The Ketogenic Diet and Alzheimer's Disease

Mitophagy in Alzheimer's disease and other metabolic disorders: A focus on mitochondrial-targeted therapeutics

Mitochondria, as central regulators of cellular processes such as energy production, apoptosis, and metabolic homeostasis, are essential to cellular function and health. The maintenance of mitochondrial integrity, especially through mitophagy-the selective removal of impaired mitochondria-is crucial for cellular homeostasis. Dysregulation of mitochondrial function, dynamics, and biogenesis is linked to neurodegenerative and metabolic diseases, notably Alzheimer's disease (AD), which is increasingly recognized as a metabolic disorder due to its shared pathophysiologic features: insulin resistance, oxidative stress, and chronic inflammation. In this review, we highlight recent advancements in pharmacological interventions, focusing on agents that modulate mitophagy, mitochondrial uncouplers that reduce oxidative phosphorylation, compounds that directly scavenge reactive oxygen species to alleviate oxidative stress, and molecules that ameliorate amyloid beta plaque accumulation and phosphorylated tau pathology. Additionally, we explore dietary and lifestyle interventions-MIND and ketogenic diets, caloric restriction, physical activity, hormone modulation, and stress management-that complement pharmacological approaches and support mitochondrial health. Our review underscores mitochondria's central role in the pathogenesis and potential treatment of neurodegenerative and metabolic diseases, particularly AD. By advocating for an integrated therapeutic model that combines pharmacological and lifestyle interventions, we propose a comprehensive approach aimed at mitigating mitochondrial dysfunction and improving clinical outcomes in these complex, interrelated diseases.

Translating Molecular Psychiatry: From Biomarkers to Personalized Therapies-A Narrative Review

In this review, we explore the biomarkers of different psychiatric disorders, such as major depressive disorder, generalized anxiety disorder, schizophrenia, and bipolar disorder. Moreover, we show the interplay between genetic and environmental factors. Novel techniques such as genome-wide association studies (GWASs) have identified numerous risk loci and single-nucleotide polymorphisms (SNPs) implicated in these conditions, contributing to a better understanding of their mechanisms. Moreover, the impact of genetic variations on drug metabolisms, particularly through cytochrome P450 (CYP450) enzymes, highlights the importance of pharmacogenomics in optimizing psychiatric treatment. This review also explores the role of neurotransmitter regulation, immune system interactions, and metabolic pathways in psychiatric disorders. As the technology advances, integrating genetic markers into clinical practice will be crucial in advancing precision psychiatry, improving diagnostic accuracy and therapeutic interventions for individual patients.

Investigating the Therapeutic Potential of the Ketogenic Diet in Modulating Neurodegenerative Pathophysiology: An Interdisciplinary Approach

The ketogenic diet (KD) is a dietary intervention comprising a high-fat, low-carbohydrate, and moderate-protein intake designed to induce a metabolic state known as ketosis, whereby ketone bodies are produced as an alternative source of energy. Initially established as a treatment for intractable epilepsy, the KD has subsequently gained significant attention for its potential to manage neurodegenerative diseases, including Alzheimer's, Parkinson's, and Huntington's disease. Ketone bodies, such as beta-hydroxybutyrate (BHB), have been demonstrated to possess neuroprotective properties. The increasing prevalence of neurodegenerative diseases, such as Alzheimer's, Parkinson's, and Huntington's disease, poses a significant public health challenge worldwide. With neurological disorders being the second-leading cause of death globally, the need for effective therapeutic interventions has never been more urgent. Recent evidence suggests that dietary interventions, particularly the ketogenic diet, offer promising potential in mitigating the progression of these diseases by influencing metabolic processes and providing neuroprotective benefits. The ketogenic diet, characterized by high-fat and low-carbohydrate intake, induces ketosis, leading to the production of ketone bodies like beta-hydroxybutyrate, which enhance mitochondrial efficiency, reduce oxidative stress, and modulate inflammatory pathways-mechanisms critical in neurodegenerative pathophysiology. This review explores the role of the ketogenic diet in managing neurological conditions, examining its mechanisms of action, historical context, and therapeutic efficacy. The paper also discusses emerging evidence linking the ketogenic diet to improved cognitive function, reduced motor symptoms, and enhanced mitochondrial activity in patients with neurodegenerative disorders. Additionally, the review highlights the need for further research to refine the therapeutic applications of the ketogenic diet, investigate its impact on various neurodegenerative diseases, and better understand its potential long-term effects. This study underscores the importance of nutrition as a vital aspect of the treatment strategy for neurological diseases, advocating for continued exploration of dietary interventions to improve brain health and function.

Intermittent fasting and neurocognitive disorders: What the evidence shows

INTRODUCTION

Intermittent fasting (IF) has emerged as a potential lifestyle intervention for mitigating cognitive decline and enhancing brain health in individuals with mild to major neurocognitive disorders. Unlike preventive strategies, this review evaluates IF as a therapeutic approach, focusing on its effects on neuroplasticity, inflammation, and cognitive function.

