Roles of gut microbiome in epilepsy risk: A Mendelian randomization study

The Influence of the Probiotics, Ketogenic Diets, and Gut Microbiota on Epilepsy and Epileptic Models: A Comprehensive Review

About one-third of epilepsies are resistant to antiepileptic drugs; thus, uncovering new pathways in the pathophysiology of epilepsy can reduce the global disease burden. Probiotics are live, non-pathogenic microorganisms that benefit the host by regulating the gut microbiome. This review aims to study the effect of probiotics and ketogenic diets on gut microbiota and their potential as a therapy for epilepsy. We conducted a systematic search of the databases PubMed, Scopus, Embase, and the Web of Science for pertinent studies that have been published. Our search methodology was meticulously structured to be exhaustive, integrating targeted keywords and Boolean operators to guarantee the acquisition of all potentially pertinent articles. Probiotics interact with the gut microbiome, balance its composition, and influence the gut-brain axis. Moreover, they reduce neuroinflammation and oxidative stress. The ketogenic diet (KD) affects gut bacteria, influencing neurotransmitter levels and short-chain fatty acids (SCFAs), which play a role in the gut-brain axis. Studies have shown the positive effects of various probiotics in animal models of epilepsy. They demonstrate improvements in seizure activity, anxiety, and neuroinflammation. In human studies, probiotics reduced seizure frequency and enhanced quality of life in patients with drug-resistant epilepsy. We believe using probiotics or dietary interventions like KD could be a promising therapeutic strategy for managing epilepsy. This could reduce seizure frequency and make life better for patients with epilepsy.

Association of Breast Cancer and Selective Estrogen Receptor Modulators on the Risk of Meningioma: Insights from Mendelian Randomization

Considering the potential links between breast cancer (BC), selective estrogen receptor modulators, and meningioma in previous epidemiology studies, this study aimed to investigate them through the Mendelian randomization approach. We extracted instrumental variables (IVs) of different subtypes of BC from the largest genome-wide association study. Gene targets of SERMs were obtained from the Drug-Gene Interaction Database. Mendelian randomization (MR) analysis applied inverse variance weighted approach to evaluate causality. A series of sensitivity analyses and reverse MR were used to evaluate the stability of the MR results. Genetically determined estrogen receptor (ER) positive BC, luminal A-like breast cancer (OR 1.17, 95% CI 1.04 to 1.32, p = 0.01), and luminal B-like breast cancer (OR 1.20, 95% CI 1.04 to 1.37, p = 0.009) were associated with an increased odds ratio of meningioma (OR 1.18, 95% CI 1.05 to 1.32, p = 0.005). Among SERM-targeted genes, CYP2D6 (OR 1.37, 95% CI 1.23 to 1.54, p = 4.15 × 10- 8), NGR1 (OR 1.15, 95% CI 1.10 to 1.20, p = 2.59 × 10- 11), and MAPT (OR 10.20, 95% CI 2.90 to 35.84, p = 0.0003) were associated with increased meningioma risk, while BRCA1 (OR 0.67, 95% CI 0.57 to 0.80, p = 4.88 × 10- 6) showed negative causal association with meningioma risk. The outcome of the sensitivity analysis and reverse MR analysis corroborated the findings. These findings suggested a causal relationship between BC and meningioma, and identified potential target genes associated with meningioma, which was beneficial to early identification and prevention of meningioma risk.

Unraveling the role of histone acetylation in sepsis biomarker discovery

Introduction

Sepsis is a life-threatening condition caused by a dysregulated immune response to infection. Despite advances in clinical care, effective biomarkers for early diagnosis and prognosis remain lacking. Emerging evidence suggests that histone acetylation plays a crucial role in the pathophysiology of sepsis.

Methods

Transcriptomic and single-cell RNA sequencing data were used to identify histone acetylation-related genes. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were performed, followed by machine learning algorithms (LASSO, SVM-RFE, and Boruta) to screen for potential biomarkers. Mendelian randomization (MR), RT-qPCR, and functional assays were conducted for validation.

Results

BLOC1S1, NDUFA1, and SFT2D1 were identified as key biomarkers. A predictive nomogram demonstrated strong diagnostic potential. Immune infiltration and single-cell analyses linked the biomarkers to macrophage activity. MR analysis confirmed SFT2D1 as a causal factor in sepsis. Functional assays showed that knockdown of SFT2D1 suppressed CXCL10 and IL-6 expression, indicating its pro-inflammatory role.

Discussion

This study identifies novel biomarkers associated with histone acetylation and immune dysregulation in sepsis. These findings deepen our understanding of sepsis pathogenesis and may facilitate the development of improved diagnostic and therapeutic strategies.

Prenatal and Early Childhood Exposure to Antibiotics or Gastric Acid Inhibitors and Increased Risk of Epilepsy: A Nationwide Population-Based Study

Over 10 million children in the world have epilepsy, with an unknown cause in half of the cases. The gut microbiome has been associated with various neurological disorders, and certain drugs greatly disturb the microbiome. Our aim was to study the association of prenatal and childhood exposure (before the age of two) to antibiotics, proton pump inhibitors (PPIs) and histamine-2 receptor antagonists, and the risk of childhood epilepsy. Using population-based registers, we included all live singleton births in Sweden from 2006 to 2017. Exposure was considered prescription(s) to antibiotics, proton pump inhibitors, or H2-receptor antagonists (separately). Multivariable Cox regression was used to calculate hazard ratios and 95% confidence intervals. 708,903 mother-child dyads were included, and 0.5% of children had an epilepsy diagnosis. Average follow-up was 3.8 years (IQR 1-6). Prenatal exposure to antibiotics (aHR 1.09, 95% CI 1.01-1.18) and PPIs (aHR 1.38, 95% CI 1.17-1.65) were associated with an increased risk of epilepsy. Exposure to antibiotics (1.11, 95% CI 1.02-1.21), PPIs (3.40, 95% CI 2.47-4.68) and H2RAs (1.65, 95% CI 1.03-2.64) before the age of two was associated with an increased risk of epilepsy after the age of two. Dose response analysis showed that one prescription of antibiotics in pregnancy or early life was not associated with an increased risk of epilepsy, while one prescription of PPIs in pregnancy or early life had an association. To conclude, our results support the hypothesis that microbiome modulating drugs are associated with an increased risk of epilepsy. This needs to be further validated in other studies, ideally including indications for drug use.

The mediating role of circulating inflammatory cytokines in causal associations between plasma metabolites and asymptomatic bile duct and cholecyst calculus: A Mendelian randomization study

Asymptomatic gallbladder and biliary tract calculus may make into symptomatic disease or bring anxiety for patients. The formation of gallstones was associated with genetic risk factors and metabolic abnormalities. Genome-wide association studies (GWAS) data of 1400 plasma metabolites (PMs) and 91 circulating inflammatory cytokines (CICs) were obtained from the GWAS catalog, while the GWAS data of calculus of gallbladder without cholecystitis and calculus of bile duct without cholangitis or cholecystitis were retrieved from the IEU OpenGWAS project. The causalities from PMs or CICs to asymptomatic bile duct or cholecyst calculus were explored by 2-sample Mendelian randomization (MR) analysis. Furthermore, the MR analyses were implemented from the identified PMs to CICs. Following the false discovery rate adjustment, the significant causalities, including 6 CICs and 5 PMs on asymptomatic biliary stone and 5 CICs and 48 PMs on asymptomatic gallstone, were identified. Fibroblast growth factor 19 (FGF-19) and aspartate/mannose ratio were the common protective factors of asymptomatic biliary tract calculus, while Monocyte chemoattractant protein 2 (CCL-2) may serve as a disease-promoting agent. Moreover, Bilirubin degradation product, C17H18N2O4 (1) levels, and Bilirubin (Z,Z)/etiocholanolone glucuronide ratio were associated with FGF-19 level, while aspartate/mannose ratio was related to TNF-related apoptosis-inducing ligand level. Based on MR analysis, we identified the multiple PMs and CICs, especially FGF-19, which may affect the formation of gallbladder and biliary tract calculus. Moreover, the partial CICs could be the downstream mediator of PMs related to asymptomatic gallbladder and biliary tract calculus. These results contributed to supporting previous studies and provided evidence for disease prevention or management.

Deconstruct the link between gut microbiota and neurological diseases: application of Mendelian randomization analysis

Background

Recent research on the gut-brain axis has deepened our understanding of the correlation between gut bacteria and the neurological system. The inflammatory response triggered by gut microbiota may be associated with neurodegenerative diseases. Additionally, the impact of gut microbiota on emotional state, known as the "Gut-mood" relationship, could play a role in depression and anxiety disorders.

Results

This review summarizes recent data on the role of gut-brain axis in the pathophysiology of neuropsychiatric and neurological disorders including epilepsy, schizophrenia, Alzheimer's disease, brain cancer, Parkinson's disease, bipolar disorder and stroke. Also, we conducted a Mendelian randomization study on seven neurological disorders (Epilepsy, schizophrenia, Alzheimer's disease, brain cancer, Parkinson's disease, bipolar disorder and stroke). MR-Egger and MR-PRESSO tests confirmed the robustness of analysis against horizontal pleiotropy.

Conclusions

By comparing the protective and risk factors for neurological disorders found in our research and other researches, we can furtherly determine valuable indicators for disease evolution tracking and potential treatment targets. Future research should explore extensive microbiome genome-wide association study datasets using metagenomics sequencing techniques to deepen our understanding of connections and causality between neurological disorders.

Novel insights into causal effects of serum lipids, lipid metabolites, and lipid-modifying targets on the risk of intracerebral aneurysm

INTRODUCTION

Different serum lipid and lipid-lowering agents are reported to be related to the occurrence of intracerebral aneurysm (IA). However, the causal relationship between them requires further investigation.

