The interactions between host genome and gut microbiome increase the risk of psychiatric disorders: Mendelian randomization and biological annotation

Causal link between gut microbiota and obsessive-compulsive disorder: A two-sample Mendelian randomization analysis

BACKGROUND

Previous studies have indicated a potential link between the gut microbiota and obsessive-compulsive disorder (OCD). However, the exact causal relationship remains uncertain. In this study, we employed a two-sample Mendelian randomization (MR) analysis to evaluate the causal connection between gut microbiota and OCD.

METHODS

We collected Genome-Wide Association Study (GWAS) summary data on gut microbiota (n = 18, 340) and OCD (n = 199, 169), using single nucleotide polymorphisms (SNPs) as the instrumental variable. SNPs with an F-statistic of <10 were deemed weak instrumental variables and subsequently excluded. The MR analysis was conducted using five methods: inverse variance weighting (IVW), MR Egger, weighted median, weighted mode, and simple mode. Heterogeneity and pleiotropy were assessed using Cochran's Q-test and MR Egger intercept test, while sensitivity analysis was performed using a leave-one-out approach.

RESULTS

The IVW analysis revealed that at the phylum level, Proteobacteria (OR = 0.545, 95%CI: 0.347-0.855, P = 0.008) served as a protective factor for OCD, whereas at the order level, Bacillales (OR = 1.327, 95%CI: 1.032-1.707, P = 0.027) was identified as a risk factor. At the family level, Ruminococcaceae (OR = 0.570, 95%CI: 0.354-0.918, P = 0.021) also acted as a protective factor. At the genus level, Bilophila (OR = 0.623, 95%CI: 0.425-0.911, P = 0.015) was a protective factor, while Eubacterium ruminantium group (OR = 1.347, 95%CI: 1.012-1.794, P = 0.041) and Lachnospiraceae UCG001 (OR = 1.384, 95%CI: 1.003-1.910, P = 0.048) were identified risk factors. Reverse MR analysis showed no significant causal relationship between OCD and the gut microbiota, with no significant heterogeneity or horizontal pleiotropy observed.

CONCLUSION

Our analysis suggested that specific gut microbiota might have a causal relationship with OCD, revealing potential intervention strategies for the prevention and treatment of this disorder.

From Clinic to Mechanisms: Multi-Omics Provide New Insights into Cerebrospinal Fluid Metabolites and the Spectrum of Psychiatric Disorders

Cerebrospinal fluid (CSF) is crucial in maintaining brain homeostasis by facilitating waste clearance, nutrient transport, and immune signaling. However, the links between CSF metabolites and psychiatric disorders, as well as the underlying mechanisms, remain largely unexamined. We conducted a bidirectional two-sample Mendelian randomization analysis to investigate potential causal relationships between CSF metabolites and 12 psychiatric disorders. Summary data for psychiatric disorders were sourced from the Psychiatric Genomics Consortium, while information on CSF metabolites was derived from two studies within the Wisconsin Alzheimer's Disease cohort. Causal estimates and pleiotropy were assessed using several robust methods, including inverse-variance-weighted (IVW) analysis, weighted median analysis, MR-Egger regression, and the MR-Egger test. Furthermore, a transcriptome-wide association study was conducted to explore potential mechanisms and shared etiologies between CSF metabolites and psychiatric disorders. The genetic risk of eating disorders (ED) can be increased by leucine (OR = 1.55, 95% CI: 1.21-1.97, P = 4.35 × 10⁻4), salicylate (OR = 1.03, 95% CI: 1.01-1.04, P = 4.95 × 10⁻4), and 1-methylnicotinamide (OR = 1.06, 95% CI: 1.03-1.09, P = 6.94 × 10⁻6), while methylmalonate may reduce ED risk (OR = 0.95, 95% CI: 0.93-0.98, P = 1.31 × 10⁻4). Similarly, the risk of schizophrenia (SCZ) may be reduced by threonate (OR = 0.93, 95% CI: 0.89-0.97, P = 1.98 × 10⁻4), oxalate (OR = 0.94, 95% CI: 0.90-0.97, P = 3.15 × 10⁻4), phenyllactate (OR = 0.96, 95% CI: 0.94-0.98, P = 2.23 × 10⁻4), N-acetylglucosamine (OR = 0.98, 95% CI: 0.97-0.99, P = 3.57 × 10⁻5), and citramalate (OR = 0.98, 95% CI: 0.98-0.99, P = 5.78 × 10⁻4). Conversely, SCZ may upregulate gamma-glutamylleucine (β = 0.08, P = 1.97 × 10⁻4) and O-sulfo-L-tyrosine (β = 0.06, P = 1.25 × 10⁻4), while downregulating gamma-glutamylphenylalanine (β = - 0.50, P = 1.16 × 10⁻4). Signal pathways related to the mechanistic target of the rapamycin (mTOR), post-translational protein modifications, and immune regulation may mediate the causal relationship of CSF metabolites on ED and SCZ. We identified a casual genetic causal relationship between CSF metabolites and both ED and schizophrenia SCZ, which is potentially mediated by pathways related to energy metabolism, post-translational modifications, and immune regulation.

