A causal effects of gut microbiota in the development of migraine

Exploring the anti-migraine effects of Tianshu capsule: chemical profile, metabolic behavior, and therapeutic mechanisms

BACKGROUND

Migraine is widely recognized as the third most prevalent medical condition globally. Tianshu capsule (TSC), derived from "Da Chuan Xiong Fang" of the Jin dynasty, is integral in the clinical treatment of migraine. However, the chemical properties and therapeutic mechanisms of TSC different portions remain unclear.

PURPOSE

This study was designed to investigate the effects of TSC different portions (including small molecular TSCP-SM and polysaccharides TSC-P) on migraine and explore the underlying mechanisms.

STUDY DESIGN AND METHODS

First of all, migraine rats were established by nitroglycerin injection and treated with TSC, TSC-P, and TSC-SM. ELISA, qPCR, and immunofluorescence were used to evaluate the pharmacological effects on migraine rats. Secondly, UPLC-Q/TOF-MS and GC--MS were employed to detect the components of TSC-SM. PMP-HPLC, NMR, FT-IR, UV-Vis, AFM, and SEM were used for the chemical profiling of polysaccharides. Thirdly, the metabolic behavior profile of TSC-P was characterized by oral administrated fluorescence-labeled TSC-P and detected by NIRF imaging. Finally, the anti-migraine mechanisms were explored by determining the composition of gut microbiota, analyzing colonic short-chain fatty acids (SCFAs), and examining serum tryptophan-related metabolites.

RESULTS

Both small molecules (45 volatiles and 114 small molecules) and polysaccharides (including Glc, Ara, Gal, and Gal A) have exhibited effectiveness in alleviating migraine, and this efficacy is associated with reduced CGRP and iNOS levels, along with increased β-EP expressions. Further mechanistic exploration revealed that small-molecules exhibited effectiveness in migraine treatment by exerting antioxidative actions, while polysaccharides demonstrated superior therapeutic effects in regulating 5-HT levels. By monitoring the metabolic behavior of polysaccharides with fluorescent labeling, it was observed that TSC-P exhibited poor absorption. Instead, TSC-P demonstrated its therapeutic effects by modulating the aberrations in gut microbiota (including Alloprevotella, Muribaculaceae_ge, and Ruminococcaceae_UCG-005), cecum short-chain fatty acids (such as isobutyric, isovaleric, and valeric acids), and serum tryptophan-related metabolites (including indole-3-acetamide, tryptophol, and indole-3-propionic acid).

CONCLUSION

This research provides innovative insights into chemical composition, metabolic behavior, and proposed anti-migraine mechanisms of TSC from a polarity-based perspective, and pioneering an exploration focused on the polysaccharide components within TSC for the first time.

Differences in circulating alpha-calcitonin gene-related peptide levels in inflammatory bowel disease and its relation to migraine comorbidity: A cross-sectional study

OBJECTIVE

To analyze the specificity of calcitonin gene-related peptide (CGRP) levels, we measured alpha-CGRP circulating levels in a large series of patients with a recent diagnosis of inflammatory bowel disease (IBD) who were interviewed regarding comorbid headache.

BACKGROUND

Several studies have found an association between migraine and IBD.

METHODS

In this cross-sectional study performed in an IBD clinic, morning serum alpha-CGRP levels were measured by enzyme-linked immunosorbent assay in 96 patients who were recently diagnosed with IBD and compared to those from 50 similar patients with chronic migraine (CM) and 50 healthy controls (HC).