PATIENTS AND METHODS

Mendelian randomization (MR) analysis was performed on IA and its subtypes by using instrumental variants associated with six serum lipids, 249 lipid metabolic traits, and 10 lipid-lowering agents that were extracted from the largest genome-wide association study. Phenome-wide MR analyses were conducted to identify potential phenotypes associated with significant lipid-lowering agents.

RESULTS

After multiple comparison adjustments (p < 0.0083), genetically proxied triglyceride (TG) (odds ratio [OR] 1.25, 95% confidence interval [CI] 1.07-1.47, p = 0.005) and high-density lipoprotein cholesterol (HDL-C) levels (OR 0.93, 95% CI 0.89-0.98, p = 0.008) showed causal relationships with the risk of IA. Four lipid metabolic traits showed a causal relationship with the risk of IA (p < 0.0002). As confirmed by drug target MR, the causal relationship between the HMGCR target and IA, HMGCR target and subarachnoid hemorrhage (SAH), ANGPTL3 target and SAH, CETP target, and SAH remained statistically significant after multiple adjustments (p < 0.005). Additionally, phenome-wide MR did not identify other diseases linked to the significant lipid-lowering agent (p < 6.39 × 10-5).

DISCUSSION AND CONCLUSION

This study not only supports that serum lipids (TG and HDL-C) are associated with IA but also confirms the positive effect and absence of safety concerns of intervening HMGCR, ANGPTL3, and CETP targets in IA and its subtypes, opening new avenues for IA treatment.

Two-Sample Mendelian Randomization Analyses Identified Lipid Species Associated With Intracranial Aneurysm Formation

OBJECTIVES

Intracranial aneurysm (IA) poses a significant health risk, and its formation involves various factors, including lipid metabolism, while former research only focused on the standard lipid. The purpose of this study is to explore 179 lipid variants' impact on unruptured intracranial aneurysms (uIA).

MATERIALS AND METHODS

Utilizing GWAS data for lipids and uIAs, MR analyses were employed with pleiotropy, heterogeneity, and sensitivity tests. Reverse MR analyses were then conducted.

RESULTS

MR analyses revealed seven lipids associated with uIAs: TAG (51:3). SE (27:1/16:1), PC (18:2_18:2), TAG (48:1), TAG (48:2), and TAG (51:3) were identified as uIA risk factors, while SE (27:1/18:1) and SM (d34:0) exhibited protective effects. Reverse MR analysis showed no bidirectional causal relationships.

CONCLUSIONS

This study identifies specific lipid variants causally linked to uIAs, shedding light on their roles in IA formation. These findings contribute to future research on IA risk assessment and potential therapeutic interventions.

Investigating the causal impact of gut microbiota on trigeminal neuralgia: a bidirectional Mendelian randomization study

Background

The etiology and pathogenesis of trigeminal neuralgia remain unclear. This study examines the connection between gut microbiota and trigeminal neuralgia using Mendelian randomization analysis to provide insights into the disorder's origin and propose potential therapies based on our findings.

Methods

We used data from the MiBioGen consortium (13,266 participants) for gut microbiota and the IEU OpenGWAS project (800 cases, 195,047 controls) for trigeminal neuralgia. We checked for heterogeneity and horizontal pleiotropy and used the inverse variance weighting method as our main approach to study the causal link between gut bacteria and trigeminal neuralgia, MR-Egger, simple mode, weighted median, and weighted mode as supplementary methods, with a sensitivity test using leave-one-out analysis. If a bacteria-trigeminal neuralgia link was found, we conducted a reverse analysis for confirmation.

Results

According to the final results, these groups include Butyricimonas (Genus, id = 945, p-value = 0.007, OR = 1.742, 95% CI: 1.165-2.604), unknowngenus (Genus, id = 1000005479, p-value = 0.005, OR = 1.774, 95% CI: 1.187-2.651) and Bacteroidales (Family, p-value = 0.005, OR = 1.774, 95% CI: 1.187-2.651) were causally associated with trigeminal neuralgia. No significant results according to reverse Mendelian randomization analysis.

Conclusion

In our study, we identified specific gut bacteria linked to trigeminal neuralgia. To comprehensively understand their impact and mechanisms, additional randomized trials are necessary.

Bidirectional Mendelian Randomization identifies plasma proteins associated with urticaria risk

Urticaria is a prevalent autoimmune skin disorder characterized by localized wheals and intense pruritus, significantly impairing the quality of life for affected individuals. Previous research has indicated that plasma proteins may contribute to the pathogenesis of urticaria. However, these findings do not establish a causal relationship. To address this gap, we conducted a large-scale Mendelian randomization(MR) study of the plasma proteome. In this study, we employed a two-sample, bidirectional Mendelian randomization approach to evaluate the causal relationship between the plasma proteome and urticaria. Utilizing large, publicly available genome-wide association studies, we examined the association of 4907 plasma proteins with the risk of developing urticaria. To assess heterogeneity and horizontal pleiotropy, we applied Cochran's Q test, the MR-Egger intercept test, and the MR-PRESSO global test. Furthermore, a sensitivity analysis was conducted to evaluate the influence of individual single nucleotide polymorphisms on the MR findings. Additionally, we performed enrichment analysis and GeneMANIA analysis to identify and annotate the functions of the selected plasma protein genes and to determine associated genetic factors. In this study, we examined 4,907 plasma proteomes as exposures and urticaria as the outcome. The findings revealed significant associations for several proteins, including CHCHD10, HBB, GZMB, LILRB2, MICB, IL21, FTMT, JPH4, and ISOC1 with the risk of urticaria. Specifically, three plasma protein phenotypes were identified as protective factors: GZMB (odds ratio [OR] = 0.76, 95% confidence interval [CI] 0.65-0.88, P < 0.001), MICB (OR = 0.82, 95% CI 0.76-0.89, P < 0.001), and FTMT (OR = 0.79, 95% CI 0.74-0.83, P < 0.001). Conversely, other plasma protein phenotypes were identified as risk factors for urticaria: CHCHD10 (OR = 2.68, 95% CI 1.54-4.67, P < 0.001), HBB (OR = 1.21, 95% CI 1.08-1.36, P = 0.001), LILRB2 (OR = 1.08, 95% CI 1.04-1.12, P < 0.001), IL21 (OR = 1.19, 95% CI 1.08-1.31, P < 0.001), JPH4 (OR = 1.30, 95% CI 1.13-1.50, P < 0.001), and ISOC1 (OR = 1.18, 95% CI 1.07-1.30, P < 0.001). Additionally, reverse Mendelian randomization analysis indicated that urticaria was a risk factor for ISOC1 (OR = 0.93, 95% CI 0.86-0.99, P = 0.03). We identified a bidirectional causal relationship between ISOC1 and urticaria. This study successfully elucidated the causal relationship between plasma protein phenotypes and urticaria, contributing valuable information for understanding the pathophysiology of the condition. Furthermore, it offers new genetic insights that may inform the identification of potential therapeutic targets for urticaria.

Berberine Alleviates Kainic Acid-Induced Acute Epileptic Seizures in Mice via Reshaping Gut Microbiota-Associated Lipid Metabolism

BACKGROUND

Berberine (BBR) has been reported to mitigate epileptic seizures. However, the potential mechanism of its anti-seizure effect remains uncharacterized.

AIMS

This study aimed to investigate the protective effect of BBR on acute epileptic seizures induced by kainic acid (KA) in mice and further explore its mechanism of action in the aspect of analysis of gut microbiota.

MATERIALS AND METHODS

The protective effect of BBR against acute epileptic seizures was assessed via Racine score and Nissl training. Alterations of gut microbiota and metabolites in seizure mice after BBR treatment were analyzed through 16S sequencing and lipidomics, respectively.

RESULTS

Our results showed that the BBR remarkably alleviated acute epileptic seizures and hippocampal neuron damage in KA-induced mice. The analysis of gut microbiota indicated that BBR reduced the acute epileptic seizures in KA-induced mice by increasing the abundance of Bacteroidetes and Alloprevotella, regulating short-chain fatty acids (SCFAs). Results of lipidomics also identified 21 candidate metabolites in the colon and hippocampus possibly involved in the protective effect of BBR against acute seizures.

CONCLUSION

These findings suggest that BBR exerts neuroprotection against KA-induced epileptic seizures through remodeling gut microbiota-associated lipid metabolism in the colon and hippocampus. BBR may serve as a valuable candidate drug for curing patients with epilepsy.

Analysis of the brain transcriptome, microbiome and metabolome in ketogenic diet and experimental stroke

The ketogenic diet (KD) has been shown to be effective in treating various brain pathologies. In this study, we conducted detailed transcriptomic and metabolomic profiling of rat brains after KD and ischemic stroke in order to investigate the effects of KD and its underlying mechanisms. We evaluated the effect of a two-month KD on gene expression in intact brain tissue and after middle cerebral artery occlusion (MCAO). We analyzed the effects of KD on gut microbiome composition and blood metabolic profile as well as investigated the correlation between severity of neurological deficits and KD-induced changes. We found transcriptional reprogramming in the brain after stroke and KD treatment. The KD altered the expression of genes involved in the regulation of glucose and fatty acid metabolism, mitochondrial function, the immune response, Wnt-associated signaling, stem cell development, and neurotransmission, both in intact rats and after MCAO. The KD led to a significant change in the composition of gut microbiome and the levels of amino acids, acylcarnitines, polyunsaturated fatty acids, and oxylipins in the blood. However, the KD slightly worsened the neurological functions after MCAO, so that the therapeutic effect of the diet remained unproven.

Traumatic Brain Injury Increasing Risk of Meningioma? From the Genetic Evidence

BACKGROUND

Numerous studies have demonstrated a strong association between traumatic brain injury (TBI) and an increased risk of meningioma. However, this correlation remains controversial. This study utilized Mendelian randomization to explore this relationship from the perspective of genetic evidence.