Deciphering the coordinated roles of the host genome, duodenal mucosal genes, and microbiota in regulating complex traits in chickens

BACKGROUND

The complex interactions between host genetics and the gut microbiome are well documented. However, the specific impacts of gene expression patterns and microbial composition on each other remain to be further explored.

RESULTS

Here, we investigated this complex interplay in a sizable population of 705 hens, employing integrative analyses to examine the relationships among the host genome, mucosal gene expression, and gut microbiota. Specific microbial taxa, such as the cecal family Christensenellaceae, which showed a heritability of 0.365, were strongly correlated with host genomic variants. We proposed a novel concept of regulatability ( r b 2 ), which was derived from h2, to quantify the cumulative effects of gene expression on the given phenotypes. The duodenal mucosal transcriptome emerged as a potent influencer of duodenal microbial taxa, with much higher r b 2 values (0.17 ± 0.01, mean ± SE) than h2 values (0.02 ± 0.00). A comparative analysis of chickens and humans revealed similar average microbiability values of genes (0.18 vs. 0.20) and significant differences in average r b 2 values of microbes (0.17 vs. 0.04). Besides, cis ( h cis 2 ) and trans heritability ( h trans 2 ) were estimated to assess the effects of genetic variations inside and outside the cis window of the gene on its expression. Higher h trans 2 values than h cis 2 values and a greater prevalence of trans-regulated genes than cis-regulated genes underscored the significant role of loci outside the cis window in shaping gene expression levels. Furthermore, our exploration of the regulatory effects of duodenal mucosal genes and the microbiota on 18 complex traits enhanced our understanding of the regulatory mechanisms, in which the CHST14 gene and its regulatory relationships with Lactobacillus salivarius jointly facilitated the deposition of abdominal fat by modulating the concentration of bile salt hydrolase, and further triglycerides, total cholesterol, and free fatty acids absorption and metabolism.

CONCLUSIONS

Our findings highlighted a novel concept of r b 2 to quantify the phenotypic variance attributed to gene expression and emphasize the superior role of intestinal mucosal gene expressions over host genomic variations in elucidating host‒microbe interactions for complex traits. This understanding could assist in devising strategies to modulate host-microbe interactions, ultimately improving economic traits in chickens.

The Bidirectional Relationship Between the Gut Microbiome and Mental Health: A Comprehensive Review

The gut microbiome plays a fundamental role in mental health, influencing mood, cognition, and emotional regulation through the gut-brain axis. This bidirectional communication system connects the gastrointestinal and CNS, facilitated by microbial metabolites, neurotransmitters, and immune interactions. Recent research highlights the association between gut dysbiosis and psychiatric disorders, including anxiety, depression, and stress-related conditions. Key findings indicate that altered microbial diversity, decreased short-chain fatty acid (SCFA) production, and increased neuroinflammation contribute to mental health disturbances. This paper explores the mechanism linking the gut microbiome to brain function, including microbial neurotransmitter synthesis, vagus nerve signaling, and hypothalamic-pituitary-adrenal (HPA) axis modulation. Additionally, it evaluates the potential of microbiome-targeted interventions, such as probiotics, prebiotics, dietary modifications, and fecal microbiota transplantation (FMT), in alleviating psychiatric symptoms. Microbiome sequencing and bioinformatics advances further support the development of personalized microbiome-based mental health interventions. Despite promising evidence, challenges such as inter-individual variability, methodological inconsistencies, and the need for longitudinal studies remain. Future research should focus on standardizing microbiome assessment techniques and optimizing therapeutic applications. Integrating precision psychiatry with microbiome-based diagnostics holds immense potential in transforming mental health treatment.

