By: Sara Ondrako, Certified Canine Behavior Professional
Did you know that the microbiome in the human body is home to more living organisms than we have cells in our body? Research has shown a connection between the microbiome in the human body and our personality traits. Learning more about the microorganisms that live within us in our body's ecosystem has helped us better understand so many things about ourselves — including our personalities and mental ailments we may be prone to.
Bacteria is one of the most common living organisms, not just in the human body but also in the bodies of our furry friends. Like in humans, these tiny gut-dwellers can even indicate predispositions to anxiety and other mental health issues based on the bacterial population in the gut.
In this article, we're going to get a little nerdy by diving into the role gut bacteria play in our dogs' behavior and overall health, how to determine if your dog's gut microbiome may be off, how different bacteria affect your dog, and how to effectively use different types of supplemental bacteria and nutrition to help keep your dog's gut bacteria happy and healthy.
The Role of Gut Microbiota in Behavior
You may be wondering how tiny, microscopic organisms in your dog’s digestive tract can affect the brain.
The brain and the gut are connected through what is known as the blood/brain axis, also referred to as the blood/brain barrier. Think of it as a road that connects the brain and the gut in which messengers travel back and forth, delivering information. The bacteria in the gut send messages to the brain through this roadway, regulating the neurotransmitters (messengers). In the brain, messages are received through the neurotransmitters and responded to along the same roadway.
Not only is the communication between the gut and the brain bidirectional, but the messages transferred each way affect metabolism, your dog’s immune system, and intestinal inflammation and even play a role in neurological functions that help us better understand brain ailments such as Canine Cognitive Dysfunction and epilepsy. While it is clear how syndromes like epilepsy and Cognitive Dysfunction Syndrome can affect behavior, it is also affected by changes in the immune system, inflammation, toxins, and more. So gut bacteria has both a direct and indirect effect on behavior.
Understanding the Gut Microbiome Composition
The gut microbiome is a diverse ecosystem comprised of trillions of microorganisms, including bacteria, viruses, fungi, and other microbes. In dogs, just as in humans, the composition of this microbiome can impact behavior based on the ratios of the organisms living within an individual dog.
Research has revealed that the types and abundance of bacteria residing in the gut play a crucial role in modulating a dog's mood, temperament, and behavior. The diversity and makeup of the bacterial population are impacted by many factors, such as stress in the environment, adequate and diverse nutrition, fiber intake, traumatic events, whether your dog nursed from their mother or was bottle-fed, whether they were delivered naturally or by cesarian section, and so on. The microbiota population begins forming before your dog is born and continues to fluctuate the more they interact with the environment.
How Gut Bacteria Influence Mood and Behavior
The microorganisms inhabiting the gut produce a variety of compounds and metabolites that can influence neurotransmitters, such as serotonin and dopamine, which are known to regulate mood and behavior. Roughly 90% of serotonin is produced in the gastrointestinal tract and secreted by bacteria such as Candida, Escheria Coli, and Streptococcus. Serotonin helps modulate mood, sleep, relaxation, and calmness and affects how well food moves through the digestive tract.
When the balance of gut bacteria is disrupted, it can produce harmful metabolites, which may negatively affect a dog's mental state. Conversely, a healthy and diverse gut microbiome can support the production of beneficial compounds that promote a positive mood and behavior.
In some studies, dogs tested with dog aggression, selectivity, and other forms of aggression compared to dogs without aggression have shown a significant difference in the gut microbiome population. These results mean that we may be able to predict the likelihood of certain aggressive behaviors before they even occur. While the science is exciting, it is still new, and more research is needed to determine which bacterial populations are connected to aggressive behaviors and how to correct those populations appropriately.
The Impact of a Balanced vs. Imbalanced Microbiota
A balanced gut microbiota, characterized by a rich diversity of bacterial species, contributes to physiological (normal bodily functions) and mental well-being. On the other hand, dysbiosis, also known as an imbalance in the gut, can contribute to behavioral issues and other health concerns.
Studies have linked dysbiosis in dogs to conditions like anxiety, aggression, and compulsive behaviors. Therefore, maintaining a harmonious gut microbiota is crucial for a dog's mental and emotional well-being.
Anxiety, Stress, and Gut Health — the Chicken, the Egg — or Both?
Anxiety is a common behavioral problem in dogs, and emerging evidence suggests that the gut microbiome can play a significant role in its development or existence. When the gut microbiota is imbalanced, it can lead to chronic inflammation and an overactive stress response, both of which are associated with anxiety.
Furthermore, certain species of gut bacteria can produce neurotransmitters like GABA (gamma-aminobutyric acid) that have calming effects on the brain. An unhealthy gut microbiome may lead to a deficiency in these calming compounds, contributing to anxiety-related behaviors in dogs.