METHODS

We employed 6 TBI genome-wide association study datasets from the integrative epidemiology unit genome-wide association study database. Summary statistics for meningioma were sourced from the FinnGen R10 database. We assessed heterogeneity and horizontal pleiotropy within the analyzed data. The primary method was inverse variance weighting (IVW) to investigate the causal relationship between TBI and meningioma, excluding cases with horizontal pleiotropy. Four supplementary analysis methods were also used, with abnormal results excluded based on leave-one-out sensitivity analysis.

RESULTS

All 6 Mendelian randomization analyses indicated no causal relationship between TBI and meningiomas (focal brain injury IVW P value = 0.98; diffuse brain injury IVW P value = 0.41; TBI without concussion IVW P value = 0.45; intracranial trauma IVW P value = 0.34; traumatic subdural hemorrhage IVW P value = 0.80; traumatic subarachnoid hemorrhage IVW P value = 0.92).

CONCLUSIONS

The Mendelian randomization study revealed that TBI does not increase the risk of meningioma based on genetic evidence.

Exploring the causal relationship between gut microbiota and atopic dermatitis: A Mendelian randomization study

Accumulating evidence indicates a correlation between gut microbiota (GM) and atopic dermatitis (AD). Nevertheless, the causal relationship between specific pathogenic bacterial taxa and AD remains uncertain. This investigation utilized a two-sample Mendelian randomization (MR) analysis to assess the causal association between GM and AD, identifying the most influential GM taxa. An MR study was conducted utilizing summary statistics derived from genome-wide association studies encompassing 207 GM taxa and their association with AD risk. The genome-wide association studies summary statistics for 207 GM taxa (from phylum to species level) were generated by the Dutch Microbiome Project. The genetic variants (P < 1 × 10-5) correlated with GM (n = 7738) were identified from this investigation. Additionally, 4 supplementary MR approaches, simple mode, MR-Egger, weighted mode, and weighted median, supported the inverse-variance weighted approach. Furthermore, sensitivity analyses were executed using leave-one-out analysis, Cochran Q test, MR-Egger intercept test, MR pleiotropy residual sum and outlier global test, and MR Steiger test. The MR analysis identified 17 distinct bacterial taxa involving 2 orders, 4 families, 5 genera, and 6 species. The inverse-variance weighted method demonstrated that 6 bacterial taxa were positively associated with AD. These taxa included the order Pasteurellales, family Burkholderiales noname, family Pasteurellaceae, genus Burkholderiales noname, species Burkholderiales bacterium_1_1_47, and species Desulfovibrio piger. Eleven bacterial taxa were negatively associated with AD, comprising the order Actinomycetales, family Micrococcaceae, family Oscillospiraceae, genus Rothia, genus Collinsella, genus Oscillibacter, genus Pseudoflavonifractor, species Oscillibacter_unclassified, species Roseburia hominis, species R mucilaginosa, and species Parabacteroides merdae. Moreover, the MR-Egger intercept test and MR pleiotropy residual sum and outlier global test validated that the MR analysis remained unaffected by horizontal pleiotropy (P > .05). Furthermore, the leave-one-out analysis contributed to validating the robustness of the outcomes. Finally, an MR Steiger directionality test confirmed the assessment of potential causal direction (P < .001). This investigation identified specific intestinal flora causally associated with AD risk, offering novel insights for future investigations and innovative avenues for AD diagnosis, therapeutic intervention, and prognostic assessment.

Association between gut microbiota and male infertility: a two-sample Mendelian randomization study

Previous research has confirmed the significant association between gut microbiota (GM) and male infertility (MI), but the causality between them remains unclear. This study aims to investigate the causal relationship between GM and MI using Mendelian randomization (MR) and provide supplementary information for the optimization of future randomized controlled trials (RCTs). Instrumental variables for 211 GM taxa were obtained from genome-wide association studies (GWAS), and inverse variance weighted (IVW) method was used as the main analysis method for two-sample MR analysis to assess the impact of GM on the risk of MI. Four methods were used to test for horizontal pleiotropy and heterogeneity of MR results to ensure the reliability of the MR findings. A total of 50 single-nucleotide polymorphisms (SNPs) closely related to GM were included, and ultimately identified 1 family and 4 general are causally associated with MI. Among them, Anaerotruncus (OR = 1.96, 95% CI 1.31-3.40, P = 0.016) is significantly associated with increased MI risk. Furthermore, we used four MR methods to evaluate the causality, and the results supported these findings. The leave-one-out analysis showed stable results with no instrumental variables exerting strong influence on the results. The causal direction indicated a positive effect, and the effects of heterogeneity and horizontal pleiotropy on the estimation of causal effect were minimized. We confirmed a causal relationship between GM taxa and MI, providing new insights into the mechanisms underlying GM-mediated MI.

The associations between oxidative stress and epilepsy: a bidirectional two-sample Mendelian randomization study

BACKGROUND

Studies on the association between oxidative stress and epilepsy have yielded varied results. In this study, we aimed to investigate the causal relationship between oxidative stress markers and epilepsy.

METHODS

A bidirectional two-sample Mendelian randomization (MR) study was performed based on publicly available statistics from genome-wide association studies. To explore the causal effects, single nucleotide polymorphisms were selected as instrumental variables. Inverse-variance weighted method was performed for primary analysis, supplemented by weighted median, MR-Egger, simple mode, and weighted mode. Furthermore, sensitivity analyses were performed to detect heterogeneity and pleiotropy.

RESULTS

Our results showed that part of the oxidative stress biomarkers are associated with epilepsy and its subtypes. Zinc is associated with increased risk of epilepsy and generalized epilepsy (odds ratio [OR] = 1.064 and 1.125, respectively). Glutathione transferase is associated with increased risk of generalized epilepsy (OR = 1.055), while albumin is associated with decreased risk of generalized epilepsy (OR = 0.723). Inverse MR analysis revealed that epilepsy is associated with increased levels of uric acid and total bilirubin (beta = 1.266 and 0.081, respectively), as well as decreased zinc level (beta =  - 0.278). Furthermore, generalized epilepsy is associated with decreased ascorbate and retinol levels (beta =  - 0.029 and - 0.038, respectively).

CONCLUSIONS

Our study presented novel evidence of potential causal relationships between oxidative stress and epilepsy, suggesting potential therapeutic targets for epilepsy.

Gut Microbiota, Circulating Metabolites and Risk of Endometriosis: A Two-Step Mendelian Randomization Study

Epidemiological studies and animal models have suggested a possible link between gut microbiota (GM), circulating metabolites, and endometriosis (EMs) pathogenesis. However, whether these associations are causal or merely due to confounding factors remains unclear. We conducted a two-sample and two-step Mendelian randomization (MR) study to elucidate the potential causal relationship between GM and EMs, and the mediating role of circulating metabolites. Our MR analysis revealed that higher abundances of class Negativicutes, and order Selenomonadales, as well as genera Dialister, Enterorhabdus, Eubacterium xylanophilum group, Methanobrevibacter were associated with an increased risk of EMs (Odds Ratio (OR) range: 1.0019-1.0037). Conversely, higher abundances of genera Coprococcus 1 and Senegalimassilia were linked to reduced risk of EMs (OR range: 0.9964-0.9967). Additionally, elevated levels of circulating metabolites such as 1-eicosatrienoyl-glycerophosphocholine and 1-oleoylglycerophosphocholine were found to be associated with heightened risk of EMs (OR range: 2.21-3.16), while higher concentrations of 3-phenylpropionate and dihomo-linolenate were protective (OR range: 0.285-0.535). Two-step MR analysis indicated that specific microbial taxa, notably genus Enterorhabdus and order Selenomonadales, might function as mediators linking circulating metabolites to the risk of EMs. Our findings suggest a probable causal relationship between GM, circulating metabolites, and EMs, indicating that GM may mediate the influence of circulating metabolites on the pathophysiology of EMs. These results offer new leads for future mechanistic studies and could inform clinical translational research.

Changes in gut flora in patients with epilepsy: a systematic review and meta-analysis

Background

Epilepsy is a prevalent chronic neurological disorder that is strongly associated with a wide range of psychological, cognitive and social problems. It affects a significant proportion of the global population and has a number of complex etiologies. A growing body of research indicates that there is a strong association between epilepsy and the gut microbiota. Indeed, a substantial body of research has investigated the potential role of epilepsy in relation to the gut microbiota, examining alterations in the abundance, diversity, and relative abundance of the gut microbiota in patients with epilepsy.

Methods

This study was conducted in accordance with the PRISMA guidelines and included multiple studies that met specific criteria. A keyword search was conducted in the following databases: PubMed, Embase, and Web of Science. The data extraction and quality assessment were conducted by two independent researchers. A systematic review and meta-analysis of the relationship between patients with epilepsy and gut flora was conducted using the R 4.3.4 software.

Results

The results of the analyses indicated that the intestinal flora of patients with epilepsy did not differ significantly in alpha diversity compared to healthy controls. However, the relative abundance of specific flora, such as Verrucomicrobia and Ackermannia was significantly increased in patients, whereas Lactobacillus was significantly decreased.

Conclusion

The relationship between epilepsy and gut flora is reciprocal. The present meta-analysis demonstrated that there were no statistically significant alterations in the overall characteristics of the intestinal flora of the patients. However, significant changes were observed in the relative abundance of certain phyla and genera. Consequently, it is hypothesized that epilepsy can cause changes in the relative abundance of specific flora in patients. Furthermore, in conjunction with previous studies, it is believed that changes in intestinal flora can also have an effect on seizures. For example, Lactobacillus may be a beneficial genus that potentially reduces seizures. Conversely, the effect of Akkermansia is two-sided.

