A modified ketogenic gluten-free diet with MCT improves behavior in children with autism spectrum disorder

Ketogenic diet has a positive association with mental and emotional well-being in the general population

OBJECTIVES

A ketogenic diet reduces pathologic stress and improves mood in neurodegenerative and neurodevelopmental disorders. However, the effects of a ketogenic diet for people from the general population have largely been unexplored. A ketogenic diet is increasingly used for weight loss. Research in healthy individuals primarily focuses on the physical implications of a ketogenic diet. It is important to understand the holistic effects of a ketogenic diet, not only the physiological but also the psychological effects, in non-clinical samples. The aim of this cross-sectional study with multiple cohorts was to investigate the association of a ketogenic diet with different aspects of mental health, including calmness, contentedness, alertness, cognitive and emotional stress, depression, anxiety, and loneliness, in a general healthy population.

METHODS

Two online surveys were distributed: cohort 1 used Bond-Lader visual analog scales and Perceived Stress Scale (n = 147) and cohort 2 the Depression Anxiety Stress Scale and revised UCLA Loneliness Scale (n = 276).

RESULTS

A ketogenic diet was associated with higher self-reported mental and emotional well-being behaviors, including calmness, contentedness, alertness, cognitive and emotional stress, depression, anxiety, and loneliness, compared with individuals on a non-specific diet in a general population.

CONCLUSION

This research found that a ketogenic diet has potential psychological benefits in the general population.

Depression and emotional eating in children and adolescents: A systematic review and meta-analysis

Major Depressive Disorder in youth is associated with obesity and adult cardiovascular disease (CVD) risk. Eating in response to emotions (emotional eating) is a potential contributing factor to this association. Although emotional eating is associated with Major Depressive Disorder in adults, findings in children and adolescents are mixed. This systematic review and meta-analysis aims to determine the association between depression and emotional eating in children and adolescents. Systematic searches were conducted in seven databases. Studies were included if the study population had a mean age of ≤18 years and assessed both depression and emotional eating using validated measures. The search generated 12,241 unique studies, of which 37 met inclusion criteria. Random-effects meta-analyses of study outcomes were performed. Thirty-seven studies (26,026 participants; mean age = 12.4 years, SD = 3.1) were included. The mean effect size was significant for both cross-sectional and longitudinal data (Hedges' g = 0.48, p < 0.0001; g = 0.37, p = 0.002, respectively), revealing a positive moderately strong association between depressive symptoms and emotional eating in youth. Among longitudinal studies, the association was stronger when depressive symptoms and emotional eating were assessed using child and adolescent self-report versus parent-report. No studies examined youth with a clinical diagnosis of depression. Meta-analyses revealed that depressive symptoms and emotional eating are positively associated in children and adolescents. However, further research in clinical samples is needed. Results raise the possibility for the importance of emotional eating in the link between depression and early CVD risk, though further examination is required to determine whether emotional eating is a potential treatment target to decrease CVD risk among adolescents with increased depression symptoms.

Ketogenic Diet Induced Shifts in the Gut Microbiome Associate with Changes to Inflammatory Cytokines and Brain-Related miRNAs in Children with Autism Spectrum Disorder

In this interventional pilot study, we investigated the effects of a modified ketogenic diet (KD) on children with autism spectrum disorder (ASD). We previously observed improved behavioral symptoms in this cohort following the KD; this trial was registered with Clinicaltrials.gov (NCT02477904). This report details the alterations observed in the microbiota, inflammation markers, and microRNAs of seven children following a KD for a duration of 4 months. Our analysis included blood and stool samples, collected before and after the KD. After 4 months follow up, we found that the KD led to decreased plasma levels of proinflammatory cytokines (IL-12p70 and IL-1b) and brain-derived neurotrophic factor (BDNF). Additionally, we observed changes in the gut microbiome, increased expression of butyrate kinase in the gut, and altered levels of BDNF-associated miRNAs in the plasma. These cohort findings suggest that the KD may positively influence ASD sociability, as previously observed, by reducing inflammation, reversing gut microbial dysbiosis, and impacting the BDNF pathway related to brain activity.

The impact of ketogenic diet on some metabolic and non-metabolic diseases: Evidence from human and animal model experiments

The ketogenic diet (KD) is recognized as minimum carbohydrate and maximum fat intakes, which leads to ketosis stimulation, a state that is thought to metabolize fat more than carbohydrates for energy supply. KD has gained more interest in recent years and is for many purposes, including weight loss and managing serious diseases like type 2 diabetes. On the other hand, many believe that KD has safety issues and are uncertain about the health drawbacks. Thus, the outcomes of the effect of KD on metabolic and non-metabolic disease remain disputable. The current narrative review aims to evaluate the effect of KD on several diseases concerning the human health. To our best knowledge, the first report aims to investigate the efficacy of KD on multiple human health issues including type 2 diabetes and weight loss, cardiovascular disease, kidney failure and hypertension, non-alcoholic fatty liver, mental problem, oral health, libido, and osteoporosis. The literature searches were performed in Databases, PubMed, Scopus, and web of Science looking for both animal and human model designs. The results heterogeneity seems to be explained by differences in diet composition and duration. Also, the available findings may show that proper control of carbohydrates, a significant reduction in glycemic control and glycated hemoglobin, and weight loss by KD can be an approach to improve diabetes and obesity, hypertension, non-alcoholic fatty liver, PCOS, libido, oral health, and mental problem if isocaloric is considered. However, for some other diseases like cardiovascular disease and osteoporosis, more robust data are needed. Therefore, there is robust data to support the notion that KD can be effective for some metabolic and non-metabolic diseases but not for all of them. So they have to be followed cautiously and under the supervision of health professionals.

Autism spectrum disorders and the gastrointestinal tract: insights into mechanisms and clinical relevance

Autism spectrum disorders (ASDs) are recognized as central neurodevelopmental disorders diagnosed by impairments in social interactions, communication and repetitive behaviours. The recognition of ASD as a central nervous system (CNS)-mediated neurobehavioural disorder has led most of the research in ASD to be focused on the CNS. However, gastrointestinal function is also likely to be affected owing to the neural mechanistic nature of ASD and the nervous system in the gastrointestinal tract (enteric nervous system). Thus, it is unsurprising that gastrointestinal disorders, particularly constipation, diarrhoea and abdominal pain, are highly comorbid in individuals with ASD. Gastrointestinal problems have also been repeatedly associated with increased severity of the core symptoms diagnostic of ASD and other centrally mediated comorbid conditions, including psychiatric issues, irritability, rigid-compulsive behaviours and aggression. Despite the high prevalence of gastrointestinal dysfunction in ASD and its associated behavioural comorbidities, the specific links between these two conditions have not been clearly delineated, and current data linking ASD to gastrointestinal dysfunction have not been extensively reviewed. This Review outlines the established and emerging clinical and preclinical evidence that emphasizes the gut as a novel mechanistic and potential therapeutic target for individuals with ASD.

