The neuropharmacology of the ketogenic diet

Gut Microbiome, Diet and Depression: Literature Review of Microbiological, Nutritional and Neuroscientific Aspects

PURPOSE OF REVIEW

This review explores the intricate relationships among the gut microbiota, dietary patterns, and mental health, focusing specifically on depression. It synthesizes insights from microbiological, nutritional, and neuroscientific perspectives to understand how the gut-brain axis influences mood and cognitive function.

RECENT FINDINGS

Recent studies underscore the central role of gut microbiota in modulating neurological and psychological health via the gut-brain axis. Key findings highlight the importance of dietary components, including probiotics, prebiotics, and psychobiotics, in restoring microbial balance and enhancing mood regulation. Different dietary patterns exhibit a profound impact on gut microbiota composition, suggesting their potential as complementary strategies for mental health support. Furthermore, mechanisms like tryptophan metabolism, the HPA axis, and microbial metabolites such as SCFAs are implicated in linking diet and microbiota to depression. Clinical trials show promising effects of probiotics in alleviating depressive symptoms. This review illuminates the potential of diet-based interventions targeting the gut microbiota to mitigate depression and improve mental health. While the interplay between microbial diversity, diet, and brain function offers promising therapeutic avenues, further clinical research is needed to validate these findings and establish robust, individualized treatment strategies.

Dietary fiber content in clinical ketogenic diets modifies the gut microbiome and seizure resistance in mice

The gut microbiome modulates the anti-seizure effects of the ketogenic diet, but how specific dietary formulations differentially modify the gut microbiome in ways that impact seizure outcome is poorly understood. We find that medical ketogenic infant formulas vary in macronutrient ratio, fat source, and fiber content and differentially promote resistance to 6-Hz seizures in mice. Dietary fiber, rather than fat ratio or source, drives substantial metagenomic shifts in a model human infant microbial community. Addition of fiber to a fiber-deficient ketogenic formula restores seizure resistance, and supplementing protective formulas with excess fiber potentiates seizure resistance. By screening 13 fiber sources and types, we identify metagenomic responses in the model community that correspond with increased seizure resistance. Supplementing with seizure-protective fibers enriches microbial genes related to queuosine biosynthesis and preQ0 biosynthesis and decreases genes related to sucrose degradation and TCA cycle, which are also seen in seizure-protected mice that are fed fiber-containing ketogenic formulas. This study reveals that different formulations of ketogenic diets, and dietary fiber content in particular, differentially impact seizure outcome in mice, likely by modifying the gut microbiome. Understanding interactions between diet, microbiome, and host susceptibility to seizures could inform novel microbiome-guided approaches to treat refractory epilepsy.

Exploring the potential of the ketogenic diet in autism spectrum disorder: metabolic, genetic, and therapeutic insights

Current treatment approaches for Autism spectrum disorder (ASD) primarily focus on symptom management rather than addressing underlying dysfunctions. The ketogenic diet (KD), a high-fat, low-carbohydrate diet inducing nutritional ketosis, has shown promise in treating epilepsy and may offer therapeutic benefits for ASD by modulating metabolic and neuroprotective pathways. This review examined the potential impact of KD on underlying mechanisms in ASD. While evidence from human studies on underlying mechanisms is limited, animal research has shown a large overlap of mechanisms modulated by KD and dysfunctions in ASD. As such, targeting multiple disrupted pathways at once, KD presents a potential multifaceted treatment approach for ASD. However, more evidence from human studies is needed on the effectiveness of KD in the modulation of underlying dysfunctions in ASD. Additionally, precision medicine approaches could help identify individuals who would benefit most from the intervention, potentially extending its use to other psychiatric conditions with similar metabolic patterns. Consequently, KD interventions might show the potential to induce a drastic paradigm shift in understanding and treating ASD.

Human gut microbiome, diet, and mental disorders

Diet is one of the most important external factor shaping the composition and metabolic activities of the gut microbiome. The gut microbiome plays a crucial role in host health, including immune system development, nutrients metabolism, and the synthesis of bioactive molecules. In addition, the gut microbiome has been described as critical for the development of several mental disorders. Nutritional psychiatry is an emerging field of research that may provide a link between diet, microbial function, and brain health. In this study, we have reviewed the influence of different diet types, such as Western, Mediterranean, vegetarian, and ketogenic, on the gut microbiota composition and function, and their implication in various neuropsychiatric and psychological disorders.

Noradrenergic Projections from the Locus Coeruleus to the Medial Prefrontal Cortex Enhances Stress Coping Behavior in Mice Following Long-Term Intermittent Fasting

Intermittent fasting has been shown to alleviate stress, anxiety, and depressive symptoms. Although noradrenaline, also known as norepinephrine (NE), is implicated in stress regulation, the dynamics of NE release and the associated neural pathways during stress coping behaviors in fasting mice remain poorly understood. In this study, we employed the forced swimming test (FST) to evaluate the effects of intermittent fasting on stress coping behavior in mice. Our results demonstrate that mice subjected to long-term intermittent fasting exhibited significantly more active coping behaviors in the FST compared to control mice. In contrast, acute fasting did not produce similar effects. Using the fluorescent GRAB-NE sensor to measure NE release with sub-second temporal resolution during the FST, we found that intermittent fasting modulates the locus coeruleus-medial prefrontal cortex (LC-mPFC) pathway, which underlies these behavioral adaptations. Moreover, chemogenetic activation of LC-mPFC projections strongly promoted active coping in the FST. These findings suggest that enhanced LC-mPFC activity mediates the increased active coping behavior observed in fasting mice. This study provides new insights into the neural mechanisms through which intermittent fasting may ameliorate depressive-like behaviors, offering potential therapeutic targets for stress-related disorders.

Element Changes Occurring in Brain Point at the White Matter Abnormalities in Rats Exposed to the Ketogenic Diet During Prenatal Life

A large number of clinical studies demonstrate that the ketogenic diet (KD) may be an effective approach to the reduction of epileptic seizures in children and adults. Such dietary therapy could also help pregnant women with epilepsy, especially since most antiseizure drugs have teratogenic action. However, there is a lack of medical data, considering the safety of using KD during gestation for the progeny. Therefore, we examined the influence of KD used prenatally in rats on the elemental composition of the selected brain regions in their offspring. For this purpose, synchrotron radiation-induced X-ray fluorescence (SR-XRF) microscopy was utilized, and elements such as P, S, K, Ca, Fe, and Zn were determined. Moreover, to verify whether the possible effects of KD are temporary or long-term, different stages of animal postnatal development were taken into account in our experiment. The obtained results confirmed the great applicability of SR-XRF microscopy to track the element changes occurring in the brain during postnatal development as well as those induced by prenatal exposure to the high-fat diet. The topographic analysis of the brains taken from offspring of mothers fed with KD during pregnancy and appropriate control individuals showed a potential influence of such dietary treatment on the brain levels of elements such as P and S. In the oldest progeny, a significant reduction of the surface of brain areas characterized by an increased P and S content, which histologically/morphologically correspond to white matter structures, was noticed. In turn, quantitative elemental analysis showed significantly decreased levels of Fe in the striatum and white matter of 30-day-old rats exposed prenatally to KD. This effect was temporary and was not noticed in adult animals. The observed abnormalities may be related to the changes in the accumulation of sphingomyelin and sulfatides and may testify about disturbances in the structure and integrity of the myelin, present in the white matter.

