Fecal metagenomic profiles in subgroups of patients with myalgic encephalomyelitis/chronic fatigue syndrome

Persistent SOMAtic symptoms ACROSS diseases - from risk factors to modification: scientific framework and overarching protocol of the interdisciplinary SOMACROSS research unit (RU 5211)

INTRODUCTION

Persistent somatic symptoms (PSS) are highly prevalent in all areas of medicine; they are disabling for patients and costly for society. The subjective symptom burden often correlates poorly with the underlying disease severity, and patients' needs for effective treatment are far from being met. Initial evidence indicates that, in addition to disease-specific pathophysiological processes, psychological factors such as expectations, somatosensory amplification and prior illness experiences contribute to symptom persistence in functional as well as in somatic diseases. However, prospective studies investigating the transition from acute to chronic somatic symptoms, integrating pathophysiological, psychological and social factors, are scarce. A better understanding of the multifactorial mechanisms of symptom persistence is crucial for developing targeted mechanism-based interventions for effective prevention and treatment of PSS. Thus, the overall aim of the interdisciplinary SOMACROSS research unit is to identify generic and disease-specific risk factors and aetiological mechanisms of symptom persistence across a range of diseases.

METHODS AND ANALYSIS

Seven projects will investigate risk factors and mechanisms of symptom persistence in a total of 3916 patients across 10 medical conditions. All study designs are prospective and share common assessment points, core instruments and outcome variables to allow comparison and validation of results across projects and conditions. Research will focus on the identification of generic and disease-specific mechanisms associated with unfavourable symptom course. The development of a multivariate prediction model will facilitate the understanding of the course of PSS across diseases.

ETHICS AND DISSEMINATION

All individual SOMACROSS studies were approved by the ethics committees of the Medical Chambers Hamburg and Münster, Germany. Findings will be disseminated through peer-reviewed publications, scientific conferences and the involvement of relevant stakeholders, patients and the lay public. This interdisciplinary research unit will fundamentally contribute to earlier recognition of patients at risk, and to the development of prevention and tailored treatment concepts for PSS.

Evidence for Peroxisomal Dysfunction and Dysregulation of the CDP-Choline Pathway in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Background

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic and debilitating disease that is characterized by unexplained physical fatigue unrelieved by rest. Symptoms also include cognitive and sensory dysfunction, sleeping disturbances, orthostatic intolerance, and gastrointestinal problems. A syndrome clinically similar to ME/CFS has been reported following well-documented infections with the coronaviruses SARS-CoV and MERS-CoV. At least 10% of COVID-19 survivors develop post acute sequelae of SARS-CoV-2 infection (PASC). Although many individuals with PASC have evidence of structural organ damage, a subset have symptoms consistent with ME/CFS including fatigue, post exertional malaise, cognitive dysfunction, gastrointestinal disturbances, and postural orthostatic intolerance. These common features in ME/CFS and PASC suggest that insights into the pathogenesis of either may enrich our understanding of both syndromes, and could expedite the development of strategies for identifying those at risk and interventions that prevent or mitigate disease.

Methods

Using regression, Bayesian and enrichment analyses, we conducted targeted and untargeted metabolomic analysis of 888 metabolic analytes in plasma samples of 106 ME/CFS cases and 91 frequency-matched healthy controls.

Results

In ME/CFS cases, regression, Bayesian and enrichment analyses revealed evidence of peroxisomal dysfunction with decreased levels of plasmalogens. Other findings included decreased levels of several membrane lipids, including phosphatidylcholines and sphingomyelins, that may indicate dysregulation of the cytidine-5’-diphosphocholine pathway. Enrichment analyses revealed decreased levels of choline, ceramides and carnitines, and increased levels of long chain triglycerides (TG) and hydroxy-eicosapentaenoic acid. Elevated levels of dicarboxylic acids were consistent with abnormalities in the tricarboxylic acid cycle. Using machine learning algorithms with selected metabolites as predictors, we were able to differentiate female ME/CFS cases from female controls (highest AUC=0.794) and ME/CFS cases without self-reported irritable bowel syndrome (sr-IBS) from controls without sr-IBS (highest AUC=0.873).

Conclusion

Our findings are consistent with earlier ME/CFS work indicating compromised energy metabolism and redox imbalance, and highlight new abnormalities that may provide insights into the pathogenesis of ME/CFS.

Plasma levels of plasmalogens are decreased in patients with myalgic encephalomyelitis/chronic fatigue syndrome suggesting peroxisome dysfunction.

The Role of Kynurenine Pathway and NAD+ Metabolism in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious, complex, and highly debilitating long-term illness. People with ME/CFS are typically unable to carry out their routine activities. Key hallmarks of the disease are neurological and gastrointestinal impairments accompanied by pervasive malaise that is exacerbated after physical and/or mental activity. Currently, there is no validated cure of biomarker signature for this illness. Impaired tryptophan (TRYP) metabolism is thought to play significant role in the pathobiology of ME/CFS. TRYP is an important precursor for serotonin and the essential pyridine nucleotide nicotinamide adenine dinucleotide (NAD⁺). TRYP has been associated with the development of some parts of the brain responsible for behavioural functions. The main catabolic route for TRYP is the kynurenine pathway (KP). The KP produces NAD⁺ and several neuroactive metabolites with neuroprotective (i.e., kynurenic acid (KYNA)) and neurotoxic (i.e., quinolinic acid (QUIN)) activities. Hyperactivation of the KP, whether compensatory or a driving mechanism of degeneration can limit the availability of NAD⁺ and exacerbate the symptoms of ME/CFS. This review discusses the potential association of altered KP metabolism in ME/CFS. The review also evaluates the role of the patient’s gut microbiota on TRYP availability and KP activation. We propose that strategies aimed at raising the levels of NAD⁺ (e.g., using nicotinamide mononucleotide and nicotinamide riboside) may be a promising intervention to overcome symptoms of fatigue and to improve the quality of life in patients with ME/CFS. Future clinical trials should further assess the potential benefits of NAD⁺ supplements for reducing some of the clinical features of ME/CFS.

Epstein-Barr Virus and the Origin of Myalgic Encephalomyelitis or Chronic Fatigue Syndrome

Myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) affects approximately 1% of the general population. It is a chronic, disabling, multi-system disease for which there is no effective treatment. This is probably related to the limited knowledge about its origin. Here, we summarized the current knowledge about the pathogenesis of ME/CFS and revisit the immunopathobiology of Epstein-Barr virus (EBV) infection. Given the similarities between EBV-associated autoimmune diseases and cancer in terms of poor T cell surveillance of cells with EBV latency, expanded EBV-infected cells in peripheral blood and increased antibodies against EBV, we hypothesize that there could be a common etiology generated by cells with EBV latency that escape immune surveillance. Albeit inconclusive, multiple studies in patients with ME/CFS have suggested an altered cellular immunity and augmented Th2 response that could result from mechanisms of evasion to some pathogens such as EBV, which has been identified as a risk factor in a subset of ME/CFS patients. Namely, cells with latency may evade the immune system in individuals with genetic predisposition to develop ME/CFS and in consequence, there could be poor CD4 T cell immunity to mitogens and other specific antigens, as it has been described in some individuals. Ultimately, we hypothesize that within ME/CFS there is a subgroup of patients with DRB1 and DQB1 alleles that could confer greater susceptibility to EBV, where immune evasion mechanisms generated by cells with latency induce immunodeficiency. Accordingly, we propose new endeavors to investigate if anti-EBV therapies could be effective in selected ME/CFS patients.

mapMECFS: a portal to enhance data discovery across biological disciplines and collaborative sites

Background

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease which involves multiple body systems (e.g., immune, nervous, digestive, circulatory) and research domains (e.g., immunology, metabolomics, the gut microbiome, genomics, neurology). Despite several decades of research, there are no established ME/CFS biomarkers available to diagnose and treat ME/CFS. Sharing data and integrating findings across these domains is essential to advance understanding of this complex disease by revealing diagnostic biomarkers and facilitating discovery of novel effective therapies.

