Interaction between gut microbiota and sex hormones and their relation to sexual dimorphism in metabolic diseases

Exploring the role of gut microbiota in antibiotic resistance and prevention

BACKGROUND/INTRODUCTION

Antimicrobial resistance (AMR) and the evolution of multiple drug-resistant (MDR) bacteria is of grave public health concern. To combat the pandemic of AMR, it is necessary to focus on novel alternatives for drug development. Within the host, the interaction of the pathogen with the microbiome plays a pivotal role in determining the outcome of pathogenesis. Therefore, microbiome-pathogen interaction is one of the potential targets to be explored for novel antimicrobials.

MAIN BODY

This review focuses on how the gut microbiome has evolved as a significant component of the resistome as a source of antibiotic resistance genes (ARGs). Antibiotics alter the composition of the native microbiota of the host by favouring resistant bacteria that can manifest as opportunistic infections. Furthermore, gut dysbiosis has also been linked to low-dosage antibiotic ingestion or subtherapeutic antibiotic treatment (STAT) from food and the environment.

DISCUSSION

Colonization by MDR bacteria is potentially acquired and maintained in the gut microbiota. Therefore, it is pivotal to understand microbial diversity and its role in adapting pathogens to AMR. Implementing several strategies to prevent or treat dysbiosis is necessary, including faecal microbiota transplantation, probiotics and prebiotics, phage therapy, drug delivery models, and antimicrobial stewardship regulation.

Enteric nervous system dysfunction as a driver of central nervous system disorders: The Forgotten brain in neurological disease

The Enteric Nervous System (ENS), often called the "second brain," is a complex network of neurons and glial cells within the gastrointestinal (GI) tract. It functions autonomously while maintaining close communication with the central nervous system (CNS) via the gut-brain axis (GBA). ENS dysfunction plays a crucial role in neurodegenerative and neurodevelopmental disorders, including Parkinson's disease, Alzheimer's disease, and autism spectrum disorder. Disruptions such as altered neurotransmission, gut microbiota imbalance, and neuroinflammation contribute to disease pathogenesis. The GBA enables bidirectional communication through the vagus nerve, gut hormones, immune signaling, and microbial metabolites, linking gut health to neurological function. ENS dysregulation is implicated in conditions like irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD), influencing systemic and CNS pathology through neuroinflammation and impaired barrier integrity. This review highlights emerging therapeutic strategies targeting ENS dysfunction, including prebiotics, probiotics, fecal microbiota transplantation (FMT), and vagus nerve stimulation, which offer novel ways to modulate gut-brain interactions. Unlike previous perspectives that view the ENS as a passive disease marker, this review repositions it as an active driver of neurological disorders. By integrating advances in ENS biomarkers, therapeutic targets, and GBA modulation, this article presents a paradigm shift-emphasizing ENS dysfunction as a fundamental mechanism in neurodegeneration and neurodevelopmental disorders. This perspective paves the way for innovative diagnostics, personalized gut-targeted therapies, and a deeper understanding of the ENS's role in brain health and disease.

Gut Microbiota of Ruminants and Monogastric Livestock: An Overview

The diversity and composition of the gut microbiota are widely recognized as fundamental factors influencing the well-being and productivity of domestic animals. Advancements in sequencing technologies have revolutionized studies in this research field, allowing for deeper insights into the composition and functionality of microbiota in livestock. Ruminants and monogastric animals exhibit distinct digestive systems and microbiota characteristics: ruminants rely on fermentation, while monogastrics use enzymatic digestion, and monogastric animals have simpler stomach structures, except for horses and rabbits, where both processes coexist. Understanding the gut microbiota's impact and composition in both animal types is essential for optimizing production efficiency and promoting animal health. Following this perspective, the present manuscript review aims to provide a comprehensive overview of the gut microbiota in ruminants (such as cattle, sheep, and goats) and monogastric animals (including horses, pigs, rabbits, and chickens).

Navigating nutrition through the decades: Tailoring dietary strategies to women's life stages

The female-specific hormones are responsible for the different metabolic changes occurring in the overall well-being of a woman. Especially highlighted phases are the onset of puberty, menarche, pregnancy, lactation, and menopause. They involve significant metabolic changes, which alter the nutritional requirements. Women, in general, are often unaware of these varied nutritional requirements and fail to inculcate them in their diet, influencing their health. Increased calories, protein, iron, and calcium consumption during adolescence is required for bone growth and the prevention of osteoporosis later in life. The availability through a balanced diet of zinc and essential vitamins such as D, K, and B12 is also critical for a rapidly growing body. At present, infertility is also a pressing issue for couples. Female fertility can be enhanced by a diet high in plant-based protein, dietary fiber, omega-3 fatty acids, vitamins, and minerals. Foods rich in omega-3 fatty acids can help to enhance the quality of eggs, and plant-based proteins reduce the incidence of infertility. Thereafter, during pregnancy, nutritional requirements increase, especially for vitamins B6, B12, and D, calcium, proteins, folate, zinc, and iron. A properly balanced diet can satisfy basic nutritional requirements. However, iron supplements are essential for supporting the blood supply to the placenta and fetus. During menopause and menopausal transition, symptoms are observed like vaginal dryness, hot flashes, and irregular menstruation, followed by an increased threat of cardiovascular diseases, tumors, type 2 diabetes, and osteoporosis. Sufficient intake of protein, calcium, vitamins B, C, and D, and omega-3 fatty acids is important in managing the symptoms. The strategic combination of antioxidant-rich foods with a low-fat, plant-based diet can reduce the risk of cardiovascular disease and regulate body mass. The conclusion of this review is that timely changes in nutrition and strategizing dietary supplements can ease the transition phases of the female lifecycle and improve quality of life.

Sexual dimorphism in aortic aneurysm: A review of the contributions of sex hormones and sex chromosomes

Aortic aneurysm is a common cardiovascular disease. Over time, the disease damages the structural and functional integrity of the aorta, causing it to abnormally expand and potentially rupture, which can be fatal. Sex differences are evident in the disease, with men experiencing an earlier onset and higher incidence. However, women may face a worse prognosis and a higher risk of rupture. While there are some studies on the cellular and molecular mechanisms of aneurysm formation, it remains unclear how sex factors contribute to sexual dimorphism. Therefore, this review aims to summarize the role of sex in the occurrence of aortic aneurysms, offering valuable insights for disease prevention and the development of appropriate treatment options.

Differences in Gut Microbiota Composition Depending on the Site of Pain in Patients with Chronic Pain

Background

There are many factors associated with chronic pain, including changes in the nervous and musculoskeletal systems and so on. Recently, it has become clear that the gut microbiota (GM) influences these factors, and there are many reports of GM dysbiosis in patients with chronic pain. However, the relationship between pain and GM remains unclear. Our previous study reported that defecation status, which reflects GM composition, was associated with pain intensity and that this relationship was different for each pain site. Our study investigated the association between pain site and the GM composition of feces in chronic pain patients.

Methods

The subjects were 136 patients with chronic pain and 125 healthy controls. Patients were classified into four groups, whole body (WB) pain, lower back and lower extremity (LL) pain, headache, and upper back and upper extremity pain, based on the site of pain, and we investigated differences in GM taxonomy groups compared with healthy subject.

Results

Chronic pain patients had a lower alpha diversity (effect size=0.16, p=0.02). But each pain site group did not differ in alpha diversity. WB pain patients showed higher Eggerthellaceae (LDA=3.09, p<0.01) and lower Halomonas (LDA =-2.72, p<0.01). LL pain patients had increased Fusobacterium and Sellimonas (LDA=4.09,3.03 p<0.01, 0.01) but reduced Halomonas (LDA=-2.59, p<0.01), and other key taxa.

Conclusion

WB and LL patients may have GM compositions different from healthy controls, but larger studies are needed to confirm this.

Association of novel metabolic status with asymptomatic intracranial arterial stenosis: A cross-sectional study

OBJECTIVES

To investigate the association of metabolic status newly defined or obesity with asymptomatic intracranial arterial stenosis (aICAS) among populations in rural China.

METHODS

The cross-sectional study is based on the Rose asymptomatic IntraCranial Artery Stenosis (RICAS) cohort, which enrolled 2005 participants aged 40 years or older without a history of clinical stroke or transient ischemic attack. Metabolically healthy status (MH) was defined by a newly proposed criterion: (1) systolic blood pressure (SBP) < 130 mmHg and without antihypertensive medication; (2) a waist-to-hip ratio (WHR) below 1.03 for men and below 0.95 for women; (3) no diabetes. All participants were categorized based on their metabolic status and obesity. Multivariate logistic regression models were used to investigate the association between metabolic status or obesity and aICAS.