Therapeutic ketogenic diet as treatment for anorexia nervosa

Anorexia nervosa (AN) is a severe psychiatric disorder. However, we lack neurobiological models and interventions to explain and treat the core characteristics of food restriction, feeling fat, and body size overestimation. Research has made progress in understanding brain function involved in the pathophysiology of AN, but translating those results into biological therapies has been challenging. Studies have suggested that metabolic factors could contribute to developing and maintaining AN pathophysiology. Here, we describe a neurobiological model for why using a therapeutic ketogenic diet could address key alterations in brain function in AN and prevent the desire for weight loss and associated eating disorder-specific symptoms. This translational model is based on animal studies and human data and integrates behavioral traits, brain neural energy metabolism, and neurotransmitter function. Pilot data indicate that the intervention can dramatically reduce eating and body-related fears, although larger studies across illness stages still need to be conducted.

Dietary fiber content in clinical ketogenic diets modifies the gut microbiome and seizure resistance in mice

The gut microbiome is emerging as an important modulator of the anti-seizure effects of the classic ketogenic diet. However, many variations of the ketogenic diet are used clinically to treat refractory epilepsy, and how different dietary formulations differentially modify the gut microbiome in ways that impact seizure outcome is poorly understood. We find that clinically prescribed ketogenic infant formulas vary in macronutrient ratio, fat source, and fiber content and also in their ability to promote resistance to 6-Hz psychomotor seizures in mice. By screening specific dietary variables for their effects on a model human infant microbial community, we observe that dietary fiber, rather than fat ratio or source, drives substantial metagenomic shifts. Addition of dietary fiber to a fiber-deficient ketogenic formula restores seizure resistance, and supplementing protective ketogenic formulas with excess dietary fiber further potentiates seizure resistance. By screening 13 fiber sources and types, we identify distinct subsets of metagenomic responses in the model human infant microbial community that correspond with increased seizure resistance in mice. In particular, supplementation with seizure-protective fibers enriches microbial representation of genes related to queuosine biosynthesis and preQ0 biosynthesis and decreases representation of microbial genes related to sucrose degradation, which is also seen in seizure-protected mice that are fed fiber-containing ketogenic infant formulas. Overall, this study reveals that different formulations of clinical ketogenic diets, and dietary fiber content in particular, differentially impact seizure outcome in mice, likely through modification of the gut microbiome. Understanding interactions between dietary components of the ketogenic diet, the gut microbiome, and host susceptibility to seizures could inform novel microbiome-guided approaches to treat refractory epilepsy.

Long-term ketogenic diet causes hyperlipidemia, liver dysfunction, and glucose intolerance from impaired insulin trafficking and secretion in mice

A ketogenic diet (KD) is a very low-carbohydrate, very high-fat diet proposed to treat obesity and type 2 diabetes. While KD grows in popularity, its effects on metabolic health are understudied. Here we show that, in male and female mice, while KD protects against weight gain and induces weight loss, over long-term, mice develop hyperlipidemia, hepatic steatosis, and severe glucose intolerance. Unlike high fat diet-fed mice, KD mice are not insulin resistant and have low levels of insulin. Hyperglycemic clamp and ex vivo GSIS revealed cell-autonomous and whole-body impairments in insulin secretion. Major ER/Golgi stress and disrupted ER-Golgi protein trafficking was indicated by transcriptomic profiling of KD islets and confirmed by electron micrographs showing a dilated Golgi network likely responsible for impaired insulin granule trafficking and secretion. Overall, our results suggest long-term KD leads to multiple aberrations of metabolic parameters that caution its systematic use as a health promoting dietary intervention.

D-β-hydroxybutyrate stabilizes hippocampal CA3-CA1 circuit during acute insulin resistance

The brain primarily relies on glycolysis for mitochondrial respiration but switches to alternative fuels such as ketone bodies (KBs) when less glucose is available. Neuronal KB uptake, which does not rely on glucose transporter 4 (GLUT4) or insulin, has shown promising clinical applicability in alleviating the neurological and cognitive effects of disorders with hypometabolic components. However, the specific mechanisms by which such interventions affect neuronal functions are poorly understood. In this study, we pharmacologically blocked GLUT4 to investigate the effects of exogenous KB D-β-hydroxybutyrate (D-βHb) on mouse brain metabolism during acute insulin resistance (AIR). We found that both AIR and D-βHb had distinct impacts across neuronal compartments: AIR decreased synaptic activity and long-term potentiation (LTP) and impaired axonal conduction, synchronization, and action potential (AP) properties, while D-βHb rescued neuronal functions associated with axonal conduction, synchronization, and LTP.

The Potential Role of the Ketogenic Diet in Serious Mental Illness: Current Evidence, Safety, and Practical Advice

The ketogenic diet (KD) is a high-fat, low-carbohydrate diet that mimics the physiological state of fasting. The potential therapeutic effects in many chronic conditions have led to the gaining popularity of the KD. The KD has been demonstrated to alleviate inflammation and oxidative stress, modulate the gut microbiota community, and improve metabolic health markers. The modification of these factors has been a potential therapeutic target in serious mental illness (SMI): bipolar disorder, major depressive disorder, and schizophrenia. The number of clinical trials assessing the effect of the KD on SMI is still limited. Preliminary research, predominantly case studies, suggests potential therapeutic effects, including weight gain reduction, improved carbohydrate and lipid metabolism, decrease in disease-related symptoms, increased energy and quality of life, and, in some cases, changes in pharmacotherapy (reduction in number or dosage of medication). However, these findings necessitate further investigation through larger-scale clinical trials. Initiation of the KD should occur in a hospital setting and with strict care of a physician and dietitian due to potential side effects of the diet and the possibility of exacerbating adverse effects of pharmacotherapy. An increasing number of ongoing studies examining the KD's effect on mental disorders highlights its potential role in the adjunctive treatment of SMI.

D-ꞵ-hydroxybutyrate stabilizes hippocampal CA3-CA1 circuit during acute insulin resistance

The brain primarily relies on glycolysis for mitochondrial respiration but switches to alternative fuels such as ketone bodies (KBs) when less glucose is available. Neuronal KB uptake, which does not rely on glucose transporter 4 (GLUT4) or insulin, has shown promising clinical applicability in alleviating the neurological and cognitive effects of disorders with hypometabolic components. However, the specific mechanisms by which such interventions affect neuronal functions are poorly understood. In this study, we pharmacologically blocked GLUT4 to investigate the effects of exogenous KB D-ꞵ-hydroxybutyrate (D-ꞵHb) on mouse brain metabolism during acute insulin resistance (AIR). We found that both AIR and D-ꞵHb had distinct impacts across neuronal compartments: AIR decreased synaptic activity and long-term potentiation (LTP) and impaired axonal conduction, synchronization, and action potential properties, while D-ꞵHb rescued neuronal functions associated with axonal conduction, synchronization, and LTP.

Effect of Ketogenic Diet on Obesity and Other Metabolic Disorders: Narrative Review

Obesity is defined as an abnormal or excessive accumulation of fat that increases the burden of different chronic diseases in the population. It has reached epidemic proportions and is a major risk factor for a variety of diseases, including hypertension, cardiovascular disease, type 2 diabetes, dyslipidaemia, atherosclerosis, and some malignancies. Weight gain is a result of excessive energy intake compared to energy expenditure (energy loss from metabolism and physical exercise). A ketogenic diet has a more useful effect on obesity than other diets. A ketogenic diet is a low-carbohydrate, high-fat, moderate-protein diet that induces the production of ketone bodies by mimicking the breakdown of a fasting state. The mechanism behind the ketogenic diet is still unknown, although it obviously helps people with obesity lose weight. Several pathways for the ketogenic diet effect on weight loss have been hypothesized by researchers, including reduced appetite due to effects on appetite control hormones and a possible direct appetite suppressant action of ketone bodies; reduced lipogenesis and increased lipolysis; greater metabolic efficiency; and increased metabolic costs.