RESULTS

Alpha-CGRP levels were higher in patients with IBD (median [interquartile range] 56.9 [35.6-73.9] pg/mL) and patients with CM (53.0 [36.7-73.9] pg/mL) compared to HC (37.2 [30.0-51.8] pg/mL; p = 0.003; p = 0.019, respectively). Regarding IBD diagnostic subtypes, alpha-CGRP levels for ulcerative colitis (67.2 ± 49.3 pg/mL; 57.0 [35.6-73.4] pg/mL) and Crohn's disease (54.9 ± 27.5 pg/mL; 57.7 [29.1-76.1] pg/mL) were significantly higher than those of HC (p = 0.013, p = 0.040, respectively). Alpha-CGRP levels were further different in patients with IBD with migraine (70.9 [51.8-88.7] pg/mL) compared to HC (p < 0.001), patients with IBD without headache (57.5 [33.3-73.8] pg/mL; p = 0.049), and patients with IBD with tension-type headache but without migraine (41.7 [28.5-66.9] pg/mL; p = 0.004), though alpha-CGRP levels in patients with IBD without migraine (53.7 [32.9-73.5] pg/mL) remained different over HC (p = 0.028).

CONCLUSION

Together with CM, circulating alpha-CGRP levels are different in patients with IBD, perhaps reflecting a chronic inflammatory state. IBD is an example of how alpha-CGRP levels are not a totally specific migraine biomarker. However, alpha-CGRP levels were further increased in patients with IBD who have a history of migraine, which reinforces its role as a biomarker in migraine patients, always bearing in mind their comorbidities.

A Narrative Review of Intestinal Microbiota's Impact on Migraine with Psychopathologies

Migraine is a common and debilitating neurological disorder characterized by the recurrent attack of pulsating headaches typically localized on one side of the head associated with other disabling symptoms, such as nausea, increased sensitivity to light, sound and smell and mood changes. Various clinical factors, including the excessive use of migraine medication, inadequate acute treatment and stressful events, can contribute to the worsening of the condition, which may evolve to chronic migraine, that is, a headache present on >15 days/month for at least 3 months. Chronic migraine is frequently associated with various comorbidities, including anxiety and mood disorders, particularly depression, which complicate the prognosis, response to treatment and overall clinical outcomes. Emerging research indicates a connection between alterations in the composition of the gut microbiota and mental health conditions, particularly anxiety and depression, which are considered disorders of the gut-brain axis. This underscores the potential of modulating the gut microbiota as a new avenue for managing these conditions. In this context, it is interesting to investigate whether migraine, particularly in its chronic form, exhibits a dysbiosis profile similar to that observed in individuals with anxiety and depression. This could pave the way for interventions aimed at modulating the gut microbiota for treating difficult-to-manage migraines.

Good girl goes bad: Understanding how gut commensals cause disease

This review examines the complex connection between commensal microbiota and the development of opportunistic infections. Several underlying conditions, such as metabolic diseases and weakened immune systems, increase the vulnerability of patients to opportunistic infections. The increasing antibiotic resistance adds significant complexity to the management of infectious diseases. Although commensals have long been considered beneficial, recent research contradicts this notion by uncovering chronic illnesses linked to atypical pathogens or commensal bacteria. This review examines conditions in which commensal bacteria, which are usually beneficial, contribute to developing diseases. Commensals' support for opportunistic infections can be categorized based on factors such as colonization fitness, pathoadaptive mutation, and evasion of host immune response. Individuals with weakened immune systems are especially susceptible, highlighting the importance of mucosal host-microbiota interaction in promoting infection when conditions are inappropriate. Dysregulation of gut microbial homeostasis, immunological modulation, and microbial interactions are caused by several factors that contribute to the development of chronic illnesses. Knowledge about these mechanisms is essential for developing preventive measures, particularly for susceptible populations, and emphasizes the importance of maintaining a balanced gut microbiota in reducing the impact of opportunistic infections.

Benefit of Dietary Supplementation of Nutraceuticals as an Integrative Approach for Management of Migraine: Evidence From Preclinical and Clinical Studies

PURPOSE OF REVIEW

To provide information from preclinical and clinical studies on the biological activity and health benefits of dietary inclusion of nutraceuticals as a safe, effective, non-pharmacological approach for the treatment of migraine.

