Age-specific microbiota in altering host inflammatory and metabolic signaling as well as metabolome based on the sex

Increased intestinal bile acid absorption contributes to age-related cognitive impairment

Cognitive impairment in the elderly is associated with alterations in bile acid (BA) metabolism. In this study, we observe elevated levels of serum conjugated primary bile acids (CPBAs) and ammonia in elderly individuals, mild cognitive impairment, Alzheimer's disease, and aging rodents, with a more pronounced change in females. These changes are correlated with increased expression of the ileal apical sodium-bile acid transporter (ASBT), hippocampal synapse loss, and elevated brain CPBA and ammonia levels in rodents. In vitro experiments confirm that a CPBA, taurocholic acid, and ammonia induced synaptic loss. Manipulating intestinal BA transport using ASBT activators or inhibitors demonstrates the impact on brain CPBA and ammonia levels as well as cognitive decline in rodents. Additionally, administration of an intestinal BA sequestrant, cholestyramine, alleviates cognitive impairment, normalizing CPBAs and ammonia in aging mice. These findings highlight the potential of targeting intestinal BA absorption as a therapeutic strategy for age-related cognitive impairment.

Global metabolomics revealed deviations from the metabolic aging clock in colorectal cancer patients

Background: Markers of aging hold promise in the context of colorectal cancer (CRC) care. Utilizing high-resolution metabolomic profiling, we can unveil distinctive age-related patterns that have the potential to predict early CRC development. Our study aims to unearth a panel of aging markers and delve into the metabolomic alterations associated with aging and CRC. Methods: We assembled a serum cohort comprising 5,649 individuals, consisting of 3,002 healthy volunteers, 715 patients diagnosed with colorectal advanced precancerous lesions (APL), and 1,932 CRC patients, to perform a comprehensive metabolomic analysis. Results: We successfully identified unique age-associated patterns across 42 metabolic pathways. Moreover, we established a metabolic aging clock, comprising 9 key metabolites, using an elastic net regularized regression model that accurately estimates chronological age. Notably, we observed significant chronological disparities among the healthy population, APL patients, and CRC patients. By combining the analysis of circulative carcinoembryonic antigen levels with the categorization of individuals into the "hypo" metabolic aging subgroup, our blood test demonstrates the ability to detect APL and CRC with positive predictive values of 68.4% (64.3%, 72.2%) and 21.4% (17.8%, 25.9%), respectively. Conclusions: This innovative approach utilizing our metabolic aging clock holds significant promise for accurately assessing biological age and enhancing our capacity to detect APL and CRC.

AgeAnnoMO: a knowledgebase of multi-omics annotation for animal aging

Aging entails gradual functional decline influenced by interconnected factors. Multiple hallmarks proposed as common and conserved underlying denominators of aging on the molecular, cellular and systemic levels across multiple species. Thus, understanding the function of aging hallmarks and their relationships across species can facilitate the translation of anti-aging drug development from model organisms to humans. Here, we built AgeAnnoMO (https://relab.xidian.edu.cn/AgeAnnoMO/#/), a knowledgebase of multi-omics annotation for animal aging. AgeAnnoMO encompasses an extensive collection of 136 datasets from eight modalities, encompassing 8596 samples from 50 representative species, making it a comprehensive resource for aging and longevity research. AgeAnnoMO characterizes multiple aging regulators across species via multi-omics data, comprehensively annotating aging-related genes, proteins, metabolites, mitochondrial genes, microbiotas and age-specific TCR and BCR sequences tied to aging hallmarks for these species and tissues. AgeAnnoMO not only facilitates a deeper and more generalizable understanding of aging mechanisms, but also provides potential insights of the specificity across tissues and species in aging process, which is important to develop the effective anti-aging interventions for diverse populations. We anticipate that AgeAnnoMO will provide a valuable resource for comprehending and integrating the conserved driving hallmarks in aging biology and identifying the targetable biomarkers for aging research.

Uncovering the Gut-Liver Axis Biomarkers for Predicting Metabolic Burden in Mice

Western diet (WD) intake, aging, and inactivation of farnesoid X receptor (FXR) are risk factors for metabolic and chronic inflammation-related health issues ranging from metabolic dysfunction-associated steatotic liver disease (MASLD) to dementia. The progression of MASLD can be escalated when those risks are combined. Inactivation of FXR, the receptor for bile acid (BA), is cancer prone in both humans and mice. The current study used multi-omics including hepatic transcripts, liver, serum, and urine metabolites, hepatic BAs, as well as gut microbiota from mouse models to classify those risks using machine learning. A linear support vector machine with K-fold cross-validation was used for classification and feature selection. We have identified that increased urine sucrose alone achieved 91% accuracy in predicting WD intake. Hepatic lithocholic acid and serum pyruvate had 100% and 95% accuracy, respectively, to classify age. Urine metabolites (decreased creatinine and taurine as well as increased succinate) or increased gut bacteria (Dorea, Dehalobacterium, and Oscillospira) could predict FXR deactivation with greater than 90% accuracy. Human disease relevance is partly revealed using the metabolite-disease interaction network. Transcriptomics data were also compared with the human liver disease datasets. WD-reduced hepatic Cyp39a1 (cytochrome P450 family 39 subfamily a member 1) and increased Gramd1b (GRAM domain containing 1B) were also changed in human liver cancer and metabolic liver disease, respectively. Together, our data contribute to the identification of noninvasive biomarkers within the gut-liver axis to predict metabolic status.