METHODS

A narrative review was conducted using a comprehensive PubMed search with the terms "intermittent fasting AND neurocognition" and "intermittent fasting AND neuroplasticity". Studies published in English within the last ten years involving human and animal models were included. Exclusion criteria focused on studies primarily examining mood disorders or unrelated metabolic outcomes.

RESULTS

Preclinical evidence demonstrates that IF enhances hippocampal neurogenesis and synaptic plasticity through pathways involving BDNF and CREB. IF also reduces neuroinflammation, as shown in animal models of Alzheimer's disease, vascular cognitive impairment, and high-fat diet-induced cognitive impairment. Human studies, though limited, suggest that regular IF may improve cognitive function and reduce markers of oxidative stress and inflammation in individuals with mild cognitive impairment.

CONCLUSION

Current findings highlight the therapeutic potential of IF for individuals with existing cognitive impairment. While preclinical studies provide robust evidence of neuroprotective mechanisms, human studies remain sparse and require standardization. Further clinical research is necessary to confirm long-term safety and efficacy and to refine IF protocols for broader clinical application.

In vivo Detection and Correlation of Cerebral Ketone Bodies with Neurotransmitters in Streptozotocin-Induced Type 1 Diabetic Rats

Cerebral ketone bodies are crucial for understanding both physiological brain metabolism and pathological states, such as diabetic ketoacidosis (DKA). However, the metabolic consequences of elevated ketone body levels on brain metabolism during DKA remain poorly described to date. In this study, we utilized non-invasive magnetic resonance spectroscopy to detect and quantify ketone bodies and their correlation with neurotransmitter and neurotransmitter precursor levels in situ in the living brain of the streptozotocin (STZ)-induced type 1 diabetes (T1D) rat model. This well-characterized T1D model develops insulin deficiency with chronic hyperglycemia, which can trigger DKA. We report the detection and quantification of the acetone signal at 2.22 ppm in the STZ-induced T1D rat brain, along with two other ketone bodies, β-hydroxybutyrate and acetoacetate at 9.4 T. Cerebral levels of all three ketone bodies significantly increased as diabetes progressed compared to baseline levels prior to STZ injection. Moreover, ketone body levels correlated strongly with the inhibitory neurotransmitter γ-aminobutyric acid (GABA) and glutamine, as well as several other neurochemicals. Overall, DKA is characterized by a marked increase in brain ketone bodies as T1D progresses, accompanied by elevated GABA and glutamine levels. This study demonstrates the direct measurement of ketone bodies in the brain in vivo, enabling further investigation of their impact on brain metabolism in both health and disease.

Bibliometric analysis and description of research trends on nutritional management in Alzheimer's disease patients (1988-2024)

Background

Alzheimer's disease (AD) is a severe neurodegenerative disorder. Nutritional management has been recognized as a potential therapeutic approach to mitigate AD progression. This study aimed to analyze the bibliometric characteristics and research trends of publications on nutritional management in AD.

Methods

A systematic search was conducted on the Web of Science Core Collection database to identify publications related to nutritional management in AD from 1988 to 2024. Bibliometric analysis was performed using VOSviewers (V 1.6.20), CiteSpace (V 6.3.R1) and R 4.3.3.

Results

A total of 554 publications from 311 countries led by the USA were identified. The number of publications has increased annually. The most cited article discussed the role of diet in providing antioxidants to combat oxidative stress in neurodegenerative diseases. The University of California system published the most articles, and Rush University had the most international collaborations. These publications came from 3,298 authors, among which Mattson MP had the highest total publications and citations. The Journal of Alzheimer's Disease published the most articles and received the most citations. Keywords analysis revealed evolving trends, with early emphasis on "precursor protein" and later shifts to "dietary restriction," and more recently, "insulin resistance" and "synaptic plasticity." Emerging keywords include "obesity," "cognitive impairment" and "association."

Conclusion

This study represents the first summary of research trends in AD nutritional management. Future research is likely to focus on the associations between nutrition, insulin resistance, synaptic plasticity, and cognitive impairment in AD patients. This information provides valuable insights for scholars and practitioners in the field.

