The microgenderome revealed: sex differences in bidirectional interactions between the microbiota, hormones, immunity and disease susceptibility

Fecal microbiota transplantation in allergic diseases

Microorganisms such as bacteria, fungi, viruses, parasites living in the human intestine constitute the human intestinal microbiota. Dysbiosis refers to compositional and quantitative changes that negatively affect healthy gut microbiota. In recent years, with the demonstration that many diseases are associated with dysbiosis, treatment strategies targeting the correction of dysbiosis in the treatment of these diseases have begun to be investigated. Faecal microbiota transplantation (FMT) is the process of transferring faeces from a healthy donor to another recipient in order to restore the gut microbiota and provide a therapeutic benefit. FMT studies have gained popularity after probiotic, prebiotic, symbiotic studies in the treatment of dysbiosis and related diseases. FMT has emerged as a potential new therapy in the treatment of allergic diseases as it is associated with the maintenance of intestinal microbiota and immunological balance (T helper 1/T helper 2 cells) and thus suppression of allergic responses. In this article, the definition, application, safety and use of FMT in allergic diseases will be discussed with current data.

Effects of Prebiotics and Probiotics on Symptoms of Depression and Anxiety in Clinically Diagnosed Samples: Systematic Review and Meta-analysis of Randomized Controlled Trials

CONTEXT

The use of prebiotics and probiotics as a treatment for psychiatric conditions has gained interest due to their potential to modulate the gut-brain axis. This review aims to assess the effectiveness of these interventions in reducing symptoms of depression and anxiety in psychiatric populations.

OBJECTIVE

The aim was to comprehensively review and appraise the effectiveness of prebiotic, probiotic, and synbiotic interventions in reducing clinical depression and anxiety symptoms.

DATA SOURCES

Systematic searches were conducted across Embase, Medline, PsycINFO, CINAHL, Cochrane Library, and Science Citation Index from database inception to May 22, 2023.

DATA EXTRACTION

Randomized controlled trials investigating prebiotic, probiotic, or synbiotic interventions for treating clinical depression or anxiety symptoms in clinical samples were included. Data were extracted on study characteristics, intervention details, and outcome measures. The Cochrane Collaboration Tool was used to assess the risk of bias.

DATA ANALYSIS

The standardized mean difference (SMD) was calculated using Hedge's g as the metric of effect size. A random-effects model was applied to estimate pooled effect sizes with 95% CIs. Subgroup analyses were performed based on study characteristics, methodological factors, and intervention types. Sensitivity analyses excluded studies with a high risk of bias.

RESULTS

Twenty-three RCTs involving 1401 patients met the inclusion criteria, with 20 trials providing sufficient data for meta-analysis. Of these, 18 trials investigated probiotics for depression, 9 trials assessed probiotics for anxiety, and 3 trials examined prebiotics for depression. Probiotics demonstrated a significant reduction in depression symptoms (SMD: -0.96; 95% CI: -1.31, -0.61) and a moderate reduction in anxiety symptoms (SMD: -0.59; 95% CI: -0.98, -0.19). Prebiotics did not show a significant effect on depression (SMD: -0.28; 95% CI: -0.61, 0.04). High heterogeneity was observed across studies, and subgroup analyses indicated that study duration and probiotic formulations contributed to the variation in effect sizes.

CONCLUSION

Probiotics showed substantial reductions in depression symptoms and moderate reductions in anxiety symptoms. Prebiotics showed a nonsignificant trend toward reducing depression. An adjunctive mental health treatment approach that diagnoses, monitors, and treats the gut microbiome alongside traditional pharmacological treatment holds promise for clinical practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023424136.

Mechanisms of gut homeostasis regulating Th17/Treg cell balance in PMOP

Postmenopausal osteoporosis (PMOP) is a metabolic bone disease driven by estrogen deficiency, primarily manifesting as reduced bone mass and heightened fracture risk. Its development is intricately linked to the balance between Th17 and Treg cells. Recent studies have highlighted the significant role of gut homeostasis in PMOP. The gut microbiota profoundly impacts bone health by modulating the host's immune system, metabolic pathways, and endocrine functions. In particular, the regulation of Th17 and Treg cell balance by gut homeostasis plays a pivotal role in the onset and progression of PMOP. Th17 cells secrete pro-inflammatory cytokines that stimulate osteoclast activity, accelerating bone resorption, while Treg cells counteract this process through anti-inflammatory mechanisms, preserving bone mass. The gut microbiota and its metabolites can influence Th17/Treg equilibrium, thereby modulating bone metabolism. Furthermore, the integrity of the gut barrier is critical for systemic immune stability, and its disruption can lead to immune dysregulation and metabolic imbalances. Thus, targeting gut homeostasis to restore Th17/Treg balance offers a novel therapeutic avenue for the prevention and treatment of PMOP.

Gut Microbiota: Association with Fiber Intake, Ultra-Processed Food Consumption, Sex, Body Mass Index, and Socioeconomic Status in Medical Students

The gut microbiota plays a vital role in various physical and physiological processes, including immune system regulation, neurotransmitter production, inflammatory response modulation, and the inhibition of pathogenic organisms. An imbalance in the microbial community, known as dysbiosis, has been associated with numerous health issues. Biological influences, health behaviors, socioeconomic determinants, and nutritional status can disrupt this balance.

OBJECTIVE

To evaluate the differences in the gut microbiota composition in medical students according to fiber intake, ultra-processed food (UPF) consumption, sex, body mass index, and socioeconomic status.

METHODS

A cross-sectional study was conducted with 91 medical students, and 82 fecal samples were analyzed. Sociodemographic and dietary data were collected via questionnaires, UPF consumption was assessed using the NOVA classification, and trained nutritionists performed anthropometry. DNA extraction and 16S rRNA sequencing were performed for the microbial analysis. Bioinformatics and statistical tests included the Dunn and Kruskal-Wallis tests, a PCoA analysis, PERMANOVA, ANOVA, Spearman's rank correlation, and alpha and beta diversity metrics.

RESULTS

Dietary fiber intake strongly influences gut microbiota composition. Lower fiber intake was associated with a higher prevalence of Parabacteroides and Muribaculaceae. Prevotella was more prevalent in individuals with lower UPF intake, while Phascolarctobacterium was prevalent in those with higher UPF consumption. Significant differences were associated with sex and UPF consumption but not BMI or SES. Women consumed more UPF, which correlated with distinct gut microbiota profiles.

CONCLUSIONS

This study highlights the significant impact of diet, particularly fiber intake and UPF, on gut microbiota composition, emphasizing the importance of dietary habits in maintaining gut health.

Revisiting microgenderome: detecting and cataloguing sexually unique and enriched species in human microbiomes

BACKGROUND

Microgenderome or arguably more accurately microsexome refers to studies on sexual dimorphism of human microbiomes aimed at investigating bidirectional interactions between human microbiomes, sex hormones, and immune systems. It is important because of its implications to disease susceptibility and therapy, in which men and women demonstrate divergence in many diseases especially autoimmune diseases. In a previous report [1], we presented analyses of several key ecological aspects of microgenderome by leveraging the large datasets of the HMP (human microbiome project) but failed to offer species-level composition differences such as sexually unique species (US) and enriched species (ES). Existing approaches, for such tasks, including differential species relative abundance analysis and differential network analysis, possess certain limitations given that virtually all rely on species abundance alone or are univariate, while ignoring species distribution information across samples. Obviously, it is both species abundance and distribution that shape/drive the structure and dynamics of human microbiomes, and both should be equally responsible for the universal heterogeneity of microbiomes including the sexual dimorphism.

RESULTS

Here, we fill the gap by taking advantages of a recently developed computational algorithm, species specificity, and specificity diversity (SSD) framework (refer to the companion article) to reanalyze the HMP and complementary seminovaginal microbiome datasets. The SSD framework can randomly search and catalogue the sexually specific unique/enriched species with statistical rigor, guided by species specificity (a synthetic metric of abundance and distribution) and specificity diversity (SD). The SSD framework reveals that men seem to have more unique species than women in their gut and reproductive system microbiomes, but women seem to have more unique species than men in the airway, oral, and skin microbiomes, which is likely due to sexual dimorphism in the hormone and immune systems. We further investigate co-dependency and heterogeneity of those sexually unique/enriched species across 15 body sites, with core/periphery network analyses.

CONCLUSIONS

This study not only produced sexually unique/enriched species in the human microbiomes and analyzed their codependency and heterogeneity but also further validated the robustness of the SSD framework presented in the companion article, by performing all negative control tests based on the HMP gut microbiome samples.

