Altered serum bile acid profile in fibromyalgia is associated with specific gut microbiome changes and symptom severity

Fibromyalgia patients have altered lipid concentrations associated with disease symptom severity and anti-satellite glial cell IgG antibodies

Autoimmunity and immunoglobulin G (IgG) autoantibodies may contribute to pain in a subset of fibromyalgia (FM) patients. Previously, IgG from FM patients was found to induce pain-like behavior in mice and bind to satellite glial cells (anti-SGC IgG). The anti-SGC IgG levels were also associated with more severe symptomatology. Lipid metabolism in FM subjects is altered with lysophosphatidylcholines (LPCs) acting as pain mediators. The relationship between autoantibodies, lipid metabolism, and FM symptomatology remains unclear. Serum lipidomics with liquid chromatography mass spectrometry, anti-SGC IgG levels, and clinical measures were examined in 35 female FM subjects and 33 age- and body mass index-balanced healthy controls (HC). Fibromyalgia subjects with higher anti-SGC IgG levels experienced more intense pain than those with lower levels. Sixty-three lipids were significantly altered between FM subjects and HC or between FM subjects with severe (FM severe) and mild symptoms (FM mild). Compared to HC, FM subjects had lower concentrations of lipid species belonging to the classes LPC (n = 10), lysophosphatidylethanolamine (n = 7), phosphatidylcholine (n = 4), and triglyceride (n = 5), but higher concentrations of diglyceride (n = 3). Additionally, FM severe had higher LPC 19:0, 22:0, and 24:1 and lower sphingomyelin (n = 9) concentrations compared to FM mild. Positive associations were seen for LPC 22:0 and 24:1 with pain intensity and anti-SGC IgG levels in FM subjects. Taken together, these results suggest an association between altered lipid metabolism and autoimmune mechanisms in FM.

The role of the PKCζ/JNK signaling pathway in regulating the development of femoral head necrosis

Osteonecrosis of the femoral head (ONFH) is a debilitating condition characterized by the death of bone cells in the hip joint, resulting in profound disability. This condition has a significant global prevalence. Glucocorticoid (GC)-induced apoptosis of bone cells serves as a crucial cellular mechanism underlying ONFH. The protein kinase C zeta (PKCζ) and c-Jun N-terminal kinase (JNK)/c-Jun cascades have been implicated in the progression of ONFH, yet their interrelationship and contributions to disease development remain unclear. The objective of this study was to investigate the combined impact of PKCζ and JNK/c-Jun signaling on dexamethasone (Dex)-induced apoptosis in osteoblasts in vitro and in GC-induced ONFH rat models in vivo. In vitro experiments were conducted using hFOB1.19 osteoblastic cells to scrutinize the effects of Dex-induced apoptosis. The role of the PKCζ/JNK/c-Jun signaling pathway in this process was examined using naringenin-7-O-β-D-Glucuronide (N7G), a PKC inhibitor, and anisomycin, a JNK activator. The findings were further validated using a rat model of ONFH in vivo. Our results revealed that PKCζ activation augmented JNK/c-Jun signaling and facilitated Dex-induced osteoblast apoptosis. Inhibition of PKCζ with N7G mitigated these effects, while JNK activation with anisomycin intensified them. Similar regulatory effects on osteoblast apoptosis and ONFH progression were observed in the in vivo rat models. Glucocorticoids can induce osteoblast apoptosis and contribute to the development of ONFH by activating the PKCζ/JNK/c-Jun signaling pathway. This study provides compelling evidence supporting the potential therapeutic value of comprehending the pathogenesis of ONFH and developing targeted treatments for this debilitating condition.

Treating chronic stress and chronic pain by manipulating gut microbiota with diet: can we kill two birds with one stone?

