Canine behavioral problems like anxiety and aggression can have many causes, and an out-of-balance microbiome may be one of them.
Source: Animal Wellness Magazine
ALL of us have a microbiome...it is the term used to describe the vast ecosystem of bacteria, fungi and viral organisms that live within the bodies of all other living organisms, including you and your dog. Our microbe populations actually far exceed the number of our cells. In fact, the number of microbial organisms living in just the intestinal environment is ten times greater than the number of cells in the host’s body!
The link between canine aggression and gut microbes
A new groundbreaking study at the University of Oregon shows a clear link between aggressive behavior in dogs and the microbes that live in their guts. The study analyzed a population of similar-breed rescued dogs in a shelter setting, and compared evaluations of behavior with microbiome status via a series of fecal tests. While this study could not distinguish the exact relationship between cause and effect, it reveals that the gut microbiome may contribute to aggression or its severity, and that manipulation of the microbiome, via probiotics or dietary changes, may modify behavior.
The results also suggest that analyzing the canine gut microbiome may have some predictive value in the diagnosis of aggressive behavior conditions. However, it is not yet fully understood if both aggressive behavior and the gut microbiome are similarly affected by other variables such as inflammation or cortisol levels (which are elevated by chronic stress).
Another recent study, reported in Science Direct (January 2020), evaluated gut microbiome and adrenal gland activity in dogs with aggression and fear-related behavioral issues. The study evaluated the connections between the dog’s gut microbiome and the central nervous system, and discussed the potential for using probiotic interventions aimed at restoring a balance for mitigating behavioral disorders. The researchers also found that long-term stress scenarios do influence gut microbiome composition.
More research is needed to decipher the precise cause and effect relationships between canine behavioral disorders and the gut microbiome.
Bacteria in the gut communicate with the brain
Gut bacteria make chemicals that communicate with the brain through the nerves and hormones — this connection is called the gut-brain axis. In fact, it is now known that many key chemicals and hormones used by the brain and nervous system, such as serotonin, dopamine and GABA, are produced in the gut.
Serotonin impacts mood and anxiety, and has actually been termed the “happy chemical” because it contributes to emotional well-being, while low levels of serotonin have been associated with depression. It is estimated that 70% of serotonin is made in the gut.
Dopamine is involved in motor function, mood, decision-making, and the control of other hormones. Reports estimate that about 50% of dopamine is produced in the gastrointestinal tract by enteric neurons and intestinal cells.
GABA regulates stress, anxiety and sleep patterns, and is known to be modulated by bacteria in the gut microbiome.
In summary, there is growing interest in the connection between dog behaviour and their diets, gut health and microbiome status.
“While I recommend working with a behavioral trainer on issues of aggression and anxiety, we have seen many cases of improved behavior after the rebalancing the gut microbiome,” says microbial ecologist and Animal Biome founder, Holly Ganz, PhD. “I am excited and encouraged by the current research into the relationship between the gut microbiome and behavior, and am optimistic that manipulations of the microbiome through diet and fecal transplants may one day help manage anxiety or aggression in companion animals.”