While we know that dysbiosis can contribute to these changes in the brain, it's often challenging to nail down whether the imbalance in the gut contributed to the development of anxiety or stress or whether the anxiety or stress led to the imbalance in the gut. Though some cases may be complex to discern where the problem started in this vicious cycle, some direct contributors to dysbiosis include stress-induced changes, prenatal influence, inflammation, pain, and nutritional influence.
Stress-Induced Changes in Gut Microbiota
Stress and anxiety can disrupt the balance of the gut microbiota. The release of stress hormones like cortisol can alter the composition of gut bacteria, leading to gut imbalance. Additionally, gut function may be disrupted when your dog changes their eating behaviors, such as going on a hunger strike, becoming a picky eater, eating things they usually would not, developing stress colitis (diarrhea related to stress), or even nausea. These symptoms can lead to further disruption of the gut microbiome, and, as you may have guessed — gut imbalances worsen stress.
Inflammation, Immunity, and Behavior
Gut Inflammation and Its Connection to Behavior
Chronic gut inflammation, often linked to an imbalanced microbiome, can have notable effects on behavior. Inflammation can trigger pro-inflammatory cytokines (cells secreted by the immune system) that alter the permeability of the blood/brain barrier (the ability for molecules to travel into and out of the barrier). The openness created means that molecules that affect the brain can enter more quickly, possibly leading to depression, anxiety, and even memory loss.
Immune Response Modulation Through Gut Health
The gut microbiota plays a notable role in immune system functions. A healthy gut microbiome can help modulate immune responses, reducing the risk of inflammatory conditions that may negatively impact behavior. Conversely, an imbalanced microbiota can lead to a dysregulated immune system, potentially exacerbating behavioral problems.
The intricate ways our body weaves into the functions and lives of the microorganisms living within is fascinating. Even a life-threatening condition, Gastric Dilation and Volvulus (GDV), where the dog’s stomach flips, most commonly in giant breed dogs like Great Danes, can be connected to the gut bacteria and the immune system. Immune genes may play a role in predisposition to GDV, and those immune genes can alter the gut microbiome.
Implications for Behavior-Related Disorders
Understanding the connection between gut health, inflammation, and immunity opens up new avenues for addressing behavior-related disorders in dogs. Targeted interventions to restore gut balance and reduce inflammation complement traditional dog behavior modification and training methods to provide more well-rounded and encompassing solutions for these challenges.
Nutritional Impact: Diet, Digestion, and Behavior
The Relationship Between Diet Quality and Gut Health
While we can't control what happened while our little fluffy love muffins were still baking to perfection in Mom's uterus, we can control our dog's nutrition, which can tremendously impact the microbiome's health.
Diet plays a fundamental role in shaping the gut microbiome. The nutrients and compounds found in a dog's diet can either support a healthy gut microbiota or disrupt its balance. High-quality, well-balanced diets with adequate fiber and nutrients can promote the growth of beneficial gut bacteria.
When we feed our dogs, we also feed the bacteria in their gut. A common argument is that a "natural" diet for domesticated dogs would mirror the diet of their wolf ancestors — raw meat without vegetables or grains. “Grain-free” has become a very marketable buzzword in the dog food industry, but, unfortunately, this diet can essentially starve good bacteria in the gut, which differ from the bacteria found in the gut of wild wolves, leaving the bad bacteria to thrive. Domesticated dogs, believed to be from a common ancestor of the wolf, have developed omnivorous abilities (meaning they eat and use plants and animals in the body for energy), whereas wolves are strictly carnivores.
Gut bacteria are part of the family unit in both us and dogs. The next time you hand your pup a plump frozen green bean or a slice of carrot, you are also feeding the bacteria in their gut!
Nutrients That Support a Healthy Gut and Balanced Behavior
Certain nutrients, such as prebiotics, fiber, and omega-3 fatty acids, support a healthy gut microbiome. These dietary elements can improve behavior by promoting good gut health and reducing inflammation.
Common Dietary Contributors to Gut-Related Behavior Issues
Scientists are still investigating the effects of specific ingredients on the populations of bacterial species in the gut. Though we don't have it nailed down perfectly yet, a few common disruptive foods are known to alter the gut microbiome in a potentially harmful way. These are generally diets high in processed foods, sugars, and low-quality ingredients.
Food allergies or intolerances can also lead to gastrointestinal discomfort, affecting a dog's mood and behavior from changes within the bacterial populations.
Improving Gut Health for Positive Behavior Changes
Food Choices Matter
Fresh food diets aren't just the most popular dog food fad; they significantly increase the diversity and health of the gut microbiome — and even the microbiome on the skin! Not all fresh food diets are created equal, so it does help to consult a Veterinary Nutritionist or select a fresh food that a Board Certified Veterinary Nutritionist has formulated.