Impact of Diets on Cognitive and Clinical Outcomes in Alzheimer's Disease: A Scoping Review

Alzheimer's disease (AD) is characterized by beta-amyloid plaques and neurofibrillary tangles, leading to damage of neuronal synapses, negatively impacting memory and cognition. Research efforts have shown the benefit of proper nutrition in reducing the progression of AD and slowing the condition's progression. Specifically, nutritional intake has been demonstrated to influence neuro-inflammatory pathways. Various diets, including ketogenic, Mediterranean, Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, and Dietary Approaches to Stop Hypertension (DASH), have been shown to prevent the onset of AD to different degrees. The primary objective of this scoping review was to assess the impacts of various diets on AD onset and progression to identify unmet needs and gaps in understanding. Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, peer-reviewed literature was searched using Boolean operators: "Alzheimer's" AND "ketogenic" OR "DASH diet" OR "MIND diet" OR "Mediterranean diet" on EMBASE, MEDLINE, and Web of Science databases. The search was restricted to articles written in English and published in the United States between January 1, 2013, and September 30, 2023. The initial search yielded 121 articles after removing duplicates. After filtering based on inclusion and exclusion criteria, 24 articles were selected for further critical appraisal screening. The critical appraisal yielded 12 articles for the analysis included in this scoping review. This review supported the Mediterranean diet as the most effective in improving outcomes among patients with AD. The Mediterranean diet consists of a high intake of vegetables, fruits, legumes, nuts, olive oil, and unrefined cereals, a moderate intake of fish and wine, and a low intake of dairy products, meat, poultry, and saturated fat. Other diets reviewed, including the DASH and MIND diets, also have promising effects on AD, with less conclusive evidence when compared to the Mediterranean diet. Limitations, including small sample sizes, short durations, and socioeconomic constraints impacting compliance, were noted. This scoping review supports the need for dietary recommendation guidelines for patients with AD.

The potential protective effects and mechanisms of fasting on neurodegenerative disorders: A narrative review

This study aimed to review the potential neuroprotective effects and underlying mechanisms of fasting in neurodegenerative disorders by synthesizing the existing literature. Research indicates that fasting may induce substantial modifications in both brain structure and function through diverse metabolic and cellular pathways. Preclinical studies utilizing animal models have elucidated several key mechanisms mediating these effects. The other significant proposed mechanism involves the modulation of gut microbiota during fasting periods. The intestinal microbiome functions as a crucial intermediary in the complex interplay between feeding patterns, circadian rhythms, and immune responses. These microbiome alterations may subsequently exert considerable influence on central nervous system functionality. Moreover, by reducing glucose availability, fasting has been shown to enhance the survival and resistance of healthy cells to adjuvant treatments in central nervous system tumors. Fasting presents a promising non-pharmacological intervention for neurodegenerative disorders, potentially offering both preventive and therapeutic benefits. However, the current evidence base remains preliminary, warranting extensive further investigation to validate these initial findings and establish robust clinical protocols for both efficacy and safety.

The influence of time-restricted eating/feeding on Alzheimer's biomarkers and gut microbiota

OBJECTIVES

Alzheimer's disease (AD) is a progressive neurodegenerative disorder affecting approximately 55 million individuals globally. Diagnosis typically occurs in advanced stages, and there are limited options for reversing symptoms. Preventive strategies are, therefore, crucial. Time Restricted Eating (TRE) or Time Restricted Feeding (TRF) is one such strategy. Here we review recent research on AD and TRE/TRF in addition to AD biomarkers and gut microbiota.

METHODS

A comprehensive review of recent studies was conducted to assess the impact of TRE/TRF on AD-related outcomes. This includes the analysis of how TRE/TRF influences circadian rhythms, beta-amyloid 42 (Aß42), pro-inflammatory cytokines levels, and gut microbiota composition.

RESULTS

TRE/TRF impacts circadian rhythms and can influence cognitive performance as observed in AD. It lowers beta-amyloid 42 deposition in the brain, a key AD biomarker, and reduces pro-ininflammatory cytokines. The gut microbiome has emerged as a modifiable factor in AD treatment. TRE/TRF changes the structure and composition of the gut microbiota, leading to increased diversity and a decrease in harmful bacteria.

DISCUSSION

These findings underscore the potential of TRE/TRF as a preventive strategy for AD. By reducing Aß42 plaques, modulating pro-inflammatory cytokines, and altering gut microbiota composition, TRE/TRF may slow the progression of AD. Further research is needed to confirm these effects and to understand the mechanisms involved. This review highlights TRE/TRF as a promising non-pharmacological intervention in the fight against AD.

Maternal Diet and Vulnerability to Cognitive Impairment in Adulthood: Possible Link with Alzheimer's Disease?

BACKGROUND

Aging is the main risk factor for developing cognitive impairments and associated neurodegenerative diseases. However, environmental factors, including nutritional health, are likely to promote or reduce cognitive impairments and neurodegenerative pathologies. An intricate relationship exists between maternal nutrition and adult eating behavior, metabolic phenotype, and cognitive abilities.