RESULTS

Among 2005 participants, 1597 (79.65%) were defined as metabolically unhealthy status (MU) according to the new criterion. MU was significantly associated with aICAS (OR 2.02, 95% CI 1.11-3.68, P = 0.021), especially moderate-to-severe aICAS (OR 2.43, 95% CI 1.04-5.72, P = 0.042). The prevalence of aICAS increased with the numbers of metabolic disorders (P for linear trend <0.001). Both metabolically unhealthy normal-weight (MUN) (OR 2.11, 95% CI 1.10-4.03, P = 0.025) and metabolically unhealthy obesity (MUO) (OR 3.30, 95% CI 1.64-6.64, P = 0.001) were significantly correlated with aICAS, but not metabolically healthy obesity (MHO). Subgroup analysis further confirmed the association between MU and aICAS risk only in men (P for interaction = 0.042).

CONCLUSIONS

MU defined by the new criterion was significantly associated with aICAS, especially with moderate-to-severe aICAS. This novel criterion effectively identifies individuals with a high prevalence of aICAS among populations with obesity, which could be crucial for stroke prevention.

The association between oxidative balance score with constipation and diarrhea in US adults: a cross-sectional analysis of NHANES 2007-2010

BACKGROUND

Oxidative stress is associated with functional bowel disorders. The Oxidative Balance Score (OBS) is used to represent the overall level of oxidative stress experienced by an individual. Sex differences are exhibited in the occurrence of constipation and diarrhea. This population-based study aimed to examine the association between the OBS, constipation, and diarrhea, among adults in the United States (US), stratified by sex.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) database spanning from 2007 to 2010, a cross-sectional study including 4,462 participants (2,386 males and 2,076 females) was performed to assess the relationship between the OBS, constipation, and diarrhea, among adult men and women in the US. Constipation and diarrhea were identified according to bowel frequency and stool type, as outlined in the Bowel Health Questionnaire. The independent variable was the OBS based on 20 types of dietary and lifestyle components. We conducted a binary logistic regression subgroup analysis by sex, and a univariate subgroup analysis; and used a restricted cubic spline (RCS) to illustrate the relationship between the OBS and abnormal bowel health.

RESULTS

After adjusting for all covariates, a multivariate binary logistic regression analysis revealed that the OBS was negatively correlated with constipation in males [odds ratios (OR) (95% confidence intervals (CI)): 0.937 (0.888, 0.988), P = 0.017], and diarrhea in females [OR (95%CI): 0.951 (0.916, 0.987), P = 0.009]. RCS analysis identified a negative linear trend between OBS and constipation in males (P for non-linearity = 0.63), as well as between OBS and diarrhea in females (P for non-linearity > 0.05).

CONCLUSION

The current study found a negative correlation between the OBS and the risk of constipation in males, along with diarrhea in females. Oxidative stress, gut microbiota, and sex differences may be associated with intestinal dysfunction. These findings suggest that antioxidant-rich dietary modifications may be an effective strategy for preventing constipation in males and diarrhea in females.

Chemical interplay between gut microbiota and epigenetics: Implications in circadian biology

Circadian rhythms are intrinsic molecular mechanisms that synchronize biological functions with the day/night cycle. The mammalian gut is colonized by a myriad of microbes, collectively named the gut microbiota. The microbiota impacts host physiology via metabolites and structural components. A key mechanism is the modulation of host epigenetic pathways, especially histone modifications. An increasing number of studies indicate the role of the microbiota in regulating host circadian rhythms. However, the mechanisms remain largely unknown. Here, we summarize studies on microbial regulation of host circadian rhythms and epigenetic pathways, highlight recent findings on how the microbiota employs host epigenetic machinery to regulate circadian rhythms, and discuss its impacts on host physiology, particularly immune and metabolic functions. We further describe current challenges and resources that could facilitate research on microbiota-epigenetic-circadian rhythm interactions to advance our knowledge of circadian disorders and possible therapeutic avenues.

Sex differences in gut microbiota, hypertension, and cardiovascular risk

The intricate ecosystem of the gut microbiome exhibits sex-specific differences, influencing the susceptibility to cardiovascular diseases (CVD). Imbalance within the gut microbiome compromises the gut barrier, activates inflammatory pathways, and alters the production of metabolites, all of which initiate chronic diseases including CVD. In particular, the interplay between lifestyle choices, hormonal changes, and metabolic byproducts uniquely affects sex-specific gut microbiomes, potentially shaping the risk profiles for hypertension and CVD differently in men and women. Understanding the gut microbiome's role in CVD risk offers informative reasoning behind the importance of developing tailored preventative strategies based on sex-specific differences in CVD risk. Furthermore, insight into the differential impact of social determinants and biological factors on CVD susceptibility emphasizes the necessity for more nuanced approaches. This review also outlines specific dietary interventions that may enhance gut microbiome health, offering a glimpse into potential therapeutic avenues for reducing CVD risk that require greater awareness. Imbalance in natural gut microbiomes may explain etiologies of chronic diseases; we advocate for future application to alter the gut microbiome as possible treatment of the aforementioned diseases. This review mentions the idea of altering the gut microbiome through interventions such as fecal microbiota transplantation (FMT), a major application of microbiome-based therapy that is first-line for Clostridium difficile infections and patient-specific probiotics highlights more innovative approaches to hypertension and CVD prevention. Through increased analysis of gut microbiota compositions along with patient-centric probiotics and microbiome transfers, this review advocates for future preventative strategies for hypertension.

Gestational diabetes mellitus causes genome hyper-methylation of oocyte via increased EZH2

Gestational diabetes mellitus (GDM), a common pregnancy disease, has long-term negative effects on offspring health. Epigenetic changes may have important contributions to that, but the underlying mechanisms are not well understood. Here, we report the influence of GDM on DNA methylation of offspring (GDF1) oocytes and the possible mechanisms. Our results show that GDM induces genomic hyper-methylation of offspring oocytes, and at least a part of the altered methylation is inherited by F2 oocytes, which may be a reason for the inheritance of metabolic disorders. We further find that GDM exposure increases the expression of Ezh2 in oocytes. Ezh2 regulates DNA methylation via DNMT1, and Ezh2 knockdown reduces the genomic methylation level of GDF1 oocytes. These results suggest that GDM may induce oocyte genomic hyper-methylation of offspring via enhancing the Ezh2 expression recruiting more DNMT1 into nucleus.

Gut feeling: Exploring the intertwined trilateral nexus of gut microbiota, sex hormones, and mental health

The complex interplay between the gut microbiota, sex hormones, and mental health is emerging as a pivotal factor in understanding and managing psychiatric disorders. Beyond their traditional roles, sex hormones exert profound effects on various physiological systems including the gut microbiota. Fluctuations in sex hormone levels, notably during the menstrual cycle, influence gut physiology and barrier function, shaping gut microbiota composition and immune responses. Conversely, the gut microbiota actively modulates sex hormone levels via enzymatic processes. This bidirectional relationship underscores the significance of the gut-brain axis in maintaining mental well-being. This review explores the multifaceted interactions between sex hormones, the gut microbiota, and mental health outcomes. We highlight the potential of personalized interventions in treating psychiatric disorders, particularly in vulnerable populations such as premenopausal women and individuals with depressive disorders. By elucidating these complex interactions, we aim to provide insights for future research into targeted interventions, enhancing mental health outcomes.

Mechanisms of microbiota-gut-brain axis communication in anxiety disorders

Anxiety disorders, prevalent mental health conditions, receive significant attention globally due to their intricate etiology and the suboptimal effectiveness of existing therapies. Research is increasingly recognizing that the genesis of anxiety involves not only neurochemical brain alterations but also changes in gut microbiota. The microbiota-gut-brain axis (MGBA), serving as a bidirectional communication pathway between the gut microbiota and the central nervous system (CNS), is at the forefront of novel approaches to deciphering the complex pathophysiology of anxiety disorders. This review scrutinizes the role and recent advancements in the MGBA concerning anxiety disorders through a review of the literature, emphasizing mechanisms via neural signals, endocrine pathways, and immune responses. The evidence robustly supports the critical influence of MGBA in both the development and progression of these disorders. Furthermore, this discussion explores potential therapeutic avenues stemming from these insights, alongside the challenges and issues present in this realm. Collectively, our findings aim to enhance understanding of the pathological mechanisms and foster improved preventative and therapeutic strategies for anxiety disorders.