Ketogenic diet and behavior: insights from experimental studies

As a journal page for full details. The ketogenic diet (KD) has been established as a treatment for epilepsy, but more recently it has been explored as an alternative or add-on therapy for many other diseases ranging from weight loss to neurological disorders. Animal models are widely used in studies investigating the therapeutic effects of the KD as well as underlying mechanisms. Especially in the context of neurological, psychiatric, and neurodevelopmental disorders essential endpoints are assessed by behavioral and motor tests. Here we summarized research evaluating the influence of the KD on cognition, depressive and anxiety-related behaviors, and social and nutritional behaviors of laboratory rodents. Each section contains a brief description of commonly used behavioral tests highlighting their limitations. Ninety original research articles, written in English, performed on mice or rats, providing measurement of blood beta-hydroxybutyrate (BHB) levels and behavioral evaluation were selected for the review. The majority of research performed in various disease models shows that the KD positively impacts cognition. Almost an equal number of studies report a reduction or no effect of the KD on depressive-related behaviors. For anxiety-related behaviors, the majority of studies show no effect. Despite the increasing use of the KD in weight loss and its appetite-reducing properties the behavioral evaluation of appetite regulation has not been addressed in preclinical studies. This review provides an overview of the behavioral effects of nutritional ketosis addressed to a broad audience of scientists interested in the KD field but not necessarily specializing in behavioral tests.

Molecular Mechanisms of Neuroprotection by Ketone Bodies and Ketogenic Diet in Cerebral Ischemia and Neurodegenerative Diseases

Ketone bodies (KBs), such as acetoacetate and β-hydroxybutyrate, serve as crucial alternative energy sources during glucose deficiency. KBs, generated through ketogenesis in the liver, are metabolized into acetyl-CoA in extrahepatic tissues, entering the tricarboxylic acid cycle and electron transport chain for ATP production. Reduced glucose metabolism and mitochondrial dysfunction correlate with increased neuronal death and brain damage during cerebral ischemia and neurodegeneration. Both KBs and the ketogenic diet (KD) demonstrate neuroprotective effects by orchestrating various cellular processes through metabolic and signaling functions. They enhance mitochondrial function, mitigate oxidative stress and apoptosis, and regulate epigenetic and post-translational modifications of histones and non-histone proteins. Additionally, KBs and KD contribute to reducing neuroinflammation and modulating autophagy, neurotransmission systems, and gut microbiome. This review aims to explore the current understanding of the molecular mechanisms underpinning the neuroprotective effects of KBs and KD against brain damage in cerebral ischemia and neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease.

A Review of the Nutritional Approach and the Role of Dietary Components in Children with Autism Spectrum Disorders in Light of the Latest Scientific Research

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects several areas of mental development. The onset of ASD occurs in the first few years of life, usually before the age of 3 years. Proper nutrition is important to ensure that an individual's nutrient and energy requirements are met, and it can also have a moderating effect on the progression of the disorder. A systematic database search was conducted as a narrative review to determine whether nutrition and specific diets can potentially alter gastrointestinal symptoms and neurobehavioral disorders. Databases such as Science Direct, PubMed, Scopus, Web of Science (WoS), and Google Scholar were searched to find studies published between 2000 and September 2023 on the relationship between ASD, dietary approaches, and the role of dietary components. The review may indicate that despite extensive research into dietary interventions, there is a general lack of conclusive scientific data about the effect of therapeutic diets on ASD; therefore, no definitive recommendation can be made for any specific nutritional therapy as a standard treatment for ASD. An individualized dietary approach and the dietician's role in the therapeutic team are very important elements of every therapy. Parents and caregivers should work with nutrition specialists, such as registered dietitians or healthcare providers, to design meal plans for autistic individuals, especially those who would like to implement an elimination diet.

Does the ketogenic diet improve neurological disorders by influencing gut microbiota? A systematic review

BACKGROUND

The aim of this systematic review is to evaluate the changes in gut microbiota (GM) induced by the Ketogenic Diets (KD) as a potential underlying mechanism in the improvement of neurological diseases.

METHODS

A comprehensive search was conducted on three electronic databases, including PubMed/Medline, Web of Science, and Scopus until December 2022. The inclusion criteria were studies that described any changes in GM after consuming KD in neurological patients. Full text of studies such as clinical trials and cohorts were added. The quality assessment of cohort studies was conducted using the Newcastle-Ottawa Quality Assessment Scale and for the clinical trials using the Cochrane Collaboration tool. The search, screening, and data extraction were performed by two researchers independently.

RESULTS

Thirteen studies examining the effects of the KD on the GM in neurological patients were included. Studies have shown that KD improves clinical outcomes by reducing disease severity and recurrence rates. An increase in Proteobacteria phylum, Escherichia, Bacteroides, Prevotella, Faecalibacterium, Lachnospira, Agaricus, and Mrakia genera and a reduction in Firmicutes, and Actinobacteria phyla, Eubacterium, Cronobacter, Saccharomyces, Claviceps, Akkermansia and Dialister genera were reported after KD. Studies showed a reduction in concentrations of fecal short-chain fatty acids and branched-chain fatty acids and an increase in beta Hydroxybutyrate, trimethylamine N-oxide, and N-acetylserotonin levels after KD.

CONCLUSION

The KD prescribed in neurological patients has effectively altered the GM composition and GM-derived metabolites.

Metabolic shift toward ketosis in asocial cavefish increases social-like affinity

BACKGROUND

Social affinity and collective behavior are nearly ubiquitous in the animal kingdom, but many lineages feature evolutionarily asocial species. These solitary species may have evolved to conserve energy in food-sparse environments. However, the mechanism by which metabolic shifts regulate social affinity is not well investigated.

RESULTS

In this study, we used the Mexican tetra (Astyanax mexicanus), which features riverine sighted surface (surface fish) and cave-dwelling populations (cavefish), to address the impact of metabolic shifts on asociality and other cave-associated behaviors in cavefish, including repetitive turning, sleeplessness, swimming longer distances, and enhanced foraging behavior. After 1 month of ketosis-inducing ketogenic diet feeding, asocial cavefish exhibited significantly higher social affinity, whereas social affinity regressed in cavefish fed the standard diet. The ketogenic diet also reduced repetitive turning and swimming in cavefish. No major behavioral shifts were found regarding sleeplessness and foraging behavior, suggesting that other evolved behaviors are not largely regulated by ketosis. We further examined the effects of the ketogenic diet via supplementation with exogenous ketone bodies, revealing that ketone bodies are pivotal molecules positively associated with social affinity.

CONCLUSIONS

Our study indicated that fish that evolved to be asocial remain capable of exhibiting social affinity under ketosis, possibly linking the seasonal food availability and sociality.

Ratings of the Effectiveness of 13 Therapeutic Diets for Autism Spectrum Disorder: Results of a National Survey

This study presents the results of the effectiveness of 13 therapeutic diets for autism spectrum disorder from 818 participants of a national survey, including benefits, adverse effects, and symptom improvements. The average Overall Benefit of diets was 2.36 (0 = no benefit, 4 = great benefit), which was substantially higher than for nutraceuticals (1.59/4.0) and psychiatric/seizure medications (1.39/4.0), p < 0.001. The average Overall Adverse Effects of diets was significantly lower than psychiatric/seizure medications (0.10 vs. 0.93, p < 0.001) and similar to nutraceuticals (0.16). Autism severity decreased slightly over time in participants who used diet vs. increasing slightly in those that did not (p < 0.001). Healthy and Feingold diets were the two top-rated diets by Overall Benefit; the ketogenic diet was the highest for nine symptoms (though had fewer respondents); and the gluten-free/casein-free diet was among the top for overall symptom improvements. Different diets were reported to affect different symptoms, suggesting that an individual's symptoms could be used to guide which diet(s) may be the most effective. The results suggest that therapeutic diets can be safe and effective interventions for improving some ASD-related symptoms with few adverse effects. We recommend therapeutic diets that include healthy foods and exclude problematic foods. Therapeutic diets are inexpensive treatments that we recommend for consideration by most people with ASD.