Direct and indirect effects of estrogens, androgens and intestinal microbiota on colorectal cancer

Sex differences in colorectal cancer (CRC) has received considerable research attention recently, particularly regarding the influence of sex hormones and the intestinal microbiota. Estrogen, at the genetic and epigenetic levels, directly inhibits CRC cell proliferation by enhancing DNA mismatch repair, regulating miRNAs, blocking the cell cycle, and modulating ion channels. However, estradiol's activation of GPER promotes oncogene expression. Conversely, androgen contributes to epigenetic dysregulation and CRC progression via nuclear receptors while inducing apoptosis through membrane receptors. Specific gut microorganisms produce genotoxins and oncogenic metabolites that damage colonic cell DNA and contribute to cancer induction. Regarding the tumor microenvironment, estrogen mitigates intestinal inflammation, reverses immunosuppression, increases gut microbiome diversity and commensal bacteria abundance, and decreases pathogen enrichment. On the contrary, androgen disrupts intestinal microecology, diminish immunotherapy efficacy, and exacerbate colonic inflammation and tumor growth. The impact of estrogen and androgen is closely tied to their receptor status, elucidating their dual roles in CRC pathogenesis. This review comprehensively discusses the direct and indirect effects of sex hormones and the intestinal microbiota on CRC, considering environmental factors such as diet and lifestyle to propose novel prevention and treatment strategies.

Testosterone treatment impacts the intestinal microbiome of transgender individuals

Medical modulation of sex hormone levels is a cornerstone of treatment for many conditions that impact well-being, including cancer, fertility/infertility, gender dysphoria, and chronic metabolic diseases such as diabetes and obesity. The microbial residents of the intestine, known as the microbiota, interact with sex hormones in the intestine, and there is correlative evidence that this interaction is bidirectional. Based on these published findings, we hypothesized that transgender individuals receiving exogenous testosterone as part of their gender-affirming medical treatment might undergo changes in their intestinal microbiome. To test this, we collected 26 stool samples from nine individuals before and up to 8 months after initiation of treatment with exogenous testosterone and subjected these samples to metagenomic analysis. While no species were significantly associated with the duration of testosterone therapy, pathways that generate glutamate increased in abundance, while those that consume glutamate decreased. Glutamate is a precursor of arginine, and testosterone is known to increase levels of arginine and its metabolites in the plasma. We hypothesize that testosterone increases the uptake of glutamate by enterocytes, thus decreasing access of the microbiota to this amino acid. While this pilot study establishes the impact of testosterone therapy on the intestinal microbiome, a more comprehensive study is necessary to establish the impact of testosterone-driven metagenomic shifts on the stool metatranscriptome, the stool metabolome, and the plasma metabolome.IMPORTANCEThe human intestine is inhabited by a large community of microbes known as the microbiome. Members of the microbiome consume the diet along with their human host. Thus, the metabolomes of the host and microbe are intricately linked. Testosterone alters the plasma metabolome. In particular, plasma levels of arginine and its metabolites and testosterone are positively correlated. To investigate the impact of exogenous testosterone on the microbiome, we analyzed the stool metagenomes of transgender individuals before and after the initiation of testosterone treatment. In this pilot project, we found a modest impact on the microbiome community structure but an increase in the abundance of metabolic pathways that generate glutamate and spare glutamate consumption. We propose that the host uses glutamate to generate arginine, decreasing the amount available for the microbiome.

Consumption of a Probiotic Blend with Vitamin D Improves Immunity, Redox, and Inflammatory State, Decreasing the Rate of Aging-A Pilot Study

There is evidence of the effect of probiotic intake on the immune system. However, the effect probiotics may have on the rate of aging is unknown. The aim of this study is to determine the effect of a probiotic blend on immunity, redox state, inflammation, and the rate of aging or biological age. A group of 10 men and 14 women took, daily for 2 months, a sachet with three probiotics (Bifidobacterium animalis subsp. lactis BSO1, Lactobacillus reuteri LRE02, Lactobacillus plantarum LP14) and vitamin D. Before starting the treatment and after 2 months, peripheral blood was collected. Immune functions were assessed in isolated immune cells, and cytokine concentrations were also measured both in mononuclear cell cultures and plasma. Redox state parameters were also analyzed in whole blood cells. Finally, the Immunity Clock was applied to determine the biological age. Results show that the intake of this probiotic blend in general, in both men and women, improves immunity and decreases the oxidative and inflammatory state. In addition, it rejuvenates the biological age by 10 years on average. It can be concluded that this probiotic blend could be proposed as a good strategy to slow down the aging process, and to achieve healthy aging.

Recommendations for the Application of Sex and Gender Medicine in Preclinical, Epidemiological and Clinical Research

Gender medicine studies how health status and diseases differ between men and women in terms of prevention, therapeutic approach, prognosis, and psychological and social impact. Sex and gender analyses have been demonstrated to improve science, contributing to achieving real appropriateness and equity in the cure for each person. Therefore, it is fundamental to consider, both in preclinical and clinical research, the different clinical and biological features associated with sex and/or gender, where sex differences are mainly influenced by biological determinants and gender ones by socio-cultural and economic matters. This article was developed to provide knowledge and methodological tools for the development of studies/research protocols in which sex and gender should be taken into account.

The Possible Preventative Role of Lactate- and Butyrate-Producing Bacteria in Colorectal Carcinogenesis

Background/Aims

: The gut microbiome has emerged as a key player that mechanistically links various risk factors to colorectal cancer (CRC) etiology. However, the role of the gut microbiome in CRC pathogenesis remains unclear. This study aimed to characterize the gut microbiota in healthy controls (HCs) and patients with colorectal adenoma (AD) and CRC in subgroups based on sex and age.

Methods

: Study participants who visited the hospital for surveillance of CRC or gastrointestinal symptoms were prospectively enrolled, and the gut microbiome was analyzed based on fecal samples.

Results

: In terms of HC-AD-CRC sequence, commensal bacteria, including lactate-producing (Streptococcus salivarius) and butyrate-producing (Faecalibacterium prausnitzii, Anaerostipes hadrus, and Eubacterium hallii) bacteria, were more abundant in the HC group than in the AD and CRC groups. In the sex comparison, the female HC group had more lactate-producing bacteria (Bifidobacterium adolescentis, Bifidobacterium catenulatum, and Lactobacillus ruminis) than the male HC group. In age comparison, younger subjects had more butyrate-producing bacteria (Agathobaculum butyriciproducens and Blautia faecis) than the older subjects in the HC group. Interestingly, lactate-producing bacteria (B. catenulatum) were more abundant in females than males among younger HC group subjects. However, these sex- and age-dependent differences were not observed in the AD and CRC groups.

Conclusions

: The gut microbiome, specifically lactate- and butyrate-producing bacteria, which were found to be abundant in the HC group, may play a role in preventing the progression of CRC. In particular, lactate-producing bacteria, which were found to be less abundant in healthy male controls may contribute to the higher incidence of CRC in males.

Sex as a predictor of clinical phenotype and determinant of immune response in IgG4-related disease: a retrospective study of patients fulfilling the American College of Rheumatology-European League Against Rheumatism classification criteria

BACKGROUND

IgG4-related disease is a multiorgan fibroinflammatory disease considered to have an autoimmune origin. Case series describing individual organ involvement have suggested differences in phenotypic expression between males and females. We aimed to characterise differences in IgG4-related disease manifestations between male and female patients in a large single-centre cohort.

METHODS

In this retrospective, single-centre cohort study, patients were recruited from the Massachusetts General Hospital Rheumatology Clinic (Boston, MA, USA) and classified according to the American College of Rheumatology-European Alliance of Associations for Rheumatology (ACR-EULAR) classification criteria. Only patients satisfying the ACR-EULAR classification criteria were included in the study. Data on age at diagnosis, organ involvement at baseline, treatment status, and pre-treatment laboratory values were collected. Circulating plasmablasts and B-cell subsets were quantitated by flow cytometry. Active disease was defined by an IgG4-related disease Responder Index score of more than 0. Laboratory values were analysed for patients who were untreated at baseline and had active IgG4-related disease. The main outcomes were assessed in all participants with available data.

FINDINGS

Of the 564 participants enrolled in the Massachusetts General Hospital Rheumatology Clinic IgG4-related disease Registry, 328 fulfilled ACR-EULAR classification criteria and were included between January, 2008, and May, 2023. There was a strong male predominance (male:female ratio 2·2:1) with 226 (69%) males and 102 (31%) females, which contrasted markedly with our general rheumatology clinic population (0·4:1; p<0·001). The male predominance increased with each decade of life starting at age 40 years. On average, male patients were 5·5 years older at diagnosis than female patients (63·7 years vs 58·2 years; p=0·0031). We observed male patients to have higher ACR-EULAR classification criteria scores at baseline with a median score of 35·0 (IQR 28·0-46·0), compared with 29·5 (25·0-39·0) for females (p=0·0010). The proportion of male patients with pancreatic and renal involvement was almost double the proportion observed in female patients (50% of the male patients had pancreatic involvement, compared with about 26% of the female patients; p<0·0001). Male patients were more likely to have serological abnormalities at baseline. The distribution of IgG4 values differed significantly between male an female sexes, favouring higher values in males. We found that male patients with IgG4-related disease were more likely to have active B-cell responses in the blood as defined by plasmablast expansions.