Paternal impact on the developmental programming of sexual dimorphism

Sexual dimorphism involves distinct anatomical, physiological, behavioral, and developmental differences between males and females of the same species, influenced by factors prior to conception and during early development. These sex-specific traits contribute to varied phenotypes and individual disease risks within and across generations and understanding them is essential in mammalian studies. Hormones, sex chromosomes, and imprinted genes drive this dimorphism, with over half of quantitative traits in wildtype mice showing sex-based variation. This review focuses on the impact of paternal non-genetic factors on sexual dimorphism. We synthesize current research on how paternal health before conception affects offspring phenotypes in a sex-specific manner, examining mechanisms such as DNA methylation, paternally imprinted genes, sperm RNA, and seminal plasma. Additionally, we explore how paternal influences indirectly shape offspring through maternal behavior, uterine environment, and placental changes, affecting males and females differently. We propose mechanisms modulating sexual dimorphism during development, underscoring the need for sex-specific documentation in animal studies.

Sex-Dependent Gut Microbiota Features and Functional Signatures in Metabolic Disfunction-Associated Steatotic Liver Disease

Background/Objectives: This study investigates the gut microbiota's role in metabolic dysfunction-associated steatotic liver disease (MASLD), focusing on microbial and functional signatures and sex-based differences. Methods: Using baseline data from 98 MASLD patients and 45 controls from the Fatty Liver in Obesity (FLiO) study, the gut microbiota was profiled with 16S gene sequencing, followed by statistical and machine learning analyses to identify disease-associated microbial signatures. Results: Notable alpha and beta diversity differences were observed between MASLD patients and the controls, varying by sex. Machine learning models highlighted specific microbial signatures for each sex, achieving high accuracy (area under the receiver operating characteristic curves of 0.91 for women and 0.72 for men). The key microbial taxa linked to MASLD included Christensenella and Limosilactobacillus in women and Beduinibacterium and Anaerotruncus in men. Functional profiling showed that MASLD patients had increased pathways for amine biosynthesis and amino acid degradation, while the controls exhibited enhanced fermentation pathways. These microbial features were associated with systemic inflammation, insulin resistance, and metabolite production linked to gut dysbiosis. Conclusions: The findings support the potential of gut microbiota signatures to be used as non-invasive indicators of MASLD and highlight sex-specific variations that could inform personalized diagnostic and therapeutic approaches.

Exploring the hypothetical links between environmental pollutants, diet, and the gut-testis axis: The potential role of microbes in male reproductive health

The gut system, commonly referred to as one of the principal organs of the human "superorganism," is a home to trillions of bacteria and serves an essential physiological function in male reproductive failures or infertility. The interaction of the endocrine-immune system and the microbiome facilitates reproduction as a multi-network system. Some recent studies that link gut microbiota to male infertility are questionable. Is the gut-testis axis (GTA) real, and does it affect male infertility? As a result, this review emphasizes the interconnected links between gut health and male reproductive function via changes in gut microbiota. However, a variety of harmful (endocrine disruptors, heavy metals, pollutants, and antibiotics) and favorable (a healthy diet, supplements, and phytoconstituents) elements promote microbiota by causing dysbiosis and symbiosis, respectively, which eventually modify the activities of male reproductive organs and their hormones. The findings of preclinical and clinical studies on the direct and indirect effects of microbiota changes on testicular functions have revealed a viable strategy for exploring the GTA-axis. Although the GTA axis is poorly understood, it may have potential ties to reproductive issues that can be used for therapeutic purposes in the future.

Gut microbiota and mycobiota change with feeding duration in mice on a high-fat and high-fructose diet

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is becoming the most common chronic liver disease. The gut microbiome is regarded to play a crucial role in MAFLD, but the specific changes of gut microbiome, especially fungi, in different stages of MAFLD are not well understood. This study aimed to observe the longitudinal changes of colon bacteria and fungi of mice at different feeding duration of a high-fat and high-fructose diet (HFHFD), and explore the association between the changes and the progression of MAFLD.

METHODS

Twenty-eight male C57BL6J mice were randomly assigned to the normal diet (ND) group and HFHFD group. At the 8th and 16th weeks, mice were sacrificed to compare the diversity, composition, and co-abundance network of bacteria and fungi in colon contents among groups.

RESULTS

HFHFD-8W mice exhibited increases in Candida and Dorea, and decreases in Oscillospira and Prevotella in comparison to ND-8W mice, HFHFD-16W mice had increases in Bacteroides, Candida, Desulfovibrio, Dorea, Lactobacillus, and Rhodotorula, and decreases in Akkermansia, Aspergillus, Sterigmatomyces, and Vishniacozyma in comparison to ND-16W mice. And compared to HFHFD-8W mice, HFHFD-16W mice had increases in Desulfovibrio, Lactobacillus, Penicillium, and Rhodotorula, and decreases in Talaromyces and Wallemia. Spearman and GEE correlation analysis revealed that Bacteroides, Candida, Desulfovibrio, and Lactobacillus positively correlated with NAFLD activity score (NAS).

CONCLUSION

Gut microbiota and mycobiota undergo diverse changes at different stages of MAFLD.

CLINICAL TRIAL NUMBER

Not applicable.

Antibiotic exposure and risk of overweight/obesity in children: a biomonitoring-based study from eastern Jiangsu, China

Objective

To describe antibiotic exposure in children and explore its association with overweight/obesity.

Methods

In June 2022, 328 kindergarten and primary school children were selected from Nantong city in Jiangsu Province. Questionnaires were distributed, and morning urine samples were obtained. Total urinary concentrations of 41 antibiotics were measured using ultra-performance liquid chromatography and tandem mass spectrometry. The rates of antibiotic exposure were expressed as percentages (%), specific percentiles (P 95 and P 99), and the maximum values were used to describe the concentration of antibiotics. The association between urinary antibiotic creatinine-adjusted and overweight/obesity was analyzed using logistic regression.

Results

A total of 328 children were initially recruited, of which 295 aged 3-8 years met the inclusion criteria and were finally included in the study. The biomonitoring results revealed that 35 antibiotics were detected, with a total detection frequency of 98.31%. Among the included children, 24.75% were classified as overweight/obesity. Multinomial logistic regression analyses revealed significant associations between overweight/obese and exposure to veterinary antibiotics (VAs) and preferred veterinary antibiotics (PVAs). After adjusting for various overweight/obesity-relevant variables, higher exposure to sulfamethoxazole [OR = 2.35, 95% confidence interval (CI):1.17-4.70], norfloxacin (OR = 2.66, 95% CI: 1.01-7.08), and fluoroquinolones (OR = 1.97, 95% CI: 1.02-3.78) were significantly associated with overweight/obesity (p < 0.05). In addition, after stratification by sex and adjustment for confounding variables, sex-specific differences were observed in the association between antibiotic exposure and overweight/obesity. Notably, these associations were predominantly observed among boys.

Conclusion

Children were extensively exposed to antibiotics. Exposure to certain types of veterinary antibiotics and preferred veterinary antibiotic exposure, mainly through food or drinking water, are associated with an increased risk of overweight/obesity in children.

An In Vivo Model of Estrogen Supplementation Concerning the Expression of Ca2+-Dependent Exchangers and Mortality, Vitality and Survival After Myocardial Infarction in Ovariectomized Rats

BACKGROUND

Ischemic-reperfusion damage of cardiomyocytes due to myocardial infarction (MI) often leads to the death of an individual. Premenopausal women have been observed to have a significantly lower risk of cardiovascular disease (CVD) than men of the same age. In menopausal women, this trend is significantly reversed, and the risk of CVD increases up to 10-fold. Estrogens affect the development and function of the heart muscle, and as they decrease, the risk and poor prognosis of CVD increase. This study is focused on the effects of estrogen supplementation on morbidity, vitality, and NCX1 expression after MI on a model system.

METHODS

In this study, female Sprague Dawley rats (n = 58), which were divided into three experimental groups (NN-control group, non-supplemented; OVX-N-ovariectomized, non-supplemented; OVX-S-ovariectomized, supplemented), received left thoracotomy in the fourth intercostal space. The left anterior descendent coronary artery was ligated 2 mm from its origin with an 8.0 suture. An immunohistological analysis as well as an RT-PCR analysis of NCX1 expression were performed.