Methods

The National Institutes of Health funded the development of a data sharing portal to support collaborative efforts among an initial group of three funded research centers. This was subsequently expanded to include the global ME/CFS research community. Using the open-source comprehensive knowledge archive network (CKAN) framework as the base, the ME/CFS Data Management and Coordinating Center developed an online portal with metadata collection, smart search capabilities, and domain-agnostic data integration to support data findability and reusability while reducing the barriers to sustainable data sharing.

Results

We designed the mapMECFS data portal to facilitate data sharing and integration by allowing ME/CFS researchers to browse, share, compare, and download molecular datasets from within one data repository. At the time of publication, mapMECFS contains data curated from public data repositories, peer-reviewed publications, and current ME/CFS Research Network members.

Conclusions

mapMECFS is a disease-specific data portal to improve data sharing and collaboration among ME/CFS researchers around the world. mapMECFS is accessible to the broader research community with registration. Further development is ongoing to include novel systems biology and data integration methods.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03127-3.

The Emerging Role of Gut Microbiota in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Current Evidence and Potential Therapeutic Applications

The well-known symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) are chronic pain, cognitive dysfunction, post-exertional malaise and severe fatigue. Another class of symptoms commonly reported in the context of ME/CFS are gastrointestinal (GI) problems. These may occur due to comorbidities such as Crohn's disease or irritable bowel syndrome (IBS), or as a symptom of ME/CFS itself due to an interruption of the complex interplay between the gut microbiota (GM) and the host GI tract. An altered composition and overall decrease in diversity of GM has been observed in ME/CFS cases compared to controls. In this review, we reflect on genetics, infections, and other influences that may factor into the alterations seen in the GM of ME/CFS individuals, we discuss consequences arising from these changes, and we contemplate the therapeutic potential of treating the gut to alleviate ME/CFS symptoms holistically.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): An Overview

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic systemic disease that manifests via various symptoms such as chronic fatigue, post-exertional malaise, and cognitive impairment described as “brain fog”. These symptoms often prevent patients from keeping up their pre-disease onset lifestyle, as extended periods of physical or mental activity become almost impossible. However, the disease presents heterogeneously with varying severity across patients. Therefore, consensus criteria have been designed to provide a diagnosis based on symptoms. To date, no biomarker-based tests or diagnoses are available, since the molecular changes observed also largely differ from patient to patient. In this review, we discuss the infectious, genetic, and hormonal components that may be involved in CFS pathogenesis, we scrutinize the role of gut microbiota in disease progression, we highlight the potential of non-coding RNA (ncRNA) for the development of diagnostic tools and briefly mention the possibility of SARS-CoV-2 infection causing CFS.

The Probiotic VSL#3® Does Not Seem to Be Efficacious for the Treatment of Gastrointestinal Symptomatology of Patients with Fibromyalgia: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Gastrointestinal symptomatology is frequent among patients with fibromyalgia, which increases disease burden and lacks specific treatment, either pharmacological or non-pharmacological. We aimed to evaluate the efficacy and tolerability of a multi-strain probiotic, VSL#3^®, for the treatment of fibromyalgia-associated gastrointestinal manifestations. This randomized, placebo-controlled trial included 12 weeks of probiotic or placebo treatment followed by 12 weeks of follow up. The primary outcome variable was the mean change from the baseline to the endpoint in the composite severity score of the three main gastrointestinal symptoms reported by patients with fibromyalgia (abdominal pain, abdominal bloating and meteorism). Secondary outcome variables were the severity of additional gastrointestinal symptoms, fibromyalgia severity, depression, sleep disturbance, health-related quality of life and patients' overall impression of improvement. No differences were found between VSL#3^® (n = 54) and the placebo (n = 56) in the primary outcome (estimated treatment difference: 1.1; 95% confidence interval [CI]: -2.1, 4.2; p = 0.501), or in any of the secondary outcomes. However, responders to VSL#3 were more likely to maintain any improvement during the follow-up period compared to responders in the placebo arm. Overall, VSL#3 tolerability was good. Our data could not demonstrate any beneficial effects of VSL#3^® either on the composite score of severity of abdominal pain, bloating and meteorism or in any of the secondary outcome variables. More research is needed to elucidate specific factors that may predict a favourable response to treatment in patients with fibromyalgia.

Gut microbiota as a potential target for developing anti-fatigue foods

Fatigue has many negative effects on human health. As such, it is desirable to develop anti-fatigue foods and understand the mechanisms of their action. Based on a comprehensive review of the literature, this article discusses the important roles of gut microbiota in fatigue and anti-fatigue. Studies have shown that an increase in pathogenic bacteria and a decrease in beneficial bacteria co-exist when fatigue is present in both rodents and humans, whereas changes in gut microbiota were reported after intervention with anti-fatigue foods. The roles of gut microbiota in the activities of anti-fatigue foods can also be explained in the causes and the effects of fatigue. Among the causes of fatigue, the accumulation of lactic acid, decrease of energy, and reduction of central nervous system function were related to gut microbiota metabolism. Among the harmful effects of fatigue, oxidative stress, inflammation, and intestinal barrier dysfunction were related to gut microbiota dysbiosis. Furthermore, gut microbiota, together with anti-fatigue foods, can inhibit pathogen growth, convert foods into highly anti-oxidative or anti-inflammatory products, produce short-chain fatty acids, maintain intestinal barrier integrity, inhibit intestinal inflammation, and stimulate the production of neurotransmitters that regulate the central nervous system. Therefore, it is believed that gut microbiota play important roles in the activities of anti-fatigue foods and may provide new insights on the development of anti-fatigue foods.

MetaGeneBank: a standardized database to study deep sequenced metagenomic data from human fecal specimen

BACKGROUND

Microbiome big data from population-scale cohorts holds the key to unleash the power of microbiomes to overcome critical challenges in disease control, treatment and precision medicine. However, variations introduced during data generation and processing limit the comparisons among independent studies in respect of interpretability. Although multiple databases have been constructed as platforms for data reuse, they are of limited value since only raw sequencing files are considered.

DESCRIPTION

Here, we present MetaGeneBank, a standardized database that provides details on sample collection and sequencing, and abundances of genes, microbiota and molecular functions for 4470 raw sequencing files (over 12 TB) collected from 16 studies covering over 10 types of diseases and 14 countries using a unified data-processing pipeline. The incorporation of tools that enable browsing and searching with descriptive attributes, gene sequences, microbiota and functions makes the database user-friendly. We found that the source of specimen contributes more than sequencing centers or platforms to the variations of microbiota. Special attention should be paid when re-analyzing sequencing files from different countries.

CONCLUSIONS

Collectively, MetaGeneBank provides a gateway to utilize the untapped potential of gut metagenomic data in helping fighting against human diseases. With the continuous updating of the database in terms of data volume, data types and sample types, MetaGeneBank would undoubtedly be the benchmarking database in the future in respect of data reuse, and would be valuable in translational science.

Insights from myalgic encephalomyelitis/chronic fatigue syndrome may help unravel the pathogenesis of postacute COVID-19 syndrome

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause chronic and acute disease. Postacute sequelae of SARS-CoV-2 infection (PASC) include injury to the lungs, heart, kidneys, and brain that may produce a variety of symptoms. PASC also includes a post-coronavirus disease 2019 (COVID-19) syndrome ('long COVID') with features that can follow other acute infectious diseases and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Here we summarize what is known about the pathogenesis of ME/CFS and of 'acute' COVID-19, and we speculate that the pathogenesis of post-COVID-19 syndrome in some people may be similar to that of ME/CFS. We propose molecular mechanisms that might explain the fatigue and related symptoms in both illnesses, and we suggest a research agenda for both ME/CFS and post-COVID-19 syndrome.