RECENT FINDINGS

There is emerging evidence of the therapeutic benefit of nutraceuticals to inhibit oxidative stress, suppress inflammation, and prevent changes in the normal gut microbiome, which are implicated in migraine pathology. Nutraceuticals can be enriched in polyphenols, which act as molecular scavengers to reduce the harmful effects of reactive oxygen species and phytosterols that suppress inflammation. Nutraceuticals also function to inhibit dysbiosis and to maintain the commensal intestinal bacteria that produce anti-inflammatory molecules including short-chain fatty acids that can act systemically to maintain a healthy nervous system. Dietary inclusion of nutraceuticals that exhibit antioxidant, anti-inflammatory, and anti-nociceptive properties and maintain the gut microbiota provides a complementary and integrative therapeutic strategy for migraine.

Genetics of migraine: complexity, implications, and potential clinical applications

Migraine is a common neurological disorder with large burden in terms of disability for individuals and costs for society. Accurate diagnosis and effective treatments remain priorities. Understanding the genetic factors that contribute to migraine risk and symptom manifestation could improve individual management. Migraine has a strong genetic basis that includes both monogenic and polygenic forms. Some distinct, rare, familial migraine subtypes are caused by pathogenic variants in genes involved in ion transport and neurotransmitter release, suggesting an underlying vulnerability of the excitatory-inhibitory balance in the brain, which might be exacerbated by disruption of homoeostasis and lead to migraine. For more prevalent migraine subtypes, genetic studies have identified many susceptibility loci, implicating genes involved in both neuronal and vascular pathways. Genetic factors can also reveal the nature of relationships between migraine and its associated biomarkers and comorbidities and could potentially be used to identify new therapeutic targets and predict treatment response.

The Gut Microbiota and Chronic Pain

PURPOSE OF REVIEW

To examine the effects and interactions between gut microbia and chronic pain.

RECENT FINDINGS

The gut microbiome has been an area of interest in both the scientific and general audience due to a growing body of evidence suggesting its influence in a variety of health and disease states. Communication between the central nervous system (CNS) and gut microbiome is said to be bidirectional, in what is referred to as the gut-brain axis. Chronic pain is a prevalent costly personal and public health burden and so, there is a vested interest in devising safe and efficacious treatments. Numerous studies, many of which are animal studies, have been conducted to examine the gut microbiome's role in the pathophysiology of chronic pain states, such as neuropathy, inflammation, visceral pain, etc. As the understanding of this relationship grows, so does the potential for therapeutic targeting of the gut microbiome in chronic pain.

Identification of bidirectional causal links between gut microbiota and narcolepsy type 1 using Mendelian randomization

STUDY OBJECTIVES

Narcolepsy type 1 (NT1), characterized by cataplexy and orexin deficiency, is a rare and frequently debilitating neurological disorder. It has been noted to have connections with the gut microbiota, yet the exact causal relationships remain unclear.

METHODS

We conducted a comprehensive bidirectional Mendelian randomization (MR) study to rigorously investigate the causal links between the gut microbiota and NT1, utilizing genetic datasets from the MiBioGen consortium and FinnGen consortium, respectively. The inverse-variance weighted (IVW) method was employed to obtain the primary MR estimates, supplemented by several alternative methods as well as sensitivity analyses including Cochran's Q, MR-Egger, MR pleiotropy residual sum and outlier, leave-one-out, and genetic colocalization.

RESULTS

Our findings indicated that an increased relative abundance of five genera including Blautia (p = 4.47E-5), Collinsella (p = 0.036), Gordonibacter (p = 0.047), Hungatella (p = 0.015), and Lachnospiraceae UCG010 (p = 0.027) may be associated with a decreased risk of NT1. Conversely, an increased relative abundance of class Betaproteobacteria (p = 0.032), genus Alloprevotella (p = 0.009), and genus Ruminiclostridium6 (p = 0.029) may potentially heighten the risk of NT1. The onset of NT1 may lead to a decrease in the relative abundance of genus Eubacterium eligens group (p = 0.022), while a increase in the family Family XI (p = 0.009), genus Hungatella (p = 0.005), genus Prevotella (p = 0.013), and unknown genus id.2001 (p = 0.019). These findings remained robust under all sensitivity analyses.