A Spectrum of Solutions: Unveiling Non-Pharmacological Approaches to Manage Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a developmental disorder that causes difficulty while socializing and communicating and the performance of stereotyped behavior. ASD is thought to have a variety of causes when accompanied by genetic disorders and environmental variables together, resulting in abnormalities in the brain. A steep rise in ASD has been seen regardless of the numerous behavioral and pharmaceutical therapeutic techniques. Therefore, using complementary and alternative therapies to treat autism could be very significant. Thus, this review is completely focused on non-pharmacological therapeutic interventions which include different diets, supplements, antioxidants, hormones, vitamins and minerals to manage ASD. Additionally, we also focus on complementary and alternative medicine (CAM) therapies, herbal remedies, camel milk and cannabiodiol. Additionally, we concentrate on how palatable phytonutrients provide a fresh glimmer of hope in this situation. Moreover, in addition to phytochemicals/nutraceuticals, it also focuses on various microbiomes, i.e., gut, oral, and vaginal. Therefore, the current comprehensive review opens a new avenue for managing autistic patients through non-pharmacological intervention.

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.

Epigenetic Aberrations in Major Psychiatric Diseases Related to Diet and Gut Microbiome Alterations

Nutrition and metabolism modify epigenetic signatures like histone acetylation and DNA methylation. Histone acetylation and DNA methylation in the central nervous system (CNS) can be altered by bioactive nutrients and gut microbiome via the gut-brain axis, which in turn modulate neuronal activity and behavior. Notably, the gut microbiome, with more than 1000 bacterial species, collectively contains almost three million functional genes whose products interact with millions of human epigenetic marks and 30,000 genes in a dynamic manner. However, genetic makeup shapes gut microbiome composition, food/nutrient metabolism, and epigenetic landscape, as well. Here, we first discuss the effect of changes in the microbial structure and composition in shaping specific epigenetic alterations in the brain and their role in the onset and progression of major mental disorders. Afterward, potential interactions among maternal diet/environmental factors, nutrition, and gastrointestinal microbiome, and their roles in accelerating or delaying the onset of severe mental illnesses via epigenetic changes will be discussed. We also provide an overview of the association between the gut microbiome, oxidative stress, and inflammation through epigenetic mechanisms. Finally, we present some underlying mechanisms involved in mediating the influence of the gut microbiome and probiotics on mental health via epigenetic modifications.

Diet in treatment of autism spectrum disorders

Altering the diet to treat disease dates to c. 400 BC when starvation was used to reduce seizures in persons with epilepsy. The current diversity of symptomology and mechanisms underlying autism spectrum disorders (ASDs) and a corresponding lack of disorder-specific effective treatments prompts an evaluation of diet as a therapeutic approach to improve symptoms of ASDs. In this review article, we summarize the main findings of nutritional studies in ASDs, with an emphasis on the most common monogenic cause of autism, Fragile X Syndrome (FXS), and the most studied dietary intervention, the ketogenic diet as well as other dietary interventions. We also discuss the gut microbiota in relation to pre- and probiotic therapies and provide insight into future directions that could aid in understanding the mechanism(s) underlying dietary efficacy.

The Relationship of Ketogenic Diet with Neurodegenerative and Psychiatric Diseases: A Scoping Review from Basic Research to Clinical Practice

BACKGROUND

The ketogenic diet (KD) has become widespread for the therapy of epileptic pathology in childhood and adulthood. In the last few decades, the current re-emergence of its popularity has focused on the treatment of obesity and diabetes mellitus. KD also exerts anti-inflammatory and neuroprotective properties, which could be utilized for the therapy of neurodegenerative and psychiatric disorders.

PURPOSE

This is a thorough, scoping review that aims to summarize and scrutinize the currently available basic research performed in in vitro and in vivo settings, as well as the clinical evidence of the potential beneficial effects of KD against neurodegenerative and psychiatric diseases. This review was conducted to systematically map the research performed in this area as well as identify gaps in knowledge.

METHODS

We thoroughly explored the most accurate scientific web databases, e.g., PubMed, Scopus, Web of Science, and Google Scholar, to obtain the most recent in vitro and in vivo data from animal studies as well as clinical human surveys from the last twenty years, applying effective and characteristic keywords.

RESULTS

Basic research has revealed multiple molecular mechanisms through which KD can exert neuroprotective effects, such as neuroinflammation inhibition, decreased reactive oxygen species (ROS) production, decreased amyloid plaque deposition and microglial activation, protection in dopaminergic neurons, tau hyper-phosphorylation suppression, stimulating mitochondrial biogenesis, enhancing gut microbial diversity, restoration of histone acetylation, and neuron repair promotion. On the other hand, clinical evidence remains scarce. Most existing clinical studies are modest, frequently uncontrolled, and merely assess the short-term impacts of KD. Moreover, several clinical studies had large dropout rates and a considerable lack of compliance assessment, as well as an increased level of heterogeneity in the study design and methodology.

CONCLUSIONS

KD can exert substantial neuroprotective effects via multiple molecular mechanisms in various neurodegenerative and psychiatric pathological states. Large, long-term, randomized, double-blind, controlled clinical trials with a prospective design are strongly recommended to delineate whether KD may attenuate or even treat neurodegenerative and psychiatric disease development, progression, and symptomatology.

Ketogenic Diet in Children and Adolescents: the Effects on Growth and Nutritional Status

The ketogenic diet is known to be a possible adjuvant treatment in several medical conditions, such as in patients with severe or drug-resistant forms of epilepsy. Its use has recently been increasing among adolescents and young adults due to its supposed weight-loss effect, mediated by lipolysis and lowered insulin levels. However, there are still no precise indications on the possible use of ketogenic diets in pediatric age for weight loss. This approach has also recently been proposed for other types of disorder such as inherited metabolic disorders, Prader-Willi syndrome, and some specific types of cancers. Due to its unbalanced ratio of lipids, carbohydrates and proteins, a clinical evaluation of possible side effects with a strict evaluation of growth and nutritional status is essential in all patients following a long-term restrictive diet such as the ketogenic one. The prophylactic use of micronutrients supplementation should be considered before starting any ketogenic diet. Lastly, while there is sufficient literature on possible short-term side effects of ketogenic diets, their possible long-term impact on growth and nutritional status is not yet fully understood, especially when started in pediatric age.

The ketogenic diet for Dravet syndrome: A multicenter retrospective study

OBJECTIVE

The ketogenic diet (KD) is one of the main treatments for drug-resistant epilepsy. However, there have been few multicenter reports on the use of the KD for the treatment of Dravet syndrome (DS). The aim of this study was to analyze the efficacy and safety of this approach based on a large number of multicenter cases.

METHODS

This was a retrospective, multicenter cohort study from 14 centers in China. All patients were treated with the KD. We compared the effects of KD intervention time, age, and other factors.

RESULTS

From March 2014 to March 2020, we treated 114 patients with DS with the KD. The male-to-female ratio was 67:47. The KD median initiation age was 3 y and 4 mo, and the median number of antiseizure medications (ASMs) was 2.4. KD therapy was the first choice for three patients. Exactly 10.5% of the patients started KD therapy after failure of the first ASM therapy, with 35.1% after failure of the second, 44.7% after the third, and 7% after the fourth or more. After KD therapy for 1, 3, 6, and 12 mo, the seizure-free rates were 14%, 32.5%, 30.7%, and 19.3%, respectively; KD efficacy (≥50% reduction in seizure frequency) were 57.9%, 76.3%, 59.6%, and 43%, respectively; the retention rates were 97.4%, 93%, 71.9%, and 46.5%, respectively; and the rates of adverse events were 25.2%, 19.9%, 11%, and 5.7%, respectively.