An association between chronic widespread pain and the gut microbiome

OBJECTIVES

Chronic widespread musculoskeletal pain (CWP) is a characteristic symptom of fibromyalgia, which has been shown to be associated with an altered gut microbiome. Microbiome studies to date have not examined the milder CWP phenotype specifically nor have they explored the role of raised BMI. The aim of this study was to investigate whether the microbiome is abnormal in CWP.

METHODS

CWP was assessed using a standardized screening questionnaire in female volunteers from the TwinsUK cohort including 113 CWP cases and 1623 controls. The stool microbiome was characterized using 16S rRNA amplicon sequencing and amplicon sequence variants, and associations with CWP examined using linear mixed-effects models adjusting for BMI, age, diet, family relatedness and technical factors.

RESULTS

Alpha diversity was significantly lower in CWP cases than controls (Mann-Whitney test, P-values 2.3e-04 and 1.2e-02, for Shannon and Simpson indices respectively). The species Coprococcus comes was significantly depleted in CWP cases (Padj = 3.04e-03). A genome-wide association study (GWAS) performed for C. comes in TwinsUK followed by meta-analysis with three Dutch cohorts (total n = 3521) resulted in nine suggestive regions, with the most convincing on chromosome 4 near the TRAM1L1 gene (rs76957229, P = 7.4e-8). A Mendelian randomization study based on the results of the GWAS did not support a causal role for C. comes on the development of CWP.

CONCLUSIONS

We have demonstrated reduced diversity in the microbiome in CWP, indicating an involvement of the gut microbiota in CWP; prospectively the microbiome may offer therapeutic opportunities for this condition.

Review article: The aetiology of fatigue in inflammatory bowel disease and potential therapeutic management strategies

BACKGROUND

Fatigue is the inability to achieve or maintain an expected work output resulting from central or peripheral mechanisms. The prevalence of inflammatory bowel disease (IBD) fatigue can reach 86% in active disease, persisting in 50%-52% of patients with mild to inactive disease. Fatigue is the commonest reason for work absence in IBD, and patients often report fatigue burden to be greater than that of primary disease symptoms. Relatively few evidence-based treatment options exist, and the aetiology is poorly understood.

AIM

To review the available data and suggest a possible aetiology of IBD fatigue and to consider the efficacy of existing management strategies and highlight potential future interventions.

METHODS

We reviewed fatigue-related literature in IBD using PubMed database.

RESULTS

Disease related factors such as inflammation and pharmacological treatments negatively impact skeletal muscle and brain physiology, likely contributing to fatigue symptoms. Secondary factors such as malnutrition, anaemia, sleep disturbance and psychological comorbidity are potential determinants. Immune profile, faecal microbiota composition and physical fitness differ significantly between fatigued and non-fatigued patients, suggesting these may be aetiological factors. Solution-focused therapy, high-dosage thiamine supplementation and biological therapy may reduce fatigue perception in IBD. The effect of physical activity interventions is inconclusive.

CONCLUSIONS

A multimodal approach is likely required to treat IBD fatigue. Established reversible factors like anaemia, micronutrient deficiencies and active disease should initially be resolved. Psychosocial intervention shows potential efficacy in reducing fatigue perception in quiescent disease. Restoring physical deconditioning by exercise training intervention may further improve fatigue burden.

Profile of gut microbiota in patients with traumatic thoracic spinal cord injury and its clinical implications: a case-control study in a rehabilitation setting

Gut microbiota are the candidate biomarkers for neurogenic bowel dysfunction (NBD) in patients with spinal cord injury (SCI). We aimed to identify the common features between patients with varying degree of thoracic SCI and healthy individuals and subpopulations of microbiota correlated with the serum biomarkers. Twenty-one patients with complete thoracic SCI (CTSCI), 24 with incomplete thoracic SCI (ITSCI), and 24 healthy individuals (HC) were enrolled in this study. Fresh stool samples and clinical data were collected from all participants, and their bowel functions with SCI were assessed. Microbial diversity and composition were analyzed by sequencing the 16S rRNA gene. The features of gut microbiota correlated with the serum biomarkers and their functions were investigated. The mean NBD score of patients with CTSCI was higher than that of patients with ITSCI. Diversity of the gut microbiota in SCI group was reduced, and with an increase in the degree of damage, alpha diversity had decreased gradually. The composition of gut microbiota in patients with SCI was distinct from that in healthy individuals, and CTSCI group exhibited further deviation than ITSCI group compared to healthy individuals. Four serum biomarkers were found to be correlated with most differential genera. Patients with thoracic SCI present gut dysbiosis, which is more pronounced in patients with CTSCI than in those with ITSCI. Therefore, the gut microbiota profile may serve as the signatures for bowel and motor functions in patients with thoracic SCI.

Anti-fatigue property of the oyster polypeptide fraction and its effect on gut microbiota in mice

We aimed to evaluate the anti-fatigue effects of the oyster polypeptide (OP) fraction and its regulatory effect on the gut microbiota in mice. Our exhaustive swimming experiment showed that the swimming time of the low-, middle- and high-dose groups of the OP fraction was increased by 1.82, 2.18 and 2.44 times compared with the control group, respectively. Besides, the liver glycogen levels of the three groups were increased by 19.3%, 42.02% and 65.07%, while the lactate levels were decreased by 18.85%, 21.18% and 28.74%, respectively. Moreover, administration of the OP fraction upregulated the expressions of PEPCK and AMPK, but downregulated the TNF-α expression. Correlation analysis between the gut microbiota and fatigue-related biochemical indicators showed that Faecalibacterium, Desulfovibri and Intestinibacter were negatively correlated with the swimming time, blood lactate, blood urea nitrogen, liver glycogen and muscle glycogen, while Yaniella and Romboutsia were positively correlated. Therefore, the OP fraction had anti-fatigue effects, and could regulate the abundance of gut microbiota and maintain its balance.

Transcriptome analysis reveals the protective role of fructo-oligosaccharide in colonic mucosal barriers in exercise-induced stressed mice

Most athletes continually endure mental and physical stress from intense exercise. Fructo-oligosaccharide (FOS) can reduce physical exhaustion, but the concrete mechanism behind it still needs further research. In this study, the effect of FOS on colonic mucosal barriers was investigated using an exercise-induced stress mouse model. Except for control individuals, mice were subject to cycles of 2-day exercise (at 20 rpm) interleaved by 5-day rest. The mice experienced a total of 6 days of exercise during the feeding period. FOS improved common indicators of exhaustion, such as glycogen storage in muscle. 16S rRNA data supported that changes in the gut microbiome were also closely related to stress status. Notably, Anaerotruncus was increased in mice under stress, while FOS facilitated the growth of Dorea, which is negatively associated with exhaustion. The RNA-seq analysis revealed that FOS could maintain the integrity of colonic epithelial barriers. For example, FOS significantly restored the expression of tight junctions (Occludin and Zonula occludens-1) in the colon, which was impaired under a stress state. Besides, the NOD-like receptor family pyrin domain containing 6 (NLRP6) inflammasome might contribute to the protection of the colonic mucosa by promoting the secretion of IL-18, Mucin2 (Muc2) and intestine lectin 1 (Itln1) in FOS-treated individuals. In short, FOS administration attenuated the damage of colonic mucosal barriers in exercise-induced stressed mice.