RESULTS

A higher survival rate was recorded in the OVX-N group (86%) in comparison with the OVX-S group (53%) (p < 0.05). In addition, higher NCX1 expression 7 days/14 days after MI in the OVX-S group in comparison with the NN and OVX-N (p < 0.001 and p < 0.05) groups was recorded. Seven days after MI, a significantly higher expression (p < 0.005) of mRNA NCX1 in the OVX-N group was also recorded in comparison with the NN group.

CONCLUSIONS

This study provides a comprehensive description of the effect of estrogen supplementation on NCX1 expression and overall vitality in ovariectomized rats that survived MI.

Differences in Gut Microbes Across Age and Sex Linked to Metabolism and Microbial Stability in a Hibernating Mammal

The gut microbiome has a well-documented relationship with host fitness, physiology, and behavior. However, most of what is known comes from captive animals where diets and environments are more homogeneous or controlled. Studies in wild populations that experience dynamic environments and have natural life history variation are less common but are key to understanding the drivers of variation in the gut microbiome. Here we examine a wild population of yellow-bellied marmots (Marmota flaviventer), an obligate winter hibernator, to quantify multivariate associations between host-associated factors (e.g., age, sex, environmental harshness, and social behavior) and gut microbial composition. Across 5 years and 143 individuals, we found that males had a higher relative abundance of microbes associated with mass gain and cellulose digestion, which suggests a metabolic investment in mass gain (such as phylum Firmicutes and family Lachnospiraceae). By contrast, females had higher relative abundances of microbes associated with inflammation and metabolism (from microbial groups such as Tenericutes and Ruminococcus), possibly reflecting the importance of lactation and offspring investment. Post hoc analyses of lactating females showed a negative relationship with the abundance of microbes associated with mass gain but a positive relationship with microbes associated with metabolic energy, suggesting a trade-off between investment in pups and maternal mass gain. Older animals also had reduced Proteobacteria relative abundance, a phylum associated with reduced inflammation. Results demonstrate that sex and age-based traits, not sociality or environmental harshness, are associated with microbe-mediated metabolism and inflammation in a wild, hibernating mammal.

Development of shoulder osteoarthritis and bone lesions in female and male rats subjected to a high fat/sucrose diet

Oligofructose prebiotic fiber supplementation has been reported to mitigate the effects of a high fat/high sucrose diet and reduce knee joint degeneration in male rats. However, few studies investigated the development of osteoarthritis and bone lesions as a function of sex and in joints other than the knee. This study was aimed at to quantifying the effect of a HFS diet and prebiotic fiber supplementation on shoulder joint health in male and female Sprague-Dawley rats. Rats were randomized into 6 groups: 2 groups fed a chow diet: Chow-Male n = 11, Chow-female n = 12; 2 groups fed a HFS diet: HFS-Male n = 11, HFS-Female n = 12; and 2 groups fed a prebiotic fiber supplement in addition to the HFS diet: Fiber-Male n = 6, Fiber- Female n = 12. After 12 weeks, shoulder joints were histologically assessed for OA. Body composition, serum lipid profile, insulin resistance and fecal microbiota were also assessed. Shoulders in male and female rats appear to be protected against degeneration when exposed to a HFS diet. Male rats developed bone lesions while females did not. Fiber supplementation was more effective in males than in females suggesting that fiber supplementation may have sex-specific effects on the gut microbiota.

Influence of Early Life Factors on the Breast Milk and Fecal Microbiota of Mother-Newborn Dyads

Maternal gut and breast milk (BM) are key in vertically transmission bacteria to infants, shaping their gut microbiota in early life. Although the establishment of early gut microbiota is known, the role of the combined influence of maternal factors and newborn characteristics is not explored. In this study, we aimed to assess the influence of maternal BMI and total body fat, age, delivery mode, and newborn sex on the diversity and composition of the BM and gut microbiota (GM) in mother-newborn dyads. In this cross-sectional study, of the 986 pregnant women candidates, 53 participated, and, finally, 40 mother-newborn dyads exclusively breastfeeding at 20-28 days postpartum were included. Metataxonomic profiling of DNA extracted from BM and fecal samples was conducted using 16S rRNA sequencing. Globally, the findings offer valuable insights that excessive adiposity, age, and C-section delivery influence a lower abundance of specific taxa in the BM, maternal gut, and gut of newborns. Also, the simultaneous analysis of maternal factors and newborn characteristics shows that maternal age and newborn sex explain an important variation in the microbiota composition. These results add to the understanding of the intricate interplay between maternal factors and the microbial communities that influence early-life gut and BM microbiota.

Sex differences and testosterone interfere with the structure of the gut microbiota through the bile acid signaling pathway

Background

The gut microbiome has a significant impact on human wellness, contributing to the emergence and progression of a range of health issues including inflammatory and autoimmune conditions, metabolic disorders, cardiovascular problems, and psychiatric disorders. Notably, clinical observations have revealed that these illnesses can display differences in incidence and presentation between genders. The present study aimed to evaluate whether the composition of gut microbiota is associated with sex-specific differences and to elucidate the mechanism.

Methods

16S-rRNA-sequencing technology, hormone analysis, gut microbiota transplantation, gonadectomy, and hormone treatment were employed to investigate the correlation between the gut microbiome and sex or sex hormones. Meanwhile, genes and proteins involved bile acid signaling pathway were analyzed both in the liver and ileum tissues.

Results

The composition and diversity of the microbiota from the jejunum and feces and the level of sex hormones in the serum differed between the sexes in young and middle-aged Sprague Dawley (SD) rats. However, no similar phenomenon was found in geriatric rats. Interestingly, whether in young, middle-aged, or old rats, the composition of the microbiota and bacterial diversity differed between the jejunum and feces in rats. Gut microbiota transplantation, gonadectomy, and hormone replacement also suggested that hormones, particularly testosterone (T), influenced the composition of the gut microbiota in rats. Meanwhile, the mRNA and protein level of genes involved bile acid signaling pathway (specifically SHP, FXR, CYP7A1, and ASBT) exhibited gender-specific differences, and T may play a significant role in mediating the expression of this pathway.

Conclusion

Sex-specific differences in the structure of the gut microbiota are mediated by T through the bile acid signaling pathway, pointing to potential targets for disease prevention and management techniques by indicating that sex differences and T levels may alter the composition of the gut microbiota via the bile acid signaling pathway.

17β-Estradiol, through activating the G protein-coupled estrogen receptor, exacerbates the complication of benign prostatic hyperplasia in type 2 diabetes mellitus patients by inducing prostate proliferation

Benign prostatic hyperplasia (BPH) is one of the major chronic complications of type 2 diabetes mellitus (T2DM), and sex steroid hormones are common risk factors for the occurrence of T2DM and BPH. The profiles of sex steroid hormones are simultaneously quantified by LC-MS/MS in the clinical serum of patients, including simple BPH patients, newly diagnosed T2DM patients, T2DM complicated with BPH patients and matched healthy individuals. The G protein-coupled estrogen receptor (GPER) inhibitor G15, GPER knockdown lentivirus, the YAP1 inhibitor verteporfin, YAP1 knockdown/overexpression lentivirus, targeted metabolomics analysis, and Co-IP assays are used to investigate the molecular mechanisms of the disrupted sex steroid hormones homeostasis in the pathological process of T2DM complicated with BPH. The homeostasis of sex steroid hormone is disrupted in the serum of patients, accompanying with the proliferated prostatic epithelial cells (PECs). The sex steroid hormone metabolic profiles of T2DM patients complicated with BPH have the greatest degrees of separation from those of healthy individuals. Elevated 17β-estradiol (E2) is the key contributor to the disrupted sex steroid hormone homeostasis, and is significantly positively related to the clinical characteristics of T2DM patients complicated with BPH. Activating GPER by E2 via Hippo-YAP1 signaling exacerbates high glucose (HG)-induced PECs proliferation through the formation of the YAP1-TEAD4 heterodimer. Knockdown or inhibition of GPER-mediated Hippo-YAP1 signaling suppresses PECs proliferation in HG and E2 co-treated BPH-1 cells. The anti-proliferative effects of verteporfin, an inhibitor of YAP1, are blocked by YAP1 overexpression in HG and E2 co-treated BPH-1 cells. Inactivating E2/GPER/Hippo/YAP1 signaling may be effective at delaying the progression of T2DM complicated with BPH by inhibiting PECs proliferation.

