Accruing evidence suggests that gut microbiota help shape normal neural development, brain biochemistry and behavior, and that gut microbiome dysbiosis plays a role in the development or progression of anxiety, cognitive impairment and dementia.1
The gut microbiome affects brain function and behavior, and the brain, in turn, influences the microbiome through bidirectional intercommunication. The term ‘gut-brain axis’ refers to the constant bidirectional communication between the gastrointestinal tract and the brain via the enteric nervous system and the vagus nerve, sympathetic nervous system, hypothalamic-pituitary-adrenal axis, immune system, and microbial metabolites. 1,2
Altering the microbiome via nutritional interventions has the potential to facilitate this cross-talk between the gut and brain, and influence behavior and mood. 2,3 The gut-brain axis plays a key role in the regulation of feeding and glucose homeostasis,2 and therefore may also play an important role in the development of obesity.
An intact microbiome and intestinal barrier are essential for maintaining a healthy gut-brain axis, and gut dysbiosis and intestinal barrier dysfunction have been associated with neuroinflammation.1,2
The microbiome and intestinal barrier are affected by age, and these changes play a role in age-related cognitive impairment and dementia.1,2
Gut health is important for brain health, and gut dysbiosis may increase the risk of cognitive impairment. Therefore, efforts to maintain and preserve the health of the gut microbiome are important, especially in older pets, to protect brain health and cognitive abilities.
Chronic gastrointestinal inflammation can induce anxiety-like behaviors, and the probiotic Bifidobacterium longum NCC3001 (BL999) acts through the gut-brain axis to produce anxiolytic effects.3,4 Up to 70% of behavioral disorders in dogs can be attributed to some form of anxiety.5 The role of the veterinary general practitioner in identifying and treating their patients’ behavior problems – such as anxiety – is a crucial one.6 Pet owners may not recognize all signs of fear and anxiety, or may only reach out once the problem has escalated to the point of crisis.7 In a blinded, crossover study, dogs supplemented with B. longum BL999 were less reactive (as indicated by lower cortisol levels), more calm (as indicated by lower mean heart rates), and potentially in a better emotional state (as indicated by increased heart rate variability) when experiencing anxiety-provoking stimuli versus when they were supplemented with a placebo. In addition, the dogs exhibited significant reduction in some anxious behaviors when supplemented with B. longum BL999 compared to when they were supplemented with placebo.15
The probiotic strain Bifidobacterium longum NCC3001 (BL999) can reduce anxious behaviors, potentially improve emotional state, and help maintain calm behavior in dogs.
The microbiome is a key driver of the response to ketogenic diets in human and rodent studies.16-18
A medium-chain triglyceride-based ketogenic diet significantly reduced seizure frequency,19 reduced ADHD-like behaviors,20 and altered lipid metabolism in dogs with refractory canine idiopathic epilepsy.21
A medium-chain triglyceride (MCT)-based diet provides an additional tool for management of canine idiopathic epilepsy, providing an opportunity to help manage epilepsy through the microbiome and gut-brain axis. More information on MCTs is available in the Brain Conditions section of our site.