Roles of skin microbiota in hidradenitis suppurativa: insights from a two-sample mendelian randomization analysis

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease associated with unique lesional dysbiotic features. However, the role of the microbiology in the pathogenesis of HS remains in dispute. We aimed to conduct a two-sample Mendelian randomization study to investigate the relationship between skin microbiota and HS. A two-sample Mendelian randomization study was performed using the summary statistics of skin microbiota from summary GWAS data of the European descent from two cross-sectional, population-based German cohorts, KORA FF4 (n = 324) and PopGen (n = 273). The summary statistics of hidradenitis suppurativa were obtained from the FinnGen DF10 (1,070 cases and 394,105 controls). Inverse variance weighted (IVW), MR-Egger regression, weighted median, simple mode, weighted mode, and MRPRESSO were used to examine the causal association between skin microbiota and hidradenitis suppurativa. Cochran's Q statistics were used to quantify the heterogeneity of instrumental variables. Our study suggested that genus Corynebacterium in dry skin is significantly associated with HS after false discovery rate (FDR) correction (odds ratio (OR) = 1.04, 95% confidence interval (CI): 1.02-1.06, P = 0.0002, FDR adjusted P = 0.035). Additionally, we found genus Micrococcus in moist skin (OR = 1.10, 95% CI: 1.03-1.18, P = 0.0060, FDR adjusted P = 0.360), species Streptococcus salivarius in dry skin (OR = 1.03, 95% CI: 1.01-1.05, P = 0.0070, FDR adjusted P = 0.360), and species Propionibacterium granulosum (OR = 1.02, 95% CI: 1.00-1.04, P = 0.0460, FDR adjusted P = 0.970) are potentially associated with HS before FDR adjustment. No evidence of the effect in the reverse direction for HS on skin microbial features. This two-sample Mendelian randomization study found that genus Corynebacterium was causally associated with HS. Further studies are needed to clarify the protective effect of prebiotics, probiotics or microbiome transplants on HS.

Alterations in fecal bacteriome virome interplay and microbiota-derived dysfunction in patients with schizophrenia

Rising studies have consistently reported gut bacteriome alterations in schizophrenia (SCZ). However, little is known about the role of the gut virome on shaping the gut bacteriome in SCZ. Here in, we sequenced the fecal virome, bacteriome, and host peripheral metabolome in 49 SCZ patients and 49 health controls (HCs). We compared the gut bacterial community composition and specific abundant bacteria in SCZ patients and HCs. Specific gut viruses and host peripheral metabolites co-occurring with differential bacteria were identified using Multiple Co-inertia Analysis (MCIA). Additionally, we construct a latent serial mediation model (SMM) to investigate the effect of the gut virome on SCZ through the bacteriome and host metabolic profile. SCZ patients exhibited a decreased gut bacterial β-diversity compared to HCs, with seven differentially abundant bacteria, including Coprobacillaceae, Enterococcaceae etc. Gut viruses including Suoliviridae and Rountreeviridae, co-occur with these SCZ-related bacteria. We found that the viral-bacterial transkingdom correlations observed in HCs were dramatically lost in SCZ. The altered correlations profile observed in SCZ may impact microbiota-derived peripheral metabolites enriched in the bile acids pathway, eicosanoids pathway, and others, contributing to host immune dysfunction and inflammation. The SMM model suggested potential causal chains between gut viruses and SCZ, indicating that the effect of gut virome on SCZ is significantly mediated by bacteriome and metabolites. In conclusion, these findings provide a comprehensive perspective on the role of gut microbiota in the pathogenesis of SCZ. They reveal that patients with schizophrenia harbor an abnormal virome-bacteriome ecology, shedding light on the potential development of microbial therapeutics.

Gut microbiota and interstitial cystitis: exploring the gut-bladder axis through mendelian randomization, biological annotation and bulk RNA sequencing

Background

Several observational studies have indicated an association between interstitial cystitis and the composition of the gut microbiota; however, the causality and underlying mechanisms remain unclear. Understanding the link between gut microbiota and interstitial cystitis could inform strategies for prevention and treatment.

Methods

A two-sample Mendelian randomization analysis was conducted using published genome-wide association study summary statistics. We employed inverse variance weighted, weighted mode, MR-Egger, weighted median, simple mode, and cML-MA methods to investigate the causal relationship between gut microbiota and interstitial cystitis. Sensitivity analysis was performed to validate the results. Relevant gut microbiota was examined through reverse MR. Single nucleotide polymorphisms were annotated using FUMA to identify genes associated with these genetic variants, thereby revealing potential host gene-microbiota associations in interstitial cystitis patients.

