Mediterranean diet intervention alters the gut microbiome in older people reducing frailty and improving health status: the NU-AGE 1-year dietary intervention across five European countries

Gut microbiota and microbial metabolites for osteoporosis

Osteoporosis is an age-related bone metabolic disease. As an essential endocrine organ, the skeletal system is intricately connected with extraosseous organs. The crosstalk between bones and other organs supports this view. In recent years, the link between the gut microecology and bone metabolism has become an important research topic, both in preclinical studies and in clinical trials. Many studies have shown that skeletal changes are accompanied by changes in the composition and structure of the gut microbiota (GM). At the same time, natural or artificial interventions targeting the GM can subsequently affect bone metabolism. Moreover, microbiome-related metabolites may have important effects on bone metabolism. We aim to review the relationships among the GM, microbial metabolites, and bone metabolism and to summarize the potential mechanisms involved and the theory of the gut‒bone axis. We also describe existing bottlenecks in laboratory studies, as well as existing challenges in clinical settings, and propose possible future research directions.

A novel framework for assessing causal effect of microbiome on health: long-term antibiotic usage as an instrument

Assessing causality is undoubtedly one of the key questions in microbiome studies for the upcoming years. Since randomized trials in human subjects are often unethical or difficult to pursue, analytical methods to derive causal effects from observational data deserve attention. As simple covariate adjustment is not likely to account for all potential confounders, the idea of instrumental variable (IV) analysis is worth exploiting. Here we propose a novel framework of antibiotic instrumental variable regression (AB-IVR) for estimating the causal relationships between microbiome and various diseases. We rely on the recent studies showing that antibiotic treatment has a cumulative long-term effect on the microbiome, resulting in individuals with higher antibiotic usage to have a more perturbed microbiome. We apply the AB-IVR method on the Estonian Biobank data and show that the microbiome has a causal role in numerous diseases including migraine, depression and irritable bowel syndrome. We show with a plethora of sensitivity analyses that the identified causal effects are robust and propose ways for further methodological developments.

Personalized prediction of glycemic responses to food in women with diet-treated gestational diabetes: the role of the gut microbiota

We developed a prediction model for postprandial glycemic response (PPGR) in pregnant women, including those with diet-treated gestational diabetes mellitus (GDM) and healthy women, and explored the role of gut microbiota in improving prediction accuracy. The study involved 105 pregnant women (77 with GDM, 28 healthy), who underwent continuous glucose monitoring (CGM) for 7 days, provided food diaries, and gave stool samples for microbiome analysis. Machine learning models were created using CGM data, meal content, lifestyle factors, biochemical parameters, and microbiota data (16S rRNA gene sequence analysis). Adding microbiome data increased the explained variance in peak glycemic levels (GLUmax) from 34 to 42% and in incremental area under the glycemic curve (iAUC120) from 50 to 52%. The final model showed better correlation with measured PPGRs than one based only on carbohydrate count (r = 0.72 vs. r = 0.51 for iAUC120). Although microbiome features were important, their contribution to model performance was modest.

Achieving healthy aging through gut microbiota-directed dietary intervention: Focusing on microbial biomarkers and host mechanisms

BACKGROUND

Population aging has become a primary global public health issue, and the prevention of age-associated diseases and prolonging healthy life expectancies are of particular importance. Gut microbiota has emerged as a novel target in various host physiological disorders including aging. Comprehensive understanding on changes of gut microbiota during aging, in particular gut microbiota characteristics of centenarians, can provide us possibility to achieving healthy aging or intervene pathological aging through gut microbiota-directed strategies.

AIM OF REVIEW

This review aims to summarize the characteristics of the gut microbiota associated with aging, explore potential biomarkers of aging and address microbiota-associated mechanisms of host aging focusing on intestinal barrier and immune status. By summarizing the existing effective dietary strategies in aging interventions, the probability of developing a diet targeting the gut microbiota in future is provided.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review is focused on three key notions: Firstly, gut microbiota has become a new target for regulating health status and lifespan, and its changes are closely related to age. Thus, we summarized aging-associated gut microbiota features at the levels of key genus/species and important metabolites through comparing the microbiota differences among centenarians, elderly people and younger people. Secondly, exploring microbiota biomarkers related to aging and discussing future possibility using dietary regime/components targeted to aging-related microbiota biomarkers promote human healthy lifespan. Thirdly, dietary intervention can effectively improve the imbalance of gut microbiota related to aging, such as probiotics, prebiotics, and postbiotics, but their effects vary among.

Lifestyle interventions for dementia risk reduction: A review on the role of physical activity and diet in Western and Asian Countries

Dementia, is a critical global public health challenge with no effective pharmacological treatments. Recent research highlights the significant role of lifestyle interventions, particularly physical activity and dietary habits, in mitigating cognitive decline among the elderly and preventing the progression to dementia in individuals with Mild Cognitive Impairment (MCI). This comprehensive review explores the impact of physical exercise and dietary approaches on cognitive health, comparing strategies adopted in Western and Asian countries. Physical activity, including aerobic, resistance, balance training, and dual-task exercises, has been shown to enhance neurogenesis, improve cerebral blood flow, and delay cognitive decline. In Western countries, structured regimens such as the Mediterranean (MedDiet) and MIND diets are prominent, while Asian countries often integrate traditional mind-body practices like Tai Chi and culturally relevant diets rich in antioxidants and polyphenols. Although both regions recognize the importance of lifestyle changes in reducing dementia risk, their approaches differ significantly, shaped by cultural norms and dietary preferences. This review underscores the need for culturally tailored public health strategies to promote cognitive health globally, highlighting the importance of individualized approaches in MCI and dementia prevention.

The impact of dietary patterns on gut microbiota for the primary and secondary prevention of cardiovascular disease: a systematic review

BACKGROUND

Previous studies found that it is promising to achieve the protective effects of dietary patterns on cardiovascular health through the modulation of gut microbiota. However, conflicting findings have been reported on how dietary patterns impact gut microbiota in individuals either established or at risk of cardiovascular disease (CVD). Our systematic review aimed to explore the effect of dietary patterns on gut microbiota composition and on risk factors for CVD in these populations.

METHODS

We systematically searched seven databases, including PubMed/MEDLINE, MEDLINE (Ovid), Embase (Ovid), CINHAL (EBSCO), Web of Science, CNKI (Chinese), and Wanfang (Chinese), covering literature from inception to October 2024. Studies were included if they focused on adults aged 18 years and older with CVD or at least two CVD risk factors, implemented dietary pattern interventions, and incorporated outcomes related to microbiome analysis. The risk of bias for included studies was assessed using the revised Cochrane risk of bias tool (RoB2) for randomized trials and the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) for non-randomized studies. Changes in the relative abundance of the gut microbiome were summarized at various taxonomic levels, including phylum, class, order, family, genus, and species. Random-effects meta-analysis was conducted to analyze the mean difference in cardiometabolic parameters pre- and post-intervention.

RESULTS

Nineteen studies were identified, including 17 RCT and two self-controlled trails. Risk of bias across the studies was mixed but mainly identified as low and unclear. The most frequently reported increased taxa were Faecalibacterium (N = 8) with plant-rich diets, Bacteroides (N = 3) with restrictive diets, and Ruminococcaceae UCG 005 and Alistipes (N = 9) with the polyphenol-rich diets. The most frequently reported decreased taxa were Parabacteroides (N = 7) with plant-rich diets, Roseburia (N = 3) with restrictive diets, and Ruminococcus gauvreauii group (N = 6) with the polyphenol-rich diets. Plant-rich diets showed a significant decrease in total cholesterol (TC) with a mean difference of -6.77 (95% CI, -12.36 to -2.58; I2 = 84.7%), while restrictive diets showed a significant decrease in triglycerides (TG) of -22.12 (95% CI, -36.05 to -8.19; I2 = 98.4%).

CONCLUSIONS

Different dietary patterns showed distinct impacts on gut microbiota composition. Plant-rich diets promoted the proliferation of butyrate-producing bacteria, suggesting promising prospects for modulating gut microbiota and butyrate production through dietary interventions to enhance cardiovascular health. Further research is warranted to investigate the long-term effects of dietary patterns on clinical endpoints, such as CVD events or mortality.

REVIEW REGISTRATION

Registration number: CRD42024507660.

