Metabolic fingerprinting of dogs with idiopathic epilepsy receiving a ketogenic medium-chain triglyceride (MCT) oil

Medium-Chain Triglycerides Supplementation Protects Epilepsy-Associated Behavioral Impairments in a Mouse Model

Presently there has been a growing interest in the development of dietary-based interventions as alternative therapies to combat chronic neurological conditions like epilepsy. Medium-chain triglycerides (MCT) are composed of three fatty acids attached to a glycerol backbone and have shown several beneficial effects in various neurological diseases. The present study investigated MCT supplementation's impact on seizure severity and associated neurobehavioral comorbidities in a pentylenetetrazole (PTZ) mouse kindling model. Mice were administered 35 mg/kg (i.p.) of PTZ every other day for kindling induction. The kindled mice were then subjected to MCT supplementation for over 25 days with seizure scoring at every 5th day following PTZ exposure. Behavioral analysis was initiated at the end of 25 days of the MCT supplementation. After that, lipid peroxidation assay, and, gene and protein expression studies were performed in the isolated hippocampus. MCT significantly decreased seizure severity scores compared to control. The treatment reduced immobility duration in the forced swim and tail suspension tests, indicating a reversal of seizures-associated depression-like behavior. A significant reduction in the percentage of spontaneous alternation was observed in the kindled control group in the T-maze test, which remained unchanged following MCT supplementation in the treated group. Furthermore, no change was observed in the locomotion and anxiety index of the kindled mice supplemented with MCT compared to the control group. In addition, the supplementation attenuated the altered hippocampal lipid peroxidation, and mRNA and protein levels of mTOR and Gsk-3β. The study concluded that MCT supplementation suppresses epileptic seizures and associated depression-like behavior in kindled mice via interacting mTOR and Gsk-3β signaling.

Treatment-Refractory Epilepsy Alimentary Therapy (TREAT): A canine case study

Half of all epilepsy cases in both humans and canines are identified as idiopathic. Of these cases, 30 to 40% remain treatment-refractory to antiepileptic medications. Several human and dog studies have demonstrated low-carbohydrate diets and dietary medium-chain triglyceride (MCT) supplementation are effective for seizure reduction, with some patients achieving a seizure-free status. Recent evidence suggests the gut-brain axis has an important role in the pathology of neurological disease among both humans and dogs. Altered gut microbiota may have a major role in treatment-refractory epilepsy. This case report describes a dog with treatment-refractory epilepsy experiencing cluster seizures triggered by an altered gut microbiome despite therapeutic drug concentrations of multiple agents. Consideration of an underlying gastrointestinal disorder should be investigated in patients with treatment-refractory epilepsy, despite therapeutic concentrations of several antiepileptic medications. Dietary and gastrointestinal health-promoting interventions for epilepsy should also be considered before add-on pharmacotherapy or euthanasia. For difficult epilepsy cases, we suggest exploring the role of a limited-ingredient, low-carbohydrate diet, MCT supplementation, and/or pre/probiotics to augment pharmacotherapeutic strategies. This information may be critically valuable in designing high-quality, diet-based therapies for epileptic dogs. Key clinical message: Gastrointestinal workup, dietary changes to a low-carbohydrate diet, supplementation with MCTs, and addition of pre/probiotics could be considered to augment pharmacotherapeutic strategies in treatmentrefractory epilepsy cases in dogs.

Idiopathic epilepsy in dogs is associated with dysbiotic faecal microbiota

BACKGROUND

The gut microbiota plays a crucial role in modulating various physiological and pathological processes through its metabolites, including short-chain fatty acids (SCFA), which impact immune system development, gastrointestinal health, and brain functions via the gut-brain axis. Dysbiosis, an imbalance in gut microbiota composition, has been linked to neuroinflammatory and neurodegenerative conditions, including epilepsy. In dogs, idiopathic epilepsy has been hypothesized to be influenced by gut microbiota composition, although studies on this association are limited and show inconsistent results. Here, we compared the faecal microbiota of idiopathic epileptic drug-naïve dogs and healthy controls. To this aim, we recruited 19 idiopathic epileptic dogs and 17 healthy controls which met stringent inclusion criteria and characterized their faecal microbiome by 16 S rRNA sequencing.