Results

Eight bacterial taxa were identified in our analysis as associated with interstitial cystitis. Among these, Butyricimonas, Coprococcus, Lactobacillales, Lentisphaerae, and Bilophila wadsworthia were positively correlated with interstitial cystitis risk, while taxa such as Desulfovibrio piger, Oscillibacter unclassified and Ruminococcus lactaris exhibited protective effects against interstitial cystitis. The robustness of these associations was confirmed through sensitivity analyses. Reverse MR analysis did not reveal evidence of reverse causality. Single nucleotide polymorphisms were annotated using FUMA and subjected to biological analysis. Seven hub genes (SPTBN1, PSME4, CHAC2, ERLEC1, ASB3, STAT5A, and STAT3) were identified as differentially expressed between interstitial cystitis patients and healthy individuals, representing potential therapeutic targets.

Conclusion

Our two-sample Mendelian randomization study established a causal relationship between gut microbiota and interstitial cystitis. Furthermore, our identification of a host gene-microbiota association offers a new avenue for investigating the potential pathogenesis of interstitial cystitis and suggests avenues for the development of personalized treatment strategies.

Exploring causal effects and potential mediating mechanisms of genetically linked environmental senses with intracerebral hemorrhage

The occurrence mechanism of intracerebral hemorrhage remains unclear. Several recent studies have highlighted the close relationship between environmental senses and intracerebral hemorrhage, but the mechanisms of causal mediation are inconclusive. We aimed to investigate the causal relationships and potential mechanisms between environmental senses and intracerebral hemorrhage. Multiple Mendelian randomization methods were used to identify a causal relationship between environmental senses and intracerebral hemorrhage. Gut microbiota and brain imaging phenotypes were used to find possible mediators. Enrichment and molecular interaction analyses were used to identify potential mediators and molecular targets. No causal relationship between temperature and visual perception with intracerebral hemorrhage was found, whereas long-term noise was identified as a risk factor for intracerebral hemorrhage (OR 2.95, 95% CI: 1.25 to 6.93, PIVW = 0.01). The gut microbiota belonging to the class Negativicutes and the order Selenomonadales and the brain image-derived phenotypes ICA100 node 54, edge 803, edge 1149, and edge 1323 played mediating roles. "Regulation of signaling and function in synaptic organization" is the primary biological pathway of noise-induced intracerebral hemorrhage, and ARHGAP22 may be the critical gene. This study emphasized the importance of environmental noise in the prevention, disease management, and underlying biological mechanisms of intracerebral hemorrhage.

Microbiota-Short Chain Fatty Acid Relationships Underlie Clinical Heterogeneity and Identify Key Microbial Targets in Irritable Bowel Syndrome (IBS)

Background

Identifying microbial targets in irritable bowel syndrome (IBS) and other disorders of gut-brain interaction (DGBI) is challenging due to the dynamic nature of microbiota-metabolite-host interactions. SCFA are key microbial metabolites that modulate intestinal homeostasis and may influence IBS pathophysiology. We aimed to assess microbial features associated with short chain fatty acids (SCFA) and determine if features varied across IBS subtypes and endophenotypes. Among 96 participants who were screened, 71 completed the study. We conducted in-depth investigations of stool microbial metagenomes, stool SCFA, and measurable IBS traits (stool bile acids, colonic transit, stool form) in 41 patients with IBS (IBS with constipation [IBS-C] IBS with diarrhea [IBS-D]) and 17 healthy controls. We used partial canonical correspondence analyses (pCCA), conditioned on transit, to quantify microbe-SCFA associations across clinical groups. To explore relationships between microbially-derived SCFA and IBS traits, we compared gut microbiome-encoded potential for substrate utilization across groups and within a subset of participants selected by their stool characteristics as well as stool microbiomes of patients with and without clinical bile acid malabsorption.

Results

Overall stool microbiome composition and individual taxa abundances differed between clinical groups. Microbes-SCFA associations differed across groups and revealed key taxa including Dorea sp. CAG:317 and Bifidobacterium pseudocatenulatum in IBS-D and Akkermansia muciniphila and Prevotella copri in IBS-C that that may drive subtype-specific microbially-mediated mechanisms. Strongest microbe-SCFA associations were observed in IBS-D and several SCFA-producing species surprisingly demonstrated inverse correlations with SCFA. Fewer bacterial taxa were associated with acetate to butyrate ratios in IBS compared to health. In participants selected by stool form, we demonstrated differential abundances of microbial genes/pathways for SCFA metabolism and degradation of carbohydrates and mucin across groups. SCFA-producing taxa were reduced in IBS-D patients with BAM.