Potential role of microbiome in Chronic Fatigue Syndrome/Myalgic Encephalomyelits (CFS/ME)

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) is a severe multisystemic disease characterized by immunological abnormalities and dysfunction of energy metabolism. Recent evidences suggest strong correlations between dysbiosis and pathological condition. The present research explored the composition of the intestinal and oral microbiota in CFS/ME patients as compared to healthy controls. The fecal metabolomic profile of a subgroup of CFS/ME patients was also compared with the one of healthy controls. The fecal and salivary bacterial composition in CFS/ME patients was investigated by Illumina sequencing of 16S rRNA gene amplicons. The metabolomic analysis was performed by an UHPLC-MS. The fecal microbiota of CFS/ME patients showed a reduction of Lachnospiraceae, particularly Anaerostipes, and an increased abundance of genera Bacteroides and Phascolarctobacterium compared to the non-CFS/ME groups. The oral microbiota of CFS/ME patients showed an increase of Rothia dentocariosa. The fecal metabolomic profile of CFS/ME patients revealed high levels of glutamic acid and argininosuccinic acid, together with a decrease of alpha-tocopherol. Our results reveal microbial signatures of dysbiosis in the intestinal microbiota of CFS/ME patients. Further studies are needed to better understand if the microbial composition changes are cause or consequence of the onset of CFS/ME and if they are related to any of the several secondary symptoms.

Alterations in Fecal Microbiomes and Serum Metabolomes of Fatigued Patients With Quiescent Inflammatory Bowel Diseases

BACKGROUND & AIMS

Fatigue is frequent and disabling in patients with inflammatory bowel diseases (IBD) but its mechanisms are poorly understood. We investigated alterations in fecal microbiomes and serum metabolomes and proteomes in patients with quiescent IBD, with vs without fatigue.

METHODS

We performed a prospective observational study of patients (44% women; mean age, 39.8 y) with clinically and endoscopically quiescent Crohn's disease (n = 106) or ulcerative colitis (n = 60) at a tertiary hospital, from March 2016 through December 2018. Fatigue was assessed using the functional assessment of chronic illness therapy-fatigue scoring system and defined as a score of 43 or less. We performed metabolomic analysis of serum samples using liquid chromatography-mass spectrometry methods and proteomic analysis using multiplex proximity extension assay (PEA) technology. Stool samples were obtained from 50 patients and analyzed by shotgun metagenomic sequencing on Illumina HiSeq platform.

RESULTS

Of the 166 study participants, 91 (55%) were fatigued. Serum samples from patients with fatigue (n = 59) did not have significant increases in levels of inflammatory cytokines compared with serum samples from nonfatigued patients (n = 72). We found a statistically significant difference in a cluster of 18 serum metabolites between patients with fatigue (n = 84) vs without fatigue (n = 72) (P = .033); serum samples from patients with fatigue had significant reductions in levels of methionine (P = .020), tryptophan (P = .042), proline (P = .017), and sarcosine (P = .047). Fecal samples from patients with fatigue had a less diverse gut microbiome, with significant reductions in butyrate-producing bacteria, including Faecalibacterium prausnitzii (P = .0002, q =.007) and Roseburia hominis (P = .0079, q = 0.105). This fatigue-like microbiome was associated with fatigue scales and correlated with progressive depletion of metabolites from serum samples.

CONCLUSIONS

In an analysis of fecal and serum samples from 166 patients with IBD, we found alterations in serum metabolites and fecal microbes that were associated with fatigue.

Fecal Microbiota Transplantation: A New Therapeutic Attempt from the Gut to the Brain

Gut dysbacteriosis is closely related to various intestinal and extraintestinal diseases. Fecal microbiota transplantation (FMT) is a biological therapy that entails transferring the gut microbiota from healthy individuals to patients in order to reconstruct the intestinal microflora in the latter. It has been proved to be an effective treatment for recurrent Clostridium difficile infection. Studies show that the gut microbiota plays an important role in the pathophysiology of neurological and psychiatric disorders through the microbiota-gut-brain axis. Therefore, reconstruction of the healthy gut microbiota is a promising new strategy for treating cerebral diseases. We have reviewed the latest research on the role of gut microbiota in different nervous system diseases as well as FMT in the context of its application in neurological, psychiatric, and other nervous system-related diseases (Parkinson's disease, Alzheimer's disease, multiple sclerosis, epilepsy, autism spectrum disorder, bipolar disorder, hepatic encephalopathy, neuropathic pain, etc.).

Metagenomics analysis of the gut microbiome in healthy and bacterial pneumonia forest musk deer

BACKGROUND

The forest musk deer (FMD, Moschus berezovskii) is an threatened species in China. Bacterial pneumonia was found to seriously restrict the development of FMD captive breeding. Historical evidence has demonstrated the relationship between immune system and intestinal Lactobacillus in FMD.

OBJECTIVE

We sought to elucidate the differences in the gut microbiota of healthy and bacterial pneumonia FMD.

METHODS

The bacterial pneumonia FMD was demonstrated by bacterial and pathological diagnosis, and the gut microbiome of healthy and bacterial pneumonia FMD was sequenced and analysed.

RESULTS

There are three pathogens (Pseudomonas aeruginosa, Streptococcus equinus and Trueperella pyogenes) isolated from the bacterial pneumonia FMD individuals. Compared with the healthy group, the abundance of Firmicutes and Proteobacteria in the pneumonia group was changed, and a high level of Proteobacteria was found in the pneumonia group. In addition, a higher abundance of Acinetobacter (p = 0.01) was observed in the population of the pneumonia group compared with the healthy group. Several potentially harmful bacteria and disease-related KEGG subsystems were only found in the gut of the bacterial pneumonia group. Analysis of KEGG revealed that many genes related to type IV secretion system, type IV pilus, lipopolysaccharide export system, HTH-type transcriptional regulator/antitoxin MqsA, and ArsR family transcriptional regulator were significantly enriched in the metagenome of the bacterial pneumonia FMD.

CONCLUSION

Our results demonstrated that the gut microbiome was significantly altered in the bacterial pneumonia group. Overall, our research improves the understanding of the potential role of the gut microbiota in the FMD bacterial pneumonia.

The gut-brain axis and beyond: Microbiome control of spinal cord injury pain in humans and rodents

Spinal cord injury (SCI) is a devastating injury to the central nervous system in which 60 to 80% of patients experience chronic pain. Unfortunately, this pain is notoriously difficult to treat, with few effective options currently available. Patients are also commonly faced with various compounding injuries and medical challenges, often requiring frequent hospitalization and antibiotic treatment. Change in the gut microbiome from the "normal" state to one of imbalance, referred to as gut dysbiosis, has been found in both patients and rodent models following SCI. Similarities exist in the bacterial changes observed after SCI and other diseases with chronic pain as an outcome. These changes cause a shift in the regulation of inflammation, causing immune cell activation and secretion of inflammatory mediators that likely contribute to the generation/maintenance of SCI pain. Therefore, correcting gut dysbiosis may be used as a tool towards providing patients with effective pain management and improved quality of life.

Relationships Between Abdominal Pain and Fatigue With Psychological Distress as a Mediator in Women With Irritable Bowel Syndrome

Women with irritable bowel syndrome often report fatigue, along with abdominal pain and psychological distress (i.e., depression and anxiety). There is little information about the relationships among these symptoms. Using a secondary data analysis (N = 356), we examined the relationship between abdominal pain and fatigue and whether psychological distress mediates the effect of abdominal pain on fatigue in both across women and within woman with irritable bowel syndrome. Data gathered through a 28-day diary were analyzed with linear regressions. The across-women and within-woman relationships among same-day abdominal pain, fatigue, and psychological distress were examined. Within-woman relationships were also examined for directionality among symptoms (i.e., prior-day abdominal pain predicts next-day fatigue and prior-day fatigue predicts next-day abdominal pain). In across-women and within-woman analyses on the same day, abdominal pain and fatigue were positively correlated. In within-woman analyses, abdominal pain predicted next-day fatigue, but fatigue did not predict next-day pain. In across-women and within-woman analyses, psychological distress partially mediated the effects of abdominal pain on fatigue. Symptom management incorporating strategies to decrease both abdominal pain and psychological distress are likely to reduce fatigue. Nursing interventions, such as self-management skills to reduce abdominal pain and psychological distress, may have the added benefit of reducing fatigue in irritable bowel syndrome.