SUMMARY

The objective of the present review was to collect available data, suggesting a link between maternal overnutrition and the latter impairment of cognitive functions in the progeny, and to relate this relationship with Alzheimer's disease (AD). Indeed, cognitive impairments are major behavioral signs of AD. We first reviewed studies showing an association between unbalanced maternal diet and cognitive impairments in the progeny in humans and rodent models. Then we looked for cellular and molecular hallmarks which could constitute a breeding ground for AD in those models. With this end, we focused on synaptic dysfunction, altered neurogenesis, neuroinflammation, oxidative stress, and pathological protein aggregation. Finally, we proposed an indirect mechanism linking maternal unbalanced diet and progeny's vulnerability to cognitive impairments and neurodegeneration through promoting metabolic diseases. We also discussed the involvement of progeny's gut microbiota in the maternal diet-induced vulnerability to metabolic and neurodegenerative diseases.

KEY MESSAGES

Further investigations are needed to fully decipher how maternal diet programs the fetus and infant brain. Addressing this knowledge gap would pave the way to precise nutrition and personalized medicine to better handle cognitive impairments in adulthood.

Exogenous ketone bodies and the ketogenic diet as a treatment option for neurodevelopmental disorders

Background

Despite being the most prevalent neurodevelopmental disorders, there are comparatively few treatment options available to patients presenting with autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). The ketogenic diet has historically shown therapeutic utility in treating refractory epilepsy, an adjacent neuropsychiatric condition, in children, adolescents and adults. The following review explores preclinical and clinical literature focusing on the therapeutic potential of the ketogenic diet and exogenous ketone body supplementation in treating common neurodevelopmental disorders.

Method

A narrative review of extant literature was conducted across the domains of perinatal nutrition, ASD, and ADHD. Preclinical and clinical studies focusing on the effect of either the ketogenic diet or exogenous ketone supplementation as a treatment option were included for review.

Results

14 preclinical and 10 clinical studies were included for discussion. Data supporting the use of a ketogenic intervention for neurodevelopmental disorders is mixed. High heterogeneity in study design was noted for preclinical models, ketogenic intervention, and outcomes measured.

Conclusion

Studies evaluating ketogenic interventions for neurodevelopmental disorders remain in their infancy in terms of both the depth and scope of available literature. The safety and tolerability of ketogenic diets and supplements means there would be value in exploring their effectiveness further in clinical studies.

Alzheimer's Disease, Obesity, and Type 2 Diabetes: Focus on Common Neuroglial Dysfunctions (Critical Review and New Data on Human Brain and Models)

BACKGROUND/OBJECTIVES

Obesity, type 2 diabetes (T2D), and Alzheimer's disease (AD) are pathologies that affect millions of people worldwide. They have no effective therapy and are difficult to prevent and control when they develop. It has been known for many years that these diseases have many pathogenic aspects in common. We highlight in this review that neuroglial cells (astroglia, oligodendroglia, and microglia) play a vital role in the origin, clinical-pathological development, and course of brain neurodegeneration. Moreover, we include the new results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we are investigating.

METHODS

Critical bibliographic revision and biochemical neuropathological study of neuroglia in a T2D-AD model.

RESULTS

T2D and AD are not only "connected" by producing complex pathologies in the same individual (obesity, T2D, and AD), but they also have many common pathogenic mechanisms. These include insulin resistance, hyperinsulinemia, hyperglycemia, oxidative stress, mitochondrial dysfunction, and inflammation (both peripheral and central-or neuroinflammation). Cognitive impairment and AD are the maximum exponents of brain neurodegeneration in these pathological processes. both due to the dysfunctions induced by metabolic changes in peripheral tissues and inadequate neurotoxic responses to changes in the brain. In this review, we first analyze the common pathogenic mechanisms of obesity, T2D, and AD (and/or cerebral vascular dementia) that induce transcendental changes and responses in neuroglia. The relationships between T2D and AD discussed mainly focus on neuroglial responses. Next, we present neuroglial changes within their neuropathological context in diverse scenarios: (a) aging involution and neurodegenerative disorders, (b) human obesity and diabetes and obesity/diabetes models, (c) human AD and in AD models, and (d) human AD-T2D and AD-T2D models. An important part of the data presented comes from our own studies on humans and experimental models over the past few years. In the T2D-AD section, we included the results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we investigated, which showed that neuroglial dysfunctions (astrocytosis and microgliosis) manifest before the appearance of amyloid neuropathology, and that the amyloid pathology is greater than that presented by mice fed a normal, non-high-caloric diet A broad review is finally included on pharmacological, cellular, genic, and non-pharmacological (especially diet and lifestyle) neuroglial-related treatments, as well as clinical trials in a comparative way between T2D and AD. These neuroglial treatments need to be included in the multimodal/integral treatments of T2D and AD to achieve greater therapeutic efficacy in many millions of patients.