Background: Chronic stress and chronic pain are closely linked by the capacity to exacerbate each other, sharing common roots in the brain and in the gut. The strict intersection between these two neurological diseases makes important to have a therapeutic strategy aimed at preventing both to maintain mental health in patients. Diet is an modifiable lifestyle factor associated with gut-brain axis diseases and there is growing interest in its use as adjuvant to main therapies. Several evidence attest the impact of specific diets or nutrients on chronic stress-related disorders and pain with a good degree of certainty. A daily adequate intake of foods containing micronutrients such as amino acids, minerals and vitamins, as well as the reduction in the consumption of processed food products can have a positive impact on microbiota and gut health. Many nutrients are endowed of prebiotic, anti-inflammatory, immunomodulatory and neuroprotective potential which make them useful tools helping the management of chronic stress and pain in patients. Dietary regimes, as intermittent fasting or caloric restriction, are promising, although further studies are needed to optimize protocols according to patient's medical history, age and sex. Moreover, by supporting gut microbiota health with diet is possible to attenuate comorbidities such as obesity, gastrointestinal dysfunction and mood disorders, thus reducing healthcare costs related to chronic stress or pain.Objective: This review summarize the most recent evidence on the microbiota-mediated beneficial effects of macro- and micronutrients, dietary-related factors, specific nutritional regimens and dietary intervention on these pathological conditions.

Distinctive salivary oral microbiome in patients with burning mouth syndrome depending on pain intensity compared to healthy subjects

Background/purpose

Burning moouth syndrome (BMS) is a chronic pain condition similar to neuropathic pain. It is characterized by a persistent burning sensation in the oral cavity. Despite the lack of clarity regarding the etiology of BMS, recent studies have reported an association between the gut microbiome and neuropathic pain. However, few studies have investigated the association between the oral microbiome and orofacial pain, such as BMS. This study aimed to compare the oral microbial profiles of healthy controls (HC) and patients with BMS.

Materials and methods

The BMS group was further divided into BMS_low and BMS_high groups according to pain intensity. A total of 60 patients with BMS (BMS_low, n = 16; BMS_high, n = 44) and 30 HC provided saliva samples, which were sequenced and analyzed for the V1-V2 region of the 16S rRNA gene.

Results

The alpha diversity was similar among the three groups. However, a significant difference in the distribution of microbiome composition was observed between BMS_high and HC, as revealed by the Bray-Curtis distance analysis (P < 0.01). At the genus level, Prevotella and Alloprevotella were the most abundant genera in the BMS group. Compared to HC, BMS_high exhibited a relatively higher abundance of bacterial species. Some bacteria, including Prevotella spp., exhibit an increasing pattern with subjective pain intensity.

Conclusion

These results suggest the potential involvement of oral microbiota in BMS pathogenesis. Additionally, variations in the microbiome may occur not only in the presence or absence of pain, but also with pain severity.

Exploring the role of a novel postbiotic bile acid: Interplay with gut microbiota, modulation of the farnesoid X receptor, and prospects for clinical translation

The gut microbiota, mainly resides in the colon, possesses a remarkable ability to metabolize different substrates to create bioactive substances, including short-chain fatty acids, indole-3-propionic acid, and secondary bile acids. In the liver, bile acids are synthesized from cholesterol and then undergo modification by the gut microbiota. Beyond those reclaimed by the enterohepatic circulation, small percentage of bile acids escaped reabsorption, entering the systemic circulation to bind to several receptors, such as farnesoid X receptor (FXR), thereby exert their biological effects. Gut microbiota interplays with bile acids by affecting their synthesis and determining the production of secondary bile acids. Reciprocally, bile acids shape out the structure of gut microbiota. The interplay of bile acids and FXR is involved in the development of multisystemic conditions, encompassing metabolic diseases, hepatobiliary diseases, immune associated disorders. In the review, we aim to provide a thorough review of the intricate crosstalk between the gut microbiota and bile acids, the physiological roles of bile acids and FXR in mammals' health and disease, and the clinical translational considerations of gut microbiota-bile acids-FXR in the treatment of the diseases.