Conclusion

Keystone taxa responsible for SCFA production differ according to IBS subtype and traits and the IBS microbiome is characterized by reduced functional redundancy. Differences in microbial substrate preferences are also linked to bowel functions. Focusing on taxa that drive SCFA profiles and stool form may be a rational strategy for identifying relevant microbial targets in IBS and other DGBI.

Add-On Bifidobacterium Bifidum Supplement in Children with Attention-Deficit/Hyperactivity Disorder: A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial

We conducted a 12-week randomized double-blind placebo-controlled clinical trial to investigate the potential impact of Bifidobacterium bifidum (Bf-688) supplementation on attention-deficit/hyperactivity disorder (ADHD). Children with ADHD who were already receiving a stable dose of methylphenidate (MPH) treatment were enrolled and were randomly assigned to two groups: one receiving add-on Bf-688 (daily bacterial count of 5 × 109 CFUs) (n = 51) and the other receiving a placebo (n = 51). All participants underwent assessments using Conners' Continuous Performance Test (CPT) and Conners' Continuous Auditory Test of Attention (CATA). Additionally, fecal samples were collected at the beginning of the trial (week 0) and at the endpoint (week 12). Remarkably, the group receiving Bf-688 supplementation, but not the placebo group, exhibited significant improvements in omission errors in CPT as well as Hit reaction time in both CPT and CATA. Gut microbiome analysis revealed a significant increase in the Firmicutes to Bacteroidetes ratio (F/B ratio) only in the Bf-688 group. Furthermore, we identified significant negative correlations between N-Glycan biosynthesis and Hit reaction time in both CPT and CATA. Our results demonstrate that the probiotic Bf-688 supplement can enhance neuropsychological performance in children with ADHD, possibly by altering the composition of the gut microbiota, ultimately leading to reduced N-Glycan biosynthesis.

Neurobiology and systems biology of stress resilience

Stress resilience is the phenomenon that some people maintain their mental health despite exposure to adversity or show only temporary impairments followed by quick recovery. Resilience research attempts to unravel the factors and mechanisms that make resilience possible and to harness its insights for the development of preventative interventions in individuals at risk for acquiring stress-related dysfunctions. Biological resilience research has been lagging behind the psychological and social sciences but has seen a massive surge in recent years. At the same time, progress in this field has been hampered by methodological challenges related to finding suitable operationalizations and study designs, replicating findings, and modeling resilience in animals. We embed a review of behavioral, neuroimaging, neurobiological, and systems biological findings in adults in a critical methods discussion. We find preliminary evidence that hippocampus-based pattern separation and prefrontal-based cognitive control functions protect against the development of pathological fears in the aftermath of singular, event-type stressors [as found in fear-related disorders, including simpler forms of posttraumatic stress disorder (PTSD)] by facilitating the perception of safety. Reward system-based pursuit and savoring of positive reinforcers appear to protect against the development of more generalized dysfunctions of the anxious-depressive spectrum resulting from more severe or longer-lasting stressors (as in depression, generalized or comorbid anxiety, or severe PTSD). Links between preserved functioning of these neural systems under stress and neuroplasticity, immunoregulation, gut microbiome composition, and integrity of the gut barrier and the blood-brain barrier are beginning to emerge. On this basis, avenues for biological interventions are pointed out.

Is thyroid function associated with polycystic ovary syndrome? A bidirectional Mendelian randomization study

OBJECTIVE

Some observational studies have suggested the association between thyroid function and polycystic ovary syndrome (PCOS). However, it remains to be determined whether these associations are causal or not. The aim of this study was to investigate the underlying causal association between different thyroid function status and PCOS.

METHODS

Bidirectional Mendelian randomization (MR) analysis was conducted to explore the impact of different thyroid function statuses on PCOS. The study included 10,074 individuals with PCOS and 103,164 controls for the primary analysis, with validation analysis repeated in the FinnGen R9 and EstBB PCOS cohorts. Female-specific thyroid function GWAS data were obtained from European population, including Hyperthyroidism (22,383 cases and 54,288 controls) and Hypothyroidism (27,383 cases and 54,288 controls) from the UK Biobank, and TSH (54,288 cases and 72,167 controls) and FT4 (49,269 cases and 72,167 controls) within the reference range from the ThyroidOmics Consortium. Inverse variance weighting (IVW) was chosen as the principal method, and sensitivity analysis was conducted to test for the presence of horizontal pleiotropy or heterogeneity.

