Calorie restriction or dietary restriction: how far they can protect the brain against neurodegenerative diseases?

Long-term calorie restriction reduces oxidative DNA damage to oligodendroglia and promotes homeostatic microglia in the aging monkey brain

Calorie restriction (CR) is a robust intervention that can slow biological aging and extend lifespan. In the brain, terminally differentiated neurons and glia accumulate oxidative damage with age, reducing their optimal function. We investigated if CR could reduce oxidative DNA damage to white matter oligodendrocytes and microglia. This study utilized post-mortem brain tissue from rhesus monkeys that died after decades on a 30 % reduced calorie diet. We found that CR subjects had significantly fewer cells with oxidative damage within the corpus callosum and the cingulum bundle. Oligodendrocytes specifically showed the greatest response to CR with a robust reduction in DNA damage. Additionally, we observed alterations in microglia morphology with CR subjects having a higher proportion of ramified, homeostatic microglia and fewer pro-inflammatory, hypertrophic microglia relative to controls. Furthermore, we determined that the observed attenuation in damaged DNA occurs primarily within mitochondria. Overall, these data suggest that long-term CR can reduce oxidative DNA damage and offer a neuroprotective effect in a cell-type-specific manner in the aging monkey brain.

Sex-specific resilience of neocortex to food restriction

Mammals have evolved sex-specific adaptations to reduce energy usage in times of food scarcity. These adaptations are well described for peripheral tissue, though much less is known about how the energy-expensive brain adapts to food restriction, and how such adaptations differ across the sexes. Here, we examined how food restriction impacts energy usage and function in the primary visual cortex (V1) of adult male and female mice. Molecular analysis and RNA sequencing in V1 revealed that in males, but not in females, food restriction significantly modulated canonical, energy-regulating pathways, including pathways associated waith AMP-activated protein kinase, peroxisome proliferator-activated receptor alpha, mammalian target of rapamycin, and oxidative phosphorylation. Moreover, we found that in contrast to males, food restriction in females did not significantly affect V1 ATP usage or visual coding precision (assessed by orientation selectivity). Decreased serum leptin is known to be necessary for triggering energy-saving changes in V1 during food restriction. Consistent with this, we found significantly decreased serum leptin in food-restricted males but no significant change in food-restricted females. Collectively, our findings demonstrate that cortical function and energy usage in female mice are more resilient to food restriction than in males. The neocortex, therefore, contributes to sex-specific, energy-saving adaptations in response to food restriction.

Metabolic regulation of the Th17/Treg balance in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a long-lasting and inflammatory autoimmune condition affecting the gastrointestinal tract, impacting millions of individuals globally. The balance between T helper 17 (Th17) cells and regulatory T cells (Tregs) is pivotal in the pathogenesis and progression of IBD. This review summarizes the pivotal role of Th17/Treg balance in maintaining intestinal homeostasis, elucidating how its dysregulation contributes to the development and exacerbation of IBD. It comprehensively synthesizes the current understanding of how dietary factors regulate the metabolic pathways influencing Th17 and Treg cell differentiation and function. Additionally, this review presents evidence from the literature on the potential of dietary regimens to regulate the Th17/Treg balance as a strategy for the management of IBD. By exploring the intersection between diet, metabolic regulation, and Th17/Treg balance, the review reveals innovative therapeutic approaches for IBD treatment, offering a promising perspective for future research and clinical practice.