Exploring the Relationship between the Gut Microbiota and Ageing: A Possible Age Modulator

The gut microbiota (GM) has been the subject of intense research in recent years. Therefore, numerous factors affecting its composition have been thoroughly examined, and with them, their function and role in the individual's systems. The gut microbiota's taxonomical composition dramatically impacts older adults' health status. In this regard, it could either extend their life expectancy via the modulation of metabolic processes and the immune system or, in the case of dysbiosis, predispose them to age-related diseases, including bowel inflammatory and musculoskeletal diseases and metabolic and neurological disorders. In general, the microbiome of the elderly tends to present taxonomic and functional changes, which can function as a target to modulate the microbiota and improve the health of this population. The GM of centenarians is unique, with the faculty-promoting metabolic pathways capable of preventing and counteracting the different processes associated with age-related diseases. The molecular mechanisms by which the microbiota can exhibit anti-ageing properties are mainly based on anti-inflammatory and antioxidant actions. This review focuses on analysing the current knowledge of gut microbiota characteristics and modifiers, its relationship with ageing, and the GM-modulating approaches to increase life expectancy.

The essential roles of FXR in diet and age influenced metabolic changes and liver disease development: a multi-omics study

BACKGROUND

Aging and diet are risks for metabolic diseases. Bile acid receptor farnesoid X receptor (FXR) knockout (KO) mice develop metabolic liver diseases that progress into cancer as they age, which is accelerated by Western diet (WD) intake. The current study uncovers the molecular signatures for diet and age-linked metabolic liver disease development in an FXR-dependent manner.

METHODS

Wild-type (WT) and FXR KO male mice, either on a healthy control diet (CD) or a WD, were euthanized at the ages of 5, 10, or 15 months. Hepatic transcriptomics, liver, serum, and urine metabolomics as well as microbiota were profiled.

RESULTS

WD intake facilitated hepatic aging in WT mice. In an FXR-dependent manner, increased inflammation and reduced oxidative phosphorylation were the primary pathways affected by WD and aging. FXR has a role in modulating inflammation and B cell-mediated humoral immunity which was enhanced by aging. Moreover, FXR dictated neuron differentiation, muscle contraction, and cytoskeleton organization in addition to metabolism. There were 654 transcripts commonly altered by diets, ages, and FXR KO, and 76 of them were differentially expressed in human hepatocellular carcinoma (HCC) and healthy livers. Urine metabolites differentiated dietary effects in both genotypes, and serum metabolites clearly separated ages irrespective of diets. Aging and FXR KO commonly affected amino acid metabolism and TCA cycle. Moreover, FXR is essential for colonization of age-related gut microbes. Integrated analyses uncovered metabolites and bacteria linked with hepatic transcripts affected by WD intake, aging, and FXR KO as well as related to HCC patient survival.

CONCLUSION

FXR is a target to prevent diet or age-associated metabolic disease. The uncovered metabolites and microbes can be diagnostic markers for metabolic disease.

Intermittent fasting and immunomodulatory effects: A systematic review

Introduction

strategy of periodic food restriction and fixed eating windows, could beneficially modify individuals by losing body weight, regulating glucose or lipid metabolism, reducing blood pressure, and modulating the immune system. Specific effects of IF and its mechanisms have not yet been assessed collectively. Thus, this systematic review aims to summarize and compare clinical trials that explored the immunomodulatory effects of IF.

Methods

After screening, 28 studies were included in this systematic review.

Results

In addition to weight loss, IF could benefit health subjects by strengthening their circadian rhythms, migrating immune cells, lower inflammatory factors, and enriching microbials. In addition of the anti-inflammatory effect by regulating macrophages, protection against oxidative stress with hormone secretion and oxidative-related gene expression plays a key beneficial role for the influence of IF on obese subjects.

Discussion

Physiological stress by surgery and pathophysiological disorders by endocrine diseases may be partly eased with IF. Moreover, IF might be used to treat anxiety and cognitive disorders with its cellular, metabolic and circadian mechanisms. Finally, the specific effects of IF and the mechanisms pertaining to immune system in these conditions require additional studies.

Exploring genetic and immune underpinnings of the sexual dimorphism in tumor response to immune checkpoints inhibitors: A narrative review

Introduction

In spite of the undisputed relevance of sex as critical biologic variable of the immune landscape, still limited is our understanding of the basic mechanisms implicated in sex-biased immune response thereby conditioning the therapeutic outcome in cancer patients. This hindrance delays the actual attempts to decipher the heterogeneity of cancer and its immune surveillance, further digressing the achievement of predictive biomarkers in the current immunotherapy-driven scenario. Body: The present review concisely reports on genetic, chromosomal, hormonal, and immune features underlying sex-differences in the response to immune checkpoint inhibitors (ICIs). In addition to outline the need of robust data on ICI pharmaco-kinetics/dynamics, our survey might provide new insights on sex determinants of ICI efficacy and suggests uncovered pathways that warrant prospective investigations.