Deep phenotyping of myalgic encephalomyelitis/chronic fatigue syndrome in Japanese population

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex and debilitating disease with no molecular diagnostics and no treatment options. To identify potential markers of this illness, we profiled 48 patients and 52 controls for standard laboratory tests, plasma metabolomics, blood immuno-phenotyping and transcriptomics, and fecal microbiome analysis. Here, we identified a set of 26 potential molecular markers that distinguished ME/CFS patients from healthy controls. Monocyte number, microbiome abundance, and lipoprotein profiles appeared to be the most informative markers. When we correlated these molecular changes to sleep and cognitive measurements of fatigue, we found that lipoprotein and microbiome profiles most closely correlated with sleep disruption while a different set of markers correlated with a cognitive parameter. Sleep, lipoprotein, and microbiome changes occur early during the course of illness suggesting that these markers can be examined in a larger cohort for potential biomarker application. Our study points to a cluster of sleep-related molecular changes as a prominent feature of ME/CFS in our Japanese cohort.

Alterations in the diversity and composition of gut microbiota in weaned piglets infected with Balantioides coli

Balantioides coli is a ciliated parasite that can cause diarrhea when inhabiting the colon and cecum of pigs and humans. However, information regarding the changes in structure and composition of the gut microbiome in piglets infected with B. coli remains scarce. In this study, 16S rDNA amplicon sequencing was conducted on fecal samples from both B. coli-positive piglets with diarrhea and B. coli-negative piglets without diarrhea. The results showed that Firmicutes and Bacteroidetes were the major phyla in the two groups, and the relative abundance of the phylum Firmicutes, including Ruminococcaceae and Clostridiaceae, was significantly lower in the B. coli-positive samples than in the B. coli-negative ones (p < 0.05). Compared with B. coli-negative samples, Alloprevotella and Faecalibacterium showed distinctly higher relative abundances (p < 0.05) in the B. coli-positive samples, and the abundances of some potential pathogenic bacteria, including Escherichia-Shigella and Campylobacter, were positively correlated with B. coli infection and diarrhea of weaned piglets. In addition, there were statistically significant differences in fecal microbiota diversity and abundances of predicted functional genes between B. coli-colonized and B. coli-negative samples (p <  0.05). Taken together, these findings suggest that there were significant differences in the bacterial community composition, diversity, and functions between the B. coli-positive and B. coli-negative piglets, and the colonization by B. coli may be associated with the dysbiosis of gut microbiota structure in weaned piglets.

Myalgic encephalomyelitis/chronic fatigue syndrome patients exhibit altered T cell metabolism and cytokine associations

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease with no known cause or mechanism. There is an increasing appreciation for the role of immune and metabolic dysfunction in the disease. ME/CFS has historically presented in outbreaks, often has a flu-like onset, and results in inflammatory symptoms. Patients suffer from severe fatigue and postexertional malaise. There is little known about the metabolism of specific immune cells in patients with ME/CFS. To investigate immune metabolism in ME/CFS, we isolated CD4+ and CD8+ T cells from 53 patients with ME/CFS and 45 healthy controls. We analyzed glycolysis and mitochondrial respiration in resting and activated T cells, along with markers related to cellular metabolism and plasma cytokines. We found that ME/CFS CD8+ T cells had reduced mitochondrial membrane potential compared with those from healthy controls. Both CD4+ and CD8+ T cells from patients with ME/CFS had reduced glycolysis at rest, whereas CD8+ T cells also had reduced glycolysis following activation. Patients with ME/CFS had significant correlations between measures of T cell metabolism and plasma cytokine abundance that differed from correlations seen in healthy control subjects. Our data indicate that patients have impaired T cell metabolism consistent with ongoing immune alterations in ME/CFS that may illuminate the mechanism behind this disease.

Role of TRP Channels in Shaping the Gut Microbiome

Transient receptor potential (TRP) channel family proteins are sensors for pain, which sense a variety of thermal and noxious chemicals. Sensory neurons innervating the gut abundantly express TRPA1 and TRPV1 channels and are in close proximity of gut microbes. Emerging evidence indicates a bi-directional gut–brain cross-talk in several entero-neuronal pathologies; however, the direct evidence of TRP channels interacting with gut microbial populations is lacking. Herein, we examine whether and how the knockout (KO) of TRPA1 and TRPV1 channels individually or combined TRPA1/V1 double-knockout (dKO) impacts the gut microbiome in mice. We detect distinct microbiome clusters among the three KO mouse models versus wild-type (WT) mice. All three TRP-KO models have reduced microbial diversity, harbor higher abundance of Bacteroidetes, and a reduced proportion of Firmicutes. Specifically distinct arrays in the KO models are determined mainly by S24-7, Bacteroidaceae, Clostridiales, Prevotellaceae, Helicobacteriaceae, Rikenellaceae, and Ruminococcaceae. A1KO mice have lower Prevotella, Desulfovibrio, Bacteroides, Helicobacter and higher Rikenellaceae and Tenericutes; V1KO mice demonstrate higher Ruminococcaceae, Lachnospiraceae, Ruminococcus, Desulfovibrio and Mucispirillum; and A1V1dKO mice exhibit higher Bacteroidetes, Bacteroides and S24-7 and lower Firmicutes, Ruminococcaceae, Oscillospira, Lactobacillus and Sutterella abundance. Furthermore, the abundance of taxa involved in biosynthesis of lipids and primary and secondary bile acids is higher while that of fatty acid biosynthesis-associated taxa is lower in all KO groups. To our knowledge, this is the first study demonstrating distinct gut microbiome signatures in TRPA1, V1 and dKO models and should facilitate prospective studies exploring novel diagnostic/ therapeutic modalities regarding the pathophysiology of TRP channel proteins.

How Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Progresses: The Natural History of ME/CFS

We propose a framework for understanding and interpreting the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) that considers wider determinants of health and long-term temporal variation in pathophysiological features and disease phenotype throughout the natural history of the disease. As in other chronic diseases, ME/CFS evolves through different stages, from asymptomatic predisposition, progressing to a prodromal stage, and then to symptomatic disease. Disease incidence depends on genetic makeup and environment factors, the exposure to singular or repeated insults, and the nature of the host response. In people who develop ME/CFS, normal homeostatic processes in response to adverse insults may be replaced by aberrant responses leading to dysfunctional states. Thus, the predominantly neuro-immune manifestations, underlined by a hyper-metabolic state, that characterize early disease, may be followed by various processes leading to multi-systemic abnormalities and related symptoms. This abnormal state and the effects of a range of mediators such as products of oxidative and nitrosamine stress, may lead to progressive cell and metabolic dysfunction culminating in a hypometabolic state with low energy production. These processes do not seem to happen uniformly; although a spiraling of progressive inter-related and self-sustaining abnormalities may ensue, reversion to states of milder abnormalities is possible if the host is able to restate responses to improve homeostatic equilibrium. With time variation in disease presentation, no single ME/CFS case description, set of diagnostic criteria, or molecular feature is currently representative of all patients at different disease stages. While acknowledging its limitations due to the incomplete research evidence, we suggest the proposed framework may support future research design and health care interventions for people with ME/CFS.

