If you care about your dog’s health, you’ve probably heard that gut health matters. But until very recently, most of what we knew about the dog gut was borrowed from human research. We knew the gut was important. We just didn’t have a proper map of it.
That changed in January 2026, when researchers published the most detailed picture of the canine gut microbiome we’ve ever had.
Here’s what they found, and what it actually means for your dog.
The study in a nutshell
Researchers at the Waltham Petcare Science Institute, one of the world’s leading centres for companion animal nutrition, collected 501 samples from 107 healthy dogs across the US and Europe. Using advanced DNA sequencing, they identified 982 bacterial strains that had never been catalogued before, 89 entirely new species, and 10 new genera (that’s the classification level above species).
They also pinpointed 240 core bacterial species that make up more than 80% of a healthy dog’s gut.
In short: we now have a proper reference guide for what a healthy dog gut looks like at a level of detail that simply didn’t exist before.
Why this matters for everyday dog owners
You don’t need to memorise bacterial names for this to be relevant. Here’s what it means in practical terms.
We can now spot when something’s off. Before this study, vets and researchers didn’t have a reliable baseline for the healthy canine gut. Now they do. That means when a dog develops digestive issues, skin problems, or behavioural changes linked to gut health, there’s a much clearer picture of what “normal” looks like to compare against.
Better supplements and nutrition are coming. If you know which specific bacteria keep dogs healthy, you can design probiotics and prebiotics that actually support those bacteria, rather than taking a general approach and hoping for the best. The study identified key genera like Sutterella, Collinsella, and Fecalimonas as important players that weren’t even on the radar before.
Dogs aren’t small humans. This is the big one. Read on.
The finding that changes everything
If you’ve looked into gut health for yourself, you’ll probably have come across Akkermansia muciniphila. It’s one of the most talked-about bacteria in human wellness right now, linked to metabolic health and reduced inflammation. You can buy Akkermansia supplements for humans.
The Waltham study found that Akkermansia is essentially absent from the canine gut. Not low. Not rare. Absent.
This is significant because it confirms something that should change how we all think about dog wellness: what works for the human gut doesn’t automatically work for dogs. The canine microbiome has evolved differently, adapted to a different diet and different biology over thousands of years.
It means canine nutrition needs canine science. Not human trends repackaged with a paw print on the label.
The gut-brain connection is real
One of the most exciting areas of current research is the link between gut bacteria and behaviour. A 2025 study published in Scientific Reports found that a specific type of gut bacteria called Blautia was consistently linked to anxiety levels in pet dogs. The researchers could actually predict whether a dog fell into a higher or lower anxiety group based on their gut bacteria alone.
The connection makes sense when you consider that more than 90% of your dog’s serotonin, the chemical most associated with mood regulation, is produced in the gut.
This doesn’t mean gut health is the only factor in behaviour. But it does mean that if your dog struggles with anxiety, reactivity, or settling down, their gut could be part of the picture. It’s still a young field, and researchers are careful to note that more replication is needed. But the direction of travel is clear: the gut isn’t just about digestion.
What this means for choosing a supplement
If you’re thinking about supporting your dog’s gut health, here are three things this research tells us.
Look for canine-specific formulation. Given that the dog gut is fundamentally different from ours, a supplement formulated by people who understand canine nutrition specifically is going to be more relevant than one borrowing from human wellness trends.
Named ingredients matter more than vague labels. “Contains probiotics” tells you very little. The Waltham catalogue identified over 1,000 distinct bacterial strains, each doing different things. A supplement that names its ingredients and explains why they were chosen is more credible than one that doesn’t.
Consistency beats everything. A separate 2025 study confirmed that the healthy canine gut microbiome is stable day to day, which means it responds well to steady, daily support rather than occasional intensive doses. One scoop a day, every day, is exactly the approach the science supports.
What the study doesn’t tell us yet
It’s worth being upfront about the limits. This catalogue maps the healthy canine gut beautifully, but it doesn’t yet explain exactly how each of those 1,000+ strains functions or interacts. It also doesn’t break things down by breed or age in a way that allows truly personalised recommendations. That research is coming, and this catalogue was designed as the foundation for it.
What we do have now is the best map of the canine gut ever created. And in science, a good map is how everything else gets better.
Why we’re sharing this
We referenced this study in our April newsletter because we think it matters for anyone making decisions about their dog’s health. The canine gut microbiome isn’t a buzzword. It’s a real, complex ecosystem influencing your dog’s digestion, immunity, skin, coat, mood, and energy.
At a Dog Person, this kind of research shapes how we think about formulation. The All Rounder was designed with canine-specific gut health in mind: prebiotic fibre, digestive support, formulated by canine nutritionists who understand that dogs need their own science. The more the research advances, the more it validates that approach.
One scoop. Once a day. Under 80p.
Sources cited:
- Waltham catalogue for the canine gut microbiome (2025), Microbiome, Springer Nature: View study
- Gut microbiota composition is related to anxiety and aggression scores in companion dogs (2025), Scientific Reports, Nature: View study
- Limited day-to-day variation in the canine gut microbiome (2025), Frontiers in Veterinary Science: View study