Chronic inflammation in post-acute sequelae of COVID-19 modulates gut microbiome: a review of literature on COVID-19 sequelae and gut dysbiosis

BACKGROUND

Long COVID or Post-acute sequelae of COVID-19 is an emerging syndrome, recognized in COVID-19 patients who suffer from mild to severe illness and do not recover completely. Most studies define Long COVID, through symptoms like fatigue, brain fog, joint pain, and headache prevailing four or more weeks post-initial infection. Global variations in Long COVID presentation and symptoms make it challenging to standardize features of Long COVID. Long COVID appears to be accompanied by an auto-immune multi-faceted syndrome where the virus or viral antigen persistence causes continuous stimulation of the immune response, resulting in multi-organ immune dysregulation.

MAIN TEXT

This review is focused on understanding the risk factors of Long COVID with a special emphasis on the dysregulation of the gut-brain axis. Two proposed mechanisms are discussed here. The first mechanism is related to the dysfunction of angiotensin-converting enzyme 2 receptor due to Severe Acute Respiratory Syndrome Corona Virus 2 infection, leading to impaired mTOR pathway activation, reduced AMP secretion, and causing dysbiotic changes in the gut. Secondly, gut-brain axis dysregulation accompanied by decreased production of short-chain fatty acids, impaired enteroendocrine cell function, and increased leakiness of the gut, which favors translocation of pathogens or lipopolysaccharide in circulation causing the release of pro-inflammatory cytokines. The altered Hypothalamic-Pituitary-Adrenal axis is accompanied by the reduced level of neurotransmitter, and decreased stimulation of the vagus nerve, which may cause neuroinflammation and dysregulation of serum cortisol levels. The dysbiotic microbiome in Long COVID patients is characterized by a decrease in beneficial short chain fatty acid-producing bacteria (Faecalibacterium, Ruminococcus, Dorea, and Bifidobacterium) and an increase in opportunistic bacteria (Corynebacterium, Streptococcus, Enterococcus). This dysbiosis is transient and may be impacted by interventions including probiotics, and dietary supplements.

CONCLUSIONS

Further studies are required to understand the geographic variation, racial and ethnic differences in phenotypes of Long COVID, the influence of viral strains on existing and emerging phenotypes, to explore long-term effects of gut dysbiosis, and gut-brain axis dysregulation, as well as the potential role of diet and probiotics in alleviating those symptoms.

The interplay between gut microbiota composition and dementia

Recently, researchers have been interested in the potential connection between gut microbiota composition and various neuropsychological disorders. Dementia significantly affects the socioeconomics of families. Gut microbiota is considered as a probable factor in its pathogenesis. Multiple bacterial metabolites such as short-chain fatty acids, lipopolysaccharides, and various neurotransmitters that are responsible for the incidence and progression of dementia can be produced by gut microbiota. Various bacterial species such as Bifidobacterium breve, Akkermansia muciniphila, Streptococcus thermophilus, Escherichia coli, Blautia hydrogenotrophica, etc. are implicated in the pathogenesis of dementia. Gut microbiota can be a great target for imitating or inhibiting their metabolites as an adjunctive therapy based on their role in its pathogenesis. Therefore, some diets can prevent or decelerate dementia by altering the gut microbiota composition. Moreover, probiotics can modulate gut microbiota composition by increasing beneficial bacteria and reducing detrimental species. These therapeutic modalities are considered novel methods that are probably safe and effective. They can enhance the efficacy of traditional medications and improve cognitive function.

Normal Gut Microbiomes in Diverse Populations: Clinical Implications

The human microbiome is a sensor and modulator of physiology and homeostasis. Remarkable tractability underpins the promise of therapeutic manipulation of the microbiome. However, the definition of a normal or healthy microbiome has been elusive. This is in part due to the underrepresentation of minority groups and major global regions in microbiome studies to date. We review studies of the microbiome in different populations and highlight a commonality among health-associated microbiome signatures along with major drivers of variation. We also provide an overview of microbiome-associated therapeutic interventions for some widespread, widely studied diseases. We discuss sources of bias and the challenges associated with defining population-specific microbiome reference bases. We propose a roadmap for defining normal microbiome references that can be used for population-customized microbiome therapeutics and diagnostics.

Diets to promote healthy brain ageing

Diet is a modifiable lifestyle factor with a proven role in cardiovascular disease risk reduction that might also play an important part in cognitive health. Evidence from observational studies has linked certain healthy dietary patterns to cognitive benefits. However, clinical trials of diet interventions have demonstrated either null or, at best, small effects on cognitive outcomes. In this Review, we summarize the currently available evidence from observational epidemiology and clinical trials regarding the potential role of diet in the prevention of cognitive decline and dementia. We further discuss possible methodological limitations that might have hindered the ability of previous diet intervention trials to capture potential neuroprotective effects. Considering the overwhelming and continuously expanding societal, economic and health-care burden of Alzheimer disease and other dementias, future nutritional research must address past methodological challenges to accurately and reliably inform clinical practice guidelines and public health policies. Within this scope, we provide a roadmap for future diet intervention trials for dementia prevention. We discuss study designs involving both intensive personalized interventions - to evaluate pharmacokinetic and pharmacodynamic properties, establish neuroprotective thresholds, and test hypothesized biological mechanisms and effects on brain health and cognition through sensitive and precise biomarker measures - and large-scale, pragmatic public health interventions to study population-level benefits.

Healthy and Unhealthy Aging and the Human Microbiome

An altered gut microbiome is a feature of many multifactorial diseases, and microbiome effects on host metabolism, immune function, and possibly neurological function are implicated. Increased biological age is accompanied by a change in the gut microbiome. However, age-related health loss does not occur uniformly across all subjects but rather depends on differential loss of gut commensals and gain of pathobionts. In this article, we summarize the known and possible effects of the gut microbiome on the hallmarks of aging and describe the most plausible mechanisms. Understanding and targeting these factors could lead to prolonging health span by rationally maintaining the gut microbiome.

Effects of non-pharmacological interventions on gut microbiota and intestinal permeability in older adults: A systematic review: Non-pharmacological interventions on gut microbiota/barrier

This systematic review appraised previous findings of non-pharmacological interventions on gut microbiota and/ or intestinal permeability in older adults. A literature search was performed using PubMed, Scopus, ScienceDirect and the Cochrane Library. Relevant studies were shortlisted based on the inclusion and exclusion criteria, and evaluated for risks of bias using the "Cochrane Collaboration's Risk of Bias 2" and the "NIH Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group". The primary outcomes were the effects of non-pharmacological interventions on gut microbiota diversity and composition, and intestinal permeability in older adults. Out of 85,114 studies, 38 were shortlisted. Generally, the non-pharmacological interventions were beneficial against dysbiosis and the leaky gut in older adults. Considering specific interventions with two or more studies that reported consistent outcomes, a pattern was observed amongst the Mediterranean diet (MD), polyphenol-rich (PR) diet and supplements (i.e., probiotics, prebiotics and synbiotics). As for the other interventions, the very few studies that have been conducted did not allow a strong conclusion to be made just yet. The MD (single and multidomain interventions) restored gut microbiota by increasing species richness (alpha diversity) and reduced intestinal permeability (zonulin) and inflammation (CRP). The PR diet only showed slight changes in the gut microbiota but improved the gut barrier by reducing zonulin, CRP and IL-6. Probiotics, prebiotics and synbiotics increased the genus Bifidobacterium spp. which are considered beneficial bacteria. This review has uncovered insights into the relationship between gut microbiota and intestinal epithelial barriers of specific non-pharmacological interventions in older adults.

A Mediterranean dietary pattern intervention does not improve cardiometabolic risk but does improve quality of life and body composition in an Aotearoa New Zealand population at increased cardiometabolic risk: A randomised controlled trial

AIMS

To test if a New Zealand food-based Mediterranean diet (NZMedDiet) with behavioural intervention improves cardiometabolic health and wellbeing.

METHODS

A randomised controlled trial comparing 12 weeks of the NZMedDiet to usual diet in participants with increased cardiometabolic risk (metabolic syndrome severity score [MetSSS] > 0.35). The intervention group was provided with food and recipes to meet 75% of their energy requirements, supported by a behavioural intervention to improve adherence. The primary outcome measure was (MetSSS) after 12 weeks.