Effects of the ketogenic diet on cognition: a systematic review

INTRODUCTION

Ketogenic diet (KD) therapy has been used as a dietary intervention in drug-resistant epilepsy for several years. Research currently suggests that KD therapy may carry neuroprotective and cognition enhancing effects for individuals with non-epileptic conditions as well as for healthy individuals. Therefore, KD may have potential as a non-invasive, nutritional treatment approach for difficult to manage conditions such as neurodegenerative illnesses or mood disorders. The aim of this review is to summarize the available evidence on ketogenic interventions and the resulting cognitive outcomes.

MATERIALS AND METHODS

The paper was based on PRISMA 2020 guidelines. The search was conducted in June 2021 on the following databases: CENTRAL, PubMed, EMBASE, PsycInfo, Web of Science. The search yielded 2014 studies, of which 49 were included.

RESULTS

There were 22 animal studies assessing murine models and 27 studies on humans. The primary indications in these studies were epileptic conditions, neurodegenerative disorders, cognitive impairment, and healthy populations.

DISCUSSION

Administration of KD seems to confer cognitive-enhancing effects in areas such as working memory, reference memory and attention. Studies found that KD treatment in animals has the potential to alleviate age-related cognitive decline. Over 80% of the 27 human studies reported a favourable effect of intervention, and none reported a detrimental effect of KD. While these findings suggest that KD may improve the functioning of certain cognitive domains, definitive conclusions were limited by studies with small sample sizes, the absence of controls and randomization, and the lack of objective measures of cognition.

Novel therapeutic strategies in glioma targeting glutamatergic neurotransmission

High grade gliomas carry a poor prognosis despite aggressive surgical and adjuvant approaches including chemoradiotherapy. Recent studies have demonstrated a mitogenic association between neuronal electrical activity and glioma growth involving the PI3K-mTOR pathway. As the predominant excitatory neurotransmitter of the brain, glutamate signalling in particular has been shown to promote glioma invasion and growth. The concept of the neurogliomal synapse has been established whereby glutamatergic receptors on glioma cells have been shown to promote tumour propagation. Targeting glutamatergic signalling is therefore a potential treatment option in glioma. Antiepileptic medications decrease excess neuronal electrical activity and some may possess anti-glutamate effects. Although antiepileptic medications continue to be investigated for an anti-glioma effect, good quality randomised trial evidence is lacking. Other pharmacological strategies that downregulate glutamatergic signalling include riluzole, memantine and anaesthetic agents. Neuromodulatory interventions possessing potential anti-glutamate activity include deep brain stimulation and vagus nerve stimulation - this contributes to the anti-seizure efficacy of the latter and the possible neuroprotective effect of the former. A possible role of neuromodulation as a novel anti-glioma modality has previously been proposed and that hypothesis is extended to include these modalities. Similarly, the significant survival benefit in glioblastoma attributable to alternating electrical fields (Tumour Treating Fields) may be a result of disruption to neurogliomal signalling. Further studies exploring excitatory neurotransmission and glutamatergic signalling and their role in glioma origin, growth and propagation are therefore warranted.

Mitochondrial dysfunction: A fatal blow in depression

Mitochondria maintain the normal physiological function of nerve cells by producing sufficient cellular energy and performing crucial roles in maintaining the metabolic balance through intracellular Ca2+ homeostasis, oxidative stress, and axonal development. Depression is a prevalent psychiatric disorder with an unclear pathophysiology. Damage to the hippocampal neurons is a key component of the plasticity regulation of synapses and plays a critical role in the mechanism of depression. There is evidence suggesting that mitochondrial dysfunction is associated with synaptic impairment. The maintenance of mitochondrial homeostasis includes quantitative maintenance and quality control of mitochondria. Mitochondrial biogenesis produces new and healthy mitochondria, and mitochondrial dynamics cooperates with mitophagy to remove damaged mitochondria. These processes maintain mitochondrial population stability and exert neuroprotective effects against early depression. In contrast, mitochondrial dysfunction is observed in various brain regions of patients with major depressive disorders. The accumulation of defective mitochondria accelerates cellular nerve dysfunction. In addition, impaired mitochondria aggravate alterations in the brain microenvironment, promoting neuroinflammation and energy depletion, thereby exacerbating the development of depression. This review summarizes the influence of mitochondrial dysfunction and the underlying molecular pathways on the pathogenesis of depression. Additionally, we discuss the maintenance of mitochondrial homeostasis as a potential therapeutic strategy for depression.

Ketogenic diet influence on the elemental homeostasis of internal organs is gender dependent

The ketogenic diet (KD) is a low-carbohydrate and high-fat diet that gains increasing popularity in the treatment of numerous diseases, including epilepsy, brain cancers, type 2 diabetes and various metabolic syndromes. Although KD is effective in the treatment of mentioned medical conditions, it is unfortunately not without side effects. The most frequently occurring undesired outcomes of this diet are nutrient deficiencies, the formation of kidney stones, loss of bone mineral density, increased LDL (low-density lipoprotein) cholesterol levels and hormonal disturbances. Both the diet itself and the mentioned adverse effects can influence the elemental composition and homeostasis of internal organs. Therefore, the objective of this study was to determine the elemental abnormalities that appear in the liver, kidney, and spleen of rats subjected to long-term KD treatment. The investigation was conducted separately on males and females to determine if observed changes in the elemental composition of organs are gender-dependent. To measure the concentration of P, S, K, Ca, Fe, Cu, Zn and Se in the tissues the method of the total reflection X-ray fluorescence (TXRF) was utilized. The obtained results revealed numerous elemental abnormalities in the organs of animals fed a high-fat diet. Only some of them can be explained by the differences in the composition and intake of the ketogenic and standard diets. Furthermore, in many cases, the observed anomalies differed between male and female rats.

A Comprehensive Review of Emerging Trends and Innovative Therapies in Epilepsy Management

Epilepsy is a complex neurological disorder affecting millions worldwide, with a substantial number of patients facing drug-resistant epilepsy. This comprehensive review explores innovative therapies for epilepsy management, focusing on their principles, clinical evidence, and potential applications. Traditional antiseizure medications (ASMs) form the cornerstone of epilepsy treatment, but their limitations necessitate alternative approaches. The review delves into cutting-edge therapies such as responsive neurostimulation (RNS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS), highlighting their mechanisms of action and promising clinical outcomes. Additionally, the potential of gene therapies and optogenetics in epilepsy research is discussed, revealing groundbreaking findings that shed light on seizure mechanisms. Insights into cannabidiol (CBD) and the ketogenic diet as adjunctive therapies further broaden the spectrum of epilepsy management. Challenges in achieving seizure control with traditional therapies, including treatment resistance and individual variability, are addressed. The importance of staying updated with emerging trends in epilepsy management is emphasized, along with the hope for improved therapeutic options. Future research directions, such as combining therapies, AI applications, and non-invasive optogenetics, hold promise for personalized and effective epilepsy treatment. As the field advances, collaboration among researchers of natural and synthetic biochemistry, clinicians from different streams and various forms of medicine, and patients will drive progress toward better seizure control and a higher quality of life for individuals living with epilepsy.