INTERPRETATION

IgG4-related disease is unusual among autoimmune diseases in that it is more likely to affect males than females and to present with a striking sex-dependent organ distribution and degree of B-cell response. These findings highlight important variation between IgG4-related disease and other conditions generally believed to have an autoimmune basis. Most autoimmune diseases, by contrast to IgG4-related disease, demonstrate pronounced predilections for affecting females more frequently than males. Hypotheses surrounding the cause and pathophysiology of this condition need to consider this unusual sex distribution among patients with IgG4-related disease.

FUNDING

National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rheumatology Research Foundation, and the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Age and sex differences in pharmaceutical contamination in a keystone scavenger

Pharmaceutical contaminants have a recognized negative impact on wildlife health. However, there are still many knowledge gaps on the factors influencing exposure and metabolic processing of compound mixtures as a function of season and individual characteristics such as age and sex. We evaluated age and sex differences in a set of seventeen compounds, including eleven antibiotics, five NSAIDs and caffeine, evaluated by HPLC-MS-TOF analysis in griffon vultures (Gyps fulvus) from central Spain. Pharmaceutical cocktails (up to 10 compounds simultaneously) were found in all individuals. Lincomycin was detected in all individuals, and fluoroquinolones were found at high frequencies, while NSAIDs were at low frequencies and concentrations, including flumixin meglumine, which can be lethal to vultures. A higher total number of compounds and sum of concentrations, as well as prevalence and concentration of several of the pharmaceuticals tested was found in females than in males for both nestlings and adults. This is the first study to present evidence of sex differences in the pharmacokinetics of dietary drug contaminants in a vulture species. Chronic exposure to "medications" in entire populations can potentially have sub-lethal health effects that affect fitness differently according to age and sex, with demographic implications for population viability. Specifically, if females have higher mortality after fledging due to high pharmaceutical contamination, this should be considered when modelling the population dynamic of this species for conservation purposes.

Gonadal sex and chromosome complement influence the gut microbiome in a mouse model of allergic airway inflammation

Evidence abounds that gut microbiome components are associated with sex disparities in the immune system. However, it remains unclear whether the observed sex disparity in asthma incidence is associated with sex-dependent differences in immune-modulating gut microbiota, and/or its influence on allergic airway inflammatory processes. Using a mouse model of house dust mite (HDM)-induced allergic inflammation and the four core genotypes (FCGs) model, we have previously reported sex differences in lung inflammatory phenotypes. Here, we investigated associations of gut microbiomes with these phenotypes by challenging FCG mice [mouse with female sex chromosome and male gonad (XXM), mouse with female sex chromosome and female gonad (XXF), mouse with male sex chromosome and male gonad (XYM), and mouse with male sex chromosome and female gonad (XYF); n = 7/group] with HDM (25 μg) or PBS intranasally for 5 wk and collecting fecal samples. We extracted fecal DNA and analyzed the 16S microbiome via Targeted Metagenomic Sequencing. We compared α and β diversity across genotypes and assessed the Firmicutes/Bacteroidetes (F/B) ratio. When comparing baseline and after exposure for the FCG, we found that the gut F/B ratio was only increased in the XXM genotype. We also found that α diversity was significantly increased in all FCG mice upon HDM challenge, with the highest increase in the XXF, and the lowest in the XXM genotypes. Similarly, β diversity of the microbial community was also affected by challenge in a gonad- and chromosome-dependent manner. In summary, our results indicated that HDM treatment, gonads, and sex chromosomes significantly influence the gut microbial community composition. We concluded that allergic lung inflammation may be affected by the gut microbiome in a sex-dependent manner involving both hormonal and genetic influences.NEW & NOTEWORTHY Recently, the gut microbiome and its role in chronic respiratory disease have been the subject of extensive research and the establishment of its involvement in immune functions. Using the FCG mouse model, our findings revealed the influence of gonads and sex chromosomes on the microbial community structure before and after exposure to HDM. Our data provide a potential new avenue to better understand mediators of sex disparities associated with allergic airway inflammation.

Neutralizing gut-derived lipopolysaccharide as a novel therapeutic strategy for severe leptospirosis

Leptospirosis is an emerging infectious disease caused by pathogenic Leptospira spp. Humans and some mammals can develop severe forms of leptospirosis accompanied by a dysregulated inflammatory response, which often results in death. The gut microbiota has been increasingly recognized as a vital element in systemic health. However, the precise role of the gut microbiota in severe leptospirosis is still unknown. Here, we aimed to explore the function and potential mechanisms of the gut microbiota in a hamster model of severe leptospirosis. Our study showed that leptospires were able to multiply in the intestine, cause pathological injury, and induce intestinal and systemic inflammatory responses. 16S rRNA gene sequencing analysis revealed that Leptospira infection changed the composition of the gut microbiota of hamsters with an expansion of Proteobacteria. In addition, gut barrier permeability was increased after infection, as reflected by a decrease in the expression of tight junctions. Translocated Proteobacteria were found in the intestinal epithelium of moribund hamsters, as determined by fluorescence in situ hybridization, with elevated lipopolysaccharide (LPS) levels in the serum. Moreover, gut microbiota depletion reduced the survival time, increased the leptospiral load, and promoted the expression of proinflammatory cytokines after Leptospira infection. Intriguingly, fecal filtration and serum from moribund hamsters both increased the transcription of TNF-α, IL-1β, IL-10, and TLR4 in macrophages compared with those from uninfected hamsters. These stimulating activities were inhibited by LPS neutralization using polymyxin B. Based on our findings, we identified an LPS neutralization therapy that significantly improved the survival rates in severe leptospirosis when used in combination with antibiotic therapy or polyclonal antibody therapy. In conclusion, our study not only uncovers the role of the gut microbiota in severe leptospirosis but also provides a therapeutic strategy for severe leptospirosis.

Epidemiology and antimicrobial resistance of Salmonella serovars Typhimurium and 4,[5],12:i- recovered from hospitalized patients in China

Global emergence of multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium is a continuing challenge for modern healthcare. However, the knowledge, regarding the epidemiology of salmonellosis caused by the monophasic variant S. 4,[5],12:i:- in hospitalized patients, is limited in China. To bridge this gap, we carried out a retrospective study to determine the antimicrobial resistance, trends, and risk factors of S. Typhimurium and S. 4,[5],12:i:- (n = 329) recovered from patients in Zhejiang province between 2011 and 2019. The results showed that 90.57% (298/329) of the isolates were MDR; among them, 48.94% (161/329) and 12.46% (41/329) were phenotypically resistant to cephalosporins and fluoroquinolones, respectively, which are the drugs of choice used to treat salmonellosis in clinics. Additionally, we observed a higher incidence of infections among the young population (<5 years old). Notably, the higher prevalence of ST34 (sequence type 34) isolates, especially after 2014, with MDR (57.05%, 170/298) phenotype, and incidence of ST34 isolates co-harbouring mcr-1 (mobile colistin resistance gene) and blaCTX-M-14 (β-lactamase gene) suggest an association between STs and drug resistance. Together, the increasing prevalence of MDR ST34 calls for enhanced monitoring strategies to mitigate the spread and dissemination of MDR clones of S. Typhimurium and S. 4,[5],12:i-. Our study provides improved knowledge about non-typhoid Salmonella (NTS) infections, which could help in the effective recommendation of antimicrobials in hospitalized patients.

Fecal microbiota transplantation from female donors restores gut permeability and reduces liver injury and inflammation in middle-aged male mice exposed to alcohol

Background

Alcohol misuse, binge drinking pattern, and gender-specific effects in the middle-aged population has been clearly underestimated. In the present study, we focused on understanding gender-specific effects of alcohol exposure on the gut-liver axis and the role of gut microbiota in modulating gender-specific responses to alcohol consumption.

Methods

Fifty-two-week-old female and male C57BL/6 mice were fasted for 12 h, and then administered a single oral dose of ethanol (EtOH) (6 g/kg). Controls were given a single dose of PBS. Animals were sacrificed 8 h later. Alternatively, fecal microbiota transplantation (FMT) was performed in 52-week-old male mice from female donors of the same age. Permeability of the large intestine (colon), gut microbiota, liver injury, and inflammation was thoroughly evaluated in all groups.

Results

Middle-aged male mice exposed to EtOH showed a significant increase in gut permeability in the large intestine, evaluated by FITC-dextran assay and ZO-1, OCCLUDIN and MUCIN-2 immuno-staining, compared to PBS-treated animals, whilst female mice of the same age also increased their gut permeability, but displayed a partially maintained intestinal barrier integrity. Moreover, there was a significant up-regulation of TLRs and markers of hepatocellular injury, cell death (AST, TUNEL-positive cells) and lipid accumulation (ORO) in male mice after EtOH exposure. Interestingly, FMT from female donors to male mice reduced gut leakiness, modified gut microbiota composition, ameliorated liver injury and inflammation, TLR activation and the senescence phenotype of middle-aged mice.