RESULTS

Two hundred individuals with mean (SD) age 49.9 (10.9) years of which 62% women were enrolled with their household/whānau. After 12 weeks, the mean (SD) MetSSS was 1.0 (0.7) in the control (n = 98) and 0.8 (0.5) in the intervention (n = 102) group; estimated difference (95% confidence interval [CI]) of -0.05 (-0.16 to 0.06), p = 0.35. The Mediterranean diet score (PyrMDS) was greater in the intervention group 1.6 (1.1-2.1), p < 0.001, consistent with a change to a more Mediterranean dietary pattern. Weight reduced in the NZMedDiet group compared with control (-1.9 kg [-2.0 to -0.34]), p = 0.006 and wellbeing, assessed by the SF-36 quality of life questionnaire, and improved across all domains. For example, the physical component summary score difference (95% CI) was 4.0 (2.4-5.7), p < 0.001, and the mental component summary score difference was 3.0 (0.7-5.2), p = 0.01.

CONCLUSION

In participants with increased cardiometabolic risk, food provision with a Mediterranean dietary pattern and a behavioural intervention did not improve metabolic risk scores but was associated with reduced weight and improved quality of life.

Exploring the Pharmacological Effects of Bioactive Peptides on Human Nervous Disorders: A Comprehensive Review

A family of peptides known as bioactive peptides has unique physiological properties and may be used to improve human health and prevent illness. Because bioactive peptides impact the immunological, endocrine, neurological, and cardiovascular systems, they have drawn a lot of interest from researchers. According to recent studies, bioactive peptides have a lot to offer in the treatment of inflammation, neuronal regeneration, localized ischemia, and the blood-brain barrier. It investigates various peptide moieties, including antioxidative properties, immune response modulation, and increased blood-brain barrier permeability. It also looks at how well they work as therapeutic candidates and finds promising peptide-based strategies for better outcomes. Furthermore, it underscores the need for further studies to support their clinical utility and suggests that results from such investigations will enhance our understanding of the pathophysiology of these conditions. In order to understand recent advances in BPs and to plan future research, academic researchers and industrial partners will find this review article to be a helpful resource.

Human gut microbiome, diet, and mental disorders

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

Allogenic faecal microbiota transplantation for antibiotic-associated diarrhoea in critically ill patients (FEBATRICE)-Study protocol for a multi-centre randomised controlled trial (phase II)

BACKGROUND

Exposure of critically ill patients to antibiotics lead to intestinal dysbiosis, which often manifests as antibiotic-associated diarrhoea. Faecal microbiota transplantation restores gut microbiota and may lead to faster resolution of diarrhoea.

METHODS

Into this prospective, multi-centre, randomized controlled trial we will enrol 36 critically ill patients with antibiotic-associated diarrhoea. We will exclude patients with ongoing sepsis, need of systemic antibiotics, or those after recent bowel surgery or any other reason that prevents the FMT. Randomisation will be in 1:1 ratio. Patients in the control group will receive standard treatment based on oral diosmectite. In the intervention group, patients will receive, in addition to the standard of care, faecal microbiota transplantation via rectal tube, in the form of a preparation mixed from 7 thawed aliquots (50 mL) made from fresh stool of 7 healthy unrelated donors and quarantined deep frozen for 3 to 12 months. Primary outcome is treatment failure defined as intervention not delivered or diarrhoea persisting at day 7 after randomisation. Secondary outcomes include safety measures such as systemic inflammatory response, adverse events, and also diarrhoea recurrence within 28 days. Exploratory outcomes focus on gut barrier function and composition of intestinal microbiota.

DISCUSSION

Faecal microbiota transplantation has been effective for dysbiosis in non-critically ill patients with recurrent C. difficile infections and it is plausible to hypothesize that it will be equally effective for symptoms of dysbiosis in the critically ill patients. In addition, animal experiments and observational data suggest other benefits such as reduced colonization with multi-drug resistant bacteria and improved gut barrier and immune function. The frozen faeces from unrelated donors are immediately available when needed, unlike those from the relatives, who require lengthy investigation. Using multiple donors maximises graft microbiota diversity. Nonetheless, in vulnerable critically ill patients, Faecal microbiota transplantation might lead to bacterial translocation and unforeseen complications. From growing number of case series it is clear that its off label use in the critically ill patients is increasing and that there is a burning need to objectively assess its efficacy and safety, which this trial aims.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT05430269).

Polyphenols and Microbiota Modulation: Insights from Swine and Other Animal Models for Human Therapeutic Strategies

High consumption of ultra-processed foods, rich in sugar and unhealthy fats, has been linked to the onset of numerous chronic diseases. Consequently, there has been a growing shift towards a fiber-rich diet, abundant in fruits, vegetables, seeds, and nuts, to enhance longevity and quality of life. The primary bioactive components in these plant-based foods are polyphenols, which exert significant effects on modulating the gastrointestinal microbiota through their antioxidant and anti-inflammatory activities. This modulation has preventive effects on neurodegenerative, metabolic, and cardiovascular diseases, and even cancer. The antimicrobial properties of polyphenols against pathogenic bacteria have significantly reduced the need for antibiotics, thereby lowering the risk of antibiotic resistance. This paper advances the field by offering novel insights into the beneficial effects of polyphenols, both directly through the metabolites produced during digestion and indirectly through changes in the host's gastrointestinal microbiota, uniquely emphasizing swine as a model highly relevant to human health, a topic that, to our knowledge, has not been thoroughly explored in previous reviews. This review also addresses aspects related to both other animal models (mice, rabbits, and rats), and humans, providing guidelines for future research into the benefits of polyphenol consumption. By linking agricultural and biomedical perspectives, it proposes strategies for utilizing these bioactive compounds as therapeutic agents in both veterinary and human health sciences.

The gut microbiome across the lifespan: how diet modulates our microbial ecosystem from infancy to the elderly

This comprehensive review examines the impact of dietary patterns on gut microbiome composition and diversity from infancy to old age, linking these changes to age-related health outcomes. It investigates how the gut microbiome develops and changes across life stages, focusing on the influence of dietary factors. The review explores how early-life feeding practices, including breastfeeding and formula feeding, shape the infant gut microbiota and have lasting effects. In elderly individuals, alterations in the gut microbiome are associated with increased susceptibility to infections, chronic inflammation, metabolic disorders and cognitive decline. The critical role of diet in modulating the gut microbiome throughout life is emphasised, particularly the potential benefits of probiotics and fortified foods in promoting healthy ageing. By elucidating the mechanisms connecting food systems to gut health, this review provides insights into interventions that could enhance gut microbiome resilience and improve health outcomes across the lifespan.

Maternal Gut Microbiome-Mediated Epigenetic Modifications in Cognitive Development and Impairments: A New Frontier for Therapeutic Innovation

Cognitive impairment in various mental illnesses, particularly neuropsychiatric disorders, has adverse functional and clinical consequences. While genetic mutations and epigenetic dysregulations of several genes during embryonic and adult periods are linked to cognitive impairment in mental disorders, the composition and diversity of resident bacteria in the gastrointestinal tract-shaped by environmental factors-also influence the brain epigenome, affecting behavior and cognitive functions. Accordingly, many recent studies have provided evidence that human gut microbiota may offer a potential avenue for improving cognitive deficits. In this review, we provide an overview of the relationship between cognitive impairment, alterations in the gut microbiome, and epigenetic alterations during embryonic and adult periods. We examine how various factors beyond genetics-such as lifestyle, age, and maternal diet-impact the composition, diversity, and epigenetic functionality of the gut microbiome, consequently influencing cognitive performance. Additionally, we explore the potential of maternal gut microbiome signatures and epigenetic biomarkers for predicting cognitive impairment risk in older adults. This article also explores the potential roles of nutritional deficiencies in programming cognitive disorders during the perinatal period in offspring, as well as the promise of gut microbiome-targeted therapeutics with epigenetic effects to prevent or alleviate cognitive dysfunctions in infants, middle-aged adults, and older adults. Unsolved challenges of gut microbiome-targeted therapeutics in mitigating cognitive dysfunctions for translation into clinical practice are discussed, lastly.

Dietary Strategies to Mitigate Alzheimer's Disease: Insights into Antioxidant Vitamin Intake and Supplementation with Microbiota-Gut-Brain Axis Cross-Talk

Alzheimer's disease (AD), which is characterized by deterioration in cognitive function and neuronal death, is the most prevalent age-related progressive neurodegenerative disease. Clinical and experimental research has revealed that gut microbiota dysbiosis may be present in AD patients. The changed gut microbiota affects brain function and behavior through several mechanisms, including tau phosphorylation and increased amyloid deposits, neuroinflammation, metabolic abnormalities, and persistent oxidative stress. The lack of effective treatments to halt or reverse the progression of this disease has prompted a search for non-pharmaceutical tools. Modulation of the gut microbiota may be a promising strategy in this regard. This review aims to determine whether specific dietary interventions, particularly antioxidant vitamins, either obtained from the diet or as supplements, may support the formation of beneficial microbiota in order to prevent AD development by contributing to the systemic reduction of chronic inflammation or by acting locally in the gut. Understanding their roles would be beneficial as it may have the potential to be used as a future therapy option for AD patients.