Plasma proteometabolome in lung cancer: exploring biomarkers through bidirectional Mendelian randomization and colocalization analysis

Unlike other cancers with widespread screening (breast, colorectal, cervical, prostate, and skin), lung nodule biopsies for positive screenings have higher morbidity with clinical complications. Development of non-invasive diagnostic biomarkers could thereby significantly enhance lung cancer management for at-risk patients. Here, we leverage Mendelian Randomization (MR) to investigate the plasma proteome and metabolome for potential biomarkers relevant to lung cancer. Utilizing bidirectional MR and co-localization analyses, we identify novel associations, highlighting inverse relationships between plasma proteins SFTPB and KDELC2 in lung adenocarcinoma (LUAD) and positive associations of TCL1A with lung squamous cell carcinoma (LUSC) and CNTN1 with small cell lung cancer (SCLC). Additionally, our work reveals significant negative correlations between metabolites such as theobromine and paraxanthine, along with paraxanthine-related ratios, in both LUAD and LUSC. Conversely, positive correlations are found in caffeine/paraxanthine and arachidonate (20:4n6)/paraxanthine ratios with these cancer types. Through single-cell sequencing data of normal lung tissue, we further explore the role of lung tissue-specific protein SFTPB in carcinogenesis. These findings offer new insights into lung cancer etiology, potentially guiding the development of diagnostic biomarkers and therapeutic approaches.

A study on the causal relationship between the gut microbiome and herpes zoster using Mendelian randomization

Introduction

The relationship between herpes zoster recurrence and the gut microbiome was not studied. We analyzed data on the gut microbiome and herpes zoster from the Large-Scale Genome-Wide Association Study (GWAS) database using bidirectional Mendelian randomization. For the first time, we identified a potentially bidirectional causal relationship between the gut microbiome and herpes zoster (HZ). These findings are groundbreaking and hold promise for new directions in the treatment of HZ, a global disease.

Background and aims

HZ had a high global incidence, characterized by shingled blisters, blood blisters, and neuropathic pain, and could develop in various parts of the body, including the ear and throat. It was believed its onset was closely related to old age and infirmity. Some studies reported that the incidence of herpes zoster in patients with inflammatory intestinal diseases (such as Crohn's disease and ulcerative colitis) was higher than in the general population. Existing studies attributed this to the reactivation of varicella-zoster virus (VZV) due to autoinflammatory attacks and immunosuppressive drugs. This provided a basis for exploring the new pathogenesis of HZ and investigating whether there was a relationship between intestinal auto-flora and the development of HZ. This study aimed to examine this potential relationship using bidirectional Mendelian analyses.

Methods

GWAS data on HZ and gut microbiota were obtained from FinnGen, the Mibiogen consortium, and HZ meta-analysis data from the IEU Open GWAS Project. These data were subjected to two-sample Mendelian randomization (MR) analysis to determine if there is a causal relationship between gut microbiota and HZ. Additionally, bidirectional Mendelian analyses were conducted to identify the direction of causality and to clarify any potential interactions.

Results

In our Mendelian Randomization (MR) analysis, we identified, for the first time, two gut microbes that might be associated with HZ reactivation. In the reverse MR analysis, four gut microbiota showed a potential association between the genetic susceptibility of gut microbiota and HZ reactivation. We found that genus Tyzzerella3 (OR: 1.42, 95% CI: 1.17-1.72, FDR < 0.1) may be strongly correlated with an increased probability of HZ (ICD-10: B02.901) reactivation. Additionally, phylum Cyanobacteria was identified as a potential risk factor for the onset of HZ rekindling (OR: 1.42, 95% CI: 1.09-1.87). Analyzing the results of the reverse MR, we also identified a potential inhibitory effect (OR: 0.91, 95% CI: 0.84-0.99) of HZ onset on the genus Eubacteriumhallii group in the gut, suggesting that HZ might reduce its abundance. However, genus Escherichia/Shigella (OR: 1.11, 95% CI: 1.01-1.22), genus Veillonella (OR: 1.16, 95% CI: 1.04-1.30), and phylum Proteobacteria (OR: 1.09, 95% CI: 1.01-1.18) appeared to act as potential protective factors, indicating that the relative abundance and viability of these three bacteria increased in the HZ state.

Conclusion

We identified the influence of gut flora as a new causative factor for HZ reactivation. Additionally, we found that individuals suffering from HZ might potentially impact their gut flora. Specific bacterial taxa that could influence the onset and progression of HZ were identified, potentially providing new directions for HZ treatment.

Association of metabolites on ischemic stroke subtypes: a 2-sample Mendelian randomization study

Background

Metabolomics is increasingly being utilized in IS research to elucidate the intricate metabolic alterations that occur during ischemic stroke (IS). However, establishing causality in these associations remains unclear between metabolites and IS subtypes. In this study, we employ Mendelian randomization (MR) to identify specific metabolites and investigate potential causal relationships between metabolites and IS subtypes.

Methods

MR analysis was conducted using genome-wide association study (GWAS) summary data. We obtained 1,091 blood metabolites and 309 metabolite ratios from the GWAS Catalog (GCST90199621-90201020), which gene sequencing data from 8,299 individuals from the Canadian Longitudinal Study. We obtained GWAS summary statistics for IS subtypes which include large artery stroke (LAS), cardioembolic stroke (CES), and small vessel stroke (SVS) from the MEGASTROKE consortium that included 446,696 cases of European ancestry and 406,111 controls of European ancestry. The primary analysis utilized inverse-variance weighted (IVW) method. To validate our results, we performed supplementary analyses employing the MR-Egger, weighted median, simple mode, and weighted mode methods. Heterogeneity and pleiotropy were assessed through Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis.

Results

The study assessed the possible causality of serum metabolites in the risk of IS subtypes. The discovery of significant causal links between 33 metabolites and 3 distinct IS subtypes.

Conclusion

Metabolites show significant potential as circulating metabolic biomarkers and offer promise for clinical applications in the prevention and screening of IS subtypes. These discoveries notably advance our comprehension of the molecular processes specific to IS subtypes and create avenues for investigating targeted treatment approaches in the future.

Revealing the link between gut microbiota and brain tumor risk: a new perspective from Mendelian randomization

Background

Recent studies have shown that gut microbiota may be related to the occurrence of brain tumors, but direct evidence is lacking. This study used the Mendelian randomization study (MR) method to explore the potential causal link between gut microbiota and brain tumors.

Method

We analyzed the genome-wide association data between 211 gut microbiota taxa and brain tumors, using the largest existing gut microbiota Genome-Wide Association Studies meta-analysis data (n=13266) and combining it with brain tumor data in the IEU OpenGWAS database. We use inverse-variance weighted analysis, supplemented by methods such as Mendelian randomization-Egger regression, weighted median estimator, simple mode, and weighted mode, to assess causality. In addition, we also conducted the Mendelian randomization-Egger intercept test, Cochran's Q test, and Mendelian randomization Steiger directionality test to ensure the accuracy of the analysis. Quality control includes sensitivity analysis, horizontal gene pleiotropy test, heterogeneity test, and MR Steiger directionality test.

Result

Our study found that specific gut microbial taxa, such as order Lactobacillales and family Clostridiaceae1, were positively correlated with the occurrence of brain tumors, while genus Defluviitaleaceae UCG011 and genus Flavonifractor were negatively correlated with the occurrence of brain tumors. The Mendelian randomization-Egger intercept test showed that our analysis was not affected by pleiotropy (P>0.05).

Conclusion

This study reveals for the first time the potential causal relationship between gut microbiota and brain tumors, providing a new perspective for the prevention and treatment of early brain tumors. These findings may help develop new clinical intervention strategies and point the way for future research.

The causal relationship between gut microbiota and alopecia areata: a Mendelian randomization analysis

Background

Increasing evidence suggests a robust correlation between the gut microbiome and alopecia areata. In light of the extensive diversity of gut microbiota, this study aims to utilize state-of-the-art and comprehensive data to explore the causative association between gut microbiota and alopecia areata.

Objective

We conducted a Mendelian randomization (MR)-based two-sample study to elucidate the causal relationship between gut microbiota and alopecia areata.

Method

Summary information on Ncase = 767 and Ncontrol = 394,105 cases of alopecia areata was obtained from the FinnGen study. A total of 473 gut microbial taxa were summarized from the genome-wide association study (GWAS) catalog. The study comprised a forward Mendelian randomization (MR) analysis with the gut microbiome as the exposure factor and alopecia areata as the outcome, as well as a reverse MR analysis with alopecia areata as the exposure factor and the gut microbiome as the outcome. Various analytical methods including inverse variance weighting (IVW), Weighted Median, MR-Egger, Weighted Mode, and Simple Mode were employed. Subsequently, sensitivity analysis was conducted to ensure the robustness of our research findings.

Result

This study has established a causal relationship between gut microbiota and alopecia areata. Forward causal analysis revealed causality relationships between 16 gut microbial taxa and alopecia areata, while reverse causal analysis found that there may be a causal relationship between alopecia areata and 16 gut microbial taxa (not statistically significant).

Conclusion

Our study findings suggest a causal relationship between gut microbiota and alopecia areata, providing potential guidance for future clinical trials.

The causal relationship between gut microbiota and diabetic neuropathy: a bi-directional two-sample Mendelian randomization study

Background

Many studies suggest a strong correlation between gut microbiota (GM) and diabetic neuropathy (DN). However, the precise causal relationship between GM and DN has yet to be fully elucidated. Hence, a bi-directional Mendelian randomization (MR) analysis was used to examine the association between GM and DN.

Methods

Widely known genome-wide association study (GWAS) of GM was collected from the MiBio Gen project. Summary-level datasets for DN were taken from the FinnGen project. Inverse variance weighted approach was used for evaluating the causal relationship between GM and DN. Subsequently, pleiotropy and heterogeneity tests were performed to verify the reliability of the data. Furthermore, a bidirectional two-sample MR analysis was done to investigate the directionality of the causal relationships. Gene Ontology analysis was conducted to identify the associations that could indicate biological functions.