Conclusion

Our findings highlighted the relevance of gender in middle-aged individuals who are exposed to alcohol in the gut-liver axis. Moreover, our study revealed that gender-specific microbiota transplantation might be a plausible therapy in the management of alcohol-related disorders during aging.

17β-Estradiol protects female rats from bilateral oophorectomy-induced nonalcoholic fatty liver disease induced by improving linoleic acid metabolism alteration and gut microbiota disturbance

After surgical or natural menopause, women face a high risk of nonalcoholic fatty liver disease (NAFLD), which can be diminished by hormone replacement therapy (HRT). The gut microbiota is subject to modulation by various physiological changes and the progression of diseases. This microbial ecosystem coexists symbiotically with the host, playing pivotal roles in immune maturation, microbial defense mechanisms, and metabolic functions essential for nutritional and hormone homeostasis. E2 supplementation effectively prevented the development of NAFLD after bilateral oophorectomy (OVX) in female rats. The changes in the gut microbiota such as abnormal biosynthetic metabolism of fatty acids caused by OVX were partially restored by E2 supplementation. The combination of liver transcriptomics and metabolomics analysis revealed that linoleic acid (LA) metabolism, a pivotal pathway in fatty acids metabolism was mainly manipulated during the induction and treatment of NAFLD. Further correlation analysis indicated that the gut microbes were associated with abnormal serum indicators and different LA metabolites. These metabolites are also closely related to serum indicators of NAFLD. An in vitro study verified that LA is an inducer of hepatic steatosis. The changes in transcription in the LA metabolism pathway could be normalized by E2 treatment. The metabolic perturbations of LA may directly and secondhand impact the development of NAFLD in postmenopausal individuals. This research focused on the sex-specific pathophysiology and treatment of NAFLD, providing more evidence for HRT and calling for the multitiered management of NAFLD.

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.

Probiotic, prebiotic, synbiotic and fermented food supplementation in psychiatric disorders: A systematic review of clinical trials

The use of probiotics, prebiotics, synbiotics or fermented foods can modulate the gut-brain axis and constitute a potentially therapeutic intervention in psychiatric disorders. This systematic review aims to identify current evidence regarding these interventions in the treatment of patients with DSM/ICD psychiatric diagnoses. Forty-seven articles from 42 studies met the inclusion criteria. Risk of bias was assessed in all included studies. Major depression was the most studied disorder (n = 19 studies). Studies frequently focused on schizophrenia (n = 11) and bipolar disorder (n = 5) and there were limited studies in anorexia nervosa (n = 4), ADHD (n = 3), Tourette (n = 1), insomnia (n = 1), PTSD (n = 1) and generalized anxiety disorder (n = 1). Except in MDD, current evidence does not clarify the role of probiotics and prebiotics in the treatment of mental illness. Several studies point to an improvement in the immune and inflammatory profile (e.g. CRP, IL6), which may be a relevant mechanism of action of the therapeutic response identified in these studies. Future research should consider lifestyle and dietary habits of patients as possible confounders that may influence inter-individual treatment response.

Microbial composition, functionality, and stress resilience or susceptibility: unraveling sex-specific patterns

BACKGROUND

Following exposure to traumatic stress, women are twice as likely as men to develop mood disorders. Yet, individual responses to such stress vary, with some people developing stress-induced psychopathologies while others exhibit resilience. The factors influencing sex-related disparities in affective disorders as well as variations in resilience remain unclear; however, emerging evidence suggests differences in the gut microbiota play a role. In this study, using the single prolonged stress (SPS) model of post-traumatic stress disorder, we investigated pre- and post-existing differences in microbial composition, functionality, and metabolites that affect stress susceptibility or resilience in each sex.

METHODS

Male and female Sprague-Dawley rats were randomly assigned to control or SPS groups. Two weeks following SPS, the animals were exposed to a battery of behavioral tests and decapitated a day later. Based on their anxiety index, they were further categorized as SPS-resilient (SPS-R) or SPS-susceptible (SPS-S). On the day of dissection, cecum, and selected brain tissues were isolated. Stool samples were collected before and after SPS, whereas urine samples were taken before and 30 min into the SPS.

RESULTS

Before SPS exposure, the sympathoadrenal axis exhibited alterations within male subgroups only. Expression of tight junction protein claudin-5 was lower in brain of SPS-S males, but higher in SPS-R females following SPS. Across the study, alpha diversity remained consistently lower in males compared to females. Beta diversity revealed distinct separations between male and female susceptible groups before SPS, with this separation becoming evident in the resilient groups following SPS. At the genus level, Lactobacillus, Lachnospiraceae_Incertae_Sedis, and Barnesiella exhibited sex-specific alterations, displaying opposing abundances in each sex. Additionally, sex-specific changes were observed in microbial predictive functionality and targeted functional modules both before and after SPS. Alterations in the microbial short-chain fatty acids (SCFAs), were also observed, with major and minor SCFAs being lower in SPS-susceptible males whereas branched-chain SCFAs being higher in SPS-susceptible females.

CONCLUSION

This study highlights distinct pre- and post-trauma differences in microbial composition, functionality, and metabolites, associated with stress resilience in male and female rats. The findings underscore the importance of developing sex-specific therapeutic strategies to effectively address stress-related disorders. Highlights SPS model induces divergent anxiety and social behavioral responses to traumatic stress in both male and female rodents. SPS-resilient females displayed less anxiety-like behavior and initiated more interactions towards a juvenile rat than SPS-resilient males. Sex-specific pre-existing and SPS-induced differences in the gut microbial composition and predictive functionality were observed in susceptible and resilient rats. SPS-resilient males displayed elevated cecal acetate levels, whereas SPS-susceptible females exhibited heightened branched-chain SCFAs.

Sex-biased genetic regulation of inflammatory proteins in the Dutch population

BACKGROUND

Significant differences in immune responses, prevalence or susceptibility of diseases and treatment responses have been described between males and females. Despite this, sex-differentiation analysis of the genetic architecture of inflammatory proteins is largely unexplored. We performed sex-stratified meta-analysis after protein quantitative trait loci (pQTL) mapping using inflammatory biomarkers profiled using targeted proteomics (Olink inflammatory panel) of two population-based cohorts of Europeans.

RESULTS

Even though, around 67% of the pQTLs demonstrated shared effect between sexes, colocalization analysis identified two loci in the males (LINC01135 and ITGAV) and three loci (CNOT10, SRD5A2, and LILRB5) in the females with evidence of sex-dependent modulation by pQTL variants. Furthermore, we identified pathways with relevant functions in the sex-biased pQTL variants. We also showed through cross-validation that the sex-specific pQTLs are linked with sex-specific phenotypic traits.

CONCLUSION

Our study demonstrates the relevance of genetic sex-stratified analysis in the context of genetic dissection of protein abundances among individuals and reveals that, sex-specific pQTLs might mediate sex-linked phenotypes. Identification of sex-specific pQTLs associated with sex-biased diseases can help realize the promise of individualized treatment.

Human breastmilk-derived Bifidobacterium longum subsp. infantis CCFM1269 regulates bone formation by the GH/IGF axis through PI3K/AKT pathway

Bifidobacterium longum subsp. infantis is a prevalent member of the gut microbiota of breastfed infants. In this study, the effects of human breastmilk-derived B.longum subsp. infantis CCFM1269 on bone formation in developing BALB/c mice were investigated. Newborn female and male mice were assigned to control group (administered saline), CCFM11269 group (administered B. longum subsp. infantis CCFM1269, 1 × 109 CFU/mouse/day) and I5TI group (administered B. longum subsp. infantis I5TI, 1 × 109 CFU/mouse/day) from 1-week-old to 3-, 4- and 5-week old. B. longum subsp. infantis I5TI served as a negative control in this study. The results demonstrated that B. longum subsp. infantis CCFM1269 promoted bone formation in growing mice by modulating the composition of the gut microbiota and metabolites. The expression of genes and proteins in the PI3K/AKT pathway was stimulated by B. longum subsp. infantis CCFM1269 through the GH/IGF-1 axis in growing mice. This finding suggests B. longum subsp. infantis CCFM1269 may be useful for modulating bone metabolism during growth.