The impact of COVID-19 on accelerating of immunosenescence and brain aging

The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has profoundly impacted global health, affecting not only the immediate morbidity and mortality rates but also long-term health outcomes across various populations. Although the acute effects of COVID-19 on the respiratory system have initially been the primary focus, it is increasingly evident that the virus can have significant impacts on multiple physiological systems, including the nervous and immune systems. The pandemic has highlighted the complex interplay between viral infection, immune aging, and brain health, that can potentially accelerate neuroimmune aging and contribute to the persistence of long COVID conditions. By inducing chronic inflammation, immunosenescence, and neuroinflammation, COVID-19 may exacerbate the processes of neuroimmune aging, leading to increased risks of cognitive decline, neurodegenerative diseases, and impaired immune function. Key factors include chronic immune dysregulation, oxidative stress, neuroinflammation, and the disruption of cellular processes. These overlapping mechanisms between aging and COVID-19 illustrate how the virus can induce and accelerate aging-related processes, leading to an increased risk of neurodegenerative diseases and other age-related conditions. This mini-review examines key features and possible mechanisms of COVID-19-induced neuroimmune aging that may contribute to the persistence and severity of long COVID. Understanding these interactions is crucial for developing effective interventions. Anti-inflammatory therapies, neuroprotective agents, immunomodulatory treatments, and lifestyle interventions all hold potential for mitigating the long-term effects of the virus. By addressing these challenges, we can improve health outcomes and quality of life for millions affected by the pandemic.

Plant-Based Diets and Their Associations with Physical Performance in the Baltimore Longitudinal Study of Aging

BACKGROUND

Plant-based diets are associated with various health benefits; however, their impact on physical performance in aging populations remains unclear.

OBJECTIVES

To investigate the associations between adherence to plant-based diets and physical performance, focusing on their potential protective effects against age-related declines in function.

METHODS

Data were obtained from men and women aged 40 years or older in the Baltimore Longitudinal Study of Aging (BLSA) (mean ± SD age: 68 ± 13 years at the first dietary visit; n = 1389). Dietary intake was assessed using a food frequency questionnaire (FFQ). Plant-based diets, calculated from 18 food groups, were categorized as overall (PDI), healthful (hPDI), or unhealthful (uPDI), and their tertiles across visits were analyzed. Multivariable linear mixed-effects models were used to examine the association between repeated measurements of three physical performance outcomes-Short Physical Performance Battery (SPPB), grip strength (kg), and gait speed (m/s)-and adherence to each plant-based diet.

RESULTS

In fully adjusted models, SPPB and grip strength were significantly associated with both hPDI and uPDI, but not with PDI. For hPDI, the intermediate tertile showed the greatest benefit, with SPPB scores 0.5 points higher (βT2vs.T1 = 0.50, 95% CI: 0.30-0.70, p < 0.001) over the follow-up period. In contrast, for uPDI, a 0.27-point lower SPPB score was seen (βT3vs.T1 = -0.27, 95% CI: -0.48 to -0.07, p = 0.009). Longitudinally, grip strength was positively associated with hPDI (βT3vs.T1 = 1.14, 95% CI: 0.24-2.05, p = 0.0013). Similar results were observed in older adults aged ≥65 years.

CONCLUSIONS

Adherence to hPDI may benefit lower body function and muscle strength, while uPDI appears to have adverse effects. This suggests that the quality of plant-based foods is essential for maintaining functional well-being in older adults. Further research is needed to confirm these findings, explore underlying mechanisms, and identify strategies to optimize plant-based dietary patterns for aging populations.

Associations of three healthy dietary patterns with homeostatic dysregulation: results from the China Multi-Ethnic Cohort study

BACKGROUND

Homeostatic dysregulation (HD), the measure of aging-related physiological dysregulation, serves as an essential intervenable indicator of aging.

OBJECTIVE

To explore the associations of three healthy dietary patterns with HD, investigate the most recommended dietary patterns, and identify the significant beneficial and harmful food groups METHODS: This prospective cohort study included 8,288 participants aged 30-79 years from the China Multi-Ethnic Cohort (CMEC), with a female majority (61.6%). Dietary information was obtained through the baseline food frequency questionnaire (FFQ). Three dietary patterns were constructed: Dietary Approaches to Stop Hypertension (DASH), alternative Mediterranean diets (aMED), and Healthy Diet Score (HDS). HD was constructed based on clinical biomarkers and anthropometric measurements. Follow-up analyses adjusted for baseline data were employed to assess the longitudinal associations of three dietary patterns at baseline with HD at follow-up. Additionally, quantile G-computation was utilized to evaluate the relative contribution of each food group to the association with HD.

RESULTS

Over a follow-up period of 2.0 years, all healthy dietary patterns exhibited negative associations with HD, with βQ5/Q1 = -0.112, 95%CI (-0.172, -0.051) for HDS, with βQ5/Q1 = -0.073, 95%CI (-0.134, -0.012) for aMED, with βQ5/Q1 = -0.047, 95%CI (-0.107,0.014) for DASH. The results of the component analyses revealed that soybean products were the most significant beneficial food group (relative contribution of 24.0%), while alcohol was identified as the major harmful food group (relative contribution of 76.9%).

CONCLUSION

Healthy dietary patterns, especially HDS, are negatively associated with HD. Additionally, soybean products and alcohol are the most significant beneficial and detrimental food groups respectively. Developing appropriate nutritional strategies may help reduce the burden of disease and promote healthy aging.

Regulation of endotoxemia through the gut microbiota: The role of the Mediterranean diet and its components

Endotoxemia is closely related to many diseases. As the largest endotoxin reservoir in the human body, the gut microbiota should be a key target for alleviating endotoxemia. The intestinal microbiota is believed to cause endotoxemia directly or indirectly by modifying the intestinal barrier function through dysbiosis, changing intestinal mucosal permeability and bacterial translocation. Diet is known to be the main environmental factor affecting the intestinal microbiota, and different diets and food components have a large impact on the gut microbiota. The Mediterranean diet, which received much attention in recent years, is believed to be able to regulate the gut microbiota, thereby maintaining the function of the intestinal barrier and alleviating endotoxemia. In this review, we focus on the relationship between the gut microbiota and endotoxemia, and how the Mediterranean dietary (MD) pattern can interfere with endotoxemia through the gut microbiota.

The Mediating Role of Body Mass Index in the Association Between Dietary Index for Gut Microbiota and Biological Age: A Study Based on NHANES 2007-2018

OBJECTIVE

The dietary index for gut microbiota (DI-GM) is a newly proposed metric for assessing diet quality, and its relationship with biological age is unclear. We hypothesize that consuming foods conducive to a healthy gut microbiota environment may decelerate aging.

METHODS

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2007 to 2018. The DI-GM was calculated by averaging the intakes from two 24-h dietary recall interviews. The biological age indicators were assessed using the Klemera-Doubal Method (KDM), phenotypic age (PA), and homeostasis disorder (HD). Logistic regression, restricted cubic splines (RCS), and mediation analysis were employed to explore the association between DI-GM and KDM, PA, and HD.

RESULTS

The study included 20,671 participants. According to the logistic regression model, adjusting for all covariates, a negative association was observed between the DI-GM score and biomarkers of biological aging. Compared to participants in the lowest quartile for DI-GM scores, those in the highest quartile exhibited reduced odds ratio (OR) for all of the biological age indicators, namely biological age assessed via KDM (OR: 0.69, 95% CI: 0.60-0.79), PA (OR: 0.84, 95% CI: 0.73-0.97), and HD (OR: 0.86, 95% CI: 0.76-0.98). Additionally, RCS analysis revealed a nonlinear association between DI-GM and biological age. Mediation analysis showed that the body mass index (BMI) partly mediated the association between DI-GM and biological age.

CONCLUSIONS

Therefore, we concluded that a higher DI-GM score is associated with a lower risk of accelerated aging, with BMI mediating this association. Future research should validate these findings through the use of longitudinal studies.