Ketogenic diet for mood disorders from animal models to clinical application

Mood disorders such as major depressive disorder (MDD) and bipolar disorder (BD) are often resistant to current pharmacological treatment. Therefore, various alternative therapeutic approaches including diets are, therefore, under investigation. Ketogenic diet (KD) is effective for treatment-resistant epilepsy and metabolic diseases, however, only a few clinical studies suggest its beneficial effect also for mental disorders. Animal models are a useful tool to uncover the underlying mechanisms of therapeutic effects. Women have a twice-higher prevalence of mood disorders but very little is known about sex differences in nutritional psychiatry. In this review, we aim to summarize current knowledge of the sex-specific effects of KD in mood disorders. Ketone bodies improve mitochondrial functions and suppress oxidative stress, inducing neuroprotective and anti-inflammatory effects which are both beneficial for mental health. Limited data also suggest KD-induced improvement of monoaminergic circuits and hypothalamus-pituitary-adrenal axis-the key pathophysiological pathways of mood disorders. Gut microbiome is an important mediator of the beneficial and detrimental effects of diet on brain functioning and mental health. Gut microbiota composition is affected in mood disorders but its role in the therapeutic effects of different diets, including KD, remains poorly understood. Still little is known about sex differences in the effects of KD on mental health as well as on metabolism and body weight. Some animal studies used both sexes but did not find differences in behavior, body weight loss or gut microbiota composition. More studies, both on a preclinical and clinical level, are needed to better understand sex-specific effects of KD on mental health.

Microbiota-gut-brain axis and ketogenic diet: how close are we to tackling epilepsy?

The microbiota-gut-brain axis refers to the intricate bidirectional communication between commensal microorganisms residing in the digestive tract and the central nervous system, along neuroendocrine, metabolic, immune, and inflammatory pathways. This axis has been suggested to play a role in several neurological disorders, such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, and epilepsy, paving the way for microbiome-based intervention strategies for the mitigation and treatment of symptoms. Epilepsy is a multifaceted neurological condition affecting more than 50 million individuals worldwide, 30% of whom do not respond to conventional pharmacological therapies. Among the first-hand microbiota modulation strategies, nutritional interventions represent an easily applicable option in both clinical and home settings. In this narrative review, we summarize the mechanisms underlying the microbiota-gut-brain axis involvement in epilepsy, discuss the impact of antiepileptic drugs on the gut microbiome, and then the impact of a particular dietary pattern, the ketogenic diet, on the microbiota-gut-brain axis in epileptic patients. The investigation of the microbiota response to non-pharmacological therapies is an ever-expanding field with the potential to allow the design of increasingly accessible and successful intervention strategies.

Dietary Supplementation with Milk Lipids Leads to Suppression of Developmental and Behavioral Phenotypes of Hyperexcitable Drosophila Mutants

Dietary modifications often have a profound impact on the penetrance and expressivity of neurological phenotypes that are caused by genetic defects. Our previous studies in Drosophila melanogaster revealed that seizure-like phenotypes of gain-of-function voltage-gated sodium (Nav) channel mutants (paraShu, parabss1, and paraGEFS+), as well as other seizure-prone "bang-sensitive" mutants (eas and sda), were drastically suppressed by supplementation of a standard diet with milk whey. In the current study we sought to determine which components of milk whey are responsible for the diet-dependent suppression of their hyperexcitable phenotypes. Our systematic analysis reveals that supplementing the diet with a modest amount of milk lipids (0.26% w/v) mimics the effects of milk whey. We further found that a minor milk lipid component, α-linolenic acid, contributed to the diet-dependent suppression of adult paraShu phenotypes. Given that lipid supplementation during the larval stages effectively suppressed adult paraShu phenotypes, dietary lipids likely modify neural development to compensate for the defects caused by the mutations. Consistent with this notion, lipid feeding fully rescued abnormal dendrite development of class IV sensory neurons in paraShu larvae. Overall, our findings demonstrate that milk lipids are sufficient to ameliorate hyperexcitable phenotypes in Drosophila mutants, providing a foundation for future investigation of the molecular and cellular mechanisms by which dietary lipids modify genetically induced abnormalities in neural development, physiology, and behavior.

Metabolic markers of short and long-term exogenous DL-beta-hydroxybutyrate supplementation in episodic migraine patients: an exploratory analysis of a randomized-controlled-trial

Background: Emerging findings propose that the pathophysiology of migraine may be associated with dysfunctional metabolic mechanisms. Recent findings suggest that migraine attacks are a response to the cerebral energy deficit, and ingestion of ketone bodies stabilizes the generation of a migraine attack. Based on these findings, ketone body supplementation is postulated as a prophylactic treatment approach to restore cerebral metabolism deficiency. Metabolic markers are unexplored after exogenous ketone body supplementation in episodic migraineurs. Therefore, the present single-arm uncontrolled explorative analysis evaluated blood ketone body and glucose concentration after short and long-term 6 g exogenous DL-Mg-Ca-beta-hydroxybutyrate (DL-βHB) supplementation. Methods: The presented data are part of the MigraKet randomized-control cross-over clinical trial of 41 episodic migraineurs (Number NCT03132233). Patients were given a single dose of 6 g DL-βHB. Ketone body and glucose blood concentration were assessed before intake, 20, and 40 min after DL-βHB intake. Ketone body, glucose concentration and glycated hemoglobin values were evaluated after 12 weeks of 18 g DL-βHB ingestion (total dose), taken three times daily (6g/dose; 3x/day). Linear models explored the association between the ketone body and glucose levels. Results: Ketone body concentration increased within-group to a mean of 0.46 (0.30) mmol/L after 40 min post- DL-βHB supplementation [estimate = 0.24 mmol/L, CI = (0.20.0.27), p < 0.01]. This within-group increase of ketone body concentration did not change after repeated daily intake of DL-βHB supplementation over 12 weeks [estimate = 0.00 mmol/L, CI = (-0.03.0.04), p = 0.794]. DL-βHB intake significantly reduced blood glucose concentration within-group from a mean baseline of 4.91 (0.42) mmol/L to 4.75 (0.47) mmol/L 40 min post-DL-βHB supplementation [estimate = -0.16 mmol/L, CI = (-0.15, 0.03), p < 0.01]. Repeated DL-βHB supplementation for 12 weeks showed no change within-group in acute ketone bodies concentration [estimate = 0.00 mmol/L, CI = (-0.03.0.04), p = 0.794] and in the HbA1c value [estimate = 0.02, CI = (-0.07.0.11), p = 0.69]. Conclusion: A single dose of 6 g DL-βHB significantly elevated blood ketone bodies and decreased blood glucose concentration within-group in episodic migraineurs. Long-term DL-βHB supplementation for 12 weeks showed no effect within-group on acute ketone body concentration and had not impact on HbA1c. The elevation of the ketone body concentration was moderate, indicating that nutritional ketosis was not reached. Therefore, a dose higher than 6 g of DL-βHB is required to reach the nutritional level of ketosis. ClinicalTrials.gov Identifier: NCT03132233.