Recently, more dried kibble companies have been adding probiotics to their diets, claiming it helps maintain a healthy gut balance. However, because probiotics are not regulated, this statement is not subject to FDA standards and guidelines. Thus, it is misleading. Most bacterial strains can only tolerate being heated up to 130 degrees Fahrenheit before they die. Most kibble is processed under high heat that reaches temperatures up to 280 degrees Fahrenheit. By the time the kibble makes it to your dog’s digestive system, it's a bacterial graveyard.
This is also why, when feeding a probiotic supplement, you want to look for a product that's made in the right format. Native Pet's Probiotic Powder was specifically formulated with the sensitivity of probiotic strains in mind; the probiotic strains are more likely to stay alive in a powder format than going through an extrusion process like kibble does.
Raw food diets have become increasingly popular; however, these diets should be used with caution and under the guidance of a Veterinary Nutritionist, especially if choosing to go the DIY route.
There are many pros and cons to the different types of feeding options out there for dogs, and each dog's gut microbiome is unique to them. This means their nutritional requirements will also vary greatly, depending on what nutrients they need, if weight management is recommended, and underlying conditions or specific requirements.
The Role of Probiotics, Prebiotics, and Synbiotics in Your Dog's Gut Health
Probiotics are beneficial live bacteria or microflora that can be introduced into a dog's diet to promote a healthy gut microbiome. These supplements can help restore balance to the gut by increasing the population of beneficial bacteria. Probiotics have shown promise in reducing anxiety and improving behavior in dogs.
Prebiotics are non-digestible fibers in certain foods that nourish beneficial bacteria in the intestines. Including prebiotic-rich foods in your pet’s diet in appropriate quantities, such as chicory root, oats, pumpkin, banana, barley, and Jerusalem artichoke, can support a balanced microbiome and potentially contribute to improved behavior.
While we associate probiotics with health and benefits, not all probiotics are helpful for behavior. Recent compilations of studies (known collectively as a metastudy) have shown that the bacteria in some probiotic supplements, such as Lactobacillus casei, can actually increase anxiety in dogs.
Balancing food ingredients and the microbiome can be tricky, and weeding through the sea of supplements available to make the job easier can be confusing since they aren't regulated by the Food and Drug Administration (FDA). Adding Pumpkin Powder and Synbiotics is an easy way to inclusively support gut and anal gland function and make those beneficial bacteria happy. Synbiotics are a mixture of probiotics and prebiotics together, such as Native Pet Probiotics, which contains inulin from Jerusalem Artichokes in addition to several helpful strains of probiotics.
Consulting With Veterinarians for Tailored Dietary Recommendations
When addressing behavior issues or overall gut health and the microbiome, your best friend to tackle the job with knowledge and expertise is a Board Certified Veterinary Nutritionist. If your pup is experiencing severe behavior concerns, they may enlist the help of a Board Certified Veterinary Behaviorist to ensure that both your nutrition and behavior modification plans will help your dog overcome their troubling behavior.
Veterinary Behaviorists and Veterinary Nutritionists are experts with the most education on their respective topics. They can provide personalized dietary recommendations based on a dog's needs, considering age, breed, environmental stressors, training, and existing health conditions.
Research Advancements in Gut-Brain Axis Studies
As our understanding of the gut-brain axis continues to evolve, ongoing research holds promise for more targeted interventions to address behavior management in dogs. Scientists are exploring new ways to optimize gut health through dietary strategies and probiotics to achieve positive behavior changes.
Take a Holistic Approach to Dog Wellness by Including Gut Health
Addressing the gut microbiome and altering it is considered a holistic approach. Holistic veterinarians and experts recognize and take into account a whole-body perspective. This means including and considering all options that will benefit your dog, such as natural remedies and medical interventions when treating dogs.
There's an intricate connection between physical and behavioral health, and taking a holistic approach inclusive of the whole dog opens up the ability to recruit multiple systems within the body to solve a health or behavioral problem, including the gut.
Nurturing Gut Health for a Happier, Healthier Dog
The link between gut health and behavior in dogs is a complex and fascinating area of research. The gut microbiome's influence on mood, stress, inflammation, and immunity highlights its critical role in shaping a dog's behavior and overall well-being.
There's so much yet unknown about how to use the information we've learned about the canine gut microbiome in terms of helping dogs with behavior challenges. While we may not have treatment plans down to a science yet, we know that a healthy gut microbiome is linked to optimal mental and physical function and that a gut in dysbiosis (unbalanced) can be linked to psychological and physical ailments, everything from diarrhea to anxiety.
Taking a proactive approach to your dog’s digestive health by providing an appropriate diet, incorporating probiotics and prebiotics as needed, and seeking veterinary guidance can make for a happy and healthy dog.
Ultimately, the connection between gut health and behavior underscores the importance of a collaborative approach between dog owners and veterinarians. By working together, we can provide the best environment for our canine companions inside and out.
For more information and tips on your pet’s health, check out the Native Pet blog.