Parkinson's Disease and the Microbiota-Gut-Brain Axis: Metabolites, Mechanisms, and Innovative Therapeutic Strategies Targeting the Gut Microbiota

The human gut microbiota is diverse and abundant and plays important roles in regulating health by participating in metabolism and controlling physiological activities. The gut microbiota and its metabolites have been shown to affect the functioning of the gut and central nervous system through the microbiota-gut-brain axis. It is well established that microbiota play significant roles in the pathogenesis and progression of Parkinson's disease (PD). Disorders of the intestinal microbiota and altered metabolite levels are closely associated with PD. Here, the changes in intestinal microbiota and effects of metabolites in patients with PD are reviewed. Potential mechanisms underlying intestinal microbiota disorders in the pathogenesis of PD are briefly discussed. Additionally, we outline the current strategies for the treatment of PD that target the gut microbiota, emphasizing the development of promising novel strategies.

Depletion of core microbiome forms the shared background against diverging dysbiosis patterns in Crohn's disease and intestinal tuberculosis: insights from an integrated multi-cohort analysis

BACKGROUND/AIMS

Crohn's disease (CD) and intestinal tuberculosis (ITB) are gastrointestinal (GI) inflammatory disorders with overlapping clinical presentations but diverging etiologies. The study aims to decipher CD and ITB-associated gut dysbiosis signatures and identify disease-associated co-occurring modules to evaluate whether this dysbiosis signature is a disease-specific trait or is a shared feature across diseases of diverging etiologies.

METHODS

Disease-associated gut microbial modules were identified using statistical machine learning and co-abundance network analysis in controls, CD and ITB patients recruited as part of this study. Module reproducibility was reinvestigated through meta-network analysis encompassing >5400 bacteriomes and ~900 mycobiomes. Subsequently, >1600 Indian gut microbiomes were analyzed to identify a central-core gut microbiome of 46 taxa, whose abundances aided in the formulation of an India-specific Core Gut Microbiome Score (CGMS) to measure the degree of core retention.

RESULTS

Both diseases witness similar patterns of alterations in [alpha]-diversity, characterized by a significant reduction in gut bacterial (i.e., bacterial/archaeal) diversity and a concomitant increase in the fungal [alpha]-diversity. Specific bacterial taxa, along with the diverging mycobiome enabled distinction between the diseases. Co-abundance network analysis of these taxa, validated by integrated meta-network analysis, revealed a 'disease-depleted' module, consistent across multiple cohorts, with >75% of this module constituting the central-core Indian gut microbiome. CGMS robustly assessed the core-microbiome loss across different stages of gut inflammatory disorders, in Indian and international cohorts.

CONCLUSIONS

While the disease-specific gain of detrimental bacteria forms an important component of gut dysbiosis, loss of the core microbiome is a shared phenomenon contributing to various GI disorders.

Mediterranean Diet and Olive Oil Redox Interactions on Lactate Dehydrogenase Mediated by Gut Oscillibacter in Patients with Long-COVID-19 Syndrome

Chronic viral inflammation is associated with oxidative stress and changes in gut microbiota. The Mediterranean diet (MD), with recognized anti-inflammatory and antioxidant properties, modulates gut microorganisms, specifically on the interaction between extra virgin olive oil, a key component of the MD with well-documented antioxidant effects. This study investigated the influence of adherence to MD and antioxidant-rich foods (extra virgin olive oil) on biochemical, inflammatory, and microbiota profiles in patients with chronic inflammation defined as a prolonged inflammatory response due to immune dysregulation following the acute phase of the viral infection. Participants were classified into low (n = 54) and high (n = 134) MD adherence groups (cut-off of 7 points based on previous studies utilizing the same threshold in the assessment of MD adherence). Gut microbiota was sequenced using the 16S technique, and the adherence to MD was assessed using a validated questionnaire for a Spanish population. High adherence to the MD was linked to significant improvements in inflammatory and oxidative stress markers, including reductions in LDL-cholesterol, glucose, and lactate dehydrogenase (LDH) levels, an indicative of redox balance, as well as a significant higher consumption of antioxidant foods. Moreover, gut microbiota analysis revealed distinct compositional shifts and a lower abundance of the Oscillibacter genus in the high adherence group. Notably, a significant interaction was observed between MD adherence and extra virgin olive oil consumption, with Oscillibacter abundance influencing LDH levels, suggesting that the MD antioxidant properties may modulate inflammation through gut microbiota-mediated mechanisms. These findings provide new evidence that adherence to the Mediterranean diet can reduce inflammatory markers in patients with long-COVID-19, a population that has not been extensively studied, while also highlighting the potential role of the bacterial genus Oscillibacter in modulating this effect.

Dietary amino acids, macronutrients, vaginal birth, and breastfeeding are associated with the vaginal microbiome in early pregnancy

The vaginal microbiome is a key player in the etiology of spontaneous preterm birth. This study aimed to illustrate maternal environmental factors associated with vaginal microbiota composition and function in pregnancy. Women in healthy pregnancy had vaginal microbial sampling from the posterior vaginal fornix performed at 16 weeks gestation. After shotgun metagenomic sequencing, heatmaps of relative abundance data were generated. Community state type (CST) was assigned, and alpha diversity was calculated. Demography, obstetric history, well-being, exercise, and diet using food frequency questionnaires were collected and compared against microbial parameters. A total of 119 pregnant participants had vaginal metagenomic sequencing performed. Factors with strongest association with beta diversity were dietary lysine (adj-R2 0.113, P = 0.002), valine (adj-R2 0.096, P = 0.004), leucine (adj-R2 0.086, P = 0.003), and phenylalanine (adj-R2 0.085, P = 0.005, Fig. 2D). Previous vaginal delivery and breastfeeding were associated with vaginal beta diversity (adj-R2 0.048, P = 0.003; adj-R2 0.045, P = 0.004), accounting for 8.5% of taxonomy variation on redundancy analysis. Dietary fat, starch, and maltose were positively correlated with alpha diversity (fat +0.002 SD/g, P = 0.025; starch +0.002 SD/g, P = 0.043; maltose +0.440 SD/g, P = 0.013), particularly in secretor-positive women. Functional signature was associated with CST, maternal smoking, and dietary phenylalanine, accounting for 8.9%-11% of the variation in vaginal microbiome functional signature. Dietary amino acids, previous vaginal delivery, and breastfeeding history were associated with vaginal beta diversity. Functional signature of the vaginal microbiome differed with community state type, smoking, dietary phenylalanine, and vitamin K. Increased alpha diversity correlated with dietary fat and starch. These data provide a novel snapshot into the associations between maternal environment, nutrition, and the vaginal microbiome.

IMPORTANCE

This secondary analysis of the MicrobeMom randomized controlled trial reveals that dietary amino acids, macronutrients, previous vaginal birth, and breastfeeding have the strongest associations with vaginal taxonomy in early pregnancy. Function of the vaginal niche is associated mainly by species composition, but smoking, vitamin K, and phenylalanine also play a role. These associations provide an intriguing and novel insight into the association between host factors and diet on the vaginal microbiome in pregnancy and highlight the need for further investigation into the complex interactions between the diet, human gut, and vaginal microbiome.

The interplay between diet and the gut microbiome: implications for health and disease

Diet has a pivotal role in shaping the composition, function and diversity of the gut microbiome, with various diets having a profound impact on the stability, functionality and diversity of the microbial community within our gut. Understanding the profound impact of varied diets on the microbiome is crucial, as it will enable us not only to make well-informed dietary decisions for better metabolic and intestinal health, but also to prevent and slow the onset of specific diet-related diseases that stem from suboptimal diets. In this Review, we explore how geographical location affects the gut microbiome and how different diets shape its composition and function. We examine the mechanisms by which whole dietary regimes, such as the Mediterranean diet, high-fibre diet, plant-based diet, high-protein diet, ketogenic diet and Western diet, influence the gut microbiome. Furthermore, we underscore the need for exhaustive studies to better understand the causal relationship between diet, host and microorganisms for the development of precision nutrition and microbiome-based therapies.