CONCLUSIONS

Real-world, multicenter data analysis showed that the KD is effective for patients with DS and has a low incidence of side effects.

Epilepsy and Autism Spectrum Disorder (ASD): The Underlying Mechanisms and Therapy Targets Related to Adenosine

Epilepsy and autism spectrum disorder (ASD) are highly mutually comorbid, suggesting potential overlaps in genetic etiology, pathophysiology, and neurodevelopmental abnormalities. Adenosine, an endogenous anticonvulsant and neuroprotective neuromodulator of the brain, has been proved to affect the process of epilepsy and ASD. On the one hand, adenosine plays a crucial role in preventing the progression and development of epilepsy through adenosine receptordependent and -independent ways. On the other hand, adenosine signaling can not only regulate core symptoms but also improve comorbid disorders in ASD. Given the important role of adenosine in epilepsy and ASD, therapeutic strategies related to adenosine, including the ketogenic diet, neuromodulation therapy, and adenosine augmentation therapy, have been suggested for the arrangement of epilepsy and ASD. There are several proposals in this review. Firstly, it is necessary to further discuss the relationship between both diseases based on the comorbid symptoms and mechanisms of epilepsy and ASD. Secondly, it is important to explore the role of adenosine involved in epilepsy and ASD. Lastly, potential therapeutic value and clinical approaches of adenosine-related therapies in treating epilepsy and ASD need to be emphasized.

Treatment of Autism Spectrum Disorders by Mitochondrial-targeted Drug: Future of Neurological Diseases Therapeutics

Autism is a neurodevelopmental disorder with a complex etiology that might involve environmental and genetic variables. Recently, some epidemiological studies conducted in various parts of the world have estimated a significant increase in the prevalence of autism, with 1 in every 59 children having some degree of autism. Since autism has been associated with other clinical abnormalities, there is every possibility that a sub-cellular component may be involved in the progression of autism. The organelle remains a focus based on mitochondria's functionality and metabolic role in cells. Furthermore, the mitochondrial genome is inherited maternally and has its DNA and organelle that remain actively involved during embryonic development; these characteristics have linked mitochondrial dysfunction to autism. Although rapid stride has been made in autism research, there are limited studies that have made particular emphasis on mitochondrial dysfunction and autism. Accumulating evidence from studies conducted at cellular and sub-cellular levels has indicated that mitochondrial dysfunction's role in autism is more than expected. The present review has attempted to describe the risk factors of autism, the role of mitochondria in the progression of the disease, oxidative damage as a trigger point to initiate mitochondrial damage, genetic determinants of the disease, possible pathogenic pathways and therapeutic regimen in vogue and the developmental stage. Furthermore, in the present review, an attempt has been made to include the novel therapeutic regimens under investigation at different clinical trial stages and their potential possibility to emerge as promising drugs against ASD.

Assessing the feasibility of using the ketogenic diet in autism spectrum disorder

BACKGROUND

Evidence demonstrating efficacy of dietary interventions for autism spectrum disorder (ASD) remains inconsistent. Recent research on the ketogenic diet (KD) for the treatment of ASD has suggested a benefit. Children with ASD often demonstrate ritualised food-specific behaviours, taste and texture aversions, and an increased prevalence of food restrictions and allergies. There is a need to investigate how these features contribute to initiation and adherence of the KD. Two surveys were administered to assess the feasibility of utilising the KD for ASD.

METHODS

First, paper surveys were given to caregivers of children presenting to outpatient neurology clinics. Next, experienced clinicians were recruited and surveyed online using Qualtrics. Chi-squared analysis was used to compare ASD and non-ASD caregiver responses. Descriptive metrics were used to present clinician responses. Responses to each question were evaluated individually.

RESULTS

One hundred and fourteen surveys were collected from caregivers. There were no significant differences in (1) stated feasibility of adopting a new diet, (2) a carbohydrate restricted diet, (3) diet restrictions, (4) documented allergies or (5) personal/cultural restrictions between groups with and without ASD. Seventy clinician responses were collected. The majority (67.4%) indicated that feasibility for a child with ASD to adopt a KD for any reason depends on ASD severity. Some respondents 73% rated adherence to the KD as more difficult compared to age-matched controls, whereas 26% considered it similar. Multiple familial and child characteristics were rated as increasing the difficulty of successful KD.

CONCLUSIONS

The results of the present study suggest that it is feasible for children with ASD to adopt a KD, and success is highly individualised to child and family.

Overall Rebalancing of Gut Microbiota Is Key to Autism Intervention

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with unclear etiology, and due to the lack of effective treatment, ASD patients bring enormous economic and psychological burden to families and society. In recent years, many studies have found that children with ASD are associated with gastrointestinal diseases, and the composition of intestinal microbiota (GM) is different from that of typical developing children. Thus, many researchers believe that the gut-brain axis may play an important role in the occurrence and development of ASD. Indeed, some clinical trials and animal studies have reported changes in neurological function, behavior, and comorbid symptoms of autistic children after rebalancing the composition of the GM through the use of antibiotics, prebiotics, and probiotics or microbiota transfer therapy (MMT). In view of the emergence of new therapies based on the modulation of GM, characterizing the individual gut bacterial profile evaluating the effectiveness of intervention therapies could help provide a better quality of life for subjects with ASD. This article reviews current studies on interventions to rebalance the GM in children with ASD. The results showed that Lactobacillus plantarum may be an effective strain for the probiotic treatment of ASD. However, the greater effectiveness of MMT treatment suggests that it may be more important to pay attention to the overall balance of the patient's GM. Based on these findings, a more thorough assessment of the GM is expected to contribute to personalized microbial intervention, which can be used as a supplementary treatment for ASD.

Epigenetics of Autism Spectrum Disorder: Histone Deacetylases

The etiology of autism spectrum disorder (ASD) remains unknown, but gene-environment interactions, mediated through epigenetic mechanisms, are thought to be a key contributing factor. Prenatal environmental factors have been shown to be associated with both increased risk of ASD and altered histone deacetylases (HDACs) or acetylation levels. The relationship between epigenetic changes and gene expression in ASD suggests that alterations in histone acetylation, which lead to changes in gene transcription, may play a key role in ASD. Alterations in the acetylome have been demonstrated for several genes in ASD, including genes involved in synaptic function, neuronal excitability, and immune responses, which are mechanisms previously implicated in ASD. We review preclinical and clinical studies that investigated HDACs and autism-associated behaviors and discuss risk genes for ASD that code for proteins associated with HDACs. HDACs are also implicated in neurodevelopmental disorders with a known genetic etiology, such as 15q11-q13 duplication and Phelan-McDermid syndrome, which share clinical features and diagnostic comorbidities (e.g., epilepsy, anxiety, and intellectual disability) with ASD. Furthermore, we highlight factors that affect the behavioral phenotype of acetylome changes, including sensitive developmental periods and brain region specificity in the context of epigenetic programming.