Results

We identified potential causal associations between GM and DN (p< 0.05 in all three MR methods). Among them, we found increased levels of Christensenellaceae R-7 (Odds ratio, OR= 1.52; 95% confidence interval, CI = 1.03-2.23; p = 0.03), Ruminococcaceae UCG013 (OR =1.35; 95% CI = 1.00-1.85; p = 0.04), and Eggerthella groups (OR = 1.27; 95% CI = 1.05-1.55; p = 0.01), which may be associated with a higher risk of DN, while increased levels of Peptococcaceae (OR = 0.69; 95% CI = 0.54-0.90; p< 0.01) and Eubacterium coprostanoligenes groups (OR = 0.68; 95% CI = 0.49-0.93; p = 0.01) could be associated with a lower risk. Gene Ontology pathway analysis revealed enrichment of genes regulated by the associated single-nucleotide polymorphisms (SNPs) in the apical plasma membrane, glycosyltransferase activity, hexosyltransferase activity and membrane raft. Reverse MR analyses indicated that DN was associated with five microbial taxa in all three MR methods.

Conclusion

The results of our study validate the possible causative relationship between GM and DN. This discovery gives new perspectives into the mechanism on how GM influences DN, and establishes a theoretical foundation for future investigations into targeted preventive measures.

Gut Microbiota, Human Blood Metabolites, and Esophageal Cancer: A Mendelian Randomization Study

BACKGROUND

Unbalances in the gut microbiota have been proposed as a possible cause of esophageal cancer (ESCA), yet the exact causal relationship remains unclear.

PURPOSE

To investigate the potential causal relationship between the gut microbiota and ESCA with Mendelian randomization (MR) analysis.

METHODS

Genome-wide association studies (GWASs) of 207 gut microbial taxa (5 phyla, 10 classes, 13 orders, 26 families, 48 genera, and 105 species) and 205 gut microbiota metabolic pathways conducted by the Dutch Microbiome Project (DMP) and a FinnGen cohort GWAS of esophageal cancer specified the summary statistics. To investigate the possibility of a mediation effect between the gut microbiota and ESCA, mediation MR analyses were performed for 1091 blood metabolites and 309 metabolite ratios.

RESULTS

MR analysis indicated that the relative abundance of 10 gut microbial taxa was associated with ESCA but all the 12 gut microbiota metabolic pathways with ESCA indicated no statistically significant association existing. Two blood metabolites and a metabolite ratio were discovered to be mediating factors in the pathway from gut microbiota to ESCA.

CONCLUSION

This research indicated the potential mediating effects of blood metabolites and offered genetic evidence in favor of a causal correlation between gut microbiota and ESCA.

Role of inflammatory cytokine in mediating the effect of plasma lipidome on epilepsy: a mediation Mendelian randomization study

Background

Epilepsy is one of the most prevalent serious brain disorders globally, impacting over 70 million individuals. Observational studies have increasingly recognized the impact of plasma lipidome on epilepsy. However, establishing a direct causal link between plasma lipidome and epilepsy remains elusive due to inherent confounders and the complexities of reverse causality. This study aims to investigate the causal relationship between specific plasma lipidome and epilepsy, along with their intermediary mediators.

Methods

We conducted a two-sample Mendelian randomization (MR) and mediation MR analysis to evaluate the causal effects of 179 plasma lipidomes and epilepsy, with a focus on the inflammatory cytokine as a potential mediator based on the genome-wide association study. The primary methodological approach utilized inverse variance weighting, complemented by a range of other estimators. A set of sensitivity analyses, including Cochran's Q test, I 2 statistics, MR-Egger intercept test, MR-PRESSO global test and leave-one-out sensitivity analyses was performed to assess the robustness, heterogeneity and horizontal pleiotropy of results.

Results

Our findings revealed a positive correlation between Phosphatidylcholine (18:1_18:1) levels with epilepsy risk (OR = 1.105, 95% CI: 1.036-1.178, p = 0.002). Notably, our mediation MR results propose Tumor necrosis factor ligand superfamily member 12 levels (TNFSF12) as a mediator of the relationship between Phosphatidylcholine (18,1_18:1) levels and epilepsy risk, explaining a mediation proportion of 4.58% [mediation effect: (b = 0.00455, 95% CI: -0.00120-0.01030), Z = 1.552].

Conclusion

Our research confirms a genetic causal relationship between Phosphatidylcholine (18:1_18:1) levels and epilepsy, emphasizing the potential mediating role of TNFSF12 and provide valuable insights for future clinical investigations into epilepsy.

Causal effects of gut microbiota on the risk of osteomyelitis: a Mendelian randomization study

Background

Osteomyelitis is characterized by an inflammatory process initiated by microorganisms, leading to infection and subsequent degradation of bone tissue. Several studies have indicated a potential link between gut microbiota and the occurrence of osteomyelitis. Utilizing the benefits of Mendelian randomization, which mitigates issues of confounding and reverse causation, we employed this approach to ascertain the presence of a causal connection between gut microbiota and osteomyelitis. Additionally, we aimed to pinpoint gut microbiota that could potentially exert substantial influence.

Methods

We performed a rigorous screening of single nucleotide polymorphisms in GWAS summary statistics for gut microbiota and osteomyelitis. The 2,542 instrumental variables obtained after screening were subjected to MR analyses, including inverse variance weighting, weighted median, weighted mode, MR-Egger, and Mendelian randomization pleiotropy residual sum and outlier test. We then validated the reliability of the results by performing sensitivity analyses on the MR of 196 well-defined gut microbiota.

Result

We established a causal relationship between gut microbiota and osteomyelitis through MR analysis. Additionally, we identified a taxon of significant importance and six taxons with nominal significance. Specifically, the family Bacteroidales S24.7 group exhibited an association with a diminished risk of osteomyelitis development. Conversely, the class Bacilli, class Bacteroidia, order Bacteroidales, order Lactobacillales, family Streptococcaceae, and genus Coprococcus3 displayed an increased risk of developing osteomyelitis. The MR outcomes for these seven taxa remained stable throughout a series of sensitivity analyses.

Conclusion

This study demonstrated a causal relationship between gut microbiota and osteomyelitis by Mendelian randomization. We hope that this study will provide a new direction for the treatment of osteomyelitis, which has a paucity of therapeutic options.

Effects of immune cells on ischemic stroke and the mediating roles of metabolites

Objective

Previous studies have not shown an association between IgD-CD24-B-cell absolute count (IgD-CD24-AC) and ischemic stroke (IS). Our study aimed to assess the causal effect of IgD-CD24-AC on IS and to explore the role of ascorbic acid 2-sulfate (AA2S) as a potential mediator.

Methods

Our study was based on the largest available genome-wide association study (GWAS). Inverse variance weighting (IVW), MR-Egger, weighted median (WMN), simple mode, and weighted mode methods were used to assess causal effects, with IVW as the primary outcome. Subsequently, we further performed a two-step MR analysis to evaluate whether AA2S mediated this causal effect. In addition, several sensitivity analyses were conducted to evaluate heterogeneity, including Cochran's Q test, the MR-Egger intercept test, the MR-PRESSO global test, and the leave-one-out analysis.

Results

Using the IVW approach, the risk ratio of IgD-CD24-AC to IS was estimated to be 1.216 (95% CI = 1.079-1.371, p = 0.001). This result was supported by the WMN method (OR = 1.204, 95% CI = 1.020-1.421, p = 0.028) and the MR-Egger method (OR = 1.177, 95% CI = 0.962-1.442, p = 0.133). We also observed the same trend with the simple model and weighted model. Furthermore, the proportion of genetically predicted IgD-CD24-AC mediated through AA2S levels was 3.73%.

Conclusion

Our study revealed a causal relationship between IgD-CD24-AC and IS, a small part of which was mediated by AA2S. These findings offer critical insights for developing immune-targeted therapies in the future and lay a strong foundation for advancements in precision medicine.

Absence of causative genetic association between Helicobacter pylori infection and glaucoma: a bidirectional two-sample mendelian randomization study

Background: While clinical research has indicated a potential link between Helicobacter pylori infection and the onset of glaucoma, the causality of this association remains uncertain due to the susceptibility of observational studies to confounding factors and reverse causation. Methods: A comprehensive two-sample bidirectional Mendelian randomization (MR) analysis was conducted to assess the causal connection between H. pylori infection and glaucoma. Glaucoma was categorized into primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and pseudo-exfoliation glaucoma (PEG). Various methods, including inverse variance weighted, MR-Egger regression, weighted median, and mode-based estimator, were employed for effect estimation and pleiotropy testing. To enhance result robustness, a sensitivity analysis was performed by excluding proxy single nucleotide polymorphisms. Results: Genetic predisposition for H. pylori infection has no causal effect on glaucoma: (OR 1.00; 95% CI 0.95-1.06, p = 0.980), (OR 0.97; 95% CI 0.86-1.09, p = 0.550), and (OR 0.99; 95% CI 0.90-1.08, p = 0.766) with POAG, NTG, and PEG, respectively. An inverse MR showed no causal effect of POAG, NTG, and PEG on H. pylori infection (OR 1.01; 95% CI 0.97-1.05, p = 0.693), (OR 1.00; 95% CI 0.98-1.03, p = 0.804), and (OR 0.99; 95% CI 0.96-1.01, p = 0.363), respectively. Heterogeneity (p > 0.05) and pleiotropy (p > 0.05) analysis confirmed the robustness of MR results. Conclusion: These results indicated that there was no genetic evidence for a causal link between H. pylori and glaucoma, suggesting that the eradication or prevention of H. pylori infection might not benefit glaucoma and vice versa.