RESULTS

The IVW analysis indicated nominal significance between normal TSH levels and PCOS after adjusted for age and BMI [OR (95% CI) = 0.78(0.62,0.97), P = 0.029], suggesting that maintaining normal TSH levels might act as a protective factor against the pathogenesis of PCOS. Besides, in order to increase the statistical power, we pooled PCOS GWAS above together by meta-analysis and found PCOS contributed to the occurrence of hyperthyroidism [OR(95%CI) = 1.37(0.73,2.57), P = 0.012]. However, no causal relationship was found after Bonferroni correction (P-value < 0.0031).

CONCLUSION

Although the MR analysis didn't indicate genetic causal association between thyroid function and PCOS after Bonferroni correction. Further efforts are needed to interpret the potential causal relationship between thyroid function and PCOS in different age and BMI subgroup.

Effects of immune cells in mediating the relationship between gut microbiota and myelodysplastic syndrome: a bidirectional two-sample, two-step Mendelian randomization study

BACKGROUND

The definitive establishment of a causal relationship between gut microbiota and myelodysplastic syndrome (MDS) has not been achieved. Furthermore, the involvement of immune cells in mediating the connection between gut microbiota and MDS is presently unclear.

METHODS

To elucidate the bidirectional correlation between gut microbiota and MDS, as well as to investigate the mediating role of immune cells, a bidirectional two-sample, two-step Mendelian randomization (MR) study was conducted. Summary statistics were obtained from genome-wide association studies (GWAS), including MDS (456,348 individuals), gut microbiota (18,340 individuals), and 731 immune cells signatures (3757 individuals).

RESULTS

Genetically predicted eight gut microbiota traits were significantly associated with MDS risk, but not vice versa. Through biological annotation of host-microbiome shared genes, we found that immune regulation may mediate the impact of gut microbiota on MDS. Subsequently, twenty-three immunophenotypes that exhibited significant associations with MDS risk and five of these immunophenotypes were under the causal influence of gut microbiota. Importantly, the causal effects of gut microbiota on MDS were significantly mediated by five immunophenotypes, including CD4 +T cell %leukocyte, CD127 on CD45RA - CD4 not regulatory T cell, CD45 on CD33 + HLA DR + WHR, CD33 on basophil, and Monocyte AC.

CONCLUSIONS

Gut microbiota was causally associated with MDS risk, and five specific immunophenotypes served as potential causal mediators of the effect of gut microbiota on MDS. Understanding the causality among gut microbiota, immune cells and MDS is critical in identifying potential targets for diagnosis and treatment.

Exploring the link between gut microbiota and alopecia areata: a two-sample Mendelian randomization analysis

BACKGROUND

While observational studies have suggested a link between gut microbiota diversity and alopecia areata (AA), the causal relationship remains unclear.

METHODS

We leveraged data from the MiBioGen and FinnGen consortiums' Genome-wide association studies (GWAS) encompassing gut microbiota (n = 13,266) and AA (n = 211,428) datasets. A comprehensive Mendelian randomization (MR) and reverse MR approach were employed, utilizing five statistical methods to evaluate causality. Sensitivity analyses were also conducted to corroborate the MR results.

RESULTS

Inverse variance weighted (IVW) analysis indicated a protective effect against AA from Butyricimonas (OR = 0.37, 95% CI: 0.18-0.77, P = 0.01), Enterorhabdus (OR = 0.40, 95% CI: 0.16-0.95, P = 0.04), Eubacterium (xylanophilum group) (OR = 0.36, 95% CI: 0.15-0.84, P = 0.02), and Phascolarctobacterium (OR = 0.37, 95% CI: 0.15-0.91, P = 0.03), while Ruminococcaceae UCG003 posed as a risk factor (OR = 2.79, 95% CI: 1.27-6.14, P = 0.01). Reverse MR showed no significant causal link between AA and gut microbiota, with no significant heterogeneity or horizontal pleiotropy.

CONCLUSIONS

Our analysis suggests probable causality between certain gut microbiota and AA, shedding light on its pathogenesis and potential intervention strategies.

Roles of gut microbiota in androgenetic alopecia: insights from Mendelian randomization analysis

Background

Androgenetic alopecia (AGA) is the most common type of androgen-associated hair loss. Previous studies have indicated an association between the gut microbiota and AGA. To delve deeper, we executed a two-sample Mendelian randomization (MR) analysis to investigate the potential causal relationship between the gut microbiota and AGA.