Rescue of histone hypoacetylation and social deficits by ketogenic diet in a Shank3 mouse model of autism

Human genetic sequencing has implicated epigenetic and synaptic aberrations as the most prominent risk factors for autism. Here we show that autistic patients exhibit the significantly lower histone acetylation and elevated HDAC2 expression in prefrontal cortex (PFC). The diminished histone acetylation is also recaptured in an autism mouse model with the deficiency of the Shank3 gene encoding a synaptic scaffolding protein. Treating young (5-week-old) Shank3-deficient mice with a 4-week ketogenic diet, which can act as an endogenous inhibitor of class I HDACs via the major product β-hydroxybutyrate, elevates the level of histone acetylation in PFC neurons. Behavioral assays indicate that ketogenic diet treatment leads to the prolonged rescue of social preference deficits in Shank3-deficient mice. The HDAC downstream target genes encoding NMDA receptor subunits, GRIN2A and GRIN2B, are significantly reduced in PFC of autistic humans. Ketogenic diet treatment of Shank3-deficient mice elevates the transcription and histone acetylation of Grin2a and Grin2b, and restores the diminished NMDAR synaptic function in PFC neurons. These results suggest that the ketogenic diet provides a promising therapeutic strategy for social deficits in autism via the restoration of histone acetylation and gene expression in the brain.

Malonyl/Acetyltransferase (MAT) Knockout Decreases Triacylglycerol and Medium-Chain Fatty Acid Contents in Goat Mammary Epithelial Cells

Malonyl/acetyltransferase (MAT) is a crucial functional domain of fatty acid synthase (FASN), which plays a vital role in the de novo synthesis of fatty acids in vivo. Milk fatty acids are secreted by mammary epithelial cells. Mammary epithelial cells are the units of mammary gland development and function, and it is a common model for the study of mammary gland tissue development and lactation. This study aimed to investigate the effects of MAT deletion on the synthesis of triacylglycerol and medium-chain fatty acids. The MAT domain was knocked out by CRISPR/Cas9 in the goat mammary epithelial cells (GMECs), and in MAT knockout GMECs, the mRNA level of FASN was decreased by approximately 91.19% and the protein level decreased by 51.83%. The results showed that MAT deletion downregulated the contents of triacylglycerol and medium-chain fatty acids (p < 0.05) and increased the content of acetyl-Coenzyme A (acetyl-CoA) (p < 0.001). Explicit deletion of MAT resulted in significant drop of FASN, which resulted in downregulation of LPL, GPAM, DGAT2, PLIN2, XDH, ATGL, LXRα, and PPARγ genes in GMECs (p < 0.05). Meanwhile, mRNA expression levels of ACC, FASN, DGAT2, SREBP1, and LXRα decreased following treatment with acetyl-CoA (p < 0.05). Our data reveals that FASN plays critical roles in the synthesis of medium-chain fatty acids and triacylglycerol in GMECs.

Efficacy and Safety of Diet Therapies in Children With Autism Spectrum Disorder: A Systematic Literature Review and Meta-Analysis

Objective

Autism Spectrum Disorder is a neurodevelopmental disorder, with a rapid increase in recognition over the past decade. Interest in alternative therapies is growing annually, such as dietary therapies including gluten-free and/or casein-free diet, and the ketogenic diet. However, there is no consensus on the efficacy and safety of dietary therapy in children with ASD up to now. This study aimed to assess the efficacy and safety of these diet interventions for children with ASD based on a meta-analysis of global data.

Methods

Seven databases (Cochrane Library, PubMed, EMBASE, Web of Science, VIP, CNKI, and Wanfang) were searched according to the established inclusion criteria, from the inception of the databases to August 18, 2021. The Cochrane Bias risk assessment tool was intended to assess the quality of the included studies. Review Manager 5.4 software was used as an efficacy analysis tool of the included studies, taking the core autistic symptoms and scales of ASD as therapeutic efficacy evaluations.

Results

In total, 7 RCTs with 338 participants were finally obtained. All studies assessed the association between core autistic symptoms and therapeutic diet, showing a statistically significant effect (standard mean difference (SMD) of −0.51, 95% confidence interval (Cl): −0.81 to −0.21), in which two studies which followed the GFD diet reported significant reductions in social behaviors (SMD of−0.41, 95% Cl: −0.75 to −0.06), showing no correlation with the length of the interventions (P < 0.05). Two studies were performed in KD diet suggested a significant effect in core symptoms (SMD of −0.67, 95% Cl: −1.04 to −0.31). No statistically significant changes were observed in the GFCF diet, GFD diet, cognition, communication, and stereotypical behaviors subgroups (all P > 0.05).

Conclusion

The results of a meta-analysis suggest that diet therapies can significantly ameliorate core symptoms of ASD, and GFD diets are conducive to improving social behaviors. Although the results suggest the effectiveness of dietary therapy for ASD, limited by the small sample size of RCTs, more well-designed, and high-quality clinical trials are needed to validate the above conclusions.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021277565.

Repetitive Restricted Behaviors in Autism Spectrum Disorder: From Mechanism to Development of Therapeutics

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by deficits in social communication, social interaction, and repetitive restricted behaviors (RRBs). It is usually detected in early childhood. RRBs are behavioral patterns characterized by repetition, inflexibility, invariance, inappropriateness, and frequent lack of obvious function or specific purpose. To date, the classification of RRBs is contentious. Understanding the potential mechanisms of RRBs in children with ASD, such as neural connectivity disorders and abnormal immune functions, will contribute to finding new therapeutic targets. Although behavioral intervention remains the most effective and safe strategy for RRBs treatment, some promising drugs and new treatment options (e.g., supplementary and cell therapy) have shown positive effects on RRBs in recent studies. In this review, we summarize the latest advances of RRBs from mechanistic to therapeutic approaches and propose potential future directions in research on RRBs.

Medium chain triglycerides (MCT): State-of-the-art on chemistry, synthesis, health benefits and applications in food industry

Medium chain triglycerides (MCT) are esters of fatty acids with 6 to 12 carbon atom chains. Naturally, they occur in various sources; their composition and bioactivity are source and extraction process-linked. The molecular size of MCT oil permits unique metabolic pathways and energy production rates, making MCT oil a high-value functional food. This review details the common sources of MCT oil, presenting critical information on the various approaches for MCT oil extraction or synthesis. Apart from conventional techniques, non-thermal processing methods that show promising prospects are analyzed. The biological effects of MCT oil are summarized, and the range of need-driven modification approaches are elaborated. A section is devoted to highlighting the recent trends in the application of MCT oil for food, nutraceuticals, and allied applications. While much is debated about the role of MCT oil in human health and wellness, there is limited information on daily requirements, impact on specific population groups, and effects of long-term consumption. Nonetheless, several studies have been conducted and continue to identify the most effective methods for MCT oil extraction, processing, handling, and storage. A knowledge gap exists and future research must focus on technology packages for scalability and sustainability.

Effects of nutritional interventions in children and adolescents with autism spectrum disorder: an overview based on a literature review

Background: Nutrition is important in autism spectrum disorder (ASD). Because nutritional problems of children with ASD can lead to nutritional deficiencies and this can also directly or indirectly affect symptoms related to autism. We investigated the effect of diet and supplementation treatments on gastrointestinal, behavioral or sleep problems based on the results of literature review. Methods: We generated four questions based on literature. We carried out title and abstract-based search using the Web of Science database. Of 4580 abstracts were identified, 192 papers were reviewed and 55 papers precisely meeting the inclusion criteria. Results: The studies examining the effects of vitamins, minerals, probiotics, and other supplements on ASD symptoms had different dosages, different treatment durations, small sample sizes and used different scales for evaluation. The results of the studies of the effectiveness of Gluten-Free and Casein-Free (GFCF) and ketogenic diet to reduce gastrointestinal, behavioral and sleeping problems in children and adolescents were contradictory. Conclusions: It is not possible to suggest the GFCF and/or ketogenic diet, vitamins, minerals and probiotics to individual with ASD based on the available evidence. By planning a sufficient and balanced diet, it should be aimed to prevent nutrient deficiency and to ensure growth in accordance with the age in children with ASD.