Ceratonia Siliqua L: A Natural Compound with Big Impact on Male Reproductive System

Herbal products with antioxidant properties have gained attention for their potential impact on male reproductive health. One such botanical, Ceratonia siliqua (commonly known as carob), has been empirically used by infertile men in Iran and Turkey. Carob, a pod-bearing tree native to the Mediterranean, exhibits promising therapeutic potential for various aspects of male reproductive health. Carob consumption may positively affect sperm count, motility, and morphology in infertile men. The proposed mechanisms involve antioxidant activity, improved blood flow, and enhanced energy production within sperm. Carob's richness in antioxidants like polyphenols and flavonoids might counteract oxidative stress, a major contributor to sperm dysfunction. Carob may influence male sex hormones by potentially stimulating testosterone production and inhibiting estrogen conversion. While carob demonstrates promise as a natural supplement for male fertility, more robust research is necessary to solidify its therapeutic role. This exploration could pave the way for the development of novel dietary or nutraceutical interventions to address male infertility. While preliminary research suggests positive effects on sperm health and potential hormonal influence, robust clinical trials are needed to solidify carob's therapeutic efficacy. This exploration paves the way for future research on carob as a natural supplement and potentially opens doors for novel dietary or nutraceutical interventions to address male infertility.

17β-estradiol in colorectal cancer: friend or foe?

Colorectal cancer (CRC) is a common gastrointestinal malignancy with higher incidence and mortality rates in men compared to women, potentially due to the effects of estrogen signaling. There is substantial evidence supporting the significant role of 17β-Estradiol (E2) in reducing CRC risk in females, although this perspective remains debated. E2 has been demonstrated to inhibit CRC cell proliferation and migration at the cellular level by enhancing DNA mismatch repair, modulating key gene expression, triggering cell cycle arrest, and reducing activity of migration factors. Furthermore, E2 contributes to promote a tumor microenvironment unfavorable for CRC growth by stimulating ERβ expression, reducing inflammatory responses, reversing immunosuppression, and altering the gut microbiome composition. Conversely, under conditions of high oxidative stress, hypoxia, and nutritional deficiencies, E2 may facilitate CRC development through GPER-mediated non-genomic signaling. E2's influence on CRC involves the genomic and non-genomic signals mediated by ERβ and GPER, respectively, leading to its dual roles in anticancer activity and carcinogenesis. This review aims to summarize the potential mechanisms by which E2 directly or indirectly impacts CRC development, providing insights into the phenomenon of sexual dimorphism in CRC and suggesting potential strategies for prevention and treatment.

Sex Modifies the Effect of COVID-19 on Arterial Elasticity

There is limited long-term evidence on the effects of COVID-19 on vascular injury between male and female sex. An adult cohort of COVID-19 survivors (COVID+) and confirmed SARS-CoV-2 antibody-negative participants (COVID-) were prospectively enrolled. COVID+ participants who have documented the presence of persistent symptoms four weeks following infection were considered to have post-acute sequelae of COVID-19 (PASC). Non-invasive, FDA-approved EndoPAT (Endo-PAT2000) was used for endothelial assessment. COVID-(n = 94) were 1:1 propensity score matched to COVID+ (n = 151) on baseline covariates including sex. Among COVID+, 66.2% (n = 100) had PASC. Higher levels of coagulation marker, D-dimer (p = 0.001), and gut permeability marker, zonulin (p = 0.001), were associated with female sex. Estimated differences in augmentation index (AI) between COVID- (0.9 ± 17.2) and COVID+ (8.4 ± 15.7; p = 0.001) and between female and male sex (12.9 ± 1.9; p < .0001) were observed. Among COVID+ with PASC, the average AI (10.5 ± 1.6) was 9.7 units higher than COVID- (p < .0001) and 6.2 units higher compared to COVID+ with no PASC (p = 0.03). COVID+ PASC+ female sex had the highest AI (14.3 ± 1.9). The effects of SARS-CoV-2 infection on vascular function varies across strata of sex and female sex in the post-acute phase of COVID-19 have the worse arterial elasticity (highest AI).

Do fish gut microbiotas vary across spatial scales? A case study of Diplodus vulgaris in the Mediterranean Sea

BACKGROUND

Biogeography has been linked to differences in gut microbiota in several animals. However, the existence of such a relationship in fish is not clear yet. So far, it seems to depend on the fish species studied. However, most studies of fish gut microbiotas are based on single populations. In this study, we investigated the gut microbiota of fish from three wild populations of the two-banded sea bream Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817) to determine whether its diversity, structure and potential functionality reflect the geographic origin of the fish, at large and small geographical scale. Additionally, we explored the host- and environmental-related factors explaining this relationship.

RESULTS

We showed that the taxonomy and potential functionality of the mucosa-associated gut microbiota of Diplodus vulgaris differ to varying degrees depending on the spatial scale considered. At large scale, we observed that both the taxonomical structure and the potential functionality of the fish microbiota differed significantly between populations. In contrast, the taxonomical diversity of the microbial community displayed a significant relationship with factors other than the geographic origin of the fish (i.e. sampling date). On the other hand, at small scale, the different composition and diversity of the microbiota differ according to the characteristics of the habitat occupied by the fish. Specifically, we identified the presence of Posidonia oceanica in the benthic habitat as predictor of both the microbiota composition and diversity. Lastly, we reported the enrichment of functions related to the metabolism of xenobiotics (i.e. drugs and 4-aminobenzoate) in a population and we indicated it as a potential target of future monitoring.

CONCLUSIONS

With this study, we confirmed the importance of investigating the gut microbiota of wild fish species using multiple populations, taking into account the different habitats occupied by the individuals. Furthermore, we underscored the use of the biodegradation potential of the gut microbiota as an alternative means of monitoring emerging contaminants in Mediterranean fish.

Sex-dependent effects of carbohydrate source and quantity on caspase-1 activity in the mouse central nervous system

BACKGROUND

Mounting evidence links glucose intolerance and diabetes as aspects of metabolic dysregulation that are associated with an increased risk of developing dementia. Inflammation and inflammasome activation have emerged as a potential link between these disparate pathologies. As diet is a key factor in both the development of metabolic disorders and inflammation, we hypothesize that long term changes in dietary factors can influence nervous system function by regulating inflammasome activity and that this phenotype would be sex-dependent, as sex hormones are known to regulate metabolism and immune processes.

METHODS

5-week-old male and female transgenic mice expressing a caspase-1 bioluminescent reporter underwent cranial window surgeries and were fed control (65% complex carbohydrates, 15% fat), high glycemic index (65% carbohydrates from sucrose, 15% fat), or ketogenic (1% complex carbohydrates, 79% fat) diet from 6 to 26 weeks of age. Glucose regulation was assessed with a glucose tolerance test following a 4-h morning fast. Bioluminescence in the brain was quantified using IVIS in vivo imaging. Blood cytokine levels were measured using cytokine bead array. 16S ribosomal RNA gene amplicon sequencing of mouse feces was performed to assess alterations in the gut microbiome. Behavior associated with these dietary changes was also evaluated.

RESULTS

The ketogenic diet caused weight gain and glucose intolerance in both male and female mice. In male mice, the high glycemic diet led to increased caspase-1 biosensor activation over the course of the study, while in females the ketogenic diet drove an increase in biosensor activation compared to their respective controls. These changes correlated with an increase in inflammatory cytokines present in the serum of test mice and the emergence of anxiety-like behavior. The microbiome composition differed significantly between diets; however no significant link between diet, glucose tolerance, or caspase-1 signal was established.

CONCLUSIONS

Our findings suggest that diet composition, specifically the source and quantity of carbohydrates, has sex-specific effects on inflammasome activation in the central nervous system and behavior. This phenotype manifested as increased anxiety in male mice, and future studies are needed to determine if this phenotype is linked to alterations in microbiome composition.