Necrotizing Enterocolitis and the Preterm Infant Microbiome

Preterm infants differ significantly from their term infant counterparts regarding bacterial colonization patterns related to maternal microbiota diversity, mode of delivery, feeding type, antibiotic exposure, and the environmental influences related to prolonged hospitalization in the neonatal intensive care unit (NICU). Necrotizing enterocolitis (NEC), a multifactorial intestinal disorder characterized by ischemic bowel disease, disproportionately impacts preterm infants and has a high disease burden. Recent studies in the basic, translational, and clinical scientific literature have advanced knowledge into this complex disease process. Despite the explosion of research into NEC, however, there is a still a great deal unknown about this devastating illness. Additionally, the disease morbidity and mortality for NEC remain high despite advances in therapy options. This chapter reviews the current literature into the preterm infant microbiome, pathogenesis of NEC, potential targets for altering preterm microbiome, influence of microbiome on other organ systems, long-term implications of microbiome dysbiosis, and future directions of study.

Effect of synbiotic supplementation on immune parameters and gut microbiota in healthy adults: a double-blind randomized controlled trial

Synbiotics are increasingly used by the general population to boost immunity. However, there is limited evidence concerning the immunomodulatory effects of synbiotics in healthy individuals. Therefore, we conducted a double-blind, randomized, placebo-controlled study in 106 healthy adults. Participants were randomly assigned to receive either synbiotics (containing Bifidobacterium lactis HN019 1.5 × 108 CFU/d, Lactobacillus rhamnosus HN001 7.5 × 107 CFU/d, and fructooligosaccharide 500 mg/d) or placebo for 8 weeks. Immune parameters and gut microbiota composition were measured at baseline, mid, and end of the study. Compared to the placebo group, participants receiving synbiotic supplementation exhibited greater reductions in plasma C-reactive protein (P = 0.088) and interferon-gamma (P = 0.008), along with larger increases in plasma interleukin (IL)-10 (P = 0.008) and stool secretory IgA (sIgA) (P = 0.014). Additionally, synbiotic supplementation led to an enrichment of beneficial bacteria (Clostridium_sensu_stricto_1, Lactobacillus, Bifidobacterium, and Collinsella) and several functional pathways related to amino acids and short-chain fatty acids biosynthesis, whereas reduced potential pro-inflammatory Parabacteroides compared to baseline. Importantly, alternations in anti-inflammatory markers (IL-10 and sIgA) were significantly correlated with microbial variations triggered by synbiotic supplementation. Stratification of participants into two enterotypes based on pre-treatment Prevotella-to-Bacteroides (P/B) ratio revealed a more favorable effect of synbiotic supplements in individuals with a higher P/B ratio. In conclusion, this study suggested the beneficial effects of synbiotic supplementation on immune parameters, which were correlated with synbiotics-induced microbial changes and modified by microbial enterotypes. These findings provided direct evidence supporting the personalized supplementation of synbiotics for immunomodulation.

Sex hormone signaling and regulation of immune function

Immune responses to antigens, including innocuous, self, tumor, microbial, and vaccine antigens, differ between males and females. The quest to uncover the mechanisms for biological sex differences in the immune system has intensified, with considerable literature pointing toward sex hormonal influences on immune cell function. Sex steroids, including estrogens, androgens, and progestins, have profound effects on immune function. As such, drastic changes in sex steroid concentrations that occur with aging (e.g., after puberty or during the menopause transition) or pregnancy impact immune responses and the pathogenesis of immune-related diseases. The effect of sex steroids on immunity involves both the concentration of the ligand and the density and distribution of genomic and nongenomic receptors that serve as transcriptional regulators of immune cellular responses to affect autoimmunity, allergy, infectious diseases, cancers, and responses to vaccines. The next frontier will be harnessing these effects of sex steroids to improve therapeutic outcomes.

Distinctive features of the oropharyngeal microbiome in Inuit of Nunavik and correlations of mild to moderate bronchial obstruction with dysbiosis

Inuit of Nunavik are coping with living conditions that can influence respiratory health. Our objective was to investigate associations between respiratory health in Inuit communities and their airway microbiome. Oropharyngeal samples were collected during the Qanuilirpitaa? 2017 Inuit Health Survey and subjected to metagenomic analyses. Participants were assigned to a bronchial obstruction group or a control group based on their clinical history and their pulmonary function, as monitored by spirometry. The Inuit microbiota composition was found to be distinct from other studied populations. Within the Inuit microbiota, differences in diversity measures tend to distinguish the two groups. Bacterial taxa found to be more abundant in the control group included candidate probiotic strains, while those enriched in the bronchial obstruction group included opportunistic pathogens. Crossing taxa affiliation method and machine learning consolidated our finding of distinct core microbiomes between the two groups. More microbial metabolic pathways were enriched in the control participants and these were often involved in vitamin and anti-inflammatory metabolism, while a link could be established between the enriched pathways in the disease group and inflammation. Overall, our results suggest a link between microbial abundance, interactions and metabolic activities and respiratory health in the Inuit population.

Bacteria in cancer initiation, promotion and progression

Cancer cells originate from a series of acquired genetic mutations that can drive their uncontrolled cell proliferation and immune evasion. Environmental factors, including the microorganisms that colonize the human body, can shift the metabolism, growth pattern and function of neoplastic cells and shape the tumour microenvironment. Dysbiosis of the gut microbiome is now recognized as a hallmark of cancer by the scientific community. However, only a few microorganisms have been identified that directly initiate tumorigenesis or skew the immune system to generate a tumour-permissive milieu. Over the past two decades, research on the human microbiome and its functionalities within and across individuals has revealed microbiota-focused strategies for health and disease. Here, we review the evolving understanding of the mechanisms by which the microbiota acts in cancer initiation, promotion and progression. We explore the roles of bacteria in gastrointestinal tract malignancies and cancers of the lung, breast and prostate. Finally, we discuss the promises and limitations of targeting or harnessing bacteria in personalized cancer prevention, diagnostics and treatment.

The Impacts of Fecal Microbiota Transplantation from Same Sex on the Symptoms of Ulcerative Colitis Patients

We aimed to compare the clinical efficacy of fecal microbiota transplantation (FMT) from the same sex on ulcerative colitis (UC) patients. A total of 272 UC patients were selected in the prospective clinical study, which incorporated four distinct groups, each comprising male and female patients, who were either receiving FMT or placebo, respectively. FMT was performed by sending the gut microbiota of healthy female or male adolescents to the same gender patients via gastroscope three times (one time/three weeks), and a placebo was used with an equal volume of saline. Abdominal pain, diarrhea, thick bloody stool, intestinal mucosal lesion, and Mayo scores were measured. Self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were evaluated. The changes of intestinal flora were detected by the 16S rRNA sequencing. FMT reduced the scores of diarrhea, abdominal pain, mucosal lesion, and Mayo, SAS, and SDS in UC patients compared to the placebo group (p < 0.05). Clostridiales and Desulfovibrionaceae were dominant in gut microbiota from male patients and were reduced after FMT. Meanwhile, the abundance of Prevotella, Lactobacillus, and Bifidobacterium was increased in the male group. Female patients had a higher abundance of Escherichia-Shigella, Desulfovibrionaceae, and Staphylococcaceae before FMT, and it was reduced after FMT. Meanwhile, the abundance of Porphyromonadaceae, Prevotella, Lactobacillus, and Bifidobacterium was increased in the female group. There were no significant changes for the species in the corresponding placebo groups. FMT improved the UC symptoms of male and female patients, which may be associated with different gut microbiota changes.

Carnobacterium maltaromaticum boosts intestinal vitamin D production to suppress colorectal cancer in female mice

Carnobacterium maltaromaticum was found to be specifically depleted in female patients with colorectal cancer (CRC). Administration of C. maltaromaticum reduces intestinal tumor formation in two murine CRC models in a female-specific manner. Estrogen increases the attachment and colonization of C. maltaromaticum via increasing the colonic expression of SLC3A2 that binds to DD-CPase of this bacterium. Metabolomic and transcriptomic profiling unveils the increased gut abundance of vitamin D-related metabolites and the mucosal activation of vitamin D receptor (VDR) signaling in C. maltaromaticum-gavaged mice in a gut microbiome- and VDR-dependent manner. In vitro fermentation system confirms the metabolic cross-feeding of C. maltaromaticum with Faecalibacterium prausnitzii to convert C. maltaromaticum-produced 7-dehydrocholesterol into vitamin D for activating the host VDR signaling. Overall, C. maltaromaticum colonizes the gut in an estrogen-dependent manner and acts along with other microbes to augment the intestinal vitamin D production to activate the host VDR for suppressing CRC.