Methods

A two-sample MR investigation was utilized to delve into the intricate interplay between gut microbiota and AGA. Information regarding 211 gut microbial taxa was sourced from the MiBioGen consortium. The summary statistics of the genome-wide association studies (GWAS) for AGA were obtained from the FinnGen biobank, which included 195 cases and 201,019 controls. Various analytical approaches, including Inverse Variance Weighting (IVW), Weighted Median, MR-Egger, Weighted Mode, and Simple Mode were employed to evaluate the causal impact of gut microbiota on AGA. Sensitivity analyses were subsequently conducted to affirm the robustness of the findings.

Results

A two-sample MR investigation unveiled the genus Olsenella, genus Ruminococcaceae UCG-004, and genus Ruminococcaceae UCG-010 were identified as risk factors associated with AGA. In contrast, the family Acidaminococcaceae and genus Anaerofilum, along with the genus Ruminiclostridium 9, demonstrated a protective effect. The sensitivity analyses provided additional assurance that the findings of the current study were less susceptible to the influence of confounding variables and biases.

Conclusion

The MR study has established a link between specific gut microbiota and AGA, offering evidence for the identification of more precisely targeted probiotics. This discovery has the potential to aid in the prevention, control, and reversal of AGA progression.

The enigmatic interplay of immune cells and abnormal spermatozoa through Mendelian randomization

PURPOSE

Abnormal spermatozoa significantly impact reproductive health, affecting fertility rates, potentially prolonging conception time, and increasing the risk of miscarriages. This study employs Mendelian randomization to explore their potential link with immune cells, aiming to reveal their potential causal association and wider implications for reproductive health.

METHODS

We conducted forward and reverse Mendelian randomization analyses to explore the potential causal connection between 731 immune cell signatures and abnormal spermatozoa. Using publicly available genetic data, we investigated various immune signatures such as median fluorescence intensities (MFI), relative cell (RC), absolute cell (AC), and morphological parameters (MP). Robustness was ensured through comprehensive sensitivity analyses assessing consistency, heterogeneity, and potential horizontal pleiotropy. The MR study produced a statistically significant p-value of .0000684, Bonferroni-corrected for the 731 exposures.

RESULTS

The Mendelian randomization analysis revealed strong indications of a reciprocal relationship between immune cell pathways and sperm integrity. When examining immune cell exposure, a potential causal link with abnormal sperm was observed in 35 different types of immune cells. Conversely, the reverse Mendelian randomization results indicated that abnormal sperm might causally affect 39 types of immune cells. These outcomes suggest a potential mutual influence between alterations in immune cell functionality and the quality of spermatozoa.

CONCLUSION

This study highlights the close link between immune responses and sperm development, suggesting implications for reproductive health and immune therapies. Further research may offer crucial insights into male fertility and immune disorders.

Exploring the causal relationship between gut microbiota and multiple myeloma risk based on Mendelian randomization and biological annotation

Introduction

The microbial genome-wide association studies (mbGWAS) have highlighted significant host-microbiome interactions based on microbiome heritability. However, establishing causal relationships between particular microbiota and multiple myeloma (MM) remains challenging due to limited sample sizes.

Methods

Gut microbiota data from a GWAS with 18,340 participants and MM summary statistics from 456,348 individuals. The inverse variance-weighted (IVW) method was used as the main bidirectional Mendelian randomization (MR) analysis. To assess the robustness of our results, we further performed supplementary analyses, including MR pleiotropy residual sum and outlier (MR-PRESSO) test, MR-Egger, Weighted median, Simple mode, and Weighted mode. Moreover, a backward MR analysis was conducted to investigate the potential for reverse causation. Finally, gene and gene-set-based analyses were then conducted to explore the common biological factors connecting gut microbiota and MM.

Results

We discovered that 10 gut microbial taxa were causally related to MM risk. Among them, family Acidaminococcaceae, Bacteroidales family S24-7, family Porphyromonadaceae, genus Eubacterium ruminantium group, genus Parabacteroides, and genus Turicibacter were positively correlated with MM. Conversely, class Verrucomicrobia, family Verrucomicrobiaceae, genus Akkermansia, and order Verrucomicrobiales were negatively correlated with MM. The heterogeneity test revealed no Heterogeneity. MR-Egger and MR-PRESSO tests showed no significant horizontal pleiotropy. Importantly, leave-one-out analysis confirmed the robustness of MR results. In the backward MR analysis, no statistically significant associations were discovered between MM and 10 gut microbiota taxa. Lastly, we identified novel host-microbiome shared genes (AUTS2, CDK2, ERBB3, IKZF4, PMEL, SUOX, and RAB5B) that are associated with immunoregulation and prognosis in MM through biological annotation.