Exploring the casual association between gut microbiome, circulating inflammatory cytokines and chronic pancreatitis: A Mendelian randomization analysis

It has been established that gut dysbiosis contributed to the pathogenesis of digestive disorders. We aimed to explore the causal relationships between intestinal microbiota, circulating inflammatory cytokines and chronic pancreatitis (CP). Summary statistics of genome-wide association studies (GWAS) of intestinal microbiome was retrieved from the MiBioGen study and the GWAS data of 91 circulating inflammatory cytokines and CP were obtained from the GWAS catalog. The 2-sample bidirectional Mendelian randomization (MR) analysis was performed between gut microbiota, circulating inflammatory cytokines and CP, in which the inverse variance weighted (IVW) method was regarded as the primary analysis approach. To prove the reliability of the causal estimations, multiple sensitivity analyses were utilized. IVW results revealed that genetically predicted 2 genera, including Sellimonas and Eubacteriumventriosumgroup, and plasm C-C motif chemokine 23 (CCL23) level were positively associated with CP risk, while genus Escherichia Shigella, Eubacteriumruminantiumgroup and Prevotella9, and plasma Caspase 8, Adenosine Deaminase (ADA), and SIR2-like protein 2 (SIRT2) level, demonstrated an ameliorative effect on CP. Leave-one-out analysis confirmed the robustness of the aforementioned causal effects and no significant horizontal pleiotropy or heterogeneity of the instrumental variables was detected. However, no association was found from the identified genera to the CP-related circulating inflammatory cytokines. Besides, the reverse MR analysis demonstrated no causal relationship from CP to the identified genera and circulating inflammatory cytokines. Taken together, our comprehensive analyses offer evidence in favor of the estimated causal connections from the 5 genus-level microbial taxa and 4 circulating inflammatory cytokines to CP risk, which may help to reveal the underlying pathogenesis of CP.

Investigating the causal role of the gut microbiota in esophageal cancer and its subtypes: a two-sample Mendelian randomization study

BACKGROUND

Through research on the gut microbiota (GM), increasing evidence has indicated that the GM is associated with esophageal cancer (ESCA). However, the specific cause-and-effect relationship remains unclear. In this study, Mendelian randomization (MR) analysis was applied to investigate the causal relationship between the GM and ESCA, including its subtypes.

METHODS

We collected information on 211 GMs and acquired data on ESCA and its subtypes through genome-wide association studies (GWASs). The causal relationship was primarily assessed using the inverse variance weighted (IVW) method. Additionally, we applied the weighted median estimator (WME) method, MR-Egger method, weighted mode, and simple mode to provide further assistance. Subsequent to these analyses, sensitivity analysis was conducted using the MR-Egger intercept test, MR-PRESSO global test, and leave-one-out method.

RESULT

Following our assessment using five methods and sensitivity analysis, we identified seven GMs with potential causal relationships with ESCA and its subtypes. At the genus level, Veillonella and Coprobacter were positively correlated with ESCA, whereas Prevotella9, Eubacterium oxidoreducens group, and Turicibacter were negatively correlated with ESCA. In the case of esophageal adenocarcinoma (EAC), Flavonifractor exhibited a positive correlation, while Actinomyces exhibited a negative correlation.

CONCLUSION

Our study revealed the potential causal relationship between GM and ESCA and its subtypes, offering novel insights for the advancement of ESCA diagnosis and treatment.

Causal associations between human gut microbiota and hemorrhoidal disease: A two-sample Mendelian randomization study

Hemorrhoidal disease (HEM) is a common condition affecting a significant proportion of the population. However, the causal relationship between the gut microbiota and hemorrhoids remains unclear. In this study, we employed a Mendelian randomization (MR) approach to investigate the potential associations between them. In this study, the exposure factor was determined by selecting summary statistics data from a large-scale gut microbiome whole-genome association study conducted by the MiBioGen Consortium, which involved a sample size of 18,340 individuals. The disease outcome data consisted of 218,920 cases of HEM and 725,213 controls of European ancestry obtained from the European Bioinformatics Institute dataset. Two-sample MR analyses were performed to assess the causalities between gut microbiota and hemorrhoids using various methods, including inverse-variance weighting, MR-Egger regression, MR Pleiotropy Residual Sum and Outlier (MR-PRESSO), simple mode, and weighted median. Reverse MR analyses were performed to examine reverse causal association. Our findings suggest phylum Cyanobacteria (OR = 0.947, 95% CI: 0.915-0.980, P = 2.10 × 10 - 3), genus Phascolarctobacterium (OR = 0.960, 95% CI: 0.924-0.997, P = .034) and family FamilyXI (OR = 0.974, 95% CI: 0.952-0.997, P = .027) have potentially protective causal effects on the risk of HEM, while genus Ruminococcaceae_UCG_002 (OR = 1.036, 95% CI: 1.001-1.071, P = .042), family Peptostreptococcaceae (OR = 1.042, 95% CI: 1.004-1.082, P = .029), genus Oscillospira (OR = 1.048, 95% CI: 1.005-1.091, P = .026), family Alcaligenaceae (OR = 1.048, 95% CI: 1.005-1.091, P = .036) and order Burkholderiales (OR = 1.074, 95% CI: 1.020-1.130, P = 6.50 × 10-3) have opposite effect. However, there was a reverse causal relationship between HEM and genus Oscillospira (OR = 1.140, 95% CI: 1.002-1.295, P = .046) This is the first MR study to explore the causalities between specific gut microbiota taxa and hemorrhoidal disease, which may offer valuable insights for future clinical interventions for hemorrhoidal disease.

The Causal Relationship between Plasma Myeloperoxidase Levels and Respiratory Tract Infections: A Bidirectional Mendelian Randomization Study

Background

Observational researches reported the underlying correlation of plasma myeloperoxidase (MPO) concentration with respiratory tract infections (RTIs), but their causality remained unclear. Here, we examined the cause-effect relation between plasma MPO levels and RTIs.

Materials and Methods

Datasets of plasma MPO levels were from the Folkersen et al. study (n = 21,758) and INTERVAL study (n = 3,301). Summarized data for upper respiratory tract infection (URTI) (2,795 cases and 483,689 controls) and lower respiratory tract infection (LRTI) in the intensive care unit (ICU) (585 cases and 430,780 controls) were from the UK Biobank database. The primary method for Mendelian randomization (MR) analysis was the inverse variance weighted approach, with MR-Egger and weighted median methods as supplements. Cochrane's Q test, MR-Egger intercept test, MR pleiotropy residual sum and outliers global test, funnel plots, and leave-one-out analysis were used for sensitivity analysis.

Results

We found that plasma MPO levels were positively associated with URTI (odds ratio (OR) = 1.135; 95% confidence interval (CI) = 1.011-1.274; P=0.032) and LRTI (ICU) (OR = 1.323; 95% CI = 1.006-1.739; P=0.045). The consistent impact direction is shown when additional plasma MPO level genome-wide association study datasets are used (URTI: OR = 1.158; 95% CI = 1.072-1.251; P < 0.001; LRTI (ICU): OR = 1.216; 95% CI = 1.020-1.450; P=0.030). There was no evidence of a causal effect of URTI and LRTI (ICU) on plasma MPO concentration in the reverse analysis (P > 0.050). The sensitivity analysis revealed no violations of MR presumptions.

Conclusions

Plasma MPO levels may causally affect the risks of URTI and LRTI (ICU). In contrast, the causal role of URTI and LRTI (ICU) on plasma MPO concentration was not supported in our MR analysis. Further studies are needed to identify the relationship between RTIs and plasma MPO levels.

Gut microbiota and risk of coronary heart disease: a two-sample Mendelian randomization study

Background

The relationship between gut microbiota composition and coronary heart disease (CHD) has been recently reported in several observational studies. However, the causal effect of gut microbiota on coronary heart disease is uncharted.

Objective

This study attempted to investigate the effect of gut microbiota on coronary heart disease by Mendelian randomization (MR) analysis.

Methods

Through the two-sample MR method, single-nucleotide polymorphisms relevant to gut microbiota were selected as instrument variables to evaluate the causal association between gut microbiota and the risk of CHD.

Results

According to the selection criteria of the inverse variance-weighted average method, Class Actinobacteria, Class Lentisphaeria, Family Clostridiales vadinBB60group, Genus Clostridium innocuum group, Genus Bifidobacterium, Genus Butyricicoccus, Genus Oxalobacter, Genus Turicibacter, and Order Victivallales, presented a suggestive association with coronary heart disease.

Conclusion

This two-sample Mendelian randomization study found that gut microbiota was causally associated with coronary heart disease. Further randomized controlled trials are needed to clarify the protective effect of probiotics on coronary heart disease and their specific protective mechanisms.

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.

Causal associations between gut microbiota and Cholestatic liver diseases: a Mendelian randomization study

Background

The etiological factors of Cholestatic Liver Diseases especially primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are not fully illustrated. It has been reported in previous observational studies that gut microbiota are associated with cholestatic liver diseases. However, there is uncertainty regarding the causality of this association. By using Mendelian randomization, this study aimed to examine the causal impact of gut microbiota on cholestatic liver diseases.

Methods

From large-scale genome-wide association studies, genetic instruments for each gut microbiota taxa as well as primary biliary cholangitis and primary sclerosing cholangitis were developed. Subsequently, we conducted a two-sample Mendelian randomization analysis, supplemented by multiple post hoc sensitivity analyses. Additionally, we performed reverse MR analyses to investigate the possibility of the reverse causal association.

Result

This two-sample MR study indicated that the order Bacillales, family Peptostreptococcaceae, family Ruminococcaceae, genus Anaerotruncu was associated with a decreased risk of developing PBC, and that order Selenomonadales, family Bifidobacteriaceae may be factors that increase the risk of PBC. On the other hand, we also identified order Selenomonadales, family Rhodospirillaceae, and genus RuminococcaceaeUCG013 were positively associated with PSC. The order Actinomycetales, family Actinomycetaceae, genus Actinomyces, genus Alloprevotella, genus Barnesiella, and genus Peptococcus were found negative associations with the risk of PSC. The reverse MR analysis demonstrated no statistically significant relationship between PBC, PSC and these specific gut microbial taxa.

Conclusion

Our findings offered novel evidence that the abundance of particular bacteria contributes to the risk of PBC and PSC, which may contribute to more effective approaches to PBC and PSC therapy and prevention.

Causal relationship between gut microflora and dementia: a Mendelian randomization study

Background

Numerous pertinent investigations have demonstrated a correlation between gut microflora (GM) and the occurrence of dementia. However, a causal connection between GM and dementia and its subtypes has not yet been clarified.

