Plant-based high-fiber dog food leads to changes in a dog's gut, and that's very good news. A randomized, double-blind study from 2025 shows that dogs on well-formulated plant-based diets produce more of the type of metabolic products known as a sign of healthy fiber digestion (Liversidge et al., 2025). Below, we delve deeper into what exactly was studied and what benefits this can have for your dog!
What exactly was studied?
Researchers from the University of Guelph followed a total of 61 dogs for 12 weeks. All dogs first ate the same meat-based food for 4 weeks. After that, it was randomly and double-blind determined which dogs switched to a plant-based food and which dogs continued to eat the meat-based food. At the end of the 12-week study, the researchers analyzed the feces using NMR spectroscopy, a technique that precisely measures metabolic products (Liversidge et al., 2025).
A total of 66 different substances were measured. In the dogs that continued to eat the meat-based food, only 2 of the 66 changed. In the dogs that switched to the plant-based food, there was a change in 46 of the 66. That's a significant difference, and it shows that a dog's intestines truly function differently on a plant-based diet.
What positive changes did the researchers observe?
The most significant change is that after 12 weeks, dogs on the plant-based food had more acetic acid (acetate) and propanoic acid (propionate) in their feces than dogs on the meat-based food, as well as more sugar metabolites (Liversidge et al., 2025). These are all substances released when gut bacteria ferment fiber.
That was a very positive change and something you want to see in your dog. Acetate and propionate belong to a group of substances called short-chain fatty acids. These fatty acids serve as an energy source for the cells of the intestinal wall itself and play an important role in maintaining the integrity of the intestinal barrier (Macfarlane & Macfarlane, 2003). More fiber fermentation therefore means more nutrition for the intestinal wall itself, which is incredibly important.
The reason these beneficial substances are more prevalent in plant-based food is that the plant-based test food in this study contained more soluble fiber than the meat-based food: 10.9 grams per 100 grams versus 2.1 grams for the meat-based food (Liversidge et al., 2025). Soluble fibers are precisely the type of fiber that gut bacteria can ferment best. This explains why the shift towards fermentation was so clear.
What should you consider when reading this research?
It is important to be aware that not all plant-based diets are equally effective in terms of fiber content. The researchers deliberately designed the plant-based food for this study and the meat-based food in a special way so that both were almost identical in protein, fat, and calories. However, the feed sources and fiber content differed: the plant-based food contained barley, oats, quinoa, and dried yeast, among other ingredients, while the meat-based food included rice, oatmeal, and pea fiber (Liversidge et al., 2025). It is therefore important for manufacturers of plant-based food to pay close attention to the type and amount of fiber in the food.
What does this mean for VerdaDog's nutrition?
This study supports our choice, which we have considered important from the outset when formulating our food: consciously opting for fiber-rich and easily fermentable ingredients. Examples include beets and flaxseed, both sources of fiber. If you are curious about the composition of our dry food, you can view it here. Read more about how we try to operate as sustainably as possible. If you have another question, you can always check our FAQ page or contact us.
Frequently Asked Questions (with answers!)
Is more fermentation in the gut always good?
Increased fermentation of fibers into short-chain fatty acids such as acetate and propionate is generally considered beneficial and important, as these substances provide energy to the intestinal wall and contribute to an intact intestinal barrier (Macfarlane & Macfarlane, 2003). With a gradual transition of 10 to 14 days to the new food, this process goes smoothly.
Does the bacterial composition in my dog's gut also change?
In the study by Liversidge et al. (2025), changes in bacterial composition remained limited, while metabolic products clearly shifted. Thus, the function of the gut flora changed more than its composition.
Should I gradually accustom my dog to plant-based food?
A gradual transition of 10 to 14 days is generally recommended for any food change, plant-based or not, to allow the intestines time to adjust to the new fiber composition. That is why we believe it is important that you always build this up gradually during this period.
Do the positive effects apply to all plant-based dog foods?
No. The researchers themselves emphasize that this result is specific to the recipe they tested, which has a high proportion of soluble fibers (Liversidge et al., 2025). The choice and ratio of fiber sources in a recipe determine the effect, not merely the fact that the food is plant-based.
Literature
Liversidge, B. D., Dodd, S. A. S., Adolphe, J. L., Gomez, D. E., Blois, S. L., & Verbrugghe, A. (2025). The fecal metabolomic signature of a plant-based (vegan) diet compared to an animal-based diet in healthy adult client-owned dogs. Journal of Animal Science, 103, skaf054. https://doi.org/10.1093/jas/skaf054
Macfarlane, S., & Macfarlane, G. T. (2003). Regulation of short-chain fatty acid production. Proceedings of the Nutrition Society, 62(1), 67–72. https://doi.org/10.1079/PNS2002207
About the author
David is the founder of VerdaDog. He grew up with a dog that struggled with allergies, which made him think about how he could prevent that with his own dog. He himself has been eating a plant-based diet for over ten years, and that interest in nutrition, for himself and his dog, forms the basis of VerdaDog. This article is based on peer-reviewed research. David does not claim veterinary or scientific expertise and always refers to a veterinarian for medical advice.