The potential role of mitochondria in the microbiota-gut-brain axis: Implications for brain health

Mitochondria are crucial organelles that regulate cellular energy metabolism, calcium homeostasis, and oxidative stress responses, playing pivotal roles in brain development and neurodegeneration. Concurrently, the gut microbiota has emerged as a key modulator of brain physiology and pathology through the microbiota-gut-brain axis. Recent evidence suggests an intricate crosstalk between the gut microbiota and mitochondrial function, mediated by microbial metabolites that can influence mitochondrial activities in the brain. This review aims to provide a comprehensive overview of the emerging role of mitochondria as critical mediators in the microbiota-gut-brain axis, shaping brain health and neurological disease pathogenesis. We discuss how gut microbial metabolites such as short-chain fatty acids, secondary bile acids, tryptophan metabolites, and trimethylamine N-oxide can traverse the blood-brain barrier and modulate mitochondrial processes including energy production, calcium regulation, mitophagy, and oxidative stress in neurons and glial cells. Additionally, we proposed targeting the mitochondria through diet, prebiotics, probiotics, or microbial metabolites as a promising potential therapeutic approach to maintain brain health by optimizing mitochondrial fitness. Overall, further investigations into how the gut microbiota and its metabolites regulate mitochondrial bioenergetics, dynamics, and stress responses will provide valuable insights into the microbiota-gut-brain axis in both health and disease states.

Role of gut microbiota in inflammatory bowel disease pathogenesis

The role of the gut microbiota, especially bacterial flora, in the pathogenesis of inflammatory bowel disease (IBD) is becoming clearer. Advances in gut microbiota analysis and the use of gnotobiotics models have underscored the importance of gut bacteria and their metabolites in the progression of IBD. Fecal microbiota transplantation has shown promise in clinical trials for ulcerative colitis started as Advanced Medical Care B in Japan, raising expectations for its outcomes. This review explores the gut microbiota's role in IBD, encompassing both current knowledge and future prospects.

Sarcobesity: New paradigms for healthy aging related to taurine supplementation, gut microbiota and exercise

Enigmatic sarcopenic obesity is still a challenge for science and adds to the global public health burden. The progressive accumulation of body fat combined with a dysfunctional skeletal muscle structure and composition, oxidative stress, mitochondrial dysfunction, and anabolic resistance, among other aggravating factors, together represent the seriousness and complexity of treating the metabolic disorder of sarcobesity in aging. For this reason, further studies are needed that encourage the support of therapeutic management. It is along these lines that we direct the reader to therapeutic approaches that demonstrate important, but still obscure, outcomes in the physiological conditions of sarcobesity, such as the role of taurine in modulating inflammatory and antioxidant mechanisms in muscle and adipose tissue, as well as the management of gut microbiota, able to systemically re-establish the structure and function of the gut-muscle axis, in addition to the merits of physical exercise as an instrument to improve muscular health and lifestyle quality.

A Theory-Based Nursing Intervention to Improve Self-Management Behavior and Health Status in Older Adults With Type 2 Diabetes and Frailty

PURPOSE

To evaluate the effectiveness of a nursing intervention based on the integration theory of health behavior change (ITHBC) in older adults with type 2 diabetes mellitus (T2DM) and frailty.

METHOD

This cluster randomized controlled trial has a two-group pre-/posttest design. The intervention group received a 12-week nursing intervention based on the ITHBC and routine health education, whereas the control group only received routine health education. Self-management, frailty, quality of life, fasting blood glucose, body mass index (BMI), grip strength, and functional mobility were measured.

RESULTS

Seventy-one participants (intervention group, n = 35; control group, n = 36) completed the entire study. After the intervention, participants in the intervention group exhibited significant improvements in self-management (all p < 0.001), frailty level (p = 0.006), quality of life (all p < 0.001), and grip strength (p < 0.05), and maintained ideal fasting blood glucose levels (p < 0.05) compared to participants in the control group. However, there were no statistically significant differences in BMI and functional mobility (p > 0.05).

CONCLUSION

The 12-week nursing intervention based on the ITHBC could enhance self-management, reduce frailty, improve quality of life and grip strength, and maintain optimal fasting blood glucose levels in older adults with T2DM. [Research in Gerontological Nursing, 17(6), 293-306.].

Exploring the association between lifestyle and cardiovascular health metrics and HPV infection risk: insights from the National Health and Nutrition Examination Survey 2005-2016 data

BACKGROUND

Human Papillomavirus (HPV) infection has garnered significant attention due to its high prevalence and association with various cancers and other health conditions. Composite lifestyle factors may influence the risk of HPV infection, yet their cumulative impact remains insufficiently explored. This study aims to explore the association between the Life's Essential 8 (LE8) Score and HPV infection status, highlighting the potential role of lifestyle and health behaviors in HPV infection prevention.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 2005-2016, we analyzed the health and nutritional statuses of 6,773 participants after excluding those with missing HPV infection status, inability to calculate the LE8 Score, and missing covariate data. The LE8 Score was computed based on eight cardiovascular health metrics, encompassing both health factors (BMI, non-HDL cholesterol, blood pressure, and blood glucose) and health behaviors (physical activity, diet, sleep duration, and nicotine exposure). HPV infection status was determined through vaginal swab specimens analyzed using various Roche assays. Multivariate logistic regression, the restricted cubic splines (RCS) analysis and weighted quantile sum (WQS) regression were employed to assess the association between LE8 Score and HPV infection risk.

RESULTS

Our findings indicate a significant inverse association between the LE8 Score and HPV infection risk. Participants with medium and high LE8 Scores exhibited a 21% and 31% lower risk of HPV infection, respectively, compared to those with low LE8 Scores in multivariate logistic regression models. The analysis also revealed that lifestyle factors, particularly nicotine exposure and blood pressure, significantly contributed to the observed association.

CONCLUSION

The study underscores the importance of healthy lifestyle behaviors in reducing the risk of HPV infection. Public health strategies promoting such behaviors could complement existing HPV prevention measures, potentially lowering the burden of HPV-related diseases. Future research should further investigate the mechanisms underlying this association and the effectiveness of lifestyle interventions in diverse populations.

Microbiota-Focused Dietary Approaches to Support Health: A Systematic Review

Diet affects the intestinal microbiota. Increasingly, research is linking the intestinal microbiota to various human health outcomes. Consumption of traditional prebiotics (inulin, fructo-oligosaccharides, and galacto-oligosaccharides) confers health benefits through substrate utilization by select intestinal microorganisms, namely Bifidobacterium and Lactobacilli spp. A similar but distinct concept focused on microorganisms to support human health is through direct consumption of certain live microorganisms recognized as probiotics, which classically include Lactobacilli or Bifidobacterium strains. With advances in sequencing technologies and culturing techniques, other novel functional intestinal microorganisms are being increasingly identified and studied to determine how they may underpin human health benefits. These novel microorganisms are targeted for enrichment within the autochthonous intestinal microbiota through dietary approaches and are also gaining interest as next-generation probiotics because of their purported beneficial properties. Thus, characterizing dietary approaches that nourish select microorganisms in situ is necessary to propel biotic-focused research forward. As such, we reviewed the literature to summarize findings on dietary approaches that nourish the human intestinal microbiota and benefit health to help fill the gap in knowledge on the connections between certain microorganisms, the metabolome, and host physiology. The overall objective of this systematic review was to summarize the impact of dietary interventions with the propensity to nourish certain intestinal bacteria, affect microbial metabolite concentrations, and support gastrointestinal, metabolic, and cognitive health in healthy adults. Findings from the 17 randomized controlled studies identified in this systematic review indicated that dietary interventions providing dietary fibers, phytonutrients, or unsaturated fatty acids differentially enriched Akkermansia, Bacteroides, Clostridium, Eubacterium, Faecalibacterium, Roseburia, and Ruminococcus species, with variable effects on microbial metabolites and subsequent associations with physiologic markers of gastrointestinal and metabolic health. These findings have implications for biotic-focused research on candidate prebiotic substrates as well as next-generation probiotics.

Exerkine irisin mitigates cognitive impairment by suppressing gut-brain axis-mediated inflammation

INTRODUCTION

Exercise has been recognized to improve cognitive performance by optimizing gut flora and up-regulating exerkine irisin.

OBJECTIVE

Although exercise-induced irisin is beneficial to cognitive improvement, whether this benefit is achieved by optimizing gut microbiota and metabolites is not fully explored.

METHODS

After aerobic exercise and exogenous irisin interventions for 12 weeks, the 16S rRNA and metabolites in feces of 21-month-old mice were analyzed. Meanwhile, the differential miRNAs and mRNAs in hippocampal tissues were screened by high-throughput sequencing. Relevant mRNAs and proteins were evaluated by RT-PCR, Western blot, and immunofluorescence.

