut lining and help reduce inflammation.¹³ Insoluble fibers (like cellulose) help add bulk to stool and keep the digestive system moving. A balanced mix of both helps maintain healthy gut motility and microbial diversity.

Incorporate Probiotics

Probiotics are live, beneficial bacteria that help improve your pet’s gut health by restoring balance to the digestive system. When dogs or cats experience stress, illness, antibiotic use, or changes in diet, the healthy bacteria in their gut can become unbalanced, leading to issues like diarrhea, poor stool quality, or even chronic inflammation. Probiotics work by repopulating the gut with “good” microbes that compete with harmful bacteria, reducing the chance of infection or digestive upset.⁸

Explore Postbiotics

Postbiotics may be the next big thing in pet digestive health. Postbiotics are the beneficial compounds that are naturally produced when probiotics (the “good bacteria”) break down fiber and other nutrients in the gut. These include powerful substances like short-chain fatty acids (SCFAs), enzymes, and peptides that help maintain a healthy gut environment, support the immune system, and reduce inflammation.¹⁴ Unlike live probiotics, postbiotics are non-living, which makes them incredibly stable—they retain their effectiveness even after exposure to heat, pressure, or shelf life challenges that often damage live cultures. This makes postbiotics an excellent option for supporting digestive and immune health in pet foods and supplements where probiotics might not survive processing. By helping to regulate gut pH, strengthen the intestinal barrier, and support immune cells, postbiotics offer a scientifically backed, next-generation approach to keeping your pet’s gut and overall health in balance.

Don’t Forget Hydration and Exercise

When it comes to your pet’s gut health, diet and supplements get a lot of attention, but hydration and movement are just as important. Water plays a crucial role in digestion by helping break down food, move it smoothly through the digestive tract, and keep stools soft and easy to pass. Without enough water, your dog or cat may become constipated or experience sluggish digestion, which can lead to discomfort and reduced nutrient absorption. An easy way to ensure your pet gets enough water to support healthy digestion is by feeding high-moisture foods such as gently cooked, raw frozen, and canned foods.

Exercise is just as essential. Regular physical activity helps stimulate muscle contractions in the intestines, a process known as peristalsis, which keeps food moving at a healthy pace through the digestive system. This is known as gut motility, and it helps prevent issues like bloating, constipation, or excessive gas. In dogs, studies have shown that moderate exercise can improve the diversity of the gut microbiome, which supports better overall digestion and immune health.¹⁵

Overall

Your pet’s gut health is the cornerstone of their overall well-being, impacting everything from digestion and nutrient absorption to immunity, skin health, and even emotional balance. By focusing on gut-friendly practices like feeding a highly digestible, nutrient-rich diet, adding prebiotics, probiotics, and postbiotics, and ensuring adequate hydration and exercise, you’re doing more than improving their digestion, you’re supporting their body and mind from the inside out. Gut health is not just a trend; it’s a science-backed approach to helping pets live longer, happier, and more comfortable lives. Whether your dog or cat is struggling with digestive issues or you’re simply looking to optimize their health, taking steps to nourish their microbiome is one of the most meaningful things you can do as a pet parent.

References

1. Schmitz, S. and Suchodolski, J., 2016. Understanding the canine intestinal microbiota and its modification by pro‐, pre‐and synbiotics–what is the evidence?. Veterinary medicine and science, 2(2), pp.71-94.
2. Belkaid, Y. and Hand, T.W., 2014. Role of the microbiota in immunity and inflammation. Cell, 157(1), pp.121-141.
3. Turner, J.R., 2009. Intestinal mucosal barrier function in health and disease. Nature reviews immunology, 9(11), pp.799-809.
4. Buffie, C.G. and Pamer, E.G., 2013. Microbiota-mediated colonization resistance against intestinal pathogens. Nature Reviews Immunology, 13(11), pp.790-801.
5. Furusawa, Y., Obata, Y., Fukuda, S., Endo, T.A., Nakato, G., Takahashi, D., Nakanishi, Y., Uetake, C., Kato, K., Kato, T. and Takahashi, M., 2013. Commensal microbe-derived butyrate induces the differentiation of colonic regulatory T cells. Nature, 504(7480), pp.446-450.
6. Flint, H.J., Scott, K.P., Louis, P. and Duncan, S.H., 2012. The role of the gut microbiota in nutrition and health. Nature reviews Gastroenterology & hepatology, 9(10), pp.577-589.
7. O’Hara, A.M. and Shanahan, F., 2006. The gut flora as a forgotten organ. EMBO reports, 7(7), pp.688-693.
8. Suchodolski, J.S., 2011. Intestinal microbiota of dogs and cats: a bigger world than we thought. Veterinary Clinics: Small Animal Practice, 41(2), pp.261-272.
9. Mondo, E., Barone, M., Soverini, M., D’amico, F., Cocchi, M., Petrulli, C., Mattioli, M., Marliani, G., Candela, M. and Accorsi, P.A., 2020. Gut microbiome structure and adrenocortical activity in dogs with aggressive and phobic behavioral disorders. Heliyon, 6(1).
10. Sribnick, E.A., Kigerl, K.A. and Popovich, P.G., 2023. The Microbiome and the Central Nervous System. In Youmans and Winn Neurological Surgery: Volumes 1-4, 8th Edition (pp. 213-216). Elsevier.
11. Sacoor, C., Marugg, J.D., Lima, N.R., Empadinhas, N. and Montezinho, L., 2024. Gut‐Brain Axis Impact on Canine Anxiety Disorders: New Challenges for Behavioral Veterinary Medicine. Veterinary Medicine International, 2024(1), p.2856759.
12. Middelbos, I.S., Vester Boler, B.M., Qu, A., White, B.A., Swanson, K.S. and Fahey Jr, G.C., 2010. Phylogenetic characterization of fecal microbial communities of dogs fed diets with or without supplemental dietary fiber using 454 pyrosequencing. PloS one, 5(3), p.e9768.
13. Kuzmuk, K.N., Swanson, K.S., Tappenden, K.A., Schook, L.B. and Fahey Jr, G.C., 2005. Diet and age affect intestinal morphology and large bowel fermentative end-product concentrations in senior and young adult dogs. The Journal of nutrition, 135(8), pp.1940-1945.
14. Aguilar-Toalá, J.E., Garcia-Varela, R., Garcia, H.S., Mata-Haro, V., González-Córdova, A.F., Vallejo-Cordoba, B. and Hernández-Mendoza, A., 2018. Postbiotics: An evolving term within the functional foods field. Trends in food science & technology, 75, pp.105-114.
15. Estaki, M., Pither, J., Baumeister, P., Little, J.P., Gill, S.K., Ghosh, S., Ahmadi-Vand, Z., Marsden, K.R. and Gibson, D.L., 2016. Cardiorespiratory fitness as a predictor of intestinal microbial diversity and distinct metagenomic functions. Microbiome, 4(1), p.42.