Objective

To explore the causal association between GM and dementia, including its subtypes, a two-sample Mendelian randomization (TSMR) analysis was used.

Methods

Our data comes from the Genome-Wide Association Study (GWAS). The principal approach employed for the Mendelian randomization study was the inverse-variance weighted method, supplemented by four methods: MR-Egger, weighted median, simple mode, and weighted mode. This was followed by Cochrane's Q test, MR-Egger intercept test, MR-PRESSO global test, and leave-one-out as sensitivity analysis validation.

Results

Twenty-one GMs associated with any dementia, Alzheimer's disease, vascular dementia, Lewy body dementia, Parkinson's disease, and dementia under other disease classifications were derived from the analysis, and 21 passed sensitivity tests.

Conclusion

We confirmed the causal relationship between GM and dementia and its subtypes, derived specific flora associated with increased or decreased risk of dementia, and provided new ideas for preventive, diagnostic, and therapeutic interventions for dementia mediated by gut microbiota.

Putative causal relations among gut flora, serums metabolites and arrhythmia: a Mendelian randomization study

BACKGROUND

The pathogenesis of cardiac arrhythmias is multifaceted, encompassing genetic, environmental, hemodynamic, and various causative factors. Emerging evidence underscores a plausible connection between gut flora, serum metabolites, and specific types of arrhythmias. Recognizing the role of host genetics in shaping the microbiota, we employed two-sample Mendelian randomization analyses to investigate potential causal associations between gut flora, serum metabolites, and distinct arrhythmias.

METHODS

Mendelian randomization methods were deployed to ascertain causal relationships between 211 gut flora, 575 serum metabolites, and various types of arrhythmias. To ensure the reliability of the findings, five complementary Mendelian randomization methods, including inverse variance weighting methods, were employed. The robustness of the results was scrutinized through a battery of sensitivity analyses, incorporating the Cochran Q test, leave-one-out test, and MR-Egger intercept analysis.

RESULTS

Eighteen gut flora and twenty-six serum metabolites demonstrated associations with the risk of developing atrial fibrillation. Moreover, ten gut flora and fifty-two serum metabolites were linked to the risk of developing supraventricular tachycardia, while eight gut flora and twenty-five serum metabolites were associated with the risk of developing tachycardia. Additionally, six gut flora and twenty-one serum metabolites exhibited associations with the risk of developing bradycardia.

CONCLUSION

This study revealed the potential causal relationship that may exist between gut flora, serum metabolites and different cardiac arrhythmias and highlights the need for further exploration. This study provides new perspectives to enhance diagnostic and therapeutic strategies in the field of cardiac arrhythmias.

Deciphering the Causality between Gut Microbiota Dysbiosis and Poisoning by Narcotics and Psychodysleptics: A Mendelian Randomization Analysis

BACKGROUND

This study investigates the connection between gut microbiota and poisoning caused by narcotics and psychodysleptics, using Mendelian randomization (MR) to explore possible causal relationships.

METHODS

The study employed the MR analysis, leveraging genetic variants as instrumental variables to facilitate robust causal inference. Data for gut microbiota was extracted from the MiBioGen study, integrating genome-wide genotyping data with 16S fecal microbiota profiles. Outcome metrics were based on the Finngen study. Genetic instruments were meticulously extracted based on stringent criteria, and harmonized with SNP outcomes associated with "Poisoning by narcotics and psychodysleptics (hallucinogens)". The inverse-variance weighted (IVW) method was utilized for MR analysis, supplemented by sensitivity analyses including MR-Egger Regression, Weighted Median Approach, and Leave-One-Out Cross-Validation.

RESULTS

Among various microbial groups, nine showed significant statistical links. Specifically, Class Negativicutes (OR 5.68, 95% CI 2.13-15.16, p = 0.0005) and Order Selenomonadales (OR 5.68, 95% CI 2.13-15.16, p = 0.0005) were notably associated. These findings were consistent across different sensitivity analyses.

CONCLUSION

The relationship between gut microbiota and the adverse effects of narcotics and psychodysleptics is an emerging area of research. Our MR study identifies certain microbes that might influence the body's response to these substances. These insights could help in predicting and treating the effects of narcotics and psychodysleptics in the future.

Exploring causal correlations between systemic inflammatory cytokines and epilepsy: A bidirectional Mendelian randomization study

BACKGROUND

Inflammation plays a role in the development and advancement of epilepsy, but the relationship between inflammatory cytokines and epilepsy is still not well understood. Herein, we use two-sample Mendelian randomization (MR) to examine the causal association between systemic inflammatory cytokines and epilepsy.

METHODS

We conducted a bidirectional two-sample MR analysis based on genome-wide association study data of 41 serum cytokines from 8293 Finnish individuals with various epilepsy subtypes from the International League against Epilepsy Consortium.

RESULTS

Our study showed that three inflammatory cytokines were associated with epilepsy, five were associated with generalized epilepsy, four were associated with focal epilepsy, one was associated with focal epilepsy-documented lesion negative, three were associated with juvenile absence epilepsy, one was associated with childhood absence epilepsy, two were associated with focal epilepsy-documented lesion other than hippocampal sclerosis, and two were associated with juvenile myoclonic epilepsy. Furthermore, the expression of systemic inflammatory cytokines was unaffected by genetically predicted epilepsy.

CONCLUSION

This study suggested that several inflammatory cytokines are probably the factors correlated with epilepsy. Additional research is required to ascertain if these biomarkers have therapeutic potential to prevent or manage epilepsy.

Evidence for genetic causal relationships between gut microbiome, metabolites, and myasthenia gravis: a bidirectional Mendelian randomization study

Background

Myasthenia gravis (MG) is an autoimmune disease observed to have connections with gut microbiome. We aimed to systematically assess the causal relationships between gut microbiome, gut microbiome-derived metabolites, and MG using Mendelian randomization (MR) approach.

Methods

Summary-level genetic datasets from large-scale genome-wide association studies regarding 196 gut microbial taxa from the MiBioGen consortium (n=18,340), 72 derived metabolites from the TwinsUK and KORA studies (n=7,824), and antiacetylcholine receptor (AChR) antibody-positive MG (case=1,873, control=36,370) were employed for MR causal estimates. The inverse-variance weighted (IVW) method was utilized as the main analysis with MR-Egger, maximum likelihood, simple mode, and weighted median as complements. The tests of Cochran's Q, MR-Egger intercept, Steiger, MR-PRESSO and leave-one-out were implemented for sensitivity analyses.

Results

The forward MR estimates of IVW revealed significant causal associations of the abundance of phylum Actinobacteria, class Gammaproteobacteria, family Defluviitaleac, family Family XIII, and family Peptococcaceae with a reduced risk of MG. Conversely, the abundance of phylum Lentisphaerae, order Mollicutes RF9, order Victivallales, and genus Faecalibacterium was causally associated with an increased risk of MG. The reversed MR analysis proved negative causal correlations between the MG and the abundance of family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum. Regarding the derived metabolites, the IVW estimates revealed that elevated levels of beta-hydroxyisovalerate and methionine were causally associated with a decreased risk of MG, while increased levels of choline and kynurenine were linked to an increased risk of MG. Furthermore, genetically predicted MG was associated with a decreased level of cholesterol. The results obtained from complementary MR methods were similar. These findings remained robust in all sensitivity analyses.

Conclusion

Our MR findings support the causal effects of specific gut microbiome taxa and derived metabolites on AChR antibody-positive MG, and vice versa, yielding novel insights into prevention and therapy targets of MG. Future studies may be warranted for validation and pursuing the precise mechanisms.

Investigating the causal impact of gut microbiota on glioblastoma: a bidirectional Mendelian randomization study

BACKGROUND

Currently, the influence of microbiota on the occurrence, progression, and treatment of cancer is a topic of considerable research interest. Therefore, based on the theory of the gut-brain axis proved by previous studies, our objective was to uncover the causal relationship between glioblastoma and the gut microbiome using Mendelian randomization analysis.

METHODS

We conducted a bidirectional Mendelian randomization study using summary statistics of gut microbiota derived from the MiBioGen consortium, the largest database of gut microbiota. Summary statistics for glioblastoma were obtained from IEU OpenGWAS project, which included 91 cases and 218,701 controls. We assessed the presence of heterogeneity and horizontal pleiotropy in the analyzed data. We primarily employed the inverse variance weighting method to investigate the causal relationship between gut microbiota and glioblastoma after excluding cases of horizontal pleiotropy. Four other analysis methods were employed as supplementary. Excluding abnormal results based on leave-one-out sensitivity analysis. Finally, reverse Mendelian randomization analysis was performed.

RESULTS

Four genus-level taxa and one family-level taxa exhibited causal associations with glioblastoma. And these results of reverse Mendelian randomization analysis shown glioblastoma exhibited causal associations with three genus-level taxa and one family-level taxa. However, the Prevotella7(Forward, P=0.006, OR=0.34, 95%CI:0.158-0.732; Reverse, P=0.004, OR=0.972, 95%CI:0.953-0.991) shown the causal associations with glioblastoma in the bidirectional Mendelian randomization.

CONCLUSIONS

In this bidirectional Mendelian randomization study, we identified five gut microbiota species with causal associations to glioblastoma. However, additional randomized controlled trials are required to clarify the impact of gut microbiota on glioblastoma and to reveal its precise mechanisms.

Association between gut microbiota and NAFLD/NASH: a bidirectional two-sample Mendelian randomization study

Background

Recent studies have suggested a relationship between gut microbiota and non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). However, the nature and direction of this potential causal relationship are still unclear. This study used two-sample Mendelian randomization (MR) to clarify the potential causal links.

Methods

Summary-level Genome-Wide Association Studies (GWAS) statistical data for gut microbiota and NAFLD/NASH were obtained from MiBioGen and FinnGen respectively. The MR analyses were performed mainly using the inverse-variance weighted (IVW) method, with sensitivity analyses conducted to verify the robustness. Additionally, reverse MR analyses were performed to examine any potential reverse causal associations.