CONCLUSIONS

Our results offer robust evidence for the bidirectional causal links between particular gut microbial taxa and NT1, underscoring the significance of the microbiota-gut-brain axis in the pathological process of NT1.

Increased prevalence of migraine in women with inflammatory bowel disease: A cross-sectional study

BACKGROUND

Some studies have suggested an association between migraine and inflammatory bowel disease. We determined migraine prevalence in a cohort of patients with inflammatory bowel disease.

METHODS

Patients with inflammatory bowel disease aged 18-65 years were interviewed using an ad hoc headache questionnaire. Those who admitted a history of headache in the last year answered the three questions of the ID-Migraine questionnaire. Those who answered "yes" to the three of them were classified as "definite" and those who answered "yes" to two were classified as "probable" migraine.

RESULTS

We interviewed 283 patients with inflammatory bowel disease. Of these, 176 (62.2%) had headache. Fifty-nine (20.8%; 95% CI 16.3-26.0%) met migraine criteria either definite (n = 33; 11.7%; 95% CI 8.2-16.0%) or probable (n = 26; 9.2%; 95% CI 6.1-13.2). When divided by gender, 12 men (9.6%; 95% CI 5.1-16.2%) and 47 women (29.8%; 95% CI 22.8-37.5%) met migraine criteria. The prevalence of migraine was increased in inflammatory bowel disease patients from the current cohort (20.8%) versus that reported for our general population for the same age group (12.6%; p < 0.0001). These differences remained significant in female inflammatory bowel disease patients (29.8% versus 17.2% in our general population; p < 0.0001), but not in males (9.6% in inflammatory bowel disease vs 8.0%; p = 0.30). Seventeen patients with inflammatory bowel disease (6.0%; 95% CI 3.54-9.44%) fulfilled chronic migraine criteria. There were no differences in migraine prevalence by inflammatory bowel disease subtypes.

CONCLUSION

Migraine prevalence, including chronic migraine, seems to be increased in patients with inflammatory bowel disease. The fact that this association was stronger for women suggests an influence of sex-related factors.

Causal effect of air pollution on the risk of cardiovascular and metabolic diseases and potential mediation by gut microbiota

BACKGROUND

Epidemiological studies have explored the relationship between air pollution and cardiovascular and metabolic diseases (CVMDs). Accumulating evidence has indicated that gut microbiota deeply affects the risk of CVMDs. However, the findings are controversial and the causality remains uncertain. To evaluate whether there is the causal association of four air pollutants with 19 CVMDs and the potential effect of gut microbiota on these relationships.

METHODS

Genetic instruments for particulate matter (PM) with aerodynamic diameter < 2.5 μm (PM2.5), <10 μm (PM10), PM2.5 absorbance, nitrogen oxides (NOx) and 211 gut microbiomes were screened. Univariable Mendelian randomization (UVMR) was used to estimate the causal effect of air pollutants on CVMDs in multiple MR methods. Additionally, to account for the phenotypic correlation among pollutant, the adjusted model was constructed using multivariable Mendelian randomization (MVMR) analysis to strength the reliability of the predicted associations. Finally, gut microbiome was assessed for the mediated effect on the associations of identified pollutants with CVMDs.

RESULTS

Causal relationships between NOx and angina, heart failure and hypercholesterolemia were observed in UVMR. After adjustment for air pollutants in MVMR models, the genetic correlations between PM2.5 and hypertension, type 2 diabetes mellitus (T2DM) and obesity remained significant and robust. In addition, genus-ruminococcaceae-UCG003 mediated 7.8 % of PM2.5-effect on T2DM.