Exposure to greenspaces could reduce the high global burden of pain

Painful conditions are among the leading causes of years lived with disability, and may increase following the coronavirus pandemic, which has led to temporary closure of some healthcare services for people with chronic pain. To reduce this burden, novel, cost-effective and accessible interventions are required. We propose that greenspace exposure may be one such intervention. Drawing on evidence from neuroscience, physiology, microbiology, and psychology, we articulate how and why exposure to greenspaces could improve pain outcomes and reduce the high global burden of pain. Greenspace exposure potentially provides opportunities to benefit from known or proposed health-enhancing components of nature, such as environmental microbiomes, phytoncides, negative air ions, sunlight, and the sights and sounds of nature itself. We review the established and potential links between these specific exposures and pain outcomes. While further research is required to determine possible causal links between greenspace exposure and pain outcomes, we suggest that there is already sufficient evidence to help reduce the global burden of pain by improving access and exposure to quality greenspaces.

Autoantibodies to beta-adrenergic and muscarinic cholinergic receptors in Myalgic Encephalomyelitis (ME) patients - A validation study in plasma and cerebrospinal fluid from two Swedish cohorts

Myalgic encephalomyelitis (ME) also known as ME/CFS (Chronic Fatigue Syndrome) or ME/SEID (Systemic Exertion Intolerance Disorder), is a disabling and often long-lasting disease that can drastically impair quality of life and physical/social functioning of the patients. Underlying pathological mechanisms are to a large extent unknown, but the presence of autoantibodies, cytokine pattern deviations and the presentation of cognitive and autonomic nervous system related symptoms provide evidence for ME being an immunological disorder with elements of autoimmunity. Increased levels of autoantibodies binding to adrenergic and muscarinic receptors in ME-patients have been reported. It is hypothesized that these autoantibodies have pathological significance and contribute to the ME-specific symptoms, however, these observations need to be validated. This study was designed to investigate potential differences in adrenergic and muscarinic receptor autoantibody levels in plasma and cerebrospinal fluid (CSF) samples between ME patients and gender and age-matched healthy controls, and to correlate the autoantibody levels to disease severity. We collected bodyfluids and health-related questionnaires from two Swedish ME cohorts, plasma and CSF from one of the cohorts (n ​= ​24), only plasma from the second cohort (n ​= ​24) together with plasma samples (n ​= ​24) and CSF (n ​= ​6) from healthy controls. All samples were analysed for IgG autoantibodies directed against Alpha- (α1, α2) and Beta- (β1-3) adrenergic receptors and Muscarinic (M) 1-5 acetylcholine receptors using an ELISA technique. The questionnaires were used as measures of disease severity. Significant increases in autoantibody levels in ME patients compared to controls were found for M3 and M4 -receptors in both cohorts and β1, β2, M3 and M4-receptors in one cohort. No significant correlations were found between autoantibody levels and disease severity. No significant levels of autoantibodies were detected in the CSF samples. These findings support previous findings that there exists a general pattern of increased antibody levels to adrenergic and muscarinic receptors within the ME patient group. However, the role of increased adrenergic and muscarinic receptor autoantibodies in the pathogenesis of ME is still uncertain and further research is needed to evaluate the clinical significance of these findings.

Plasma proteomic profiling suggests an association between antigen driven clonal B cell expansion and ME/CFS

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is an unexplained chronic, debilitating illness characterized by fatigue, sleep disturbances, cognitive dysfunction, orthostatic intolerance and gastrointestinal problems. Using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), we analyzed the plasma proteomes of 39 ME/CFS patients and 41 healthy controls. Logistic regression models, with both linear and quadratic terms of the protein levels as independent variables, revealed a significant association between ME/CFS and the immunoglobulin heavy variable (IGHV) region 3-23/30. Stratifying the ME/CFS group based on self-reported irritable bowel syndrome (sr-IBS) status revealed a significant quadratic effect of immunoglobulin lambda constant region 7 on its association with ME/CFS with sr-IBS whilst IGHV3-23/30 and immunoglobulin kappa variable region 3-11 were significantly associated with ME/CFS without sr-IBS. In addition, we were able to predict ME/CFS status with a high degree of accuracy (AUC = 0.774-0.838) using a panel of proteins selected by 3 different machine learning algorithms: Lasso, Random Forests, and XGBoost. These algorithms also identified proteomic profiles that predicted the status of ME/CFS patients with sr-IBS (AUC = 0.806-0.846) and ME/CFS without sr-IBS (AUC = 0.754-0.780). Our findings are consistent with a significant association of ME/CFS with immune dysregulation and highlight the potential use of the plasma proteome as a source of biomarkers for disease.

Inclusion of family members without ME/CFS in research studies promotes discovery of biomarkers specific for ME/CFS

BACKGROUND

The search for a biomarker specific for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) has been long, arduous and, to date, unsuccessful. Researchers need to consider their expenditures on each new candidate biomarker. In a previous study of antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer lymphocytes, we found lower ADCC for ME/CFS patients vs. unrelated donors but ruled against low ADCC as a biomarker because of similar ADCC for patients vs. their family members without ME/CFS.

OBJECTIVE

We applied inclusion of family members without ME/CFS, from families with multiple CFS patients, as a second non-ME/CFS control group in order to re-examine inflammation in ME/CFS.

METHOD

Total and CD16A-positive 'non-classical' anti-inflammatory monocytes were monitored.

RESULTS

Non-classical monocytes were elevated for patients vs. unrelated healthy donors but these differences were insignificant between patients vs. unaffected family members.

CONCLUSIONS

Inclusion of family members ruled against biomarker considerations for the monocytes characterized. These pilot findings for the non-classical monocytes are novel in the field of ME/CFS. We recommend that occupational therapists advocate and explain to family members without ME/CFS the need for the family members' participation as a second set of controls in pilot studies to rapidly eliminate false biomarkers, optimize patient participation, and save researchers' labor.

Comprehensive Circulatory Metabolomics in ME/CFS Reveals Disrupted Metabolism of Acyl Lipids and Steroids

The latest worldwide prevalence rate projects that over 65 million patients suffer from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), an illness with known effects on the functioning of the immune and nervous systems. We performed an extensive metabolomics analysis on the plasma of 52 female subjects, equally sampled between controls and ME/CFS patients, which delivered data for about 1750 blood compounds spanning 20 super-pathways, subdivided into 113 sub-pathways. Statistical analysis combined with pathway enrichment analysis points to a few disrupted metabolic pathways containing many unexplored compounds. The most intriguing finding concerns acyl cholines, belonging to the fatty acid metabolism sub-pathway of lipids, for which all compounds are consistently reduced in two distinct ME/CFS patient cohorts. We compiled the extremely limited knowledge about these compounds and regard them as promising in the quest to explain many of the ME/CFS symptoms. Another class of lipids with far-reaching activity on virtually all organ systems are steroids; androgenic, progestin, and corticosteroids are broadly reduced in our patient cohort. We also report on lower dipeptides and elevated sphingolipids abundance in patients compared to controls. Disturbances in the metabolism of many of these molecules can be linked to the profound organ system symptoms endured by ME/CFS patients.

Association of suboptimal health status with intestinal microbiota in Chinese youths

Suboptimal health status (SHS), a physical state between health and disease, is a subclinical and reversible stage of chronic disease. Previous studies have shown alterations in the intestinal microbiota in patients with some chronic diseases. This study aimed to investigate the association between SHS and intestinal microbiota in a case-control study with 50 SHS individuals and 50 matched healthy controls. Intestinal microbiota was analysed by MiSeq 250PE. Alpha diversity of intestinal microbiota in SHS individuals was higher compared with that of healthy controls (Simpson index, W = 2238, P = .048). Beta diversity was different between SHS and healthy controls (P = .018). At the phylum level, the relative abundance of Verrucomicrobia was higher in the SHS group than that in the controls (W = 2201, P = .049). Compared with that of the control group, nine genera were significantly higher and five genera were lower in abundance in the SHS group (all P < .05). The intestinal microbiota, analysed by a random forest model, was able to distinguish individuals with SHS from the controls, with an area under the curve of 0.79 (95% confidence interval: 0.77-0.81). We demonstrated that the alteration of intestinal microbiota occurs with SHS, an early stage of disease, which might shed light on the importance of intestinal microbiota in the primary prevention of noncommunicable chronic diseases.