Helminth-host-environment interactions: Looking down from the tip of the iceberg

In 1978, the theory behind helminth parasites having the potential to regulate the abundance of their host populations was formalized based on the understanding that those helminth macroparasites that reduce survival or fecundity of the infected host population would be among the forces limiting unregulated host population growth. Now, 45 years later, a phenomenal breadth of factors that directly or indirectly affect the host-helminth interaction has emerged. Based largely on publications from the past 5 years, this review explores the host-helminth interaction from three lenses: the perspective of the helminth, the host, and the environment. What biotic and abiotic as well as social and intrinsic host factors affect helminths? What are the negative, and positive, implications for host populations and communities? What are the larger-scale implications of the host-helminth dynamic on the environment, and what evidence do we have that human-induced environmental change will modify this dynamic? The overwhelming message is that context is everything. Our understanding of second-, third-, and fourth-level interactions is extremely limited, and we are far from drawing generalizations about the myriad of microbe-helminth-host interactions.Yet the intricate, co-evolved balance and complexity of these interactions may provide a level of resilience in the face of global environmental change. Hopefully, this albeit limited compilation of recent research will spark new interdisciplinary studies, and application of the One Health approach to all helminth systems will generate new and testable conceptual frameworks that encompass our understanding of the host-helminth-environment triad.

Exploring the alteration of gut microbiota and brain function in gender-specific Parkinson's disease based on metagenomic sequencing

Background

The role of the microbiota-gut-brain axis in Parkinson's disease (PD) has received increasing attention. Although gender differences are known to an essential role in the epidemiology and clinical course of PD, there are no studies on the sex specificity of the microbiota-gut-brain axis in the development and progression of PD.

Methods

Fresh fecal samples from 24 PD patients (13 males, 11 females) were collected for metagenomic sequencing. The composition and function of the gut microbiota were analyzed by resting-state functional magnetic resonance imaging (fMRI). Gender-dependent differences in brain ALFF values and their correlation with microbiota were further analyzed.

Results

The relative abundance of Propionivibrio, Thermosediminibacter, and Flavobacteriaceae_noname was increased in male PD patients. LEfse analysis showed that Verrucomicrobial, Akkermansiaceae, and Akkermansia were dominant in the males. In female patients, the relative abundance of Propionicicella was decreased and Escherichia, Escherichia_coli, and Lachnospiraceae were predominant. The expression of the sesquiterpenoid and triterpenoid biosynthesis pathways was increased in male PD patients and was statistically different from females. Compared to the Male PD patients, female patients showed decreased ALFF values in the left inferior parietal regions, and the relative abundance of Propionivibrio was positively correlated with the regional ALFF values.

Conclusion

Our study provides novel clinical evidence of the gender-specific relationship between gut microbiota alterations and brain function in PD patients, highlighting the critical role of the microbiota-gut-brain axis in gender differences in PD.

Sex and gender in infection and immunity: addressing the bottlenecks from basic science to public health and clinical applications

Although sex and gender are recognized as major determinants of health and immunity, their role is rarely considered in clinical practice and public health. We identified six bottlenecks preventing the inclusion of sex and gender considerations from basic science to clinical practice, precision medicine and public health policies. (i) A terminology-related bottleneck, linked to the definitions of sex and gender themselves, and the lack of consensus on how to evaluate gender. (ii) A data-related bottleneck, due to gaps in sex-disaggregated data, data on trans/non-binary people and gender identity. (iii) A translational bottleneck, limited by animal models and the underrepresentation of gender minorities in biomedical studies. (iv) A statistical bottleneck, with inappropriate statistical analyses and results interpretation. (v) An ethical bottleneck posed by the underrepresentation of pregnant people and gender minorities in clinical studies. (vi) A structural bottleneck, as systemic bias and discriminations affect not only academic research but also decision makers. We specify guidelines for researchers, scientific journals, funding agencies and academic institutions to address these bottlenecks. Following such guidelines will support the development of more efficient and equitable care strategies for all.

Effect of prebiotics, probiotics, synbiotics on depression: results from a meta-analysis

Accumulating studies have shown the effects of gut microbiota management tools in improving depression. We conducted a meta-analysis to evaluate the effects of prebiotics, probiotics, and synbiotics on patients with depression. We searched six databases up to July 2022. In total, 13 randomized controlled trials (RCTs) with 786 participants were included. The overall results demonstrated that patients who received prebiotics, probiotics or synbiotics had significantly improved symptoms of depression compared with those in the placebo group. However, subgroup analysis only confirmed the significant antidepressant effects of agents that contained probiotics. In addition, patients with mild or moderate depression could both benefit from the treatment. Studies with a lower proportion of females reported stronger effects for alleviating depressive symptoms. In conclusion, agents that manipulate gut microbiota might improve mild-to-moderate depression. It is necessary to further investigate the benefits of prebiotic, probiotic and synbiotic treatments relative to antidepressants and follow up with individuals over a longer time before these therapies are implemented in clinical practice.

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.

Gender-specific changes of the gut microbiome correlate with tumor development in murine models of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with a dismal outcome. To improve understanding of sequential microbiome changes during PDAC development we analyzed mouse models of pancreatic carcinogenesis (KC mice recapitulating pre-invasive PanIN formation, as well as KPC mice recapitulating invasive PDAC) during early tumor development and subsequent tumor progression. Diversity and community composition were analyzed depending on genotype, age, and gender. Both mouse models demonstrated concordant abundance changes of several genera influenced by one or more of the investigated factors. Abundance was significantly impacted by gender, highlighting the need to further elucidate the impact of gender differences. The findings underline the importance of the microbiome in PDAC development and indicate that microbiological screening of patients at risk and targeting the microbiome in PDAC development may be feasible in future.

The power of effective study design in animal Experimentation: Exploring the statistical and ethical implications of asking multiple questions of a data set

One of the chief advantages of using highly standardised biological models including model organisms is that multiple variables can be precisely controlled so that the variable of interest is more easily studied. However, such an approach often obscures effects in sub-populations resulting from natural population heterogeneity. Efforts to expand our fundamental understanding of multiple sub-populations are in progress. However, such stratified or personalised approaches require fundamental modifications of our usual study designs that should be implemented in Brain, Behavior and Immunity (BBI) research going forward. Here we explore the statistical feasibility of asking multiple questions (including incorporating sex) within the same experimental cohort using statistical simulations of real data. We illustrate and discuss the large explosion in sample numbers necessary to detect effects with appropriate power for every additional question posed using the same data set. This exploration highlights the strong likelihood of type II errors (false negatives) for standard data and type I errors when dealing with complex genomic data, where studies are too under-powered to appropriately test these interactions. We show this power may differ for males and females in high throughput data sets such as RNA sequencing. We offer a rationale for the use of alternative experimental and statistical strategies based on interdisciplinary insights and discuss the real-world implications of increasing the complexities of our experimental designs, and the implications of not attempting to alter our experimental designs going forward.

Breast cancer: the first comparative evaluation of oncobiome composition between males and females

BACKGROUND

Emerging evidence suggests that breast microbiota dysbiosis contributes to cancer initiation, progression, prognosis and treatment efficacy. Anyway, available data are referred only to female patients, and studies on males are completely missing. Male breast cancer (MBC) is 70-100 times less frequent, but the mortality rate adjusted to incidence is higher in men than in females. Currently, MBC diagnostic approaches and treatments have generally been extrapolated from the clinical experience gained in women, while few studies focus on characterizing male cancer biology. Taking into account the rising importance of the oncobiome field and the need of MBC targeted studies, we explored the breast cancer oncobiome of male and female patients.

METHODS

16S rRNA gene sequencing was performed in 20 tumor and 20 non-pathological adjacent FFPE breast tissues from male and female patients.

RESULTS

We documented, for the first time, the presence of a sexually dimorphic breast-associated microbiota, here defined as "breast microgenderome". Moreover, the paired analysis of tumor and non-pathological adjacent tissues suggests the presence of a cancer-associated dysbiosis in male patients, with surrounding tissue conserving a healthier microbiome, whereas in female patients, the entire breast tissue is predisposed to cancer development. Finally, the phylum Tenericutes, especially the genera Mesoplasma and Mycobacterium, could to be involved in breast carcinogenesis, in both sexes, deserving further investigation, not only for its role in cancer development but even as potential prognostic biomarker.

CONCLUSIONS

Breast microbiota characterization can enhance the understanding of male breast cancer pathogenesis, being useful for detection of new prognostic biomarkers and development of innovative personalized therapies, remarking the relevant gender differences.

Sex-dependent gut microbiota-brain-cognition associations: a multimodal MRI study

BACKGROUND

There is bidirectional communication between the gut microbiota and the brain. Empirical evidence has demonstrated sex differences in both the gut microbiome and the brain. However, the effects of sex on the gut microbiota-brain associations have yet to be determined. We aim to elucidate the sex-specific effects of gut microbiota on brain and cognition.

METHODS

One hundred fifty-seven healthy young adults underwent brain structural, perfusion, functional and diffusion MRIs to measure gray matter volume (GMV), cerebral blood flow (CBF), functional connectivity strength (FCS) and white matter integrity, respectively. Fecal samples were collected and 16S amplicon sequencing was utilized to assess gut microbial diversity. Correlation analyses were conducted to test for sex-dependent associations between microbial diversity and brain imaging parameters, and mediation analysis was performed to further characterize the gut microbiota-brain-cognition relationship.