Impact of menopause-associated frailty on traumatic brain injury

Navigating menopause involves traversing a complex terrain of hormonal changes that extend far beyond reproductive consequences. Menopausal transition is characterized by a decrease in estradiol-17β (E2), and the impact of menopause resonates not only in the reproductive system but also through the central nervous system, musculoskeletal, and gastrointestinal domains. As women undergo menopausal transition, they become more susceptible to frailty, amplifying the risk and severity of injuries, including traumatic brain injury (TBI). Menopause triggers a cascade of changes leading to a decline in muscle mass, accompanied by diminished tone and excitability, thereby restricting the availability of irisin, a crucial hormone derived from muscles. Concurrently, bone mass undergoes reduction, culminating in the onset of osteoporosis and altering the dynamics of osteocalcin, a hormone originating from bones. The diminishing levels of E2 during menopause extend their influence on the gut microbiota, resulting in a reduction in the availability of tyrosine, tryptophan, and serotonin metabolites, affecting neurotransmitter synthesis and function. Understanding the interplay between menopause, frailty, E2 decline, and the intricate metabolisms of bone, gut, and muscle is imperative when unraveling the nuances of TBI after menopause. The current review underscores the significance of accounting for menopause-associated frailty in the incidence and consequences of TBI. The review also explores potential mechanisms to enhance gut, bone, and muscle health in menopausal women, aiming to mitigate frailty and improve TBI outcomes.

Testis–Gut-Reproduction Axis: The Key to Reproductive Health

Reproductive health is an important issue for humanity. In the context of the increasing incidence rate of male infertility, it is essential to find the factors that affect male reproductive health. Gastrointestinal health is closely related to reproductive health. Gastrointestinal hormones (GIH) and gut microbiota (GM), as important material foundations for gastrointestinal function, can promote or inhibit testicular reproductive function, including spermatogenesis, sperm maturation, androgen synthesis, and even broader male diseases such as sexual function, prostate cancer, etc. On the contrary, the functional health of the testes is also of great significance for the stability of gastrointestinal function. This review mainly discusses the important regulatory effects of GIH and GM on male reproductive function.

Impact of Physiological Fluctuations of Sex Hormones During the Menstrual Cycle on Glucose Metabolism and the Gut Microbiota

Diabetes mellitus is one of the most prevalent chronic diseases. Previous studies have shown differences in glucose metabolism between males and females. Moreover, difficulties in medication adherence have been reported in females with type 2 diabetes. These observations are believed to be caused by fluctuations in sex hormone concentrations during the menstrual cycle. Furthermore, gut microbiota is linked to female host metabolism and sex hormone production. Understanding the interactions between fluctuating hormone concentrations during the menstrual cycle, gut microbiota, and glucose metabolism in humans is significant because of the increasing prevalence of diabetes and the consequent need to expand preventive efforts. A literature search was performed to determine and summarize the existing evidence, deduce future research needs to maintain female health, and investigate the relationship between the physiological menstrual cycle and glucose metabolism. Studies from 1967 to 2020 have already examined the relationship between variations during the menstrual cycle and glucose metabolism in healthy female subjects using an oral-glucose tolerance test or intravenous glucose tolerance test. However, the overall number of studies is rather small and the results are contradictory, as some studies detected differences in glucose concentrations depending on the different cycle phases, whereas others did not. Some studies reported lower glucose levels in the follicular phase than in the luteal phase, whereas another study detected the opposite. Data on gut microbiota in relation to the menstrual cycle are limited. Conflicting results exist when examining the effect of hormonal contraceptives on the gut microbiota and changes in the course of the menstrual cycle. The results indicate that the menstrual cycle, especially fluctuating sex hormones, might impact the gut microbiota composition.The menstrual cycle may affect the gut microbiota composition and glucose metabolism. These results indicate that glucose tolerance may be the greatest in the follicular phase; however, further well-conducted studies are needed to support this assumption.

Sexual dimorphism in the context of nutrition and health

Diets and dietary constituents that we consume have a considerable impact on disease risk. Intriguingly these effects may be modulated to some extent by sex. Lack of female representation in nutritional studies as well as a lack of stratification by sex has and continues to limit our understanding of these sex × diet interactions. Here we provide an overview of the current and available literature describing how exposure to certain dietary patterns (Western-style diet, Mediterranean diet, vegetarian/vegan, ketogenic diet) and dietary constituents (dietary fibre, PUFA and plant bioactive) influences disease risk in a sex-specific manner. Interestingly, these sex differences appear to be highly disease-specific. The identification of such sex differences in response to diet stresses the importance of sex stratification in nutritional research.

Microbiome Sex-Related Diversity in Non-Muscle-Invasive Urothelial Bladder Cancer

Sex-specific discrepancies in bladder cancer (BCa) are reported, and new studies imply that microbiome may partially explain the diversity. We aim to provide characterization of the bladder microbiome in both sexes diagnosed with non-muscle-invasive BCa with specific insight into cancer grade. In our study, 16S rRNA next-generation sequencing was performed on midstream urine, bladder tumor sample, and healthy-appearing bladder mucosa. Bacterial DNA was isolated using QIAamp Viral RNA Mini Kit. Metagenomic analysis was performed using hypervariable fragments of the 16S rRNA gene on Ion Torrent Personal Genome Machine platform. Of 41 sample triplets, 2153 taxa were discovered: 1739 in tumor samples, 1801 in healthy-appearing bladder mucosa and 1370 in midstream urine. Women were found to have smaller taxa richness in Chao1 index than men (p = 0.03). In comparison to low-grade tumors, patients with high-grade lesions had lower bacterial diversity and richness in urine. Significant differences between sexes in relative abundance of communities at family level were only observed in high-grade tumors.

Taxonomic and metabolic development of the human gut microbiome across life stages: a worldwide metagenomic investigation

The human gut microbiota is a dynamic community of microorganisms that undergo variable changes over the entire life span. To thoroughly investigate the possible fluctuations of the microbiota throughout human life, we performed a pooled analysis of healthy fecal samples across different age groups covering the entire human life span. Our study integrated data from 79 publicly available studies and new stool samples from an Italian cohort, i.e., the Parma Microbiota project, resulting in 6,653 samples processed through the shotgun metagenomic approach. This approach has allowed species-level taxonomic reconstruction of the gut microbiota and investigation of its metabolic potential across the human life span. From a taxonomic point of view, our findings confirmed and detailed at species-level accuracy that the microbial richness of the gut microbiota gradually increases in the first stage of life, becoming relatively stable during adolescence. Moreover, the analysis identified the potential core microbiota representative of distinct age groups, revealing age-related bacterial patterns and the continuous rearrangement of the microbiota in terms of relative abundances across the life span rather than the acquisition and loss of taxa. Furthermore, the shotgun approach provided insights into the functional contribution of the human gut microbiome. The metagenomic analysis revealed functional age-related differences, particularly in carbohydrate and fiber metabolism, suggesting a co-evolution of the microbiome assembly with diet. Additionally, we identified correlations between vitamin synthesis, such as thiamine and niacin, and early life, suggesting a potential role of the microbiome in human physiology, in particular in the functions of the host's nervous and immune systems.

IMPORTANCE

In this study, we provided comprehensive insights into the dynamic nature of the human gut microbiota across the human life span. In detail, we analyzed a large data set based on a shotgun metagenomic approach, combining public data sets and new samples from the Parma Microbiota project and obtaining a detailed overview of the possible relationship between gut microbiota development and aging. Our findings confirmed the main stages in microbial richness development and revealed specific core microbiota associated with different age stages. Moreover, the shotgun metagenomic approach allowed the disentangling of the functional changes in the microbiome across the human life span, particularly in diet-related metabolism, which is probably correlated to bacterial co-evolution with dietary habits. Notably, our study also uncovered positive correlations with vitamin synthesis in early life, suggesting a possible impact of the microbiota on human physiology.

Sex-Dependent Efficacy of Dietary Fiber in Pediatric Functional Abdominal Pain

BACKGROUND & AIMS

Functional abdominal pain disorders (FAPDs) are more prevalent in female patients. Dietary fiber may alleviate FAPD symptoms; however, whether this effect is sex dependent remains unclear. We investigated the sex dependency of dietary fiber benefit on abdominal pain in children with FAPDs and explored the potential involvement of the gut microbiome.

METHODS

In 2 cross-sectional cohorts of children with FAPDs (n = 209) and healthy control individuals (n = 105), we correlated dietary fiber intake with abdominal pain symptoms after stratifying by sex. We also performed sex-stratified and sex-interaction analyses on data from a double-blind trial in children with irritable bowel syndrome randomized to psyllium fiber (n = 39) or placebo (n = 49) for 6 weeks. Shotgun metagenomics was used to investigate gut microbiome community changes potentially linking dietary fiber intake with abdominal pain.