Results

Our analysis, primarily based on the IVW method, strongly supports the existence of causal relationships between four microbial taxa and NAFLD, and four taxa with NASH. Specifically, associations were observed between Enterobacteriales (P =0.04), Enterobacteriaceae (P =0.04), Lachnospiraceae UCG-004 (P =0.02), and Prevotella9 (P =0.04) and increased risk of NAFLD. Dorea (P =0.03) and Veillonella (P =0.04) could increase the risks of NASH while Oscillospira (P =0.04) and Ruminococcaceae UCG-013 (P=0.005) could decrease them. We also identified that NAFLD was found to potentially cause an increased abundance in Holdemania (P =0.007) and Ruminococcus2 (P =0.002). However, we found no evidence of reverse causation in the microbial taxa associations with NASH.

Conclusion

This study identified several specific gut microbiota that are causally related to NAFLD and NASH. Observations herein may provide promising theoretical groundwork for potential prevention and treatment strategies for NAFLD and its progression to NASH in future.

The relationship between gut microbiota and insomnia: a bi-directional two-sample Mendelian randomization research

Introduction

Insomnia is the second most common mental health issue, also is a social and financial burden. Insomnia affects the balance between sleep, the immune system, and the central nervous system, which may raise the risk of different systemic disorders. The gut microbiota, referred to as the "second genome," has the ability to control host homeostasis. It has been discovered that disruption of the gut-brain axis is linked to insomnia.

Methods

In this study, we conducted MR analysis between large-scale GWAS data of GMs and insomnia to uncover potential associations.

Results

Ten GM taxa were detected to have causal associations with insomnia. Among them, class Negativicutes, genus Clostridiuminnocuumgroup, genus Dorea, genus Lachnoclostridium, genus Prevotella7, and order Selenomonadalesare were linked to a higher risk of insomnia. In reverse MR analysis, we discovered a causal link between insomnia and six other GM taxa.

Conclusion

It suggested that the relationship between insomnia and intestinal flora was convoluted. Our findings may offer beneficial biomarkers for disease development and prospective candidate treatment targets for insomnia.

Causal link between gut microbiota and four types of pancreatitis: a genetic association and bidirectional Mendelian randomization study

BACKGROUND

A number of recent observational studies have indicated a correlation between the constitution of gut microbiota and the incidence of pancreatitis. Notwithstanding, observational studies are unreliable for inferring causality because of their susceptibility to confounding, bias, and reverse causality, the causal relationship between specific gut microbiota and pancreatitis is still unclear. Therefore, our study aimed to investigate the causal relationship between gut microbiota and four types of pancreatitis.

METHODS

An investigative undertaking encompassing a genome-wide association study (GWAS) comprising 18,340 participants was undertaken with the aim of discerning genetic instrumental variables that exhibit associations with gut microbiota, The aggregated statistical data pertaining to acute pancreatitis (AP), alcohol-induced AP (AAP), chronic pancreatitis (CP), and alcohol-induced CP (ACP) were acquired from the FinnGen Consortium. The two-sample bidirectional Mendelian randomization (MR) approach was utilized. Utilizing the Inverse-Variance Weighted (IVW) technique as the cornerstone of our primary analysis. The Bonferroni analysis was used to correct for multiple testing, In addition, a number of sensitivity analysis methodologies, comprising the MR-Egger intercept test, the Cochran's Q test, MR polymorphism residual and outlier (MR-PRESSO) test, and the leave-one-out test, were performed to evaluate the robustness of our findings.

RESULTS

A total of 28 intestinal microflora were ascertained to exhibit significant associations with diverse outcomes of pancreatitis. Among them, Class Melainabacteria (OR = 1.801, 95% CI: 1.288-2.519, p = 0.008) has a strong causality with ACP after the Bonferroni-corrected test, in order to assess potential reverse causation effects, we used four types of pancreatitis as the exposure variable and scrutinized its impact on gut microbiota as the outcome variable, this analysis revealed associations between pancreatitis and 30 distinct types of gut microflora. The implementation of Cochran's Q test revealed a lack of substantial heterogeneity among the various single nucleotide polymorphisms (SNP).

CONCLUSION

Our first systematic Mendelian randomization analysis provides evidence that multiple gut microbiota taxa may be causally associated with four types of pancreatitis disease. This discovery may contribute significant biomarkers conducive to the preliminary, non-invasive identification of Pancreatitis. Additionally, it could present viable targets for potential therapeutic interventions in the disease's treatment.

Integrated Macrogenomics and Metabolomics Explore Alterations and Correlation between Gut Microbiota and Serum Metabolites in Adult Epileptic Patients: A Pilot Study

Epilepsy (EP) is a complex brain disorder showing a lot of unknows reasons. Recent studies showed that gut microbiota can influence epilepsy via the brain-gut axis. Nevertheless, the mechanism by which gut microbiota affects adult epilepsy still remains unclear. In this study, fecal and serum samples were obtained from patients with epilepsy and normal controls. Using an integrated analysis, sequencing was performed by macrogenomics and high-throughput targeted metabolomics with various bioinformatics approaches. The macrogenomic sequencing revealed significant changes in microbial structure in patients suffering from epilepsy. For example, at the phylum level, the relative abundance of Actinobacteria, Bacteroidetes and Proteobacteria showed an increase in the patients with epilepsy, whereas that of Firmicutes decreased. In addition, the patients with epilepsy had significantly differential metabolite profiles compared to normal controls, and five clusters with 21 metabolites, mainly containing the upregulation of some fatty acids and downregulation of some amino acids. Tryptophan (AUC = 91.81, p < 0.0001), kynurenine (AUC = 79.09, p < 0.01) and 7Z,10Z,13Z,16Z-Docosatetraenoic acid (AUC = 80.95, p < 0.01) may be used as potential diagnostic markers for epilepsy. Differential serum metabolites have effects on tryptophan metabolism, iron death and other pathways. Furthermore, a multiomic joint analysis observed a statistically significant correlation between the differential flora and the differential serum metabolites. In our findings, a macrogenomic analysis revealed the presence of dysregulated intestinal flora species and function in adult epileptic patients. Deeper metabolomic analyses revealed differences in serum metabolites between patients with epilepsy and healthy populations. Meanwhile, the multiomic combination showed connection between the gut microbes and circulating metabolites in the EP patients, which may be potential therapeutic targets.

Association between gut microbiota and benign prostatic hyperplasia: a two-sample mendelian randomization study

Background

Recent researches have shown a correlation between the gut microbiota (GM) and various diseases. However, it remains uncertain whether the relationship between GM and benign prostatic hyperplasia (BPH) is causal.

Methods

We carried out a two-sample Mendelian randomization (MR) analysis, utilizing data from the most extensive GM-focused genome-wide association study by the MiBioGen consortium, with a sample size of 13,266. Data for BPH, encompassing 26,358 cases and 110,070 controls, were obtained from the R8 release of the FinnGen consortium. We employed multiple techniques, such as inverse variance weighted (IVW), constrained maximum likelihood and model averaging methods, maximum likelihood, MR-Pleiotropy RESidual Sum and Outlier (MRPRESSO),MR-Egger, and weighted median methods, to investigate the causal relationship between GM and BPH. To evaluate the heterogeneity among the instrumental variables, Cochran's Q statistics were employed. Additionally, the presence of horizontal pleiotropy was assessed through the application of both MR-Egger and MR-PRESSO tests. The direction of causality was scrutinized for robustness using the MR-Steiger directionality test. A reverse MR analysis examined the GM previously linked to BPH through a causal relationship in the forward MR assessment.

Results

According to the analysis conducted using IVW,Eisenbergiella (odds ratio [OR]=0.92, 95% confidence interval [CI]: 0.85-0.99,P=0.022) and Ruminococcaceae (UCG009) (OR=0.88, 95% CI: 0.79-0.99, P=0.027) were found to reduce the risk of BPH, while Escherichia shigella (OR=1.19, 95% CI: 1.05-1.36, P=0.0082) appeared to increase it. The subsequent reverse MR analysis revealed that the three GM were not significantly influenced by BPH, and there was no noticeable heterogeneity or horizontal pleiotropy among the instrumental variables.Conclusion: These results indicated a causal relationship between Eisenbergiella, Ruminococcaceae (UCG009), and Escherichia shigella and BPH. Further randomized controlled trials are needed to explore more comprehensively the roles and operational mechanisms of these GM in relation to BPH.

A causal effects of gut microbiota in the development of migraine

BACKGROUND

The causal association between the gut microbiome and the development of migraine and its subtypes remains unclear.

METHODS

The single nucleotide polymorphisms concerning gut microbiome were retrieved from the gene-wide association study (GWAS) of the MiBioGen consortium. The summary statistics datasets of migraine, migraine with aura (MA), and migraine without aura (MO) were obtained from the GWAS meta-analysis of the International Headache Genetics Consortium (IHGC) and FinnGen consortium. Inverse variance weighting (IVW) was used as the primary method, complemented by sensitivity analyses for pleiotropy and increasing robustness.

RESULTS

In IHGC datasets, ten, five, and nine bacterial taxa were found to have a causal association with migraine, MA, and MO, respectively, (IVW, all P < 0.05). Genus.Coprococcus3 and genus.Anaerotruncus were validated in FinnGen datasets. Nine, twelve, and seven bacterial entities were identified for migraine, MA, and MO, respectively. The causal association still exists in family.Bifidobacteriaceae and order.Bifidobacteriales for migraine and MO after FDR correction. The heterogeneity and pleiotropy analyses confirmed the robustness of IVW results.

CONCLUSION

Our study demonstrates that gut microbiomes may exert causal effects on migraine, MA, and MO. We provide novel evidence for the dysfunction of the gut-brain axis on migraine. Future study is required to verify the relationship between gut microbiome and the risk of migraine and its subtypes and illustrate the underlying mechanism between them.