RESULTS

We found that higher gut microbial diversity was associated with higher GMV in the right cerebellum VI, higher CBF in the bilateral calcarine sulcus yet lower CBF in the left superior frontal gyrus, higher FCS in the bilateral paracentral lobule, and lower diffusivity in widespread white matter regions in males. However, these associations were absent in females. Of more importance, these neuroimaging biomarkers significantly mediated the association between gut microbial diversity and behavioral inhibition in males.

CONCLUSIONS

These findings highlight sex as a potential influential factor underlying the gut microbiota-brain-cognition relationship, and expose the gut microbiota as a biomarker-driven and sex-sensitive intervention target for mental disorders with abnormal behavioral inhibition.

Composition and function of the Galapagos penguin gut microbiome vary with age, location, and a putative bacterial pathogen

Microbial colonization plays a direct role in host health. Understanding the ecology of the resident microbial community for a given host species is thus an important step for detecting population vulnerabilities like disease. However, the idea of integrating microbiome research into conservation is still relatively new, and wild birds have received less attention in this field than mammals or domesticated animals. Here we examine the composition and function of the gut microbiome of the endangered Galapagos penguin (Spheniscus mendiculus) with the goals of characterizing the normal microbial community and resistome, identifying likely pathogens, and testing hypotheses of structuring forces for this community based on demographics, location, and infection status. We collected fecal samples from wild penguins in 2018 and performed 16S rRNA gene sequencing and whole genome sequencing (WGS) on extracted DNA. 16S sequencing revealed that the bacterial phyla Fusobacteria, Epsilonbacteraeota, Firmicutes, and Proteobacteria dominate the community. Functional pathways were computed from WGS data, showing genetic functional potential primarily focused on metabolism-amino acid metabolism, carbohydrate metabolism, and energy metabolism are the most well-represented functional groups. WGS samples were each screened for antimicrobial resistance, characterizing a resistome made up of nine antibiotic resistance genes. Samples were screened for potential enteric pathogens using virulence factors as indicators; Clostridium perfringens was revealed as a likely pathogen. Overall, three factors appear to be shaping the alpha and beta diversity of the microbial community: penguin developmental stage, sampling location, and C. perfringens. We found that juvenile penguins have significantly lower alpha diversity than adults based on three metrics, as well as significantly different beta diversity. Location effects are minimal, but one site has significantly lower Shannon diversity than the other primary sites. Finally, when samples were grouped by C. perfringens virulence factors, we found dramatic changes in beta diversity based on operational taxonomic units, protein families, and functional pathways. This study provides a baseline microbiome for an endangered species, implicates both penguin age and the presence of a potential bacterial pathogen as primary factors associated with microbial community variance, and reveals widespread antibiotic resistance genes across the population.

Immunology of pregnancy and reproductive health in autoimmune rheumatic diseases. Update from the 11th International Conference on Reproduction, Pregnancy and Rheumatic Diseases

Autoimmune rheumatic diseases (ARD) can affect women and men during fertile age, therefore reproductive health is a priority issue in rheumatology. Many topics need to be considered during preconception counselling: fertility, the impact of disease-related factors on pregnancy outcomes, the influence of pregnancy on disease activity, the compatibility of medications with pregnancy and breastfeeding. Risk stratification and individualized treatment approach elaborated by a multidisciplinary team minimize the risk of adverse pregnancy outcomes (APO). Research has been focused on identifying biomarkers that can be predictive of APO. Specifically, preeclampsia and hypertensive disorders of pregnancy tend to develop more frequently in women with ARD. Placental insufficiency can lead to intrauterine growth restriction and small-for-gestational age newborns. Such APO have been shown to be associated with maternal disease activity in different ARD. Therefore, a key message to be addressed to the woman wishing for a pregnancy and to her family is that treatment with compatible drugs is the best way to ensure maternal and fetal wellbeing. An increasing number of medications have entered the management of ARD, but data about their use in pregnancy and lactation are scarce. More information is needed for most biologic drugs and their biosimilars, and for the so-called small molecules, while there is sufficient evidence to recommend the use of TNF inhibitors if needed for keeping maternal disease under control. Other issues related to the reproductive journey have emerged as "unmet needs", such as sexual dysfunction, contraception, medically assisted reproduction techniques, long-term outcome of children, and they will be addressed in this review paper. Collaborative research has been instrumental to reach current knowledge and the future will bring novel insights thanks to pregnancy registries and prospective studies that have been established in several Countries and to their joint efforts in merging data.

Gender Differences in Psychological Symptoms and Quality of Life in Patients with Inflammatory Bowel Disease in China: A Multicenter Study

OBJECTIVE

To explore the gender differences in the psychological symptoms, sleep quality, and quality of life of patients with inflammatory bowel disease (IBD).

METHODS

A unified questionnaire was developed to collect clinical data on the psychology and quality of life of IBD patients from 42 hospitals in 22 provinces in China from September 2021 to May 2022. The general clinical characteristics, psychological symptoms, sleep quality, and quality of life of IBD patients of different genders were analyzed via a descriptive statistical analysis. A multivariate logistic regression analysis was conducted, and independent influencing factors were screened to construct a nomogram to predict the quality of life. The consistency index (C-index), receiver operating characteristic (ROC) curve, area under the ROC curve (AUC), and calibration curve were used to evaluate the discrimination and accuracy of the nomogram model. Decision curve analysis (DCA) was used to evaluate the clinical utility.

RESULTS

A total of 2478 IBD patients (1371 patients with ulcerative colitis (UC) and 1107 patients with Crohn's disease (CD)) were investigated, including 1547 males (62.4%) and 931 females (37.6%). The proportion of anxiety in females was significantly higher than in males (IBD: 30.5% vs. 22.4%, p < 0.001; UC: 32.4% vs. 25.1%, p = 0.003; CD: 26.8% vs. 19.9%, p = 0.013), and there were differences in the severity of anxiety between the genders (IBD: p < 0.001; UC: p < 0.001; CD: p = 0.050). The proportion of depression in females was higher than in males (IBD: 33.1% vs. 27.7%, p = 0.005; UC: 34.4% vs. 28.9%, p = 0.031; CD: 30.6% vs. 26.6%, p = 0.184), and there were differences in the severity of depression between the genders (IBD: p = 0.004; UC: p = 0.022; CD: p = 0.312). The proportion suffering from sleep disturbances among females was slightly higher than among males (IBD: 63.2% vs. 58.4%, p = 0.018; UC: 63.4% vs. 58.1%, p = 0.047; CD: 62.7% vs. 58.6%, p = 0.210), and the proportion of females with a poor quality of life was higher than that of males (IBD: 41.8% vs. 35.2%, p = 0.001; UC: 45.1% vs. 39.8%, p = 0.049; CD: 35.4% vs. 30.8%, p = 0.141). The AUC values of the female and male nomogram prediction models for predicting poor quality of life were 0.770 (95% CI: 0.7391-0.7998) and 0.771 (95% CI: 0.7466-0.7952), respectively. The calibration diagrams of the two models showed that the calibration curves fitted well with the ideal curve, and the DCA that showed nomogram models could bring clinical benefits.

CONCLUSIONS

There were significant gender differences in the psychological symptoms, sleep quality, and quality of life of IBD patients, suggesting that females need more psychological support. In addition, a nomogram model with high accuracy and performance was constructed to predict the quality of life of IBD patients of different genders, which is helpful for the timely clinical formulation of personalized intervention plans that can improve the prognosis of patients and save medical costs.

Comparison of different methods of initiating lung inflammation and the sex-specific effects on inflammatory parameters

Sex as a biological variable is an essential element of preclinical research. Sex-specific differences in lung volume, alveolar number, body weight, and the relationship between lung and body weight result in important questions about generating equivalent injuries in males and females so that comparisons in their responses can be assessed. Few studies compare stimulus dosing methods for murine lung models investigating immune responses. To examine sex-specific effects, we explored several dosing techniques for three stimuli, LPS, Streptococcus pneumoniae, and influenza A, on survival, injury parameters in bronchoalveolar lavage (BAL), and immune cell numbers in single-cell lung suspensions after injury. These data demonstrate that body weight-based dosing produced fewer differences between sexes when compared with injury initiated with inocula containing the same number of organisms. Comparison of the lung and body weights showed that females had a greater lung-to-body weight ratio than males. However, in LPS-induced injury, adjusting the dose for sex differences in this ratio in addition to body weight provided no new information about sex differences compared with dosing by body weight alone, most likely due to the variability in measures of the immune response. Studies evaluating BAL volumes revealed that smaller but more lavages resulted in greater returns and lower protein concentrations, particularly in the smaller female lungs. Thus, designing dosing and measurement methods that generate equivalent injuries facilitates comparison of immune responses between sexes. Continued development of methods for both induction and evaluation of injury will likely facilitate identification of sex differences in immune responses.