RESULTS

In the cross-sectional cohorts, fiber intake inversely correlated with pain symptoms in boys (pain episodes: r = -0.24, P = .005; pain days: r = -0.24, P = 0.004) but not in girls. Similarly, in the randomized trial, psyllium fiber reduced the number of pain episodes in boys (P = .012) but not in girls. Generalized linear regression models confirmed that boys treated with psyllium fiber had greater reduction in pain episodes than girls (P = .007 for fiber × sex × time interaction). Age, sexual development, irritable bowel syndrome subtype, stool form, and microbiome composition were not significant determinants in the dietary fiber effects on pain reduction.

CONCLUSIONS

Dietary fiber preferentially reduces abdominal pain frequency in boys, highlighting the importance of considering sex in future dietary intervention studies for FAPDs. (ClincialTrials.gov, Number NCT00526903).

Immune Cells, Gut Microbiota, and Vaccines: A Gender Perspective

The development of preventive and therapeutic vaccines has played a crucial role in preventing infections and treating chronic and non-communicable diseases, respectively. For a long time, the influence of sex differences on modifying health and disease has not been addressed in clinical and preclinical studies. The interaction of genetic, epigenetic, and hormonal factors plays a role in the sex-related differences in the epidemiology of diseases, clinical manifestations, and the response to treatment. Moreover, sex is one of the leading factors influencing the gut microbiota composition, which could further explain the different predisposition to diseases in men and women. In the same way, differences between sexes occur also in the immune response to vaccines. This narrative review aims to highlight these differences, focusing on the immune response to vaccines. Comparative data about immune responses, vaccine effectiveness, and side effects are reviewed. Hence, the intricate interplay between sex, immunity, and the gut microbiota will be discussed for its potential role in the response to vaccination. Embracing a sex-oriented perspective in research may improve the efficacy of the immune response and allow the design of tailored vaccine schedules.

Sex differences in colorectal cancer: with a focus on sex hormone-gut microbiome axis

Sexual dimorphism has been observed in the incidence and prognosis of colorectal cancer (CRC), with men generally exhibiting a slightly higher incidence than women. Research suggests that this difference may be attributed to variations in sex steroid hormone levels and the gut microbiome. The gut microbiome in CRC shows variations in composition and function between the sexes, leading to the concept of 'microgenderome' and 'sex hormone-gut microbiome axis.' Conventional research indicates that estrogens, by promoting a more favorable gut microbiota, may reduce the risk of CRC. Conversely, androgens may have a direct pro-tumorigenic effect by increasing the proportion of opportunistic pathogens. The gut microbiota may also influence sex hormone levels by expressing specific enzymes or directly affecting gonadal function. However, this area remains controversial. This review aims to explore the differences in sex hormone in CRC incidence, the phenomenon of sexual dimorphism within the gut microbiome, and the intricate interplay of the sex hormone-gut microbiome axis in CRC. The objective is to gain a better understanding of these interactions and their potential clinical implications, as well as to introduce innovative approaches to CRC treatment.

From Gut to Hormones: Unraveling the Role of Gut Microbiota in (Phyto)Estrogen Modulation in Health and Disease

The human gut microbiota regulates estrogen metabolism through the "estrobolome," the collection of bacterial genes that encode enzymes like β-glucuronidases and β-glucosidases. These enzymes deconjugate and reactivate estrogen, influencing circulating levels. The estrobolome mediates the enterohepatic circulation and bioavailability of estrogen. Alterations in gut microbiota composition and estrobolome function have been associated with estrogen-related diseases like breast cancer, enometrial cancer, and polycystic ovarian syndrome (PCOS). This is likely due to dysregulated estrogen signaling partly contributed by the microbial impacts on estrogen metabolism. Dietary phytoestrogens also undergo bacterial metabolism into active metabolites like equol, which binds estrogen receptors and exhibits higher estrogenic potency than its precursor daidzein. However, the ability to produce equol varies across populations, depending on the presence of specific gut microbes. Characterizing the estrobolome and equol-producing genes across populations can provide microbiome-based biomarkers. Further research is needed to investigate specific components of the estrobolome, phytoestrogen-microbiota interactions, and mechanisms linking dysbiosis to estrogen-related pathology. However, current evidence suggests that the gut microbiota is an integral regulator of estrogen status with clinical relevance to women's health and hormonal disorders.

Structural analysis of polysaccharide from Inonotus obliquus and investigate combined impact on the sex hormones, intestinal microbiota and metabolism in SPF male mice

The dysregulation of sex hormone levels is associated with metabolic disorders such as obesity. Inonotus obliquus polysaccharide (IOP) exhibits a promising therapeutic effect on conditions like obesity and diabetes, potentially linked to its influence on intestinal microbiota and metabolism. The exact cause and mechanisms that link sex hormones, gut microbiota and metabolism are still unknown. In this research, we examined the molecular weight, monosaccharide composition, and glycosidic bond type of IOP. We found that IOP mostly consists of alpha-structured 6‑carbon glucopyranose, with a predominant (1 → 4) linkage to monosaccharides and a uniform distribution. Following this, we administered two different concentrations of IOP to mice through gavage. The results of the enzyme-linked immunosorbent assay (ELISA) demonstrated a significant increase in testosterone (T) levels in the IOP group as compared to the control group. Additionally, the results of tissue immunofluorescence indicated that increased IOP led to a decrease in adiponectin content and an increase in SET protein expression. The study also revealed changes in the intestinal microbiota and metabolic changes in mice through 16S rRNA data and non-targeted LC-MS data, respectively. The study also found that IOP mainly affects pathways linked to glycerophospholipid metabolism. In addition, it has been observed that there is an increase in the number of beneficial bacteria, such as the Eubacterium coprostanoligenes group and g.Lachnospiraceae NK4A136 group, while the levels of metabolites that are linked to obesity or diabetes, such as 1,5-anhydrosorbitol, are reduced. Furthermore, biomarker screening has revealed that the main microorganism responsible for the differences between the three groups is g.Erysipelatoclostridiaceae. In summary, these findings suggest that IOP exerts its therapeutic effects through a synergistic interplay between sex hormones, gut microbiome composition, and metabolic processes.

Gut Biogeography Accentuates Sex-Related Differences in the Murine Microbiome

Recent studies have highlighted the influence of factors such as sex and sex-linked hormones on microbiome composition, raising concerns about the generalizability of findings. Here, we explore whether gut geography, specifically the upper and lower gastrointestinal tract (GI), contributes to sex-linked microbiome differences in mice. We collected microbial samples throughout the length of the GI from male and female C57B6/J mice at 6- and 8-weeks old, and conducted 16S rRNA sequencing. Our findings revealed significant sex-related differences, with Clostridium_sensu_stricto_1 more abundant in the male colon, while females exhibited higher levels of Dubosiella newyorkensis across all organs at 6 weeks. We also observed decreased Shannon alpha diversity in the small intestine compared to the lower GI, and this diversity decreased further at 8 weeks. Interestingly, our results suggest that age mitigates sex-related, but not gut geography-related differences in beta diversity, with implications for experimental outcomes and treatment strategies. This study underscores the dynamic nature of microbial diversity, influenced by sex, age, and GI localization, emphasizing the need for a more comprehensive understanding of microbiome dynamics in experimental research and clinical interventions.

The Effect of Cross-Sex Fecal Microbiota Transplantation on Metabolism and Hormonal Status in Adult Rats

Increasing evidence of sexual dimorphism in the pathophysiology of metabolic complications caused by sex steroids is under investigation. The gut microbiota represents a complex microbial ecosystem involved in energy metabolism, immune response, nutrition acquisition, and the health of host organisms. Gender-specific differences in composition are present between females and males. The purpose of this study was to use cross-sex fecal microbiota transplantation (FMT) for the detection of sex-dependent metabolic, hormonal, and gut microbiota changes in female and male recipients. Healthy non-obese female and male Wistar rats were divided into donor, same-sex, and cross-sex recipient groups. After a 30-day period of FMT administration, biochemical markers (glucose and lipid metabolism) and sex hormones were measured, and the gut microbiota was analyzed. The cross-sex male recipients displayed a significantly lower testosterone concentration compared to the males that received same-sex FMT. Sex-dependent changes caused by cross-sex FMT were detected, while several bacterial taxa correlated with plasma testosterone levels. This study represents the first to study the effect of cross-sex changes in the gut microbiome concerning metabolic and hormonal changes/status in adult non-obese Wistar rats. Herein, we present cross-sex FMT as a potential tool to modify sex-specific pathologies.