RESULTS

Compared with the young control mice, irisin levels and cognitive capacity of aged mice revealed a significant reduction, while aerobic exercise and intraperitoneal injection of exogenous irisin reversed aging-induced cognitive impairment. Similarly, 147 up-regulated and 173 down-regulated metabolites were detected in aged mice, while 64 and 45 up-regulated and 225 and 187 down-regulated metabolites were detected in aged mice with exercise and irisin interventions, respectively. Moreover, during hippocampal miRNA and mRNA sequencing analysis, 9 differential gut flora and 35 differential genes were identified to be correlated with the inflammatory signaling mediated by the TLR4/MyD88 signal pathway.

CONCLUSION

Aging-induced cognitive impairment is due to insulin resistance induced by TLR4/MyD88 signaling activation in hippocampal tissues mediated by gut microbiota and metabolite changes. Myokine irisin may be an important mediator in optimizing gut microbiota and metabolism for an improved understanding of mitigated aging process upon exercise interventions.

Gastrointestinal germinal center B cell depletion and reduction in IgA+ plasma cells in HIV-1 infection

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high-resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. Immunoglobulin A-positive (IgA+) PCs are the major cellular output of intestinal GCs and were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling, persisted in antiretroviral therapy (ART)-treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations were associated with changes in the intestinal microbiome composition and systemic inflammation. These findings highlight a key immune defect in the GI mucosa due to HIV-1 viremia.

Intestinal barrier damage contributes to a higher prevalence of frailty in aging people living with HIV: a retrospective case control study in a Chinese cohort

Background

It has been previously demonstrated that intestinal barrier damage is one of the underlying mechanisms leading to frailty in non-HIV-infected aging populations. However, there is a paucity of direct evidence which demonstrates the association between intestinal barrier damage and frailty in people living with HIV (PLWH).

Methods

The present study is a retrospective case control study. Participants older than 50 years old were stratified into a frail/pre-frail group (case group) and non-frail group (control group) according to the Fried frailty phenotype. We collected and curated data concerning socio-demographic variables, psychological states and social functioning, and clinical information associated with the identification of biomarkers of intestinal barrier damage, microbial translocation, and levels of inflammatory cytokines of participants.

Results

The case group had significantly higher levels of Reg-3α (p=0.042) and I-FABP (p=0.045) compared to the control group. We further observed, after adjusting for confounding factors by logistic regression analysis, that I-FABP levels remained significantly higher in the case group compared to the control group (p=0.033). Also, Fried Phenotype scores positively correlated with I-FABP levels (rs=0.21, p=0.01), LPS levels (rs=0.20, p=0.02), and sCD14 levels (rs=0.18, p=0.04). Moreover, the study confirmed both the positive correlation between inflammatory cytokines (IL-6 and IP-10) with frailty in aging PLWH, and between inflammatory cytokines (IL-6, IL-8 and IP-10) with biomarkers of intestinal barrier dysfunction in older PLWH.

Conclusion

The present study indicates that the inflammation induced by intestinal barrier damage/dysfunction is likely to contribute to frailty in aging PLWH.

Yeast β-glucan supplementation lowers insulin resistance without altering microbiota composition compared with placebo in subjects with type II diabetes: a phase I exploratory study

The increased global prevalence of type II diabetes mellitus (T2DM) is associated with consumption of low fibre 'Western diets'. Characteristic metabolic parameters of these individuals include insulin resistance, high fasting and postprandial glucose, as well as low-grade systemic inflammation. Gut microbiota composition is altered significantly in these cohorts suggesting a causative link between diet, microbiota and disease. Dietary fibre consumption has been shown to alleviate these changes and improve glucose parameters in individuals with metabolic disease. We previously reported that yeast β-glucan (yeast beta-1,3/1,6-D-glucan; Wellmune) supplementation ameliorated hyperinsulinaemia and insulin resistance in a murine model. Here, we conducted a randomised, placebo-controlled, two-armed dietary fibre phase I exploratory intervention study in patients with T2DM. The primary outcome measure was alteration to microbiota composition, while the secondary outcome measures included markers of glycaemic control, inflammation as well as metabolomics. Patients were supplemented with 2·5g/day of maltodextrin (placebo) or yeast β-1,3/1,6-D-glucan (treatment). Yeast β-glucan (Wellmune) lowered insulin resistance compared with the placebo maltodextrin after 8 weeks of consumption. TNFα was significantly lower after 4 weeks of β-glucan supplementation. Significantly higher fecal concentrations of several bile acids were detected in the treatment group when compared with the placebo after 8 weeks. These included tauroursodeoxycholic acid, which was previously shown to improve glucose control and lower insulin resistance. Interestingly, the hypoglycaemic and anti-inflammatory effect of yeast β-glucan was independent of any changes in fecal microbiota composition or short-chain fatty acid levels. Our findings highlight the potential of yeast β-glucan to lower insulin resistance in patients with T2DM.

Gastrointestinal germinal center B cell depletion and reduction in IgA + plasma cells in HIV-1 infection

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. IgA + PCs are the major cellular output of intestinal GCs and were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling, persisted in antiretroviral therapy (ART)-treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations were associated with changes in the intestinal microbiome composition and systemic inflammation. These findings highlight a key immune defect in the GI mucosa due to HIV-1 viremia.

One Sentence Summary

Intestinal germinal center B cell reduction in HIV-1 infection linked to reduced IgA + plasma cells and systemic inflammation.

Gut microbial metabolism in Alzheimer's disease and related dementias

Multiple studies over the last decade have established that Alzheimer's disease and related dementias (ADRD) are associated with changes in the gut microbiome. These alterations in organismal composition result in changes in the abundances of functions encoded by the microbial community, including metabolic capabilities, which likely impact host disease mechanisms. Gut microbes access dietary components and other molecules made by the host and produce metabolites that can enter circulation and cross the blood-brain barrier (BBB). In recent years, several microbial metabolites have been associated with or have been shown to influence host pathways relevant to ADRD pathology. These include short chain fatty acids, secondary bile acids, tryptophan derivatives (such as kynurenine, serotonin, tryptamine, and indoles), and trimethylamine/trimethylamine N-oxide. Notably, some of these metabolites cross the BBB and can have various effects on the brain, including modulating the release of neurotransmitters and neuronal function, inducing oxidative stress and inflammation, and impacting synaptic function. Microbial metabolites can also impact the central nervous system through immune, enteroendocrine, and enteric nervous system pathways, these perturbations in turn impact the gut barrier function and peripheral immune responses, as well as the BBB integrity, neuronal homeostasis and neurogenesis, and glial cell maturation and activation. This review examines the evidence supporting the notion that ADRD is influenced by gut microbiota and its metabolites. The potential therapeutic advantages of microbial metabolites for preventing and treating ADRD are also discussed, highlighting their potential role in developing new treatments.

Gut microbiome alterations at acute myeloid leukemia diagnosis are associated with muscle weakness and anorexia

The gut microbiota makes critical contributions to host homeostasis, and its role in the treatment of acute myeloid leukemia (AML) has attracted attention. We investigated whether the gut microbiome is affected by AML, and whether such changes are associated with hallmarks of cachexia. Biological samples and clinical data were collected from 30 antibiotic- free AML patients at diagnosis and matched volunteers (1:1) in a multicenter, cross-sectional, prospective study. The composition and functional potential of the fecal microbiota were analyzed using shotgun metagenomics. Fecal, blood, and urinary metabolomics analyses were performed. AML patients displayed muscle weakness, anorexia, signs of altered gut function, and glycemic disorders. The composition of the fecal microbiota differed between patients with AML and control subjects, with an increase in oral bacteria. Alterations in bacterial functions and fecal metabolome support an altered redox status in the gut microbiota, which may contribute to the altered redox status observed in patients with AML. Eubacterium eligens, reduced 3-fold in AML patients, was strongly correlated with muscle strength and citrulline, a marker of enterocyte mass and function. Blautia and Parabacteroides, increased in patients with AML, were correlated with anorexia. Several bacterial taxa and metabolites (e.g., Blautia, Prevotella, phenylacetate, and hippurate) previously associated with glycemic disorders were altered. Our work revealed important perturbations in the gut microbiome of AML patients at diagnosis, which are associated with muscle strength, altered redox status, and anorexia. These findings pave the way for future mechanistic work to explore the function and therapeutic potential of the bacteria identified in this study.

Integrative Geriatric Oncology: A Review of Current Practices

PURPOSE OF REVIEW

This article aims to offer a comprehensive review of optimal integrative medicine practices for geriatric oncology patients. Given the aging population and the global rise in cancer incidence, it is crucial to identify evidence-based modalities and employ an integrated approach to enhance cancer outcomes and quality of life in older adults.