Are changes in the gut microbiome a contributor or consequence of autism-why not both?

Alterations in the gut microbiome have been associated with autism spectrum disorder (ASD), but whether they are a cause, effect, or confounder remains unclear. In a recent issue of Cell, Yap and colleagues report that ASD-associated microbiota changes are likely a consequence of low diet diversity.¹.

Comparative Study on the Exacerbating Effects of Casein-Rich vs. Gluten-Rich Diets on Biochemical-Induced Features in Rodent Model of Autism

In relation to dietary intervention in individuals with autism spectrum disorder (ASD), certain food constituents especially gluten and casein are recognized to be challenging and should be restricted. In this study, levels of glutathione S-transferase, glutathione, lipid peroxides, serotonin (5-HT), interleukin-6 (IL-6), glutamate, and gamma aminobutyric acid (GABA) were measured in the brain homogenates of ASD rodent model. Rats were treated either with single dose clindamycin (30 mg/kg) or with propionic acid (PPA) (250 mg/kg) for 3 days and then fed a standard diet, casein-rich diet (CRD), or gluten-rich diet (GRD). The obtained data demonstrates that clindamycin and PPA induced oxidative stress, which was slightly affected by CRD. A marked increase in the proinflammatory cytokine (IL-6) concentration found in clindamycin- and PPA-treated groups was lower in CRD fed rats. Both CRDs and GRDs produced similar trends in glutamate levels. 5-HT levels were higher in the clindamycin- and PPA-treated groups and increased with a GRD but were less affected by a CRD. CRD could be less deleterious compared to GRD. Although the underlying cause of gastrointestinal symptoms in patients with ASD is not exactly known, the most widely accepted one is the opioid theory which is related to GRD and CRD.

Benefits of a ketogenic diet on repetitive motor behavior in mice

Repetitive motor behaviors are repetitive and invariant movements with no apparent function, and are common in several neurological and neurodevelopmental disorders, including autism spectrum disorders (ASD). However, the neuropathology associated with the expression of these abnormal stereotypic movements is not well understood, and effective treatments are lacking. The ketogenic diet (KD) has been used for almost a century to treat intractable epilepsy and, more recently, disorders associated with inflexibility of behavioral routines. Here, we show a novel application for KD to reduce an abnormal repetitive circling behavior in a rodent model. We then explore potential mediation through the striatum, as dysregulation of cortico-basal ganglia circuitry has previously been implicated in repetitive motor behavior. In Experiments 1 and 2, adult FVB mice were assessed for levels of repetitive circling across a 3-week baseline period. Mice were then switched to KD and repetitive circling was assessed for an additional 3 weeks. In Experiment 1, time on KD was associated with reduced repetitive behavior. In Experiment 2, we replicated these benefits of KD and assessed dendritic spine density in the striatum as one potential mechanism for reducing repetitive behavior, which yielded no differences. In Experiment 3, adult female circling mice were given a single administration of a dopamine D2 receptor antagonist (L-741,646) that was associated with reduced repetitive behavior over time. Future research will explore the relationship between KD and dopamine within basal ganglia nuclei that may be influencing the benefits of KD on repetitive behavior.

The potential impact of the ketogenic diet on gut microbiota in the context of neurological disorders

One of the most important functional parts of a human intestinal tract is the microscopic intestinal barrier. Its function is to ensure the correct nutrient absorption and to protect against multiple pathogens, xenobiotics, and environmental toxins. Intestinal microbiota is an integral part of the intestinal epithelium. Human microbiota and their host interact with each other, both directly and indirectly, via multiple intermediates and metabolites. Some dietary fat that is not fully digested reaches the distal parts of the intestinal tract, where an interaction with gut microbiota takes place. Studies have shown that an animal-product based diet that provides a greater supply of saturated fat increases the number of bile-resistant microorganisms, including Bilophila. The total amount of Alistipes and Bacteroides is also increased. Long-term consumption of animal-based foods contributes to the formation of the enterotype described as the Bacteroides type. The ketogenic diet is mainly based on animal fats. The changes induced by this higher consumption of animal fats are associated with unfavorable metabolic changes. However, more and more research has shown evidence of the therapeutic properties of a ketogenic diet as far as neurodegenerative and metabolic diseases are concerned. Recent reports suggest that the protective effect of a ketogenic diet is highly dependent on the gut microbiota. This review focuses on the correlation between the influence of ketogenic diet on the intestinal microbiota changes observed while analyzing patients with diseases such as epilepsy, Alzheimer's disease, autism spectrum disorder, and multiple sclerosis.

A ketogenic diet affects brain volume and metabolome in juvenile mice

Ketogenic diet (KD) is a high-fat and low-carbohydrate therapy for medically intractable epilepsy, and its applications in other neurological conditions, including those occurring in children, have been increasingly tested. However, how KD affects childhood neurodevelopment, a highly sensitive and plastic process, is not clear. In this study, we explored structural, metabolic, and functional consequences of a brief treatment of a strict KD (weight ratio of fat to carbohydrate plus protein is approximately 6.3:1) in naive juvenile mice of different inbred strains, using a multidisciplinary approach. Systemic measurements using magnetic resonance imaging revealed that unexpectedly, the volumes of most brain structures in KD-fed mice were about 90% of those in mice of the same strain but fed a standard diet. The reductions in volumes were nonselective, including different regions throughout the brain, the ventricles, and the white matter. The relative volumes of different brain structures were unaltered. Additionally, as KD is a metabolism-based treatment, we performed untargeted metabolomic profiling to explore potential means by which KD affected brain growth and to identify metabolic changes in the brain. We found that brain metabolomic profile was significantly impacted by KD, through both distinct and common pathways in different mouse strains. To explore whether the volumetric and metabolic changes induced by this KD treatment were associated with functional consequences, we recorded spontaneous EEG to measure brain network activity. Results demonstrated limited alterations in EEG patterns in KD-fed animals. In addition, we observed that cortical levels of brain-derived neurotrophic factor (BDNF), a critical molecule in neurodevelopment, did not change in KD-fed animals. Together, these findings indicate that a strict KD could affect volumetric development and metabolic profile of the brain in inbred juvenile mice, while global network activities and BDNF signaling in the brain were mostly preserved. Whether the volumetric and metabolic changes are related to any core functional consequences during neurodevelopment and whether they are also observed in humans need to be further investigated. In addition, our results indicate that certain outcomes of KD are specific to the individual mouse strains tested, suggesting that the physiological profiles of individuals may need to be examined to maximize the clinical benefit of KD.

Altered Metabolic Characteristics in Plasma of Young Boys with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a serious neurodevelopmental disorder with no clinical biomarker. This study used untargeted metabolomic analysis to identify metabolic characteristics in plasma that can distinguish ASD children. 29 boys with ASD (3.02 ± 0.67 years) and 30 typically developing (TD) boys (3.13 ± 0.46 years) were recruited. Developmental and behavioral assessments were conducted in ASD group. Samples of plasma were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The association between metabolite concentration and scale score was assessed by Spearman rank correlation. Altered metabolic characteristics were found in boys with ASD. In Receiver Operating Characteristic (ROC) analysis, ornithine had the highest AUC (Area under ROC) value. Furthermore, the concentration of choline and ornithine was negatively correlated with ABC-language score in ASD group.