Anticonvulsant Profile of Selected Medium-Chain Fatty Acids (MCFAs) Co-Administered with Metformin in Mice in Acute and Chronic Treatment

In contrast to the other components of the medium-chain triglycerides ketogenic diet (MCT KD), i.e., caprylic acid (CA8), a comprehensive evaluation of caproic (CA6) and lauric acids' (CA12) properties in standard chemical and electrical seizure tests in mice has not yet been performed. We investigated their effects in maximal electroshock seizure threshold (MEST), 6 Hz seizure threshold and intravenous (i.v.) pentylenetetrazole (PTZ) seizure tests. Since ketone body production can be regulated by the activation of 5'AMP-activated protein kinase (AMPK), we hypothesized that metformin (an AMPK activator) enhance ketogenesis and would act synergistically with the fatty acids to inhibit convulsions. We assessed the effects of acute and chronic co-treatment with metformin and CA6/CA8 on seizures. CA6 and CA12 (p.o.) increased seizure threshold in the 6 Hz seizure test. CA6 at the highest tested dose (30 mmol/kg) developed toxicity in several mice, impaired motor performance and induced ketoacidosis. Acute and chronic co-treatment with metformin and CA6/CA8 did not affect seizure thresholds. Moreover, we observed the pro-convulsive effect of the acute co-administration of CA8 (5 mmol/kg) and metformin (100 mg/kg). Since this co-treatment was pro-convulsive, the safety profile and risk/benefit ratio of MCT KD and metformin concomitant therapy in epileptic patients should be further evaluated.

Ketogenic Diet as a Promising Non-Drug Intervention for Alzheimer’s Disease: Mechanisms and Clinical Implications

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that is mainly characterized by cognitive deficits. Although many studies have been devoted to developing disease-modifying therapies, there has been no effective therapy until now. However, dietary interventions may be a potential strategy to treat AD. The ketogenic diet (KD) is a high-fat and low-carbohydrate diet with adequate protein. KD increases the levels of ketone bodies, providing an alternative energy source when there is not sufficient energy supply because of impaired glucose metabolism. Accumulating preclinical and clinical studies have shown that a KD is beneficial to AD. The potential underlying mechanisms include improved mitochondrial function, optimization of gut microbiota composition, and reduced neuroinflammation and oxidative stress. The review provides an update on clinical and preclinical research on the effects of KD or medium-chain triglyceride supplementation on symptoms and pathophysiology in AD. We also detail the potential mechanisms of KD, involving amyloid and tau proteins, neuroinflammation, gut microbiota, oxidative stress, and brain metabolism. We aimed to determine the function of the KD in AD and outline important aspects of the mechanism, providing a reference for the implementation of the KD as a potential therapeutic strategy for AD.

Metabolic Effects of Ketogenic Diets and Their Utilization in Obesity Management: A Systematic Review

A ketogenic diet (KD), more commonly called a "keto" diet, is a dietary regime that focuses on reducing carbohydrates and replacing them with healthy fats. It has proven to improve health and has resurfaced as a trendy weight loss method. Keto, in simple terms, works by mimicking starvation and forcing the body to utilize and deplete fat as its core energy source instead of its usual source of glucose (sugar). More technically, it gives ignition to a process called 'ketosis'. Ketosis is the process of generation of ketone bodies when the liver metabolizes fat. There are several versions of this diet, each of which addresses slightly variable issues as well as hones unique requirements. Individuals will require a unique combination of fat, carbohydrates, and protein depending on their genetic and physical makeup. The advantages and hazards of using the KD to manage obesity are examined in this review of the literature.

The effects of ketogenic diet on beta-hydroxybutyrate, arachidonic acid, and oxidative stress in pediatric epilepsy

The exact mechanism of a ketogenic diet (KD) as a suitable alternative therapeutic approach for drug-resistant epilepsy (DRE) in alleviating seizures is not yet fully understood. The present study aimed to evaluate the role of the KD in reducing oxidative stress (OS) by increasing the ketone body beta-hydroxybutyrate (BHB) and Arachidonic acid (ARA), an essential polyunsaturated fatty acid, as a possible mechanism in relieving seizure attacks in children with DRE. Forty children with refractory epilepsy were included in the present study. The serum levels of BHB, ARA, and OS markers, malondialdehyde (MDA), and 8-hydroxyl-deoxyguanosine (8-OHdG), were evaluated in children with DRE and compared before and after the three months of KD therapy. Thirty-four of 40 included children could complete the three-month KD therapy. Twenty-one (61.76%) patients had more than a 50% reduction in seizure frequency after the KD (responders). The remaining 13 children were considered non-responders to the diet. The serum levels of ARA and BHB significantly (p < 0.05) increased after the KD therapy. The serum levels of OS parameters MDA and 8-OHdG before the diet therapy were significantly (p < 0.05) higher than those after the administration. The serum levels of BHB and MDA after the KD therapy in the responders were respectively higher and lower than those in the non-responders (p < 0.001). Ketogenic diet might reduce brain OS by increasing BHB and ARA. The role of BHB in diminishing OS and seizure might be more remarkable than ARA.

Brain glutamate and sleep efficiency associations following a ketogenic diet intervention in individuals with Alcohol Use Disorder

Background

We previously showed that ketogenic diet (KD) was effective in curbing alcohol withdrawal and craving in individuals with alcohol use disorder (AUD). We hypothesized that the clinical benefits were due to improvements in sleep. To test this, we performed a secondary analysis on the KD trial data to (1) examine the effects of KD on total sleep time (TST) and sleep quality and (2) investigate the association between KD-induced alterations in cingulate glutamate concentration and changes in TST and sleep quality.

Methods

AUD individuals undergoing alcohol detoxification were randomized to receive KD (n=19) or standard American diet (SA; n=14) for three weeks. TST was measured weekly by self-report, GENEActive sleep accelerometer, and X4 Sleep Profiler ambulatory device. Sleep quality was assessed using subjectively ratings of sleep depth and restedness and Sleep Profiler (Sleep Efficiency [%]). Weekly ¹H magnetic resonance spectroscopy scans measured cingulate glutamate levels.

Results

TST was lower in KD than SA and increased with effect of time. Sleep depth, restedness, and Sleep Efficiency improved with time, but exhibited no effect of diet. In KD and SA combined, week 1 cingulate glutamate levels correlated positively with Sleep Efficiency, but not with TST.

Conclusions

Although cingulate glutamate levels correlated positively with Sleep Efficiency in week 1, KD-induced glutamate elevation did not produce significant sleep improvements. Rather, KD was associated with lower TST than SA. Given the well-established associations between sleep and alcohol relapse, longer follow up assessment of KD's impact on sleep in AUD is warranted.

β-hydroxybutyrate reduces reinstatement of cocaine conditioned place preference through hippocampal CaMKII-α β-hydroxybutyrylation

Studies have shown the therapeutic effects of a ketogenic diet (KD) on epilepsy, but the effect of a KD on drug reinstatement is largely unclear. This study aims to investigate whether KD consumption possesses therapeutic potential for cocaine reinstatement and the molecular mechanism. We find that a KD significantly reduces cocaine-induced reinstatement in mice, which is accompanied by a markedly elevated level of β-hydroxybutyrate (β-OHB), the most abundant ketone body, in the hippocampus. The underlying mechanism is that β-OHB posttranslationally modifies CaMKII-α with β-hydroxybutyrylation, resulting in significant inhibition of T286 autophosphorylation and downregulation of CaMKII activity. Collectively, our results reveal that β-hydroxybutyrylation is a posttranslational modification of CaMKII-α that plays a critical role in mediating the effect of KD consumption in reducing cocaine reinstatement.

The Metabolic Role of Ketogenic Diets in Treating Epilepsy

Epilepsy is a long-term neurological condition that results in recurrent seizures. Approximately 30% of patients with epilepsy have drug-resistant epilepsy (DRE). The ketogenic diet (KD) is considered an effective alternative treatment for epileptic patients. The aim of this study was to identify the metabolic role of the KD in epilepsy. Ketone bodies induce chemical messengers and alterations in neuronal metabolic activities to regulate neuroprotective mechanisms towards oxidative damage to decrease seizure rate. Here, we discuss the role of KD on epilepsy and related metabolic disorders, focusing on its mechanism of action, favorable effects, and limitations. We describe the significant role of the KD in managing epilepsy disorders.