CONCLUSIONS

Neuroglial alterations (especially in astroglia and microglia, cornerstones of neuroinflammation) are markedly defining brain neurodegeneration in T2D and A, although there are some not significant differences between each of the studied pathologies. Neuroglial therapies are a very important and p. promising tool that are being developed to prevent and/or treat brain dysfunction in T2D-AD. The need for further research in two very different directions is evident: (a) characterization of the phenotypic changes of astrocytes and microglial cells in each region of the brain and in each phase of development of each isolated and associated pathology (single-cell studies are mandatory) to better understand the pathologies and define new therapeutic targets; (b) studying new therapeutic avenues to normalize the function of neuroglial cells (preventing neurotoxic responses and/or reversing them) in these pathologies, as well as the phenotypic characteristics in each moment of the course and place of the neurodegenerative process.

The gut microbiota-brain axis in neurological disorders

Previous studies have shown a bidirectional communication between human gut microbiota and the brain, known as the microbiota-gut-brain axis (MGBA). The MGBA influences the host's nervous system development, emotional regulation, and cognitive function through neurotransmitters, immune modulation, and metabolic pathways. Factors like diet, lifestyle, genetics, and environment shape the gut microbiota composition together. Most research have explored how gut microbiota regulates host physiology and its potential in preventing and treating neurological disorders. However, the individual heterogeneity of gut microbiota, strains playing a dominant role in neurological diseases, and the interactions of these microbial metabolites with the central/peripheral nervous systems still need exploration. This review summarizes the potential role of gut microbiota in driving neurodevelopmental disorders (autism spectrum disorder and attention deficit/hyperactivity disorder), neurodegenerative diseases (Alzheimer's and Parkinson's disease), and mood disorders (anxiety and depression) in recent years and discusses the current clinical and preclinical gut microbe-based interventions, including dietary intervention, probiotics, prebiotics, and fecal microbiota transplantation. It also puts forward the current insufficient research on gut microbiota in neurological disorders and provides a framework for further research on neurological disorders.

Role of ketogenic diet in neurodegenerative diseases focusing on Alzheimer diseases: The guardian angle

The ketogenic diet (KD) is a low-carbohydrate, adequate protein and high-fat diet. KD is primarily used to treat refractory epilepsy. KD was shown to be effective in treating different neurodegenerative diseases. Alzheimer disease (AD) is the first common neurodegenerative disease in the world characterized by memory and cognitive impairment. However, the underlying mechanism of KD in controlling of AD and other neurodegenerative diseases are not discussed widely. Therefore, this review aims to revise the fundamental mechanism of KD in different neurodegenerative diseases focusing on the AD. KD induces a fasting-like which modulates the central and peripheral metabolism by regulating mitochondrial dysfunction, oxidative stress, inflammation, gut-flora, and autophagy in different neurodegenerative diseases. Different studies highlighted that KD improves AD neuropathology by regulating synaptic neurotransmission and inhibiting of neuroinflammation and oxidative stress. In conclusion, KD improves cognitive function and attenuates the progression of AD neuropathology by reducing oxidative stress, mitochondrial dysfunction, and enhancing neuronal autophagy and brain BDNF.

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.

Polyphenols and Diets as Current and Potential Nutrition Senotherapeutics in Alzheimer's Disease: Findings from Clinical Trials

Cellular senescence, a hallmark of aging, plays an important role in age-related conditions among older adults. Targeting senescent cells and its phenotype may provide a promising strategy to delay the onset or progression of Alzheimer's disease (AD). In this review article, we investigated efficacy and safety of nutrition senotherapy in AD, with a focus on the role of polyphenols as current and potential nutrition senotherapeutic agents, as well as relevant dietary patterns. Promising results with neuroprotective effects of senotherapeutic agents such as quercetin, resveratrol, Epigallocatechin-gallate, curcumin and fisetin were reported from preclinical studies. However, in-human trials remain limited, and findings were inconclusive. In future, nutrition senotherapeutic agents should be studied both individually and within dietary patterns, through the perspective of cellular senescence and AD. Further studies are warranted to investigate bioavailability, dosing regimen, long term effects of nutrition senotherapy and provide better understanding of the underlying mechanisms. Collaboration between researchers needs to be established, and methodological limitations of current studies should be addressed.

Ketogenic diet alleviates cognitive dysfunction and neuroinflammation in APP/PS1 mice via the Nrf2/HO-1 and NF-κB signaling pathways

Alzheimer's disease is a progressive neurological disorder characterized by cognitive decline and chronic inflammation within the brain. The ketogenic diet, a widely recognized therapeutic intervention for refractory epilepsy, has recently been proposed as a potential treatment for a variety of neurological diseases, including Alzheimer's disease. However, the efficacy of ketogenic diet in treating Alzheimer's disease and the underlying mechanism remains unclear. The current investigation aimed to explore the effect of ketogenic diet on cognitive function and the underlying biological mechanisms in a mouse model of Alzheimer's disease. Male amyloid precursor protein/presenilin 1 (APP/PS1) mice were randomly assigned to either a ketogenic diet or control diet group, and received their respective diets for a duration of 3 months. The findings show that ketogenic diet administration enhanced cognitive function, attenuated amyloid plaque formation and proinflammatory cytokine levels in APP/PS1 mice, and augmented the nuclear factor-erythroid 2-p45 derived factor 2/heme oxygenase-1 signaling pathway while suppressing the nuclear factor-kappa B pathway. Collectively, these data suggest that ketogenic diet may have a therapeutic potential in treating Alzheimer's disease by ameliorating the neurotoxicity associated with Aβ-induced inflammation. This study highlights the urgent need for further research into the use of ketogenic diet as a potential therapy for Alzheimer's disease.