Conclusion

According to a sharable view, we propose to widely include sex among the co-variates when assessing the clinical response to ICI in cancer patients.

Association between maternal antibiotic exposure during pregnancy and childhood obesity in the Japan Environment and Children's Study

BACKGROUND

The association between maternal antibiotic exposure during pregnancy and childhood obesity is still unclear.

OBJECTIVES

The study aimed to evaluate the association between prenatal exposure to antibiotics and obesity at age 3 years using data from a large Japanese birth cohort.

METHODS

The Japan Environment and Children's Study is a nationwide birth cohort study. In this study, singleton vaginal full-term births were included. Obesity was defined as body mass index ≥95th percentile according to child growth standards. Prenatal antibiotic exposure was defined as antimicrobial agent use during pregnancy and was collected from maternal interviews and medical record transcripts. Logistic regression analysis was performed to evaluate the association of prenatal antibiotic exposure with child obesity at 3 years.

RESULTS

In the crude and adjusted models with all children, maternal antibiotic exposure during pregnancy showed a marginal relationship with child obesity at 3 years. In the analyses according to exposure period and sex, exposure to antibiotics during the second/third trimester was significantly associated with obesity at the age of 3 years in female infants, but not in male infants, although the exposure during the first trimester was not in both sexes.

CONCLUSION

Maternal antibiotic exposure during mid/late pregnancy may result in child obesity.

Relationship between metabolically healthy obesity and the development of hypertension: a nationwide population-based study

BACKGROUND

Metabolically healthy obesity (MHO), has been recognized as a transient phenotype with few cardiometabolic diseases; however, little is known regarding the development of hypertension in subjects with an absence of cardiometabolic abnormalities and general obesity evaluated by body mass index (BMI) or abdominal obesity evaluated by waist circumference (WC).

METHODS

A total of 4764 participants were enrolled from the China Health and Nutrition Survey and followed up from 2009 to 2015, whose fasting blood samples were collected in 2009. Obesity was classified as abdominal obesity (WC ≥ 90 cm in men and ≥ 80 cm in women) and general obesity (BMI ≥ 25.0 kg/m²). Logistic regression was used to analyze the relationship between MHO and prehypertension (120 < SBP < 140 mmHg or 80 < DBP < 90 mmHg) and hypertension (SBP ≥ 140 or DBP ≥ 90 mmHg). The age- and sex-specific impacts were further analyzed.

RESULTS

There were 412 (37.9%) participants with prehypertension and 446 (41.0%) participants with hypertension and metabolically healthy abdominal obesity (MHAO). The participants with the MHAO phenotype had significantly higher risks of prehypertension [odds ratio (OR) = 1.89 (1.51-2.36), p < 0.001] and hypertension [OR = 2.58 (2.02-3.30), p < 0.001] than those metabolically healthy but without abdominal obesity. Similar associations were observed in the subjects with metabolically healthy general obesity (MHGO) phenotype, particularly those aged under 64 years. Men with the MHAO phenotype seemed to have higher risks of prehypertension [2.42 (1.52-3.86) in men vs. 1.76 (1.36-2.29) in women] and hypertension [3.80 (2.38-6.06) in men vs. 2.22 (1.64-3.00) in women] than women, when compared with those metabolically healthy but without abdominal obesity.

CONCLUSION

The MHO phenotype, regardless of the presence of general or abdominal obesity, showed a worse effect on the development of prehypertension and hypertension, particularly in young adults. Abdominal adiposity with a healthy metabolic state is significantly associated with incident hypertension in both men and women. These findings can guide the establishment of risk-stratified obesity treatments.

Sexual dimorphism in COVID-19: potential clinical and public health implications

Current evidence suggests that severity and mortality of COVID-19 is higher in men than in women, whereas women might be at increased risk of COVID-19 reinfection and development of long COVID. Differences between sexes have been observed in other infectious diseases and in the response to vaccines. Sex-specific expression patterns of proteins mediating virus binding and entry, and divergent reactions of the immune and endocrine system, in particular the hypothalamic-pituitary-adrenal axis, in response to acute stress might explain the higher severity of COVID-19 in men. In this Personal View, we discuss how sex hormones, comorbidities, and the sex chromosome complement influence these mechanisms in the context of COVID-19. Due to its role in the severity and progression of SARS-CoV-2 infections, we argue that sexual dimorphism has potential implications for disease treatment, public health measures, and follow-up of patients predisposed to the development of long COVID. We suggest that sex differences could be considered in future pandemic surveillance and treatment of patients with COVID-19 to help to achieve better disease stratification and improved outcomes.