Cognitive profile of male mice exposed to a Ketogenic Diet

In recent years, nutritional interventions for different psychiatric diseases have gained increasing attention, such as the ketogenic diet (KD). This has led to positive effects in neurological disorders such as Parkinson's disease, addiction, autism or epilepsy. The neurobiological mechanisms through which these effects are induced and the effects in cognition still warrant investigation, and considering that other high-fat diets (HFD) can lead to cognitive disturbances that may affect the results achieved, the main aim of the present work was to evaluate the effects of a KD to determine whether it can induce such cognitive effects. A total of 30 OF1 male mice were employed to establish the behavioral profile of mice fed a KD by testing anxiety behavior (Elevated Plus Maze), locomotor activity (Open Field), learning (Hebb Williams Maze), and memory (Passive Avoidance Test). The results revealed that the KD did not affect locomotor activity, memory or hippocampal-dependent learning, as similar results were obtained with mice on a standard diet, albeit with increased anxiety behavior. We conclude that a KD is a promising nutritional approach to apply in research studies, given that it does not cause cognitive alterations.

Does Neuroinflammation Underlie the Cognitive Changes Observed With Dietary Interventions?

Dietary interventions, such as calorie restriction and ketogenic diet, have been extensively studied in ageing research, including in cognitive decline. Epidemiological studies indicate beneficial effects of certain dietary regimes on mental health, including mood disorders and dementia. However, randomised-controlled trials (the gold-standard of evidence-based medicine) on calorie restriction diets and the ketogenic diet have yet to show clinically convincing effects in neuropsychiatric disorders. This review will examine the quality of studies and evidence base for the ketogenic and calorie restriction diets in common neuropsychiatric conditions, collating findings from preclinical experiments, case reports or small clinical studies, and randomised controlled clinical trials. The major cellular mechanisms that mediate the effects of these dietary interventions on brain health include neuroinflammation, neuroprotection, and neuromodulation. We will discuss the studies that have investigated the roles of these pathways and their interactions. Popularity of the ketogenic and calorie restriction diets has grown both in the public domain and in psychiatry research, allowing for informed review of the efficacy, the limitations, and the side effects of these diets in specific patient populations. In this review we will summarise the clinical evidence for these diets in neuropsychiatry and make suggestions to improve clinical translation of future research studies.

Increased Hippocampal Afterdischarge Threshold in Ketogenic Diet is Accompanied by Enhanced Kynurenine Pathway Activity

The efficacy of a ketogenic diet (KD) in controlling seizure has been shown in many experimental and clinical studies, however, its mechanism of action still needs further clarification. The major goal of the present study was to investigate the influence of the commercially available KD and caloric restriction (CR) on the hippocampal afterdischarge (AD) threshold in rats, and concomitant biochemical changes, specifically concerning the kynurenine pathway, in plasma and the hippocampus. As expected, the rats on the KD showed higher AD threshold accompanied by increased plasma β-hydroxybutyrate level compared to the control group and the CR rats. This group presented also lowered tryptophan and elevated kynurenic acid levels in plasma with similar changes in the hippocampus. Moreover, the KD rats showed decreased levels of branched chain amino acids (BCAA) and aromatic amino acids (AAA) in plasma and the hippocampus. No regular biochemical changes were observed in the CR group. Our results are analogous to those detected after single administrations of fatty acids and valproic acid in our previous studies, specifically to an increase in the kynurenine pathway activity and changes in peripheral and central BCAA and AAA levels. This suggests that the anticonvulsant effect of the KD may be at least partially associated with those observed biochemical alternations.

Dopaminergic and glutamatergic biomarkers disruption in addiction and regulation by exercise: a mini review

INTRODUCTION

Drug addiction is associated with disruption of a multitude of biomarkers in various brain regions, particularly in the reward center. The most pronounced are dopaminergic and glutamatergic biomarkers, which are affected at various levels. Neuropathological changes in biomarkers alter the homeostasis of the glutamatergic and dopaminergic nervous systems and promote addiction-associated characteristics such as repeated intake, maintenance, withdrawal, reinstatement, and relapse. Exercise has been shown to have a buffering effect on such biomarkers and reverse the effects of addictive substances.

METHODS

A review of the literature searched in PubMed, examining drug addiction and physical exercise in relation to dopaminergic and glutamatergic systems at any of the three biomarker levels (i.e., neurotransmitter, receptor, or transporter).

RESULTS

We review the collective impact of addictive substances on the dopaminergic and glutamatergic systems and the beneficial effect of exercise in terms of reversing the damage to these systems. We propose future directions, including implications of exercise as an add-on therapy, substance use disorder (SUD) prognosis and diagnosis and designing of optimized exercise and pharmaceutical regimens based on the aforementioned biomarkers.

CONCLUSION

Exercise is beneficial for all types of drug addiction at all stages, by reversing molecular damages caused to dopaminergic and glutamatergic systems.

3-Hydroxybutyrate Ameliorates the Progression of Diabetic Nephropathy

Studies report beneficial effects of 3-hydroxybutyrate (3-OHB) on the treatment of type 2 diabetes and obesity, but the effects of 3-OHB on diabetic nephropathy have not been elucidated. This study was designed to investigate the efficacy and mechanism of 3-OHB against progression of diabetic nephropathy (DN). Mice (db/db) were fed normal chow, high-fat, or ketogenic diets (KD) containing precursors of 3-OHB. Hyperglycemia was determined based on random glucose level (≥250 mg/dL). Fasting blood glucose and body weights were measured once a week. Twenty four-hour urine albumin to creatinine ratio was determined 5 weeks after the differential diet. Energy expenditure was measured 9 weeks after the differential diet. Body weights were significantly lower in the KD group than those in other groups, but no significant differences in fasting blood glucose levels among three groups were observed. Urine albumin to creatinine ratio and serum blood urea nitrogen (BUN) to creatinine ratio in the KD group were significantly lower than in other groups. Histologic and quantitative analysis of mesangial area suggested that KD delayed the progression of DN phenotype in db/db mice. Metabolic cage analysis also revealed that KD increased energy expenditure in db/db mice. In vitro studies with proximal tubular cells revealed that 3-OHB stimulated autophagic flux. 3-OHB increased LC3 I to LC3 II ratio, phosphorylation of AMPK, beclin, p62 degradation, and NRF2 expression. Moreover, we found that 3-OHB attenuated high glucose-induced reactive oxygen species (ROS) levels in proximal tubular cells. In vivo study also confirmed increased LC3 and decreased ROS levels in the kidney of KD mice. In summary, this study shows in both in vivo and in vitro models that 3-OHB delays the progression of DN by augmenting autophagy and inhibiting oxidative stress.