[Beneficial effects of ketogenic diet for Alzheimer's disease management]

Alzheimer's disease (AD) is a neurodegenerative disease that affects almost 1 million people in France and 55 million in the world. This pathology is a global health preoccupation because of the lack of efficient curative treatment and the increase of its prevalence. During the last decade, the comprehension of pathophysiological mechanisms involved in AD have been improved. Amyloid plaques and neurofibrillary tangles accumulation are characteristic of Alzheimer's brain patients, accompanied by increased brain inflammation and oxidative stress, impaired cerebral metabolism of glucose and mitochondrial function. Treatment of AD includes different approaches, as pharmacology, psychology support, physiotherapy, and speech therapy. However, these interventions do not have a curative effect, but only compensatory on the disease. Ketogenic diet (KD), a low-carbohydrates and high-fat diet, associated with a medium-chain triglycerides intake (MCTs) might induce benefices for Alzheimer disease patients. Carbohydrate restriction and MCTs promotes the production of ketone bodies from fatty acid degradation. These metabolites replacing glucose, serve the brain as energetic substrates, and induce neuroprotective effects. Such a nutritional support might slow down the disease progression and improve cognitive abilities of patients. This review aims to examine the neuroprotective mechanisms of KD in AD progression and describes the advantages and limitations of KD as a therapeutic strategy.

Emerging Alzheimer's disease therapeutics: promising insights from lipid metabolism and microglia-focused interventions

More than 55 million people suffer from dementia, with this number projected to double every 20 years. In the United States, 1 in 3 aged individuals dies from Alzheimer's disease (AD) or another type of dementia and AD kills more individuals than breast cancer and prostate cancer combined. AD is a complex and multifactorial disease involving amyloid plaque and neurofibrillary tangle formation, glial cell dysfunction, and lipid droplet accumulation (among other pathologies), ultimately leading to neurodegeneration and neuronal death. Unfortunately, the current FDA-approved therapeutics do not reverse nor halt AD. While recently approved amyloid-targeting antibodies can slow AD progression to improve outcomes for some patients, they are associated with adverse side effects, may have a narrow therapeutic window, and are expensive. In this review, we evaluate current and emerging AD therapeutics in preclinical and clinical development and provide insight into emerging strategies that target brain lipid metabolism and microglial function - an approach that may synergistically target multiple mechanisms that drive AD neuropathogenesis. Overall, we evaluate whether these disease-modifying emerging therapeutics hold promise as interventions that may be able to reverse or halt AD progression.

[Relationships between microbiome and neurodegeneration]

BACKGROUND

Neurodegenerative diseases are often associated with changes in the (gut) microbiome.

OBJECTIVE

Based on studies in Parkinson's disease (PD) and Alzheimer's disease (AD), an overview of the current evidence of microbial changes and their possible role in the development of these diseases is given.

METHODS

Analysis, summary, and evaluation of the current literature on (gut) microbiome and neurodegeneration.

RESULTS

Numerous studies have shown dysbiotic changes in the gut microbiome of PD and AD patients compared to healthy individuals, some of which might occur even in the prodromal phase. Specifically, these patients show a reduction in bacteria involved in the synthesis of short-chain fatty acids. These microbial alterations have been associated with systemic inflammation and a compromised integrity of the intestinal barrier and blood-brain barrier. Bacterial molecules such as lipopolysaccharides may play an important role in these changes. Additionally, the bacterial protein curli, found on the surface of e.g., Escherichia coli, has been shown in vitro and in animal models to promote the misfolding of α-synuclein, thus suggesting a crucial pathomechanism. Moreover, certain oral bacteria appear to be more prevalent in AD patients and may contribute to the pathogenesis of AD.

CONCLUSION

Neurodegenerative diseases are associated with dysbiosis of the (gut) microbiome, which can have diverse systemic effects; however, it remains unclear whether this dysbiosis is a cause or a consequence of the diseases. Further investigation of this (prodromal) microbial imbalance could reveal new approaches for targeted therapeutic manipulation of the microbiome to modify and prevent these diseases.