Gengricin®: A Nutraceutical Formulation for Appetite Control and Therapeutic Weight Management in Adults Who Are Overweight/Obese

In the field of nutritional science and metabolic disorders, there is a growing interest in natural bitter compounds capable of interacting with bitter taste receptors (TAS2Rs) useful for obesity management and satiety control. This study aimed to evaluate the effect of a nutraceutical formulation containing a combination of molecules appropriately designed to simultaneously target and stimulate these receptors. Specifically, the effect on CCK release exerted by a multi-component nutraceutical formulation (Cinchona bark, Chicory, and Gentian roots in a 1:1:1 ratio, named Gengricin®) was investigated in a CaCo-2 cell line, in comparison with Cinchona alone. In addition, these nutraceutical formulations were tested through a 3-month randomized controlled trial (RCT) conducted in subjects who were overweight-obese following a hypocaloric diet. Interestingly, the Gengricin® group exhibited a significant greater weight loss and improvement in body composition than the Placebo and Cinchona groups, indicating its effectiveness in promoting weight regulation. Additionally, the Gengricin® group reported higher satiety levels and a significant increase in serum CCK levels, suggesting a physiological basis for the observed effects on appetite control. Overall, these findings highlight the potential of natural nutraceutical strategies based on the combination of bitter compounds in modulating gut hormone release for effective appetite control and weight management.

Factors affecting target caloric achievement and calorie intake improvement: the nutrition support team's role

Background

The nutrition support team (NST) works to improve malnutrition in hospitalized patients, and its role is expanding as more hospitals adopt NST. This study aimed to identify the clinical characteristics of NST-referred patients admitted to a tertiary hospital. The study focused on two groups: those who achieved the target calories, approximately 75% or more of their caloric needs relative to their body weight regardless of the period after the first NST referral, and those who improved their calorie intake 1 week after NST therapy. This study also analyzed the important factors affecting the achievement of target calorie intake and improvement in calorie intake to discover the focus of future NST therapy.

Methods

This study examined 1,171 adult patients (aged ≥18 years) who were referred to the NST from all the departments within a tertiary hospital at least twice, with a minimum one-week interval between referrals, between January 1, 2019, and December 31, 2020. The study participants consisted of patients receiving <75% of their required caloric intake at the time of their first NST referral. Patients were categorized and compared according to whether they achieved their target calorie intake regardless of the period after the first NST referral and whether they improved their calorie intake 1 week after the NST therapy. We then identified factors affecting target caloric achievement and improvement in calorie intake.

Results

The group that achieved the target calorie intake had a lower proportion of neuro department patients (31.3%), a higher proportion of patients receiving intensive care unit (ICU) care (31.9%), and a longer ICU stay (p < 0.001) than the group that did not achieve the target calorie intake. Neuro department admission negatively affected target caloric achievement [adjusted odds ratio (aOR) = 0.305, 95% confidence interval (CI) = 0.150-0.617], whereas the length of ICU stay positively affected target caloric achievement (aOR = 1.025, 95% CI = 1.007-1.043). The proportion of neuro department patients was also low (42.5%) in the group with improved calorie intake 1 week after NST therapy. Neuro department admission was a negative factor (aOR = 0.376, 95% CI = 0.264-0.537) affecting the improvement in calorie intake.

Conclusions

NST therapy significantly improved clinical outcomes for inpatients at nutritional risk. Because achieving target calories and improving calorie intake in neuro department patients is difficult, it is necessary to actively refer them to NST to achieve the target calories and improve calorie intake. Furthermore, because a longer ICU stay positively affects target calorie achievement, the system for ICU nutrition therapy should be expanded and implemented for general-ward patients, including neurological patients.

Mitochondrial Inherited Disorders and their Correlation with Neurodegenerative Diseases

Mitochondria are essential organelles for the survival of a cell because they produce energy. The cells that need more mitochondria are neurons because they perform a variety of tasks that are necessary to support brain homeostasis. The build-up of abnormal proteins in neurons, as well as their interactions with mitochondrial proteins, or MAM proteins, cause serious health issues. As a result, mitochondrial functions, such as mitophagy, are impaired, resulting in the disorders described in this review. They are also due to mtDNA mutations, which alter the heritability of diseases. The topic of disease prevention, as well as the diagnosis, requires further explanation and exploration. Finally, there are treatments that are quite promising, but more detailed research is needed.