Nutritional Impact on Metabolic Homeostasis and Brain Health

Aging in modern societies is often associated with various diseases including metabolic and neurodegenerative disorders. In recent years, researchers have shown that both dysfunctions are related to each other. Although the relationship is not fully understood, recent evidence indicate that metabolic control plays a determinant role in neural defects onset. Indeed, energy balance dysregulation affects neuroenergetics by altering energy supply and thus neuronal activity. Consistently, different diets to help control body weight, blood glucose or insulin sensitivity are also effective in improving neurodegenerative disorders, dampening symptoms, or decreasing the risk of disease onset. Moreover, adapted nutritional recommendations improve learning, memory, and mood in healthy subjects as well. Interestingly, adjusted carbohydrate content of meals is the most efficient for both brain function and metabolic regulation improvement. Notably, documented neurological disorders impacted by specific diets suggest that the processes involved are inflammation, mitochondrial function and redox balance as well as ATP production. Interestingly, processes involving inflammation, mitochondrial function and redox balance as well as ATP production are also described in brain regulation of energy homeostasis. Therefore, it is likely that changes in brain function induced by diets can affect brain control of energy homeostasis and other brain functions such as memory, anxiety, social behavior, or motor skills. Moreover, a defect in energy supply could participate to the development of neurodegenerative disorders. Among the possible processes involved, the role of ketone bodies metabolism, neurogenesis and synaptic plasticity, oxidative stress and inflammation or epigenetic regulations as well as gut-brain axis and SCFA have been proposed in the literature. Therefore, the goal of this review is to provide hints about how nutritional studies could help to better understand the tight relationship between metabolic balance, brain activity and aging. Altogether, diets that help maintaining a metabolic balance could be key to both maintain energy homeostasis and prevent neurological disorders, thus contributing to promote healthy aging.

A mutation in the neonatal isoform of SCN2A causes neonatal-onset epilepsy

SCN2A (sodium channel 2A) encodes the Nav1.2 channel protein in excitatory neurons in the brain. Nav1.2 is a critical voltage-gated sodium channel of the central nervous system. Mutations in SCN2A are responsible for a broad phenotypic spectrum ranging from autism and developmental delay to severe encephalopathy with neonatal or early infantile onset. SCN2A can be spliced into two different isoforms, a neonatal (6N) and an adult (6A) form. After birth, there is an equal or higher amount of the 6N isoform, protecting the brain from the increased neuronal excitability of the infantile brain. During postnatal development, 6N is gradually replaced by 6A. In an infant carrying the novel SCN2A mutation c.643G > A (p.Ala215Thr) only in the neonatal transcript, seizures started immediately after birth. The clinical presentation evolved from a burst-suppression pattern with 30-50 tonic seizures per day to hypsarrhythmia. The first exome analysis, focusing only on common transcripts, missed the diagnosis and delayed early therapy. A reevaluation including all transcripts revealed the SCN2A variant.

The potential roles of excitatory-inhibitory imbalances and the repressor element-1 silencing transcription factor in aging and aging-associated diseases

Disruptions to the central excitatory-inhibitory (E/I) balance are thought to be related to aging and underlie a host of neural pathologies, including Alzheimer's disease. Aging may induce an increase in excitatory signaling, causing an E/I imbalance, which has been linked to shorter lifespans in mice, flies, and worms. In humans, extended longevity correlates to greater repression of genes involved in excitatory neurotransmission. The repressor element-1 silencing transcription factor (REST) is a master regulator in neural cells and is believed to be upregulated with senescent stimuli, whereupon it counters hyperexcitability, insulin/insulin-like signaling pathway activity, oxidative stress, and neurodegeneration. This review examines the putative mechanisms that distort the E/I balance with aging and neurodegeneration, and the putative roles of REST in maintaining neuronal homeostasis.

Microbiota-gut-brain axis: A novel potential target of ketogenic diet for epilepsy

Ketogenic diet (KD) has been used to the control of seizure for 100 years because it was developed for the treatment of epilepsy in 1921. Based on current research on the microbiota-gut-brain axis to explore the new communication tool between gut bacteria and the brain and the progress of microbiota-gut-brain axis and KD for the treatment of epilepsy, the role of neurotransmitters adenosine and γ-aminobutyric acid in the epileptic brain, we propose that the balance between beneficial and harmful bacteria in the gut microbiota would be a promising target in the future to underlying the working mechanism of KD for epilepsy.

Efficacy and safety of exogenous beta-hydroxybutyrate for preventive treatment in episodic migraine: A single-centred, randomised, placebo-controlled, double-blind crossover trial

BACKGROUND

Several studies propose that brain energy deficit might be partially involved in the pathophysiology of migraine. Previously, studies demonstrated that ketogenic diet causes a substantial reduction in migraine frequency. Since the ketogenic diet is restricting and its adherence is difficult, we proposed to supplement ketone bodies exogenously to provide a prophylactic effect in migraineurs.

AIM

To evaluate the prophylactic effect of exogenous DL-beta-hydroxybutyrate supplementation in episodic migraineurs.

METHODS

A double-blind, placebo-controlled, randomised crossover trial was conducted, involving 41 patients with episodic migraine. Patients were randomised 1:1 into placebo or beta-hydroxybutyrate group before entering the first treatment period. Each treatment period was 12 weeks long, followed by four weeks of washout phase and four weeks of run-in phase before entering into the corresponding second treatment period. The primary endpoint was the number of migraine days in the last four weeks of treatment, adjusted for baseline.

RESULTS

We observed no clinically significant amelioration of migraine frequency or intensity under DL-beta-hydroxybutyrate treatment as compared to placebo regarding number of migraine days (mean difference [95% CI]: -1.1[-5.07, 2.85]), migraine intensity (0-10 VAS: 1.5[-0.8, 3.7]).

CONCLUSION

The selected dose of supplemented exogenous DL-beta-hydroxybutyrate did not demonstrate efficacy in episodic migraineurs.ClinicalTrials.gov Identifier: NCT03132233.

Ketogenic Diet Decreases Alcohol Intake in Adult Male Mice

The classic ketogenic diet is a diet high in fat, low in carbohydrates, and well-adjusted proteins. The reduction in glucose levels induces changes in the body’s metabolism, since the main energy source happens to be ketone bodies. Recent studies have suggested that nutritional interventions may modulate drug addiction. The present work aimed to study the potential effects of a classic ketogenic diet in modulating alcohol consumption and its rewarding effects. Two groups of adult male mice were employed in this study, one exposed to a standard diet (SD, n = 15) and the other to a ketogenic diet (KD, n = 16). When a ketotic state was stable for 7 days, animals were exposed to the oral self-administration paradigm to evaluate the reinforcing and motivating effects of ethanol. Rt-PCR analyses were performed evaluating dopamine, adenosine, CB1, and Oprm gene expression. Our results showed that animals in a ketotic state displayed an overall decrease in ethanol consumption without changes in their motivation to drink. Gene expression analyses point to several alterations in the dopamine, adenosine, and cannabinoid systems. Our results suggest that nutritional interventions may be a useful complementary tool in treating alcohol-use disorders.

The Chemistry of the Ketogenic Diet: Updates and Opportunities in Organic Synthesis

The high-fat, low-carbohydrate (ketogenic) diet has grown in popularity in the last decade as a weight loss tool. Research into the diet’s effects on the body have revealed a variety of other health benefits. The use of exogenous ketone supplements to confer the benefits of the diet without strict adherence to it represents an exciting new area of focus. Synthetic ketogenic compounds are of particular interest that has received very little emphasis and is an untapped area of focus for chemical synthesis. In this review, we summarize the chemical basis for ketogenicity and opportunities for further advancement of the field.