Molecular Aspects of a Diet as a New Pathway in the Prevention and Treatment of Alzheimer's Disease

Alzheimer's disease is the most common cause of dementia in the world. Lack of an established pathology makes it difficult to develop suitable approaches and treatment for the disease. Besides known hallmarks, including amyloid β peptides cumulating in plaques and hyperphosphorylated tau forming NFTs, inflammation also plays an important role, with known connections to the diet. In AD, adhering to reasonable nutrition according to age-related principles is recommended. The diet should be high in neuroprotective foods, such as polyunsaturated fatty acids, antioxidants, and B vitamins. In addition, foods capable of rising BDNF should be considered because of the known profitable results of this molecule in AD. Adhering to beneficial diets might result in improvements in memory, cognition, and biomarkers and might even reduce the risk of developing AD. In this review, we discuss the effects of various diets, foods, and nutrients on brain health and possible connections to Alzheimer's disease.

Neurodegenerative and Neurodevelopmental Diseases and the Gut-Brain Axis: The Potential of Therapeutic Targeting of the Microbiome

The human gut microbiome contains the largest number of bacteria in the body and has the potential to greatly influence metabolism, not only locally but also systemically. There is an established link between a healthy, balanced, and diverse microbiome and overall health. When the gut microbiome becomes unbalanced (dysbiosis) through dietary changes, medication use, lifestyle choices, environmental factors, and ageing, this has a profound effect on our health and is linked to many diseases, including lifestyle diseases, metabolic diseases, inflammatory diseases, and neurological diseases. While this link in humans is largely an association of dysbiosis with disease, in animal models, a causative link can be demonstrated. The link between the gut and the brain is particularly important in maintaining brain health, with a strong association between dysbiosis in the gut and neurodegenerative and neurodevelopmental diseases. This link suggests not only that the gut microbiota composition can be used to make an early diagnosis of neurodegenerative and neurodevelopmental diseases but also that modifying the gut microbiome to influence the microbiome-gut-brain axis might present a therapeutic target for diseases that have proved intractable, with the aim of altering the trajectory of neurodegenerative and neurodevelopmental diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism spectrum disorder, and attention-deficit hyperactivity disorder, among others. There is also a microbiome-gut-brain link to other potentially reversible neurological diseases, such as migraine, post-operative cognitive dysfunction, and long COVID, which might be considered models of therapy for neurodegenerative disease. The role of traditional methods in altering the microbiome, as well as newer, more novel treatments such as faecal microbiome transplants and photobiomodulation, are discussed.

Impact of Diet and Exercise Interventions on Cognition and Brain Health in Older Adults: A Narrative Review

The ability to preserve cognitive function and protect brain structure from the effects of the aging process and neurodegenerative disease is the goal of non-pharmacologic, lifestyle interventions focused on brain health. This review examines, in turn, current diet and exercise intervention trends and the collective progress made toward understanding their impact on cognition and brain health. The diets covered in this review include the Mediterranean diet (MeDi), Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), ketogenic diet, intermittent fasting, and weight loss management. The exercise approaches covered in this review include endurance, resistance, combined exercise programs, yoga, tai chi, and high-intensity interval training. Although valuable evidence is building concerning how diet and exercise influence cognitive performance and brain structure, many of the open questions in the field are concerned with why we see these effects. Therefore, more strategically designed intervention studies are needed to reveal the likely multiple mechanisms of action in humans.

A bibliometric analysis of the global trends and hotspots for the ketogenic diet based on CiteSpace

The ketogenic diet (KD) is a potential nutritional therapy that is frequently utilized in various conditions. More and more studies are being done on KD in recent years. However, as far as we know, few studies have made an effort to offer a thorough synthesis and assessment of this topic. This paper aims to do a rigorous and thorough evaluation of the knowledge structure, development trend, and research hotspot of scientific outputs connected to KD. The bibliographic records connected to KD from January 1, 2001 to April 22, 2022 were collected using the core collection database of Web of Science. The complex data input, that consisted of the amount of publications, journals, authors, institutions, countries, keywords and cited references, was generated and analyzed visually using CiteSpace. A total of 2676 literatures on the KD were published between 2001 and 2022. The most KD-related publications were found in Epilepsia and Epilepsia Research. The authors with the most KD-related papers are Kossoff EH and Rho J. The United States is the country with the most publications, and Johns Hopkins University, Johns Hopkins University Hospital, and Johns Hopkins Medical Institutions are the institutions with the most articles. The high frequency keywords are "KD," "ketone body," "children," "efficacy," "weight loss," "low carbohydrate diet," "metabolism," "epilepsy," "beta hydroxybutyrate," and "modified atkins diet." The 2018 study by Kossoff EH on epilepsia and the 2017 study by Puchalska P on ketone body metabolism earned 127 and 114 citations, respectively. The results of this bibliometric analysis provide information on the state and trends in KD and may be used by researchers to pinpoint hot issues and discover new areas of study.

The gut microbiota in obesity and weight management: microbes as friends or foe?