CONCLUSIONS

This study firstly provided the genetic evidence linking air pollution to CVMDs and gut microbiota may mediate the association of PM2.5 with T2DM. Our findings highlight the significance of air quality in CVMDs risks and suggest the potential of modulating intestinal microbiota as novel therapeutic targets between air pollution and CVMDs.

Causal relationship between gut microbiota and myasthenia gravis: a two-sample Mendelian randomization study

Background

Previous observational studies have provided cumulative data linking gut microbiota to myasthenia gravis (MG). However, the causal link between the two remains unexplored. Hence, the current study was performed to explore the causal link between them.

Methods

Mendelian randomization (MR) analysis was conducted using the summary statistics of 211 gut microbiota taxa and the largest genome-wide association studies (GWAS) for MG currently available. The inverse variance-weighted (IVW), MR-Egger, weighted median, and weighted mode methods were employed to ascertain the causal influence. Sensitivity studies utilizing several methodologies were then used to assess the robustness of the findings. Lastly, to evaluate reverse causality, a reverse MR analysis was performed.

Results

Seven suggestive causal associations between the gastrointestinal microbiota and MG were identified based on the outcomes of the MR analysis. Specifically, phylum Actinobacteria (OR: 0.602, 95% CI: 0.405-0.896, p = 0.012), class Gammaproteobacteria (OR: 0.587, 95% CI: 0.357-0.968, p = 0.037), and families Defluviitaleaceae (OR: 0.695, 95% CI: 0.485-0.996, p = 0.047), Family XIII (OR: 0.614, 95% CI: 0.412-0.916, p = 0.017), and Peptococcaceae (OR: 0.698, 95% CI: 0.505-0.964, p = 0.029) had suggestive protective effects on MG, while order Mollicutes RF9 (OR: 1.424, 95% CI: 1.015-1.998, p = 0.041) and genus Faecalibacterium (OR: 1.763, 95% CI: 1.220-2.547, p = 0.003) were suggestive risk factors for MG. The outcomes indicate that neither heterogeneity nor horizontal pleiotropy had any discernible impact. Nevertheless, this reverse analysis did not reveal any apparent effect of MG on the gut microbiota composition.

Conclusion

The MR investigation has substantiated the suggestive causal connection between gut microbiota and MG, which may provide helpful insights for innovative therapeutic and preventative approaches for MG. Further randomized controlled trials are needed to elucidate the gut microbiota's precise role and therapeutic potential in the pathogenesis of MG.

Causal association between gut microbiota and fibromyalgia: a Mendelian randomization study

Background

Fibromyalgia (FM) is a syndrome characterized by chronic and widespread musculoskeletal pain. A number of studies have implied a potential association between gut microbiota and FM. However, the casual association between gut microbiota and FM remains unknown.

Method

Mendelian randomization (MR) study was conducted using the summary statistics of genetic variants from the genome-wide association study (GWAS). Inverse variance weighted (IVW), combined with MR-Egger and weighted median were used to investigate the causal association between 119 gut microbiota genera and FM. Sensitivity analyses were performed on the MR results, including heterogeneity test, leave-one-out test and pleiotropy test.

Results

A total of 1,295 single nucleotide polymorphism (SNPs) were selected as instrumental variables (IVs), with no significant heterogeneity and pleiotropy according to the sensitivity analyses. Five gut microbiota genera were found to have significant casual association with FM. Coprococcus2 (OR = 2.317, p-value = 0.005, 95% CI: 1.289-4.167), Eggerthella (OR = 1.897, p-value = 0.001, 95% CI: 1.313-2.741) and Lactobacillus (OR = 1.576, p-value =0.020, 95% CI: 1.073-2.315) can increase the risk of FM. FamillyXIIIUCG001 (OR = 0.528, p-value = 0.038, 95% CI: 0.289-0.964) and Olsenella (OR = 0.747, p-value = 0.050, 95% CI: 0.557-1.000) can decrease the risk of FM.

Conclusion

This MR study found that gut microbiota is casually associated with FM. New insights into the mechanisms of FM mediated by gut microbiota are provided.

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.