Dominant Role of the Gut Microbiota in Chemotherapy Induced Neuropathic Pain

Chemotherapy induced peripheral neuropathy (CIPN), a toxic side effect of some cancer treatments, negatively impacts patient outcomes and drastically reduces survivor’s quality of life (QOL). Uncovering the mechanisms driving chemotherapy-induced CIPN is urgently needed to facilitate the development of effective treatments, as currently there are none. Observing that C57BL/6 (B6) and 129SvEv (129) mice are respectively sensitive and resistant to Paclitaxel-induced pain, we investigated the involvement of the gut microbiota in this extreme phenotypic response. Reciprocal gut microbiota transfers between B6 and 129 mice as well as antibiotic depletion causally linked gut microbes to Paclitaxel-induced pain sensitivity and resistance. Microglia proliferated in the spinal cords of Paclitaxel treated mice harboring the pain-sensitive B6 microbiota but not the pain-resistant 129 microbiota, which exhibited a notable absence of infiltrating immune cells. Paclitaxel decreased the abundance of Akkermansia muciniphila, which could compromise barrier integrity resulting in systemic exposure to bacterial metabolites and products – that acting via the gut-immune-brain axis – could result in altered brain function. Other bacterial taxa that consistently associated with both bacteria and pain as well as microglia and pain were identified, lending support to our hypothesis that microglia are causally involved in CIPN, and that gut bacteria are drivers of this phenotype.

The effect of comorbid medical and psychiatric diagnoses on chronic fatigue syndrome

Objective: To determine if presence of co-existing medically unexplained syndromes or psychiatric diagnoses affect symptom frequency, severity or activity impairment in Chronic Fatigue Syndrome.Patients: Sequential Chronic Fatigue Syndrome patients presenting in one clinical practice.Design: Participants underwent a psychiatric diagnostic interview and were evaluated for fibromyalgia, irritable bowel syndrome and/or multiple chemical sensitivity.Main Measures: Structured Clinical Interview [SCID] for DSM-IV; SF-36, Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Short Form; Patient Health Questionnaire-8; Multidimensional Fatigue Inventory (MFI-20), CDC Symptom InventoryResults: Current and lifetime psychiatric diagnosis was common (68%) increasing mental fatigue/health but no other illness variables and not with diagnosis of other medically unexplained syndromes. 81% of patients had at least one of these conditions with about a third having all three co-existing syndromes. Psychiatric diagnosis was not associated with their diagnosis. Increasing the number of these unexplained conditions was associated with increasing impairment in physical function, pain and rates of being unable to work.Conclusions: Patients with Chronic Fatigue Syndrome should be evaluated for current psychiatric conditions because of their impact on patient quality of life, but they do not act as a symptom multiplier for the illness. Other co-existing medically unexplained syndromes are more common than psychiatric co-morbidities in patients presenting for evaluation of medically unexplained fatigue and are also more associated with increased disability and the number and severity of symptoms.Key messagesWhen physicians see patients with medically unexplained fatigue, they often infer that this illness is due to an underlying psychiatric problem.This paper shows that the presence of co-existing psychiatric diagnoses does not impact on any aspect of the phenomenology of medically unexplained fatigue also known as chronic fatigue syndrome. Therefore, psychiatric status is not an important causal contributor to CFS.In contrast, the presence of other medically unexplained syndromes (irritable bowel syndrome; fibromyalgia and/or multiple chemical sensitivity) do impact on the illness such that the more of these that co-exist the more health-related burdens the patient has.

Dysbiotic microbiota in autistic children and their mothers: persistence of fungal and bacterial wall-deficient L-form variants in blood

Based on our hypothesis for existing microbiota of wall-deficient variants (L-forms) in human blood, we created an innovative methodology, which allowed for the development of L-form populations from blood of all investigated people. In contrast to healthy controls, blood L-forms from autistic children and their mothers converted under appropriate conditions of cultivation into detectable opportunistic bacteria and fungi, а process demonstrated by light and transmission electron microscopy. It can be distinguished into two types of states – “eubiotic” blood microbiota in healthy individuals, and “dysbiotic” in autistic children and their mothers. Remarkably, the unifying finding for autistic children and their mothers was the presence in blood of wall-free variants from life-cycle of filamentous fungi. Increased specific IgG, IgM and IgA, together with typical mold growth were a decisive argument for proven presence of Aspergillus fumigatus in almost all of the autistic children. As it was demonstrated in our previous study, filterable L-forms can be transmitted by vertical pathway from mother to child before birth. Thus, it can be suggested that autistic children may be born already colonized with fungi, while a “silent aspergillosis” could contribute or even be a leading cause for neurodevelopmental disorders in the early childhood.

Inflammatory proteins are altered in chronic fatigue syndrome-A systematic review and meta-analysis

Immune dysfunction has been posited as a key element in the aetiology of chronic fatigue syndrome (CFS) since the illness was first conceived. However, systematic reviews have yet to quantitatively synthesise inflammatory biomarkers across the literature. We undertook a systematic review and meta-analysis to quantify available data on circulating inflammatory proteins, examining studies recruiting patients with a CFS diagnosis and a non-affected control group. Results were meta-analysed from 42 studies. Patients with CFS had significantly elevated tumour necrosis factor (ES = 0.274, p < 0.001), interleukin-2 (ES = 0.203, p = 0.006), interleukin-4 (ES = 0.373, p = 0.004), transforming growth factor-β (ES = 0.967, p < 0.001) and c-reactive protein (ES = 0.622, p = 0.019). 12 proteins did not differ between groups. These data provide some support for an inflammatory component in CFS, although inconsistency of results indicates that inflammation is unlikely to be a primary feature in all those suffering from this disorder. It is hoped that further work will elucidate whether there are subgroups of patients with clinically-relevant inflammatory dysfunction, and whether inflammatory cytokines may provide a prognostic biomarker or moderate treatment effects.

Are There Potential Applications of Fecal Microbiota Transplantation beyond Intestinal Disorders?

Intestinal microbial dysbiosis is associated with various intestinal and extraintestinal disorders. Fecal microbiota transplantation (FMT), a type of fecal bacteriotherapy, is considered an effective therapeutic option for recurrent Clostridium difficile infection (rCDI) and also has important value in other intestinal diseases including irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). The purpose of this review is to discuss promising therapeutic value in extraintestinal diseases associated with gut microbial dysbiosis, including liver, metabolic, chronic kidney, neuropsychiatric, allergic, autoimmune, and hematological diseases as well as tumors.

Current Research Provides Insight into the Biological Basis and Diagnostic Potential for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe fatigue illness that occurs most commonly following a viral infection, but other physiological triggers are also implicated. It has a profound long-term impact on the life of the affected person. ME/CFS is diagnosed primarily by the exclusion of other fatigue illnesses, but the availability of multiple case definitions for ME/CFS has complicated diagnosis for clinicians. There has been ongoing controversy over the nature of ME/CFS, but a recent detailed report from the Institute of Medicine (Academy of Sciences, USA) concluded that ME/CFS is a medical, not psychiatric illness. Importantly, aspects of the biological basis of the ongoing disease have been revealed over the last 2-3 years that promise new leads towards an effective clinical diagnostic test that may have a general application. Our detailed molecular studies with a preclinical study of ME/CFS patients, along with the complementary research of others, have reported an elevation of inflammatory and immune processes, ongoing neuro-inflammation, and decreases in general metabolism and mitochondrial function for energy production in ME/CFS, which contribute to the ongoing remitting/relapsing etiology of the illness. These biological changes have generated potential molecular biomarkers for use in diagnostic ME/CFS testing.