Discussion

Overall, this study provides evidence supporting a potential causal relationship between gut microbiota and MM risk, while also revealing novel host-microbiome shared genes relevant to MM immunoregulation and clinical prognosis.

Dajianzhong decoction ameliorated D-gal-induced cognitive aging by triggering mitophagy in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Dajianzhong decoction (DJZ) is a classical famous formula for treating yang-deficiency-syndrome in traditional Chinese medicine and recorded in Jin-Kui-Yao-Lue in Dynasty of Dong Han. Cognitive aging can present similar features of mitochondrial energy deficits to the clinical features of Yang deficiency. However, there is poor understanding of the effects of DJZ treatment on mitophagy in cognitive aging.

AIM OF THE STUDY

The aims of this work were to decipher the effectiveness and mechanism of DJZ against cognitive aging, focusing on mitophagy.

MATERIALS AND METHODS

YFP-Parkin HeLa cells, D-galactose (D-gal) -induced mice (500 mg/kg for 35 d, s. c.) and SH-SY5Y cells (80 mg/ml for 6 h) were established. Firstly, the formation of YFP-Parkin puncta (a well-known mitophagy marker) in YFP-Parkin HeLa cells was employed to discover the mitophagy induction of DJZ. Moreover, the genes and proteins related to PINK1/Parkin pathway and mitochondrial functions were evaluated after treatment with DJZ in vivo (3.5 g/kg or 1.75 g/kg, i. g, 35 d) and in vitro (0.2, 2 and 20 μg/ml, 12 h). Furthermore, the effectiveness of DJZ (3.5 g/kg or 1.75 g/kg, i. g) for alleviating cognitive aging and nerve damage was measured in D-gal mice. Finally, siPINK1 was applied to reverse validation of DJZ in vitro.

RESULTS

The formation of YFP-Parkin puncta in YFP-Parkin HeLa cells was markedly induced by DJZ in a dose-dependent manner. The immunofluorescence intensity of Parkin and the protein expression of Parkin in mitochondrial membrane in D-gal mice were significantly increased after treatment of DJZ. The inhibition of PINK1/Parkin pathway in D-gal-induced mice and SH-SY5Y cells was significantly activated by DJZ. Simultaneously, the impairment of mitochondrial functions induced by D-gal were markedly reversed by DJZ. In addition, DJZ significantly ameliorated the neuropathological injury and cognitive declines in D-gal mice. Finally, after PINK1 was knocked down by siPINK1 in vitro, the neuroprotective effects of DJZ and the Parkin enhancement effect of DJZ were markedly reversed.

CONCLUSION

Our findings firstly showed DJZ could relieve cognitive aging through facilitating PINK1/Parkin-mediated mitophagy to protect against mitochondrial functions, indicating DJZ may be regarded as a promising intervention in cognitive aging.

Correlations between schizophrenia and lichen planus: a two-sample bidirectional Mendelian randomization study

Background

Several existing studies have shown a correlation between schizophrenia and lichen planus (LP). However, the causality of this relationship remains uncertain. Thus, this study aimed to examine the causal association between schizophrenia and LP.

Methods

A two-sample Mendelian randomization (MR) study was carried out to investigate whether schizophrenia is causally related to LP and vice versa, and genetic variants in this study were taken from previous genome-wide association studies. We used the inverse variance weighted (IVW) method as the main analysis. Furthermore, several sensitivity analyses were performed to assess heterogeneity, horizontal pleiotropy, and stability.

Results

Our results show that schizophrenia has a protective effect on LP (OR = 0.881, 95%CI = 0.795-0.975, p = 0.015). Conversely, we observed no significant relationship between LP and schizophrenia in reverse MR analysis (OR = 0.934, 95%CI = 0.851-1.026, p = 0.156).

Conclusion

Our two-sample Mendelian randomization study supports a significant causal relationship between LP and schizophrenia and finds that schizophrenia can reduce the incidence of LP. This is in contrast to previous findings and provides new insights into the relationship between LP and schizophrenia, but the exact mechanism needs further investigation.