RECENT FINDINGS

It has been predicted that 20.5% (6.9 million) of new cancer cases in 2050 will occur in adults over 80 years old.1 The increasing focus on lifestyle factors in healthy aging has shed light on various overlooked areas of significance. Notably, anti-inflammatory diets and the promotion of a healthy gut microbiome have demonstrated significant impacts on overall health outcomes, bolstering the body's innate capacity to combat disease. This review delves into further evidence and extrapolation concerning integrative approaches and their influence on cancer outcomes and older adults quality of life. The complexity and unique nature of cancer in older adults requires a wide range of support from medical providers. Incorporating various integrative techniques as part of cancer treatment and side effect support can improve health outcomes and patient's quality of life. Familiarity with the lifestyle interventions and other topics explored in this review equips healthcare providers to offer tailored and holistic care to geriatric patients navigating cancer.

Relationship of dietary natural folate and synthetic folic acid co-exposure patterns with biological aging: findings from NHANES 2003-2018

Background: The mandatory folic acid fortification program in the United States has inevitably exposed most Americans to both natural folate and synthetic folic acid. We aim to examine the association of dietary folate co-exposure patterns with biological aging indicators. Methods: A total of 18 889 participants were enrolled from 2003 to 2018. Dietary intake of folate from diverse sources was evaluated by 24-hour dietary recall. Biological aging indicators were developed based on age-related clinical indicators, including the phenotypic age (PA), Klemera-Doubal method (KDM), homeostatic dysregulation (HD), and allostatic load (AL). The unsupervised K-means clustering method, logistic regression model, and restricted cubic spline (RCS) regression model were used to explore the relationship of natural folate and synthetic folic acid co-exposure with biological aging indicators. Results: The results indicated that higher intake of total folate, dietary folate, and food natural folate was associated with lower PA [OR = 0.75 (0.64, 0.88); OR = 0.79 (0.70, 0.90); OR = 0.65 (0.57, 0.75)], KDM [OR = 0.63 (0.53, 0.75); OR = 0.80 (0.65, 0.98); OR = 0.62 (0.49, 0.77)], HD [OR = 0.69 (0.56, 0.84); OR = 0.78 (0.67, 0.92); OR = 0.78 (0.68, 0.90)], and AL [OR = 0.69 (0.58, 0.82); OR = 0.73 (0.63, 0.85); OR = 0.74 (0.62, 0.90)], consistently. Four co-exposure patterns were generated based on the intake of folate from diverse sources, as follows: "low folate exposure group" to cluster 1, "dietary folate exposure group" to cluster 2, "mixed source high folate exposure group" to cluster 3, and "mixed source excessive folate exposure group" to cluster 4. Compared with cluster 1, participants in cluster 2 are associated with lower biological age indicators (ORPA = 0.82 [0.72, 0.93]; ORKDM = 0.58 [0.47, 0.70]; ORHD = 0.85 [0.75, 0.97]; ORAL = 0.87 [0.77, 0.98]), while participants in cluster 3 and cluster 4 are not. Conclusion: For individuals subjected to folic acid fortification programs, a higher intake of dietary folate, especially natural folate, coupled with a lower consumption of folic acid supplements, was found to be associated with lower biological age indicators.

Dietary Polyphenols as Anti-Aging Agents: Targeting the Hallmarks of Aging

Background: Aging is a natural biological process influenced by multiple factors and is a significant contributor to various chronic diseases. Slowing down the aging process and extending health span have been pursuits of the scientific field. Methods: Examination of the effects of dietary polyphenols on hallmarks of aging such as genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, disabled macroautophagy, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis. Results: Polyphenols, abundant in nature, exhibit numerous biological activities, including antioxidant effects, free radical scavenging, neuroprotection, and anti-aging properties. These compounds are generally safe and effective in potentially slowing aging and preventing age-related disorders. Conclusions: The review encourages the development of novel therapeutic strategies using dietary polyphenols to create holistic anti-aging therapies and nutritional supplements.

Mediterranean Diet Effect on the Intestinal Microbiota, Symptoms, and Markers in Patients with Functional Gastrointestinal Disorders

The Mediterranean diet (MD) has beneficial effects on the intestinal microbiota by the promotion of bacteria associated with a healthy gut. However, its impact on intestinal fungi, among others, is still unknown, and how it affects digestive symptoms and different biomarkers in patients with gastrointestinal (GI) disorders has hardly been explored. The present study evaluated the effect of the MD on gut microbial diversity and structure and intestinal symptoms and biomarkers after 6 weeks of dietary intervention in 46 patients with GI disorders. Dysbiosis in fungal composition and diversity was observed, with a significantly lower abundance of Sordariomycetes, Leotiomycetes, and Orbiliomycetes; a significantly higher abundance of Saccharomycetes; the Chytridiomycota and Mucoromycota phyla were significantly reduced; and the bacterial microbiota remained unchanged. In addition, various GI disorders decreased and associations between stool consistency and intestinal permeability were found with the bacterial genera Alistipes and Roseburia. Thus, the data suggest that MD can alter the fungal intestinal microbiota and improve GI disorders.

Emerging Targets and Treatments for Sarcopenia: A Narrative Review

BACKGROUND

Sarcopenia is characterized by the progressive loss of skeletal muscle mass, strength, and function, significantly impacting overall health and quality of life in older adults. This narrative review explores emerging targets and potential treatments for sarcopenia, aiming to provide a comprehensive overview of current and prospective interventions.

METHODS

The review synthesizes current literature on sarcopenia treatment, focusing on recent advancements in muscle regeneration, mitochondrial function, nutritional strategies, and the muscle-microbiome axis. Additionally, pharmacological and lifestyle interventions targeting anabolic resistance and neuromuscular junction integrity are discussed.

RESULTS

Resistance training and adequate protein intake remain the cornerstone of sarcopenia management. Emerging strategies include targeting muscle regeneration through myosatellite cell activation, signaling pathways, and chronic inflammation control. Gene editing, stem cell therapy, and microRNA modulation show promise in enhancing muscle repair. Addressing mitochondrial dysfunction through interventions aimed at improving biogenesis, ATP production, and reducing oxidative stress is also highlighted. Nutritional strategies such as leucine supplementation and anti-inflammatory nutrients, along with dietary modifications and probiotics targeting the muscle-microbiome interplay, are discussed as potential treatment options. Hydration and muscle-water balance are emphasized as critical in maintaining muscle health in older adults.

CONCLUSIONS

A combination of resistance training, nutrition, and emerging therapeutic interventions holds potential to significantly improve muscle function and overall health in the aging population. This review provides a detailed exploration of both established and novel approaches for the prevention and management of sarcopenia, highlighting the need for further research to optimize these strategies.

Associations between gut microbiota and osteoporosis or osteopenia in a cohort of Chinese Han youth

Osteoporosis (OP) is a common metabolic bone disease characterized by low bone mass and microstructural deterioration of bone. Changes in the composition and structure of gut microbiota (GM) are related to changes of bone mass and bone microstructure. However, the relationship between GM and bone mineral density (BMD) is complex, and data are especially scarce for Chinese Han youth. Therefore, 62 Chinese Han youth participants were recruited. Furthermore, according to the T-score evaluation criteria of the World Health Organization (WHO), we divided the BMD levels of participants into three groups: osteoporosis\BDL, osteopenia\BDM, normal bone density\BDH, and the associations between GM community and BMD groups were conducted. According to alpha and beta diversity analysis, significant differences were found in the microbial richness and composition between groups. The dominant phyla of GM in a cohort of Chinese Han youth were Bacteroidota (50.6%) and Firmicutes (41.6%). Anaerobic microorganisms, such as g_Faecalibacterium and g_Megamonas, account for the largest proportion in the gut, which were mainly Firmicutes phylum. The dominant genera and species in the three BMD groups were g_Prevotella, g_Bacteroides, g_Faecalibacterium, g_Megamonas, s_Prevotella copri, s_unclassified_g_Faecalibacterium, s_unclassified_g_Prevotella, s_unclassified_g_Bacteroides and s_Bacteroides plebeius. g_Faecalibacterium, g_Bacteroides and g_Ruminococcus differed between the BDH and BDL groups as well as between the BDH and BDM groups. LEfSe showed three genus communities and eight species communities were enriched in the three BMD groups, respectively. The associations between microbial relative abundance and T-score was not statistically significant by Spearman and regression analysis. In conclusion, the alpha diversity indexes in the BDH group were higher than in the BDL group, and several taxa were identified that may be the targets for diagnosis and therapy of OP.