Generating dynamical neuroimaging spatiotemporal representations (DyNeuSR) using topological data analysis

In this article, we present an open source neuroinformatics platform for exploring, analyzing, and validating distilled graphical representations of high-dimensional neuroimaging data extracted using topological data analysis (TDA). TDA techniques like Mapper have been recently applied to examine the brain's dynamical organization during ongoing cognition without averaging data in space, in time, or across participants at the outset. Such TDA-based approaches mark an important deviation from standard neuroimaging analyses by distilling complex high-dimensional neuroimaging data into simple-yet neurophysiologically valid and behaviorally relevant-representations that can be interactively explored at the single-participant level. To facilitate wider use of such techniques within neuroimaging and general neuroscience communities, our work provides several tools for visualizing, interacting with, and grounding TDA-generated graphical representations in neurophysiology. Through Python-based Jupyter notebooks and open datasets, we provide a platform to assess and visualize different intermittent stages of Mapper and examine the influence of Mapper parameters on the generated representations. We hope this platform could enable researchers and clinicians alike to explore topological representations of neuroimaging data and generate biological insights underlying complex mental disorders.

Leveraging Human Microbiome Features to Diagnose and Stratify Children with Irritable Bowel Syndrome

Accurate diagnosis and stratification of children with irritable bowel syndrome (IBS) remain challenging. Given the central role of recurrent abdominal pain in IBS, we evaluated the relationships of pediatric IBS and abdominal pain with intestinal microbes and fecal metabolites using a comprehensive clinical characterization and multiomics strategy. Using rigorous clinical phenotyping, we identified preadolescent children (aged 7 to 12 years) with Rome III IBS (n = 23) and healthy controls (n = 22) and characterized their fecal microbial communities using whole-genome shotgun metagenomics and global unbiased fecal metabolomic profiling. Correlation-based approaches and machine learning algorithms identified associations between microbes, metabolites, and abdominal pain. IBS cases differed from controls with respect to key bacterial taxa (eg, Flavonifractor plautii and Lachnospiraceae bacterium 7_1_58FAA), metagenomic functions (eg, carbohydrate metabolism and amino acid metabolism), and higher-order metabolites (eg, secondary bile acids, sterols, and steroid-like compounds). Significant associations between abdominal pain frequency and severity and intestinal microbial features were identified. A random forest classifier built on metagenomic and metabolic markers successfully distinguished IBS cases from controls (area under the curve, 0.93). Leveraging multiple lines of evidence, intestinal microbes, genes/pathways, and metabolites were associated with IBS, and these features were capable of distinguishing children with IBS from healthy children. These multi-omics features, and their links to childhood IBS coupled with nutritional interventions, may lead to new microbiome-guided diagnostic and therapeutic strategies.

Identifying Gut Microbiota Associated With Colorectal Cancer Using a Zero-Inflated Lognormal Model

Colorectal cancer (CRC) is the third most common cancer worldwide. Its incidence is still increasing, and the mortality rate is high. New therapeutic and prognostic strategies are urgently needed. It became increasingly recognized that the gut microbiota composition differs significantly between healthy people and CRC patients. Thus, identifying the difference between gut microbiota of the healthy people and CRC patients is fundamental to understand these microbes' functional roles in the development of CRC. We studied the microbial community structure of a CRC metagenomic dataset of 156 patients and healthy controls, and analyzed the diversity, differentially abundant bacteria, and co-occurrence networks. We applied a modified zero-inflated lognormal (ZIL) model for estimating the relative abundance. We found that the abundance of genera: Anaerostipes, Bilophila, Catenibacterium, Coprococcus, Desulfovibrio, Flavonifractor, Porphyromonas, Pseudoflavonifractor, and Weissella was significantly different between the healthy and CRC groups. We also found that bacteria such as Streptococcus, Parvimonas, Collinsella, and Citrobacter were uniquely co-occurring within the CRC patients. In addition, we found that the microbial diversity of healthy controls is significantly higher than that of the CRC patients, which indicated a significant negative correlation between gut microbiota diversity and the stage of CRC. Collectively, our results strengthened the view that individual microbes as well as the overall structure of gut microbiota were co-evolving with CRC.

Fatigue in IBD: epidemiology, pathophysiology and management

Fatigue is an important clinical problem in patients with IBD, affecting nearly 50% of patients in clinical remission and > 80% of those with active disease. The resulting decrease in quality of life and impaired work productivity and functioning contribute markedly to the societal costs of fatigue. However, despite the burden and effects of fatigue, little is known about its aetiology and pathophysiology, which impairs our ability to effectively treat this symptom. Here, we review the theories behind the development of fatigue in IBD and the role of contributing factors, including nutritional deficiency, inflammation and altered metabolism. We also explore the potential role of the gut microbiome in mediating fatigue and other psychological symptoms through the gut-brain axis. We discuss the efficacy of nutrient repletion and various psychological and pharmacological interventions on relieving fatigue in patients with IBD and expand the discussion to non-IBD-related fatigue when evidence exists. Finally, we present a therapeutic strategy for the management of fatigue in IBD and call for further mechanistic and clinical research into this poorly studied symptom.

Epigenetic Components of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Uncover Potential Transposable Element Activation

PURPOSE

Studies to determine epigenetic changes associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) remain scarce; however, current evidence clearly shows that methylation patterns of genomic DNA and noncoding RNA profiles of immune cells differ between patients and healthy subjects, suggesting an active role of these epigenetic mechanisms in the disease. The present study compares and contrasts the available ME/CFS epigenetic data in an effort to evidence overlapping pathways capable of explaining at least some of the dysfunctional immune parameters linked to this disease.

METHODS

A systematic search of the literature evaluating the ME/CFS epigenome landscape was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Differential DNA methylation and noncoding RNA differential expression patterns associated with ME/CFS were used to screen for the presence of transposable elements using the Dfam browser, a search program nurtured with the Repbase repetitive sequence database and the RepeatMasker annotation tool.

FINDINGS

Unexpectedly, particular associations of transposable elements and ME/CFS epigenetic hallmarks were uncovered. A model for the disease emerged involving transcriptional induction of endogenous dormant transposons and structured cellular RNA interactions, triggering the activation of the innate immune system without a concomitant active infection.

IMPLICATIONS

Repetitive sequence filters (ie, RepeatMasker) should be avoided when analyzing transcriptomic data to assess the potential participation of repetitive sequences ("junk repetitive DNA"), representing >45% of the human genome, in the onset and evolution of ME/CFS. In addition, transposable element screenings aimed at designing cost-effective, focused empirical assays that can confirm or disprove the suspected involvement of transposon transcriptional activation in this disease, following the pilot strategy presented here, will require databases gathering large ME/CFS epigenetic datasets.

Environmental Exposures and Neuropsychiatric Disorders: What Role Does the Gut-Immune-Brain Axis Play?

PURPOSE OF REVIEW

Evidence is growing that environmental exposures-including xenobiotics as well as microbes-play a role in the pathogenesis of many neuropsychiatric disorders. Underlying mechanisms are likely to be complex, involving the developmentally sensitive interplay of genetic/epigenetic, detoxification, and immune factors. Here, we review evidence supporting a role for environmental factors and disrupted gut-immune-brain axis function in some neuropsychiatric conditions.

RECENT FINDINGS

Studies suggesting the involvement of an altered microbiome in triggering CNS-directed autoimmunity and neuropsychiatric disturbances are presented as an intriguing example of the varied mechanisms by which environmentally induced gut-immune-brain axis dysfunction may contribute to adverse brain outcomes. The gut-immune-brain axis is a burgeoning frontier for investigation of neuropsychiatric illness. Future translational research to define individual responses to exogenous exposures in terms of microbiome-dependent skew of the metabolome, immunity, and brain function may serve as a lens for illumination of pathways involved in the development of CNS disease and fuel discovery of novel interventions.