The efficacy comparison of classic ketogenic diet and modified Atkins diet in children with refractory epilepsy: a clinical trial

Dietary therapy has an important role in the therapeutic process in children suffering refractory epilepsy. There are two kinds of dietary therapy which are the most common in children with refractory epilepsy: The classic ketogenic diet (KD) and the modified Atkins diet (MAD). The purpose of the present study was to compare the efficacy, tolerability, and compliance of these two dietary therapies in the children who have refractory epilepsy during 6 months of treatment. From March 2017 to November 2018, 45 children aged 2-15 years who had refractory epilepsy were randomly allocated in KD or MAD group. The intervention period was 6 months in both groups. The frequencies of seizures were determined from parental reports and were compared between the groups. The patients with upper than 50% reduction in seizure frequency were deemed as responders to the diets. Twenty-four patients were assigned to the KD and 11 patients to the MAD. Overall, 45.8% of children treated with the KD and 45.5% of children treated with MAD had over than 50% response to the diet therapies. The difference was not statistically significant (P = 0.437). The MAD was more advantageous regarding better tolerability and fewer side effects. There is not much difference regarding the efficacy between the MAD and classic KD. The MAD with fewer side effects may be more suitable as the first line of dietary therapy in children with refractory epilepsy.

A Ketogenic Diet and the Treatment of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is characterized by stereotyped behavior and deficits in communication and social interaction. There are no curative treatments for children with ASD. The ketogenic diet (KD) is a high-fat, appropriate-protein, and low-carbohydrate diet that mimics the fasting state of the body and is proven beneficial in drug-resistant epilepsy and some other brain diseases. An increasing number of studies demonstrated that a KD improved autistic behavior, but the underlying mechanisms are not known. We reviewed the neuroprotective role of a KD in ASD, which is likely mediated via improvements in energy metabolism, reductions in antioxidative stress levels, control of neurotransmitters, inhibition of the mammalian target of rapamycin (mTOR) signaling pathway, and modulation of the gut microbiota. A KD is likely a safe and effective treatment for ASD.

Ketogenesis and SIRT1 as a tool in managing obesity

Obesity is a serious chronic disease and a public health concern in both developing and developed countries. Managing obesity has been a great challenge for both health care professionals and patients alike. Among the various diet programs aimed at promoting weight loss, the ketogenic diet, a diet high in fat and low in carbohydrates, has been at the forefront recently and its mechanism in weight loss is much debated. Activation of Sirtuin 1 or SIRT1 is able to circumvent various diseases, including metabolic syndrome and obesity and is thought to be a potentially reliable treatment target for both of them. Augmentation of SIRT1 may be carried out using dietary means such as nicotinamide adenine dinucleotide (NAD) supplementation and/or ketogenic diet. Although ketogenic diet may augment SIRT1 activation in people affected by obesity, recent studies have indicated that the relationship between SIRT1 and ketogenesis is unpredictable. The exact circumstances and mechanisms of SIRT1, NAD and ketogenesis in the clinical setting as an intervention tool in managing obesity remained uncertain. Although several recent literatures have documented significant weight-loss following ketogenic diet interventions, there were limitations with regards to duration of trial, choice and the number of trial subjects. Studies investigating the safety of ketogenic diet in the long term, beyond 46 weeks and related mechanism and pathways are still lacking and the sustainability of this diet remains to be determined. This review explores the recent progress on ketogenic diet and its relationships with SIRT1 as a tool in managing obesity and relevant clinical implications.

Ketogenic Diet: Impact on Cellular Lipids in Hippocampal Murine Neurons

Background: The mechanism of action of the ketogenic diet (KD), an effective treatment for pharmacotherapy refractory epilepsy, is not fully elucidated. The present study examined the effects of two metabolites accumulating under KD—beta-hydroxybutyrate (ßHB) and decanoic acid (C10) in hippocampal murine (HT22) neurons. Methods: A mouse HT22 hippocampal neuronal cell line was used in the present study. Cellular lipids were analyzed in cell cultures incubated with high (standard) versus low glucose supplemented with ßHB or C10. Cellular cholesterol was analyzed using HPLC, while phospholipids and sphingomyelin (SM) were analyzed using HPTLC. Results: HT22 cells showed higher cholesterol, but lower SM levels in the low glucose group without supplements as compared to the high glucose groups. While cellular cholesterol was reduced in both ßHB- and C10-incubated cells, phospholipids were significantly higher in C10-incubated neurons. Ratios of individual phospholipids to cholesterol were significantly higher in ßHB- and C10-incubated neurons as compared to controls. Conclusion: Changes in the ratios of individual phospholipids to cholesterol in HT22 neurons suggest a possible alteration in the composition of the plasma membrane and organelle membranes, which may provide insight into the working mechanism of KD metabolites ßHB and C10.

Ketogenic Diet: A Dietary Modification as an Anxiolytic Approach?

Anxiety disorders comprise persistent, disabling conditions that are distributed across the globe, and are associated with the high medical and socioeconomic burden of the disease. Within the array of biopsychosocial treatment modalities—including monoaminergic antidepressants, benzodiazepines, and CBT—there is an unmet need for the effective treatment of anxiety disorders resulting in full remission and recovery. Nutritional intervention may be hypothesized as a promising treatment strategy; in particular, it facilitates relapse prevention. Low-carbohydrate high-fat diets (LCHF) may provide a rewarding outcome for some anxiety disorders; more research is needed before this regimen can be recommended to patients on a daily basis, but the evidence mentioned in this paper should encourage researchers and clinicians to consider LCHF as a piece of advice somewhere between psychotherapy and pharmacology, or as an add-on to those two.

Metabolic Control of Epilepsy: A Promising Therapeutic Target for Epilepsy

Epilepsy is a common neurological disease that is not always controlled, and the ketogenic diet shows good antiepileptic effects drug-resistant epilepsy or seizures caused by specific metabolic defects via regulating the metabolism. The brain is a vital organ with high metabolic demands, and epileptic foci tend to exhibit high metabolic characteristics. Accordingly, there has been growing interest in the relationship between brain metabolism and epilepsy in recent years. To date, several new antiepileptic therapies targeting metabolic pathways have been proposed (i.e., inhibiting glycolysis, targeting lactate dehydrogenase, and dietary therapy). Promising strategies to treat epilepsy via modulating the brain's metabolism could be expected, while a lack of thorough understanding of the role of brain metabolism in the control of epilepsy remains. Herein, this review aims to provide insight into the state of the art concerning the brain's metabolic patterns and their association with epilepsy. Regulation of neuronal excitation via metabolic pathways and antiepileptic therapies targeting metabolic pathways are emphasized, which could provide a better understanding of the role of metabolism in epilepsy and could reveal potential therapeutic targets.

Can change in gut microbiota composition be used as a surrogate marker of treatment efficacy of ketogenic diet in patients with drug-resistant epilepsy?

To answer the question posed in the title of the manuscript, we critically examined the connection between ketogenic diet (KD), gut microbiota (GM), and epilepsy. We conclude that although the evidence for a KD-GM-epilepsy link is fairly robust in rodent epilepsy models, it is very hard to draw meaningful conclusions in humans. The limitations of human studies that have investigated the KD-microbiota-epilepsy relationship include small sample size, a heterogeneous patient population with regard to age and epilepsy type, failure to account for the effect of dietary habits, antiseizure drugs (ASDs) and comedications on GM composition, variability in the KD administered and in the duration of the intervention, and different approaches used in sequencing the microbiome. Although alteration in the GM composition may be a potential indicator of responsiveness/resistance to a KD, we need well-designed randomized case-control and cohort studies involving a large number of a fairly homogenous population of patients with epilepsy adjusted to their habitual dietary habits and region of residence before labeling it as a surrogate marker. Research in this direction may also help us to unravel the mysteries of GM-brain axis not only concerning epilepsy but also in other neurological diseases.