Obesity is caused by a long-term difference between energy intake and expenditure - an imbalance that is seemingly easily restored by increasing exercise and reducing caloric consumption. However, as simple as this solution appears, for many people, losing excess weight is difficult to achieve and even more difficult to maintain. The reason for this difficulty is that energy intake and expenditure, and by extension body weight, are regulated through complex hormonal, neural and metabolic mechanisms that are under the influence of many environmental factors and internal responses. Adding to this complexity, the microorganisms (microbes) that comprise the gut microbiota exert direct effects on the digestion, absorption and metabolism of food. Furthermore, the gut microbiota exerts a miscellany of protective, structural and metabolic effects both on the intestinal milieu and peripheral tissues, thus affecting body weight by modulating metabolism, appetite, bile acid metabolism, and the hormonal and immune systems. In this Review, we outline historical and recent advances in understanding how the gut microbiota is involved in regulating body weight homeostasis. We also discuss the opportunities, limitations and challenges of using gut microbiota-related approaches as a means to achieve and maintain a healthy body weight.

Therapeutic approaches for improving cognitive function in the aging brain

The rapid aging of populations around the world has become an unprecedented challenge. Aging is associated with cognitive impairment, including dementia and mild cognitive impairment. Successful drug development for improving or maintaining cognition in the elderly is critically important. Although 4 drugs for improving cognition in Alzheimer's disease have been approved, a variety of potential drugs targeting age-related cognitive impairment are still in development. In addition, non-pharmacological interventions, including cognition-oriented treatments, non-invasive brain stimulation physical exercise, and lifestyle-related interventions, have also been suggested as cognitive enhancers in the last decade. In this paper, we reviewed the recent evidence of pharmacological and non-pharmacological interventions aimed at improving or maintaining cognition in the elderly.

Ketogenic diets and Ketone suplementation: A strategy for therapeutic intervention

Ketogenic diets and orally administered exogenous ketone supplements are strategies to increase serum ketone bodies serving as an alternative energy fuel for high energy demanding tissues, such as the brain, muscles, and the heart. The ketogenic diet is a low-carbohydrate and fat-rich diet, whereas ketone supplements are usually supplied as esters or salts. Nutritional ketosis, defined as serum ketone concentrations of ≥ 0.5 mmol/L, has a fasting-like effect and results in all sorts of metabolic shifts and thereby enhancing the health status. In this review, we thus discuss the different interventions to reach nutritional ketosis, and summarize the effects on heart diseases, epilepsy, mitochondrial diseases, and neurodegenerative disorders. Interest in the proposed therapeutic benefits of nutritional ketosis has been growing the past recent years. The implication of this nutritional intervention is becoming more evident and has shown interesting potential. Mechanistic insights explaining the overall health effects of the ketogenic state, will lead to precision nutrition for the latter diseases.

Nutrients and amyloid β status in the brain: A narrative review

Amyloid beta (Aβ) is a peptide and a hallmark of Alzheimer's disease (AD). Emerging evidence suggests that Aβ levels could be influenced by diet. However, the evidence is sparse and for some nutrients, controversial. The aim of this narrative review is to gather the findings of observational and clinical trials involving human participants on the relationships between nutrients and brain Aβ status. Some dietary patterns are associated to reduced levels of Aβ in the brain, such as the Mediterranean diet, ketogenic diet as well as low intake of saturated fat, high-glycemic-index food, sodium, and junk/fast food. Low Aβ status in the brain was also associated with higher density lipoproteins (HDL) cholesterol and polyunsaturated fatty acids consumption. Data on alcohol intake is not conclusive. On the contrary, high Aβ levels in the brain were related to a higher intake of total cholesterol, triglycerides, low-density lipoproteins (LDL) cholesterol, saturated fat, sucrose, and fructose. Folic acid, cobalamin, vitamin E, and vitamin D were not associated to Aβ status, while high blood concentrations of Calcium, Aluminum, Zinc, Copper, and Manganese were associated with decreased Aβ blood levels but were not associated with Aβ cerebral spinal fluid (CSF) concentrations. In conclusion, certain dietary patterns and nutrients are associated to brain Aβ status. Further research on the association between nutrients and brain Aβ status is needed in order to pave the way to use nutritional interventions as efficacious strategies to prevent Aβ disturbance and potentially AD.

The emerging role of the microbiome in Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent form of dementia and can be influenced by genetic and environmental factors. Recent studies suggest that the intestinal microbiota is altered in AD patients when compared to healthy individuals and may play a role in disease onset and progression. Aging is the greatest risk factor for AD, and age-related changes in the microbiota can affect processes that contribute to cognitive decline. The microbiota may affect AD by modulating peripheral and central immunity or by secreting factors that influence neurogenesis or neuronal cell death. Finally, probiotic and dietary interventions that target the microbiome may have therapeutic potential to prevent or treat AD.