Underestimated health risks: Dietary restriction magnify the intestinal barrier dysfunction and liver injury in mice induced by polystyrene microplastics

Microplastics (MPs) have gained significant attention due to their widespread presence in the environment. While studies have been conducted to investigate the risks associated with MPs, the potential effects of MPs on populations with varying dietary habits, such as dietary restriction (DR), remain largely undefined. The sensitivity of the body to invasive contaminants may increase due to insufficient food intake. Here, we aimed to investigate whether dietary restriction could affect the toxicity of MPs in mice. Following a 5-week exposure to 200 μg/L polystyrene microplastics (PSMPs), DR-PSMPs treatment group exhibited significant intestinal barrier dysfunction compared to ND-PSMPs treatment group, as determined by histopathological and biochemical analysis. Dietary restriction worsened liver oxidative stress and bile acid disorder in mice exposed to PSMPs. 16S rRNA sequencing analysis revealed that DR-PSMPs treatment caused alterations in gut microbiota composition, including the downregulation of probiotics abundance and upregulation of pathogenic bacteria abundance. The negative effects caused by PSMPs in mice with dietary restriction could attribute to increased MPs bioaccumulation, declined water intake, reduced probiotics abundance, and elevated pathogenic bacteria abundance, as well as the susceptibility of the dietary restriction individual. Our findings hint that the biological effects of contaminants could be affected by dietary habits.

Alzheimer's Disease Treatment: The Search for a Breakthrough

As the search for modalities to cure Alzheimer's disease (AD) has made slow progress, research has now turned to innovative pathways involving neural and peripheral inflammation and neuro-regeneration. Widely used AD treatments provide only symptomatic relief without changing the disease course. The recently FDA-approved anti-amyloid drugs, aducanumab and lecanemab, have demonstrated unclear real-world efficacy with a substantial side effect profile. Interest is growing in targeting the early stages of AD before irreversible pathologic changes so that cognitive function and neuronal viability can be preserved. Neuroinflammation is a fundamental feature of AD that involves complex relationships among cerebral immune cells and pro-inflammatory cytokines, which could be altered pharmacologically by AD therapy. Here, we provide an overview of the manipulations attempted in pre-clinical experiments. These include inhibition of microglial receptors, attenuation of inflammation and enhancement of toxin-clearing autophagy. In addition, modulation of the microbiome-brain-gut axis, dietary changes, and increased mental and physical exercise are under evaluation as ways to optimize brain health. As the scientific and medical communities work together, new solutions may be on the horizon to slow or halt AD progression.

Dietary energy restriction in neurological diseases: what's new?

Energy-restricted diet is a specific dietary regimen, including the continuous energy-restricted diet and the intermittent energy-restricted diet. It has been proven effective not only to reduce weight and extend the lifespan in animal models, but also to regulate the development and progression of various neurological diseases such as epilepsy, cerebrovascular diseases (stroke), neurodegenerative disorders (Alzheimer's disease and Parkinson's disease) and autoimmune diseases (multiple sclerosis). However, the mechanism in this field is still not clear and a systematic neurological summary is still missing. In this review, we first give a brief summary of the definition and mainstream strategies of energy restrictions. We then review evidence about the effects of energy-restricted diet from both animal models and human trials, and update the current understanding of mechanisms underlying the biological role of energy-restricted diet in the fight against neurological diseases. Our review thus contributes to the modification of dietary regimen and the search for special diet mimics.

Aging and aging-related diseases: from molecular mechanisms to interventions and treatments

Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.

The effect of fecal microbiota transplantation on stroke outcomes: A systematic review

BACKGROUND AND PURPOSE

Fecal microbiota transplantation (FMT) is a novel microbiota-based therapeutic method that transfers stool from donor into a recipient and its application is under investigating for neurological disorders such as stroke. In this systematic review, we assessed the effect of FMT in progression and treatment of stroke and recovery of post-stroke complications.