Multi-probiotic consumption sex-dependently interferes with MSG-induced obesity and concomitant phagocyte pro-inflammatory polarization in rats: Food for thought about personalized nutrition

Epidemic scope which obesity has reached in many countries necessitates shifting the emphasis in medicine from traditional reaction to individualized and personalized prevention. Numerous trials convincingly prove sexual dimorphism of obesity in morbidity, pathophysiology, comorbidity, outcomes and prophylaxis efficacy. Obesity is characterized by chronic systemic low-grade inflammation that creates the preconditions for the emergence of numerous comorbidities. Leading role in the initiation, propagation and resolution of inflammation belongs to tissue resident and circulating phagocytes. The outcome of inflammation largely depends on phagocyte functional polarization, which in turn is governed by environmental stimuli. Gut microbiota (GM), whose disturbances are one of the key pathogenetic features in obesity, substantially affect phagocyte functions and can either aggravate or calm obesity-associated inflammation. Probiotics possess promising physiological functions, including microbiota-restoring and anti-inflammatory traits, that may possibly help prevent obesity. However, sex-specific effects of probiotic supplementation for targeted obesity prevention remain unknown. The aim of the current study was aimed to compare the effect of multi-probiotic preparation used in prophylactic regimen on the adiposity, profile of culturable GM and its short-chain fatty acids as well as on functional profile of phagocytes from different locations in male and female rats with monosodium glutamate (MSG)-induced obesity. Obesity was induced by neonatal MSG injections in male and female rats, who were given the multi-species probiotic during juvenile and adult developmental stages. Culturable fecal and mucosa-associated microbiota of the intestine were examined using selective diagnostic media. Short-chain fatty acid profile in fecal samples was determined by GC-MS. Phagocyte functional profile was evaluated using flow cytometry and colorimetric methods. Probiotic supplementation after the administration of MSG prevented weight gain and fat accumulation, inflammatory phagocyte activation and alterations in GM in female rats. In male MSG-injected rats, probiotic supplementation restricted but did not prevent weight gain and fat deposition, alleviated but did not prevent systemic inflammation, prevented the alterations in GM, but with residual imbalance in the ratio of obligate anaerobic to facultative anaerobic bacteria. Our findings emphasize the necessity of sex-centered approaches to the prophylactic use of probiotics in obesity in the context of predictive preventive and personalized medicine.

Outcomes of SARS-CoV-2 infection in cancer versus non-cancer-patients: a population-based study in northeastern Italy

INTRODUCTION

This study assesses the risk of infection and clinical outcomes in a large consecutive population of cancer and non-cancer patients tested for SARS-CoV-2 status.

METHODS

Study patients underwent SARS-CoV-2 molecular-testing between 22 February 2020 and 31 July 2020, and were found infected (CoV2+ve) or uninfected. History of malignancy was obtained from regional population-based cancer registries. Cancer-patients were distinguished by time between cancer diagnosis and SARS-CoV-2 testing (<12/⩾12 months). Comorbidities, hospitalization, and death at 15 September 2020 were retrieved from regional population-based databases. The impact of cancer history on SARS-CoV-2 infection and clinical outcomes was calculated by fitting a multivariable logistic regression model, adjusting for sex, age, and comorbidities.

RESULTS

Among 552,362 individuals tested for SARS-CoV-2, 55,206 (10.0%) were cancer-patients and 22,564 (4.1%) tested CoV2+ve. Irrespective of time since cancer diagnosis, SARS-CoV-2 infection was significantly lower among cancer patients (1,787; 3.2%) than non-cancer individuals (20,777; 4.2% - Odds Ratio (OR)=0.60; 0.57-0.63). CoV2+ve cancer-patients were older than non-cancer individuals (median age: 77 versus 57 years; p<0.0001), were more frequently men and with comorbidities. Hospitalizations (39.9% versus 22.5%; OR=1.61; 1.44-1.80) and deaths (24.3% versus 9.7%; OR=1.51; 1.32-1.72) were more frequent in cancer-patients. CoV2+ve cancer-patients were at higher risk of death (lung OR=2.90; 1.58-5.24, blood OR=2.73; 1.88-3.93, breast OR=1.77; 1.32-2.35).

CONCLUSIONS

The risks of hospitalization and death are significantly higher in CoV2+ve individuals with past or present cancer (particularly malignancies of the lung, hematologic or breast) than in those with no history of cancer.

Beyond the Gut, Emerging Microbiome Areas of Research: A Focus on Early-Life Microbial Colonization

Undoubtedly, the human body harbors trillions of microbes of different kinds performing various physiological activities, such as priming the immune system, influencing host metabolism, and improving health by providing important metabolites such as short-chain fatty acids. Although the gut is considered the "microbial organ" of our body as it hosts the most microbes, there are microbes present in various other important anatomical locations differing in numbers and type. Research has shown the presence of microbes in utero, sparking a debate on the "sterile womb" concept, and there is much scope for more work in this area. It is important to understand the early-life microbiome colonization, which has a role in the developmental origins of health and disease in later life. Moreover, seminal studies have indicated the presence of microbes beyond the gut, for example, in the adipose tissue and the liver. However, it is still unclear what is the exact source of these microbes and their exact roles in health and disease. In this review, we appraise and discuss emerging microbiome areas of research and their roles in metabolic health. Further, we review the importance of the genital microbiome in early-life microbial interactions.

Gut microbes modulate neurodegeneration

Microbiota mediate neuroinflammation in a genetic- and sex-specific manner in mice.

Combined oral contraceptives and mental health: Are adolescence and the gut-brain axis the missing links?

Combined oral contraceptives (containing synthetic forms of estradiol and progestins) are one of the most commonly used drugs among females. However, their effects on the gut-brain axis have not been investigated to a great extent despite clear evidence that suggest bi-directional interactions between the gut microbiome and endogenous sex hormones. Moreover, oral contraceptives are prescribed during adolescence, a critical period of development during which several brain structures and systems, such as hypothalamic-pituitary-gonadal axis, undergo maturation. Considering that oral contraceptives could impact the developing adolescent brain and that these effects may be mediated by the gut-brain axis, further research investigating the effects of oral contraceptives on the gut-brain axis is imperative. This article briefly reviews evidence from animal and human studies on the effects of combined oral contraceptives on the brain and the gut microbiota particularly during adolescence.

Sex-Differential and Non-specific Effects of Vaccines Over the Life Course

Biological sex and age have profound effects on immune responses throughout the lifespan and impact vaccine acceptance, responses, and outcomes. Mounting evidence from epidemiological, clinical, and animal model studies show that males and females respond differentially to vaccination throughout the lifespan. Within age groups, females tend to produce greater vaccine-induced immune responses than males, with sex differences apparent across all age groups, but are most pronounced among reproductive aged individuals. Females report more adverse effects following vaccination than males. Females, especially among children under 5 years of age, also experience more non-specific effects of vaccination. Despite these known sex- and age-specific differences in vaccine-induced immune responses and outcomes, sex and age are often ignored in vaccine research. Herein, we review the known sex differences in the immunogenicity, effectiveness, reactogenicity, and non-specific effects of vaccination over the lifespan. Ways in which these data can be leveraged to improve vaccine research are described.

Changes in Gut Microbiome upon Orchiectomy and Testosterone Administration in AOM/DSS-Induced Colon Cancer Mouse Model

PURPOSE

Sex hormones are known to affect the gut microbiota. Previously, we reported that endogenous and exogenous testosterone are associated with colorectal cancer (CRC) development and submucosal invasion. In the present study, we investigated whether the gut microbiota is affected by orchiectomy (ORX) and testosterone propionate (TP) administration using an azoxymethane/dextran sulfate sodium (AOM/DSS)-induced CRC mouse model.

MATERIALS AND METHODS

Gut microbiota was evaluated by means of 16S rRNA gene sequencing of stool DNA extracted from feces that were obtained at 13 weeks after AOM injection (from 22-week-old animals) and stored in a gas-generating pouch.

RESULTS

The increase in microbial diversity (Chao1 and Phylogenetic Diversity index) and Firmicutes/Bacteroidetes (F/B) ratio upon AOM/DSS treatment in ORX mice was significantly decreased by TP supplementation. The ratio of commensal bacteria to opportunistic pathogens was lower in the TP-administered females and ORX mice than in the AOM/DSS group. Opportunistic pathogens (Mucispirillum schaedleri or Akkermansia muciniphila) were identified only in the TP group. In addition, microbial diversity and F/B ratio were higher in male controls than in female and ORX controls. Flintibacter butyricus, Ruminococcus bromii, and Romboutsia timonensis showed similar changes in the male control group as those in the female and ORX controls.

CONCLUSION

In conclusion, testosterone determines the dysbiosis of gut microbiota, which suggests that it plays a role in the sex-related differences in colorectal carcinogenesis.