Dogs and humans more similar than we think; Even our gut microbiomes are alike!

Has anyone ever told you that you look like your dog? Well, dogs and humans may be more similar than we previously thought! Even your gut may be just like your dogs!

We have lived alongside dogs for many years now. At least 20,000 years and probably a lot longer. Dogs have become extremely important to humans, both as working compatriots and as faithful companions. Yet, we still don’t really know how or why dogs were domesticated.

Believe it or not, the importance of the dog and their similarity to us may be explained by understanding our gut microbiomes.

What are gut microbiomes?

A microbiome is a community of microorganisms, such as bacteria, fungi and viruses, that inhabit particular environments. Gut microbiomes live, as the name suggests in our digestive systems. Microbiome research is an emerging field of science, looking into how these microorganisms affect our health.

*Photo from The development of the gut microbiome*

How do gut microbiomes influence us?

Gut microbes influence their hosts in many ways. Our microbiota modulates the impact of our diet, ultimately influencing our physical and mental health. Changes in microbiome are related to stress in humans and stress, anxiety, and depression-related behaviour in mice.

A recent study* has investigated the similarity of the dog microbiome to that of humans. Similarities were found between dogs breeds (Retrievers and Beagles were tested) and also with the human gut microbiome. Our gut microbiome is more similar to the dog gut microbiome than those of pigs or mice, animals that have traditionally been used to study human health. This suggests that we may be more similar to our canine companions than we originally thought.

Domestication and evolution of dogs and humans

A second study, comparing dogs to wolves and foxes, discovered the bacterial diversity was similar between the dog and wolf but significantly higher in the fox, indicating that foxes have a different and more diverse diet than the two Canis species. The microbiome composition varied both geographically and between species, with the differing red fox samples reflecting their distinct evolutionary history.

Dogs were among the first animals to be domesticated by humans. We have shared our lives and our food resources with them during our entire histories together. This is likely to have contributed to our gut microbiota developing along similar lines.

Finding out more about the dog microbiome

Study of our microbiome has so much potential for knowledge of our evolutionary history and for future health improvements. Study of the dog microbiome has now entered citizen science project such as the study of the dog biome. Researchers will be examing dog poo to develop better diagnostics and design effective therapies to help dogs with digestive disorders.

Future of human and dog microbiome research

Understanding the dog microbiome may help with all sorts of canine disorders. Obesity, for instance, is a growing problem (pardon the pun!) in the dog world. Owners can restrict their dog’s calorie intake but this often leads to feelings of guilt (those hungry looks!) and non-compliance.

A high protein-low carbohydrate diet, known to help in weight loss while maintaining muscle strength, was fed to two groups of dogs; one overweight and the other lean. The gut microbiome changed in the overweight dog group but not significantly in the lean group. Similar results have been found in humans too. The lean dog microbiome is, apparently, far more robust, probably contributing to their ability to stay lean.

You may not like to think about this but faecal microbiota transplants – yes, taking poo and transplanting into less-healthy individuals has shown positive results in humans. Perhaps similar procedures could help with dog obesity?

So, you never know, our dog’s guts may be the answer to keeping we humans healthy and slim!

I may not look too much like my dog but it is comforting, perhaps, to know that our guts are alike!