Emerging Role of the Ketogenic Dietary Therapies beyond Epilepsy in Child Neurology

Ketogenic dietary therapies (KDTs) have been in use for refractory paediatric epilepsy for a century now. Over time, KDTs themselves have undergone various modifications to improve tolerability and clinical feasibility, including the Modified Atkins diet (MAD), medium chain triglyceride (MCT) diet and the low glycaemic index treatment (LGIT). Animal and observational studies indicate numerous benefits of KDTs in paediatric neurological conditions apart from their evident benefits in childhood intractable epilepsy, including neurodevelopmental disorders such as autism spectrum disorder, rarer neurogenetic conditions such as Rett syndrome, Fragile X syndrome and Kabuki syndrome, neurodegenerative conditions such as Pelizaeus-Merzbacher disease, and other conditions such as stroke and migraine. A large proportion of the evidence is derived from individual case reports, case series and some small clinical trials, emphasising the vast scope for research in this avenue. The term 'neuroketotherapeutics' has been coined recently to encompass the rapid strides in this field. In the 100^th year of its use for paediatric epilepsy, this review covers the role of the KDTs in non-epilepsy neurological conditions among children.

Astroglia in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is an umbrella term encompassing several neurodevelopmental disorders such as Asperger syndrome or autism. It is characterised by the occurrence of distinct deficits in social behaviour and communication and repetitive patterns of behaviour. The symptoms may be of different intensity and may vary in types. Risk factors for ASD include disturbed brain homeostasis, genetic predispositions, or inflammation during the prenatal period caused by viruses or bacteria. The number of diagnosed cases is growing, but the main cause and mechanism leading to ASD is still uncertain. Recent findings from animal models and human cases highlight the contribution of glia to the ASD pathophysiology. It is known that glia cells are not only "gluing" neurons together but are key players participating in different processes crucial for proper brain functioning, including neurogenesis, synaptogenesis, inflammation, myelination, proper glutamate processing and many others. Despite the prerequisites for the involvement of glia in the processes related to the onset of autism, there are far too little data regarding the engagement of these cells in the development of ASD.

Social-like responses are inducible in asocial Mexican cavefish despite the exhibition of strong repetitive behavior

Social behavior is a hallmark of complex animal systems; however, some species appear to have secondarily lost this social ability. In these non-social species, whether social abilities are permanently lost or suppressed is unclear. The blind cavefish Astyanax mexicanus is known to be asocial. Here, we reveal that cavefish exhibited social-like interactions in familiar environments but suppressed these interactions in stress-associated unfamiliar environments. Furthermore, the level of suppression in sociality was positively correlated with that of stereotypic repetitive behavior, as seen in mammals. Treatment with a human antipsychotic drug targeting the dopaminergic system induced social-like interactions in cavefish, even in unfamiliar environments, while reducing repetitive behavior. Overall, these results suggest that the antagonistic association between repetitive and social-like behaviors is deeply shared from teleosts through mammals.

The Effects of Intermittent Fasting on Brain and Cognitive Function

The importance of diet and the gut-brain axis for brain health and cognitive function is increasingly acknowledged. Dietary interventions are tested for their potential to prevent and/or treat brain disorders. Intermittent fasting (IF), the abstinence or strong limitation of calories for 12 to 48 h, alternated with periods of regular food intake, has shown promising results on neurobiological health in animal models. In this review article, we discuss the potential benefits of IF on cognitive function and the possible effects on the prevention and progress of brain-related disorders in animals and humans. We do so by summarizing the effects of IF which through metabolic, cellular, and circadian mechanisms lead to anatomical and functional changes in the brain. Our review shows that there is no clear evidence of a positive short-term effect of IF on cognition in healthy subjects. Clinical studies show benefits of IF for epilepsy, Alzheimer’s disease, and multiple sclerosis on disease symptoms and progress. Findings from animal studies show mechanisms by which Parkinson’s disease, ischemic stroke, autism spectrum disorder, and mood and anxiety disorders could benefit from IF. Future research should disentangle whether positive effects of IF hold true regardless of age or the presence of obesity. Moreover, variations in fasting patterns, total caloric intake, and intake of specific nutrients may be relevant components of IF success. Longitudinal studies and randomized clinical trials (RCTs) will provide a window into the long-term effects of IF on the development and progress of brain-related diseases.

Novel treatments for autism spectrum disorder based on genomics and systems biology

BACKGROUND

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with a complex underlying genetic architecture. There are currently no known pharmacologic treatments for the core ASD symptoms of social deficits and restricted/ repetitive behavior. However, there are dozens of clinical trials currently underway that are testing the impact of novel and existing agents on core and associated symptoms in ASD.

METHODS

We present a narrative synthesis of the historical and contemporary challenges to drug discovery in ASD. We then provide an overview of novel treatments currently under investigation from a genomics and systems biology perspective.

RESULTS

Data driven network and cluster analyses suggest alterations in transcriptional regulation, chromatin remodelling, synaptic transmission, neuropeptide signalling, and/or immunological mechanisms may contribute to or underlie the development of ASD. Agents and upcoming trials targeting each of the above listed systems are reviewed.

CONCLUSION

Identifying effective pharmacologic treatments for the core and associated symptom domains in ASD will require further collaboration and innovation in the areas of outcome measurement, biomarker research, and genomics, as well as systematic efforts to identify and treat subgroups of individuals with ASD who may be differentially responsive to specific treatments.

Ketogenic Dietary Therapies in Patients with Autism Spectrum Disorder: Facts or Fads? A Scoping Review and a Proposal for a Shared Protocol

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with increasing incidence. An expanding body of literature is examining connections between ASD and dietary interventions. Existing reports suggest a beneficial effect of ketogenic dietary therapies (KDTs) in improving behavioral symptoms in ASD. In this context, the purpose of this scoping review was to identify and map available evidence in the literature about the feasibility and potential efficacy of KDTs in pediatric patients with ASD and to inform clinical practice in the field. Moreover, based on the resulting data from the literature review, we aimed to provide a shared protocol to develop a personalized KDT intervention in patients with ASD. A comprehensive and structured web-based literature search was performed using PubMed and Scopus and it yielded 203 records. Seven papers were finally selected and included in the review. Data were abstracted by independent coders. High variability was identified in study designs and dietary aspects emerged among selected studies. Results supported the effectiveness of KDTs in promoting behavioral improvements. Clinical recommendations on which patients may benefit most from KDTs implementation and difficulties in dietary adherence were discussed.

The use of the ketogenic diet in the treatment of psychiatric disorders

INTRODUCTION

The ketogenic diet (KD) is a high-fat, low-carbohydrate, and moderate-protein diet that has shown benefit as a treatment in neurologic disorders and may serve as a therapeutic option in individuals with psychiatric disorders.

METHODS

A search was conducted using EBSCOhost and PubMed databases for studies relating to ketogenic or low-carbohydrate diets and psychiatric disorders.

RESULTS

A total of 32 experimental or observational studies were identified by initial search strategies, 14 of which met the criteria to be included in this analysis. Although specific diet formulations varied somewhat between studies, they all generally examined low-carbohydrate dietary intake with the goal of producing a ketotic state. The studies included in this review indicated the KD was beneficial in reducing symptoms associated with various psychiatric disorders.

DISCUSSION

This review summarizes the available evidence regarding the efficacy of the ketogenic diet in psychiatric disease states. Data from the studies analyzed demonstrated a positive response in individuals who were able to remain on the diet, regardless of the disease state. However, there is a need for more data to clearly define the specific benefits the KD may provide.