RESULTS

No significant differences were observed between the two groups regarding age, breed, body condition score, diet, or reproductive status, though males were significantly overrepresented in the idiopathic epileptic group. Epileptic dogs showed a marked reduction in bacterial richness and a trend towards lower evenness (α-diversity) compared to healthy controls, while no differences in community composition (β-diversity) were observed between the two groups. Moreover, a decrease in SCFA-producing bacteria, namely Faecalibacterium, Prevotella, and Blautia, was observed alongside an increase in Escherichia coli, Clostridium perfringens, and Bacteroides in epileptic dogs.

CONCLUSIONS

Idiopathic epileptic dogs exhibit dysbiosis, with reduced bacterial diversity, loss of beneficial genera, and overgrowth of opportunistic pathogens. These alterations in microbiota diversity and composition may contribute to epilepsy via the gut-brain axis, highlighting the need for further research to explore dietary or probiotic interventions targeting gut microbiota modulation as adjunctive therapies for managing epilepsy in dogs.

Putative Role of Adenosine A1 Receptors in Exogenous Ketone Supplements-Evoked Anti-Epileptic Effect

Approximately 30% of patients with epilepsy are drug-refractory. There is an urgent need to elucidate the exact pathophysiology of different types of epilepsies and the mechanisms of action of both antiseizure medication and metabolic therapies to treat patients more effectively and safely. For example, it has been demonstrated that exogenous ketone supplement (EKS)-generated therapeutic ketosis, as a metabolic therapy, may decrease epileptic activity in both animal models and humans, but its exact mechanism of action is unknown. However, it was demonstrated that therapeutic ketosis, among others, can increase adenosine level, which may enhance activity of A1 adenosine receptors (A1Rs) in the brain. It has also been demonstrated previously that adenosine has anti-epileptic effect through A1Rs in different models of epilepsies. Thus, it is possible that (i) therapeutic ketosis generated by the administration of EKSs may exert its anti-epileptic effect through, among other mechanisms, increased adenosine level and A1R activity and that (ii) the enhanced activity of A1Rs may be a necessary anti-epileptic mechanism evoked by EKS administration-generated ketosis. Moreover, EKSs can evoke and maintain ketosis without severe side effects. These results also suggest that the therapeutic application of EKS-generated ketosis may be a promising opportunity to treat different types of epilepsies. In this literature review, we specifically focus on the putative role of A1Rs in the anti-epileptic effect of EKS-induced ketosis.

Urinary neurotransmitter analysis and canine behavior assessment

Behavioral problems are highly prevalent in domestic dogs, negatively affecting the quality of life of dogs and their owners. In humans and dogs, neuropsychological or neurobehavioral disorders can be associated with deviations in various neurotransmitter systems. Previous evidence has revealed correlations between urinary neurotransmitters and various behavioral disorders; however, a causal relationship has not yet been conclusively demonstrated. Non-invasive urinary neurotransmitter analysis may identify specific biomarkers, which enable a more differentiated assessment of canine behavioral disorders in the future and contribute to more effective neuromodulatory treatment decisions and monitoring. This approach could offer new insights into underlying pathomechanisms of canine neurobehavioral disorders. This study assessed urinary neurotransmitter levels and the descriptive behavior profile of 100 dogs using established rating scales (Canine Behavioral Assessment and Research Questionnaire, Attention Deficit Hyperactivity Disorder Rating Scale, Dog Personality Questionnaire, Canine Cognitive Dysfunction Rating Scale), and explored relationships between these variables. No correlation was found between urinary neurotransmitters and the assessed behavior profiles; however, age-, sex- and neuter-related influences were identified. The lack of correlation could be explained by the many confounding factors influencing both behavior and urinary neurotransmitter excretion, including age, sex and neuter status effects, and methodological issues e.g., low discriminatory power between anxiety and aggression in the descriptive behavior evaluation. Urinary neurotransmitter testing could not be validated as a tool for canine behavior evaluation in this study. However, reliable assessment methods with low susceptibility to human biases could be valuable in the future to support behavioral-phenotype diagnoses.