Urinary antibiotic levels and risk of overweight/obesity in preschool children: A biomonitoring-based study from eastern China

There is limited evidence linking antibiotic exposure, particularly from contaminated food or drinking water, to childhood obesity. The study aimed to investigate the association between urinary antibiotic levels and overweight/obesity in preschool children. In the case-control study, 121 overweight/obese preschoolers and 242 controls (aged 3-6 years) from eastern China were enrolled in 2022 based on age, sex, and study site matching. Overweight/obesity was determined using body mass index (BMI) and weight for height (WFH) criteria derived from national data. A total of 50 antibiotics from 8 categories were analyzed using ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). We identified major dietary patterns using principal component analysis (PCA) and examined the associations of antibiotic exposure with childhood overweight/obesity using multivariate logistic regression. Twenty-four individual antibiotics were detected in more than 10 % of the samples, and overall detection rates were up to 100 %. Overweight/obese children had a higher exposure to veterinary antibiotics (VAs) than normal weight children. PCA analysis showed that children who were overweight/obese had higher scores of "Aquatic products preferred dietary pattern" and "Cereals preferred dietary pattern" compared to children with normal weight. Multivariate logistic regression analyses indicated that exposure to elevated levels of deoxytetracycline (OR: 1.72; 95 %CI: 1.00-2.93) and quinolones (OR: 1.63; 95 %CI: 1.04-2.57) was significantly related to an increased risk of BMI-based overweight/obesity. Quinolones exposure was also significantly associated with WFH-based overweight/obesity, primarily in boys. After adjustment for all covariates, higher exposure to ofloxacin (of the quinolones) was significantly related to overweight/obesity in girls. Exposure to certain antibiotics, especially quinolones, may increase the risk of overweight/obesity in preschoolers. More prospective, well-designed studies are needed to clarify these findings.

Unravelling the Crosstalk between Estrogen Deficiency and Gut-biotaDysbiosis in the Development of Diabetes Mellitus

Estrogens are classically considered essential hormonal signals, but they exert profound effects in a number of physiological and pathological states, including glucose homeostasis and insulin resistance. Estrogen deficiency after menopause in most women leads to increased androgenicity and changes in body composition, and it is recommended to manipulate the β-cell function of the pancreas, insulin-induced glucose transport, and hepatic glucose output, hence, the increasing incidence of type 2 diabetes mellitus. Recently, studies have reported that gut biota alteration due to estrogen deficiency contributes to altered energy metabolism and, hence, accentuates the pathology of diabetes mellitus. Emerging research suggests estrogen deficiency via genetic disposition or failure of ovaries to function in old age modulates the insulin resistance and glucose secretion workload on pancreatic beta cells by decreasing the levels of good bacteria such as Akkermansia muciniphila, Bifidobacterium spp., Lactobacillus spp., Faecalibacterium prausnitzii, Roseburia spp., and Prevotella spp., and increasing the levels of bad bacteria's such as Bacteroides spp., Clostridium difficile, Escherichia coli, and Enterococcus spp. Alteration in these bacteria's concentrations in the gut further leads to the development of impaired glucose uptake by the muscles, increased gluconeogenesis in the liver, and increased lipolysis and inflammation in the adipose tissues. Thus, the present review paper aims to clarify the intricate interactions between estrogen deficiency, gut microbiota regulation, and the development of diabetes mellitus.

Sex hormones, sex chromosomes, and microbiota: Identification of Akkermansia muciniphila as an estrogen-responsive microbiota

Microbiota composition is known to be linked to sex. However, separating sex hormones and sex chromosome roles in gut microbial diversity is yet to be determined. To investigate the sex chromosome role independent of sex hormones, we used the four-core genotype mouse model. In this mouse model, males with testes and females with ovaries have XX or XY sex chromosome complement. In gonadectomized four-core genotype mice, we observed a significant decrease in the levels of estradiol (P<0.001) and progesterone (P<0.03) in female and testosterone (P<0.0001) in male mice plasma samples. Independent of sex chromosome complement, microbial α diversity was increased in gonadectomized female but not male mice compared to sex-matched gonad-intact controls. β diversity analysis showed separation between male (P<0.05) but not female XX and XY mice. Importantly, Akkermansia muciniphila was less abundant in gonadectomized compared to gonadal intact female mice (P<0.0001). In the presence of β-estradiol, Akkermansia muciniphila growth exponentially increased, providing evidence for the identification of a female sex hormone-responsive bacterium (P<0.001).

Acupuncture as multi-targeted therapy for the multifactorial disease obesity: a complex neuro-endocrine-immune interplay

The prevalence of obesity has reached pandemic dimensions. It is associated with multiple comorbidities and is becoming a clinical and public health threat. Obesity is a multifactorial disease with a complex pathophysiology and interplay of various systems. A strong interplay exists between the neuro-endocrine system, the immune system with systemic chronic low-grade inflammation, and microbiome dysbiosis that can lead to the development of obesity, which in turn can exacerbate each of these factors, hence creating a vicious cycle. The conventional treatment with lifestyle modifications such as diet, physical exercise, pharmacotherapy, and bariatric surgery does not always result in sufficient weight control thus paving the way for other strategies. As one such strategy, acupuncture is increasingly used worldwide to treat obesity. This narrative review outlines the evidence for this neuro-endocrine-immune interplay in the pathophysiology of obesity. Furthermore, the existing experimental and clinical evidence of acupuncture as a multi-targeted therapy for obesity is explained and future research perspectives are discussed.

Microbiota Profile of the Nasal Cavity According to Lifestyles in Healthy Adults in Santiago, Chile

BACKGROUND

The respiratory microbiome is dynamic, varying between anatomical niches, and it is affected by various host and environmental factors, one of which is lifestyle. Few studies have characterized the upper respiratory tract microbiome profile according to lifestyle. We explored the association between lifestyles and microbiota profiles in the upper respiratory tract of healthy adults.

METHODS

We analyzed nasal samples from 110 healthy adults who were living in Santiago, Chile, using 16S ribosomal RNA gene-sequencing methods. Volunteers completed a structured questionnaire about lifestyle.

RESULTS

The composition and abundance of taxonomic groups varied across lifestyle attributes. Additionally, multivariate models suggested that alpha diversity varied in the function of physical activity, nutritional status, smoking, and the interaction between nutritional status and smoking, although the significant impact of those variables varied between women and men. Although physical activity and nutritional status were significantly associated with all indexes of alpha diversity among women, the diversity of microbiota among men was associated with smoking and the interaction between nutritional status and smoking.

CONCLUSIONS

The alpha diversity of nasal microbiota is associated with lifestyle attributes, but these associations depend on sex and nutritional status. Our results suggest that future studies of the airway microbiome may provide a better resolution if data are stratified for differences in sex and nutritional status.

Correlates of Insulin Resistance in Nascent Metabolic Syndrome

Background

Metabolic Syndrome (MetS), a major global problem, is a cluster of cardio-metabolic risk factors that predisposes to both type 2 diabetes mellitus (T2DM) and premature atherosclerotic cardiovascular disease (ASCVD). Insulin resistance is a major underpinning of MetS.

Objectives

We investigated the relationship between insulin resistance and biomarkers of inflammation, oxidative stress, free fatty acids (FFA) levels and adipokine dysregulation in a cohort of nascent MetS.

Design

This was a cross-sectional study comparing patients with MetS with matched controls.

Patients and Methods

Participants included 47 patients with MetS and 41 controls. Persons with diabetes, ASCVD, smoking and macro-inflammation were excluded. Fasting blood was obtained for both plasma and monocyte isolation. Homeostasis model assessment insulin resistance index (HOMA-IR) was calculated from fasting glucose and insulin levels.

Results

The patients were insulin resistant as determined by a valid measure, HOMA-IR. HOMA-IR increased with increasing severity of MetS and correlated with cardio-metabolic features, hsCRP, FFA levels, and adipose tissue insulin resistance. Insulin resistance also correlated with biomarkers of oxidative stress and both circulating and cellular biomarkers of inflammation. Receiver operating Characteristic (ROC) curve analysis revealed that HOMA-IR was an excellent predictor of MetS with an area under the curve of 0.80.

Conclusion

In our patients with nascent MetS we show that they have significant insulin resistance. Based on our findings, elevated FFA levels, oxidative stress and inflammation could contribute to the insulin resistance.