The Role of Cholesterol and Fatty Acids in the Etiology and Diagnosis of Autism Spectrum Disorders

Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders whose pathogenesis seems to be related to an imbalance of excitatory and inhibitory synapses, which leads to disrupted connectivity during brain development. Among the various biomarkers that have been evaluated in the last years, metabolic factors represent a bridge between genetic vulnerability and environmental aspects. In particular, cholesterol homeostasis and circulating fatty acids seem to be involved in the pathogenesis of ASDs, both through the contribute in the stabilization of cell membranes and the modulation of inflammatory factors. The purpose of the present review is to summarize the available data about the role of cholesterol and fatty acids, mainly long-chain ones, in the onset of ASDs. A bibliographic research on the main databases was performed and 36 studies were included in our review. Most of the studies document a correlation between ASDs and hypocholesterolemia, while the results concerning circulating fatty acids are less univocal. Even though further studies are necessary to confirm the available data, the metabolic biomarkers open to new treatment options such as the modulation of the lipid pattern through the diet.

The Effect of Exogenous Beta-Hydroxybutyrate Salt Supplementation on Metrics of Safety and Health in Adolescents

The ketogenic diet is a high-fat, very low-carbohydrate, moderate-protein diet that will induce a state of ketosis, but because of its restrictive nature, it may be difficult to adhere to, especially in adolescents. Supplementing with exogenous beta-hydroxybutyrate salts may induce a state of temporary ketosis without any undesirable side effects, thereby promoting the benefits of ketosis and minimizing adherence requirements to a ketogenic diet. To date, beta-hydroxybutyrate supplementation in healthy adolescents has not been explored. Therefore, the purpose of this study was to examine the safety of exogenous beta-hydroxybutyrate salt supplementation in a healthy adolescent population. In the present study, 22 healthy male and female adolescents consumed 3.75 g of beta-hydroxybutyrate salts or maltodextrin placebo twice daily for 90 days. Comprehensive blood safety analysis, bone densitometry, happiness and emotional intelligence surveys, and blood pressure were assessed at Pre, Day 45, and Day 90. There were no significant differences detected in subjects supplementing with beta-hydroxybutyrate salts, indicating that exogenous beta-hydroxybutyrate salts had no detrimental impact on fasting blood safety metrics, bone density, happiness, emotional intelligence, or blood pressure. We conclude that supplementing with exogenous beta-hydroxybutyrate salts is safe and well-tolerated by healthy adolescents.

Nutritional Ketosis as a Potential Treatment for Alcohol Use Disorder

Alcohol use disorder (AUD) is a chronic, relapsing brain disorder, characterized by compulsive alcohol seeking and disrupted brain function. In individuals with AUD, abstinence from alcohol often precipitates withdrawal symptoms than can be life threatening. Here, we review evidence for nutritional ketosis as a potential means to reduce withdrawal and alcohol craving. We also review the underlying mechanisms of action of ketosis. Several findings suggest that during alcohol intoxication there is a shift from glucose to acetate metabolism that is enhanced in individuals with AUD. During withdrawal, there is a decline in acetate levels that can result in an energy deficit and could contribute to neurotoxicity. A ketogenic diet or ingestion of a ketone ester elevates ketone bodies (acetoacetate, β-hydroxybutyrate and acetone) in plasma and brain, resulting in nutritional ketosis. These effects have been shown to reduce alcohol withdrawal symptoms, alcohol craving, and alcohol consumption in both preclinical and clinical studies. Thus, nutritional ketosis may represent a unique treatment option for AUD: namely, a nutritional intervention that could be used alone or to augment the effects of medications.

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.

Perioperative Management of Children on Ketogenic Dietary Therapies

Ketogenic diet therapy (KDT) is an effective treatment modality for children with drug-resistant epilepsy and certain other metabolic and neurologic disorders. With a resurgence of interest in KDT, pediatric anesthesiologists are increasingly encountering children on KDT for a variety of surgical and medical procedures. Maintenance of ketosis is critical throughout the perioperative period, and if not managed appropriately, these patients are at an increased risk of seizures. This review article provides an overview of the clinical indications, contraindications, proposed anticonvulsant mechanisms, initiation, and monitoring of children on KDTs. Recommendations for the perioperative anesthetic management of children on KDT are summarized. A comprehensive table listing the carbohydrate content of common anesthetic drugs is also included.

Importance of lipids for upper motor neuron health and disease

Building evidence reveals the importance of maintaining lipid homeostasis for the health and function of neurons, and upper motor neurons (UMNs) are no exception. UMNs are critically important for the initiation and modulation of voluntary movement as they are responsible for conveying cerebral cortex' input to spinal cord targets. To maintain their unique cytoarchitecture with a prominent apical dendrite and a very long axon, UMNs require a stable cell membrane, a lipid bilayer. Lipids can act as building blocks for many biomolecules, and they also contribute to the production of energy. Therefore, UMNs require sustained control over the production, utilization and homeostasis of lipids. Perturbations of lipid homeostasis lead to UMN vulnerability and progressive degeneration in diseases such as hereditary spastic paraplegia (HSP) and primary lateral sclerosis (PLS). Here, we discuss the importance of lipids, especially for UMNs.

Neurodevelopmental Disorders: Effect of High-Fat Diet on Synaptic Plasticity and Mitochondrial Functions

Neurodevelopmental disorders (NDDs) include diverse neuropathologies characterized by abnormal brain development leading to impaired cognition, communication and social skills. A common feature of NDDs is defective synaptic plasticity, but the underlying molecular mechanisms are only partially known. Several studies have indicated that people’s lifestyles such as diet pattern and physical exercise have significant influence on synaptic plasticity of the brain. Indeed, it has been reported that a high-fat diet (HFD, with 30–50% fat content), which leads to systemic low-grade inflammation, has also a detrimental effect on synaptic efficiency. Interestingly, metabolic alterations associated with obesity in pregnant woman may represent a risk factor for NDDs in the offspring. In this review, we have discussed the potential molecular mechanisms linking the HFD-induced metabolic dysfunctions to altered synaptic plasticity underlying NDDs, with a special emphasis on the roles played by synaptic protein synthesis and mitochondrial functions.

Gut-Brain Axis: Role of Gut Microbiota on Neurological Disorders and How Probiotics/Prebiotics Beneficially Modulate Microbial and Immune Pathways to Improve Brain Functions

The gut microbiome acts as an integral part of the gastrointestinal tract (GIT) that has the largest and vulnerable surface with desirable features to observe foods, nutrients, and environmental factors, as well as to differentiate commensals, invading pathogens, and others. It is well-known that the gut has a strong connection with the central nervous system (CNS) in the context of health and disease. A healthy gut with diverse microbes is vital for normal brain functions and emotional behaviors. In addition, the CNS controls most aspects of the GI physiology. The molecular interaction between the gut/microbiome and CNS is complex and bidirectional, ensuring the maintenance of gut homeostasis and proper digestion. Besides this, several mechanisms have been proposed, including endocrine, neuronal, toll-like receptor, and metabolites-dependent pathways. Changes in the bidirectional relationship between the GIT and CNS are linked with the pathogenesis of gastrointestinal and neurological disorders; therefore, the microbiota/gut-and-brain axis is an emerging and widely accepted concept. In this review, we summarize the recent findings supporting the role of the gut microbiota and immune system on the maintenance of brain functions and the development of neurological disorders. In addition, we highlight the recent advances in improving of neurological diseases by probiotics/prebiotics/synbiotics and fecal microbiota transplantation via the concept of the gut-brain axis.