METHODS

Preliminary studies were searched in MEDLINE via PubMed, Scopus, COCHRANE library and Google Scholar, databases up to February 2022. The search strategy was restricted to articles about FMT in stroke. The initial search yielded 4570 articles, of which 19 publications were included in our systematic review.

RESULTS

Based on outcomes transferring microbiome from healthy or ischemic donor to other ischemic recipient can affect brain infarct volume and survival rate, neurological and behavioral outcomes, and inflammatory pathways.

CONCLUSIONS

Our systematic review on preclinical studies showed that manipulating gut microbiota via FMT can be a possible therapeutic approach for treatment of stroke and recovery of post-stroke complications.

Involvement of the Intestinal Microbiota in the Appearance of Multiple Sclerosis: Aloe vera and Citrus bergamia as Potential Candidates for Intestinal Health

Multiple sclerosis (MS) is a neurological and inflammatory autoimmune disease of the Central Nervous System in which selective activation of T and B lymphocytes prompts a reaction against myelin, inducing demyelination and axonal loss. Although MS is recognized to be an autoimmune pathology, the specific causes are many; thus, to date, it has been considered a disorder resulting from environmental factors in genetically susceptible individuals. Among the environmental factors hypothetically involved in MS, nutrition seems to be well related, although the role of nutritional factors is still unclear. The gut of mammals is home to a bacterial community of about 2000 species known as the “microbiota”, whose composition changes throughout the life of each individual. There are five bacterial phylas that make up the microbiota in healthy adults: Firmicutes (79.4%), Bacteroidetes (16.9%), Actinobacteria (2.5%), Proteobacteria (1%) and Verrucomicrobia (0.1%). The diversity and abundance of microbial populations justifies a condition known as eubiosis. On the contrary, the state of dysbiosis refers to altered diversity and abundance of the microbiota. Many studies carried out in the last few years have demonstrated that there is a relationship between the intestinal microflora and the progression of multiple sclerosis. This correlation was also demonstrated by the discovery that patients with MS, treated with specific prebiotics and probiotics, have greatly increased bacterial diversity in the intestinal microbiota, which might be otherwise reduced or absent. In particular, natural extracts of Aloe vera and bergamot fruits, rich in polyphenols and with a high percentage of polysaccharides (mostly found in indigestible and fermentable fibers), appear to be potential candidates to re-equilibrate the gut microbiota in MS patients. The present review article aims to assess the pathophysiological mechanisms that reveal the role of the microbiota in the development of MS. In addition, the potential for supplementing patients undergoing early stages of MS with Aloe vera as well as bergamot fibers, on top of conventional drug treatments, is discussed.

Gut Microbiota: A Novel Therapeutic Target for Parkinson’s Disease

Parkinson’s disease (PD) is the second most common neurodegenerative disease characterized by motor dysfunction. Growing evidence has demonstrated that gut dysbiosis is involved in the occurrence, development and progression of PD. Numerous clinical trials have identified the characteristics of the changed gut microbiota profiles, and preclinical studies in PD animal models have indicated that gut dysbiosis can influence the progression and onset of PD via increasing intestinal permeability, aggravating neuroinflammation, aggregating abnormal levels of α-synuclein fibrils, increasing oxidative stress, and decreasing neurotransmitter production. The gut microbiota can be considered promising diagnostic and therapeutic targets for PD, which can be regulated by probiotics, psychobiotics, prebiotics, synbiotics, postbiotics, fecal microbiota transplantation, diet modifications, and Chinese medicine. This review summarizes the recent studies in PD-associated gut microbiota profiles and functions, the potential roles, and mechanisms of gut microbiota in PD, and gut microbiota-targeted interventions for PD. Deciphering the underlying roles and mechanisms of the PD-associated gut microbiota will help interpret the pathogenesis of PD from new perspectives and elucidate novel therapeutic strategies for PD.