Risk of fibromyalgia following antibiotic prescriptions: A population-based case-control study

BACKGROUND

The health of the gut microbiome is now recognized to be an important component of the gut-brain axis which itself appears to be implicated in pain perception. Antibiotics are known to create dysbiosis in the microbiome, so whether fibromyalgia is more commonly diagnosed after antibiotic prescriptions provides a means of exploring the role of the microbiome in the experience of chronic pain.

METHODS

A case-control study was carried out using electronic health records collected in the UK's Clinical Practice Research Datalink (CPRD), a comprehensive database of primary care consultations. For each case of diagnosed fibromyalgia, three controls were identified and matched by age, gender and GP practice. The exposure variable was the number and timing of antibiotic prescriptions over previous years. The analysis involved adjusting for a wide range of co-variates that might be possible confounders.

RESULTS

A total of 44,674 cases of fibromyalgia were identified together with 133,513 controls. After adjusting for co-variates, it was found that both the total number of prescriptions and their timing was associated with an FM diagnosis. For example, the quartile with the highest number of prescriptions and that with the longest exposure had a greater than three-fold increase in FM diagnoses (number of prescriptions: odds ratio 3.92; 95% CIs: 3.71-4.13; exposure odds ratio 3.28; CIs: 3.13-3.43). Some antibiotics (such as tetracyclines and metronidazole) seemed to confer greater risk than others.

CONCLUSIONS

The results lend support for prior antibiotics being an important risk factor for a diagnosis of FM.

SIGNIFICANCE

This study shows an association between the volume as well as timing of prior antibiotic prescriptions and of a subsequent diagnosis of fibromyalgia in primary care.

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.

Nutrition and Chronobiology as Key Components of Multidisciplinary Therapeutic Interventions for Fibromyalgia and Associated Chronic Fatigue Syndrome: A Narrative and Critical Review

Fibromyalgia (FM) is often accompanied by chronic fatigue syndrome (CFS). It is a poorly understood disorder that mainly affects women and leads to chronic pain, fatigue, and insomnia, among other symptoms, which decrease quality of life. Due to the inefficiency of current pharmacological treatments, increasing interest is being directed towards non-pharmacological multicomponent therapies. However, nutrition and chronobiology are often overlooked when developing multicomponent therapies. This narrative and critical review explore the relevance of nutritional and chronobiological strategies in the therapeutic management of FM and the often-associated CFS. Reviewed literature offers scientific evidence for the association of dietary habits, nutrient levels, body composition, gut microbiota imbalance, chronobiological alterations, and their interrelation with the development and severity of symptoms. This review highlights the key role of nutrition and chronobiology as relevant and indispensable components in a multidisciplinary approach to FM and CFS.

The importance of the gut microbiome and its signals for a healthy nervous system and the multifaceted mechanisms of neuropsychiatric disorders

Increasing evidence links the gut microbiome and the nervous system in health and disease. This narrative review discusses current views on the interaction between the gut microbiota, the intestinal epithelium, and the brain, and provides an overview of the communication routes and signals of the bidirectional interactions between gut microbiota and the brain, including circulatory, immunological, neuroanatomical, and neuroendocrine pathways. Similarities and differences in healthy gut microbiota in humans and mice exist that are relevant for the translational gap between non-human model systems and patients. There is an increasing spectrum of metabolites and neurotransmitters that are released and/or modulated by the gut microbiota in both homeostatic and pathological conditions. Dysbiotic disruptions occur as consequences of critical illnesses such as cancer, cardiovascular and chronic kidney disease but also neurological, mental, and pain disorders, as well as ischemic and traumatic brain injury. Changes in the gut microbiota (dysbiosis) and a concomitant imbalance in the release of mediators may be cause or consequence of diseases of the central nervous system and are increasingly emerging as critical links to the disruption of healthy physiological function, alterations in nutrition intake, exposure to hypoxic conditions and others, observed in brain disorders. Despite the generally accepted importance of the gut microbiome, the bidirectional communication routes between brain and gut are not fully understood. Elucidating these routes and signaling pathways in more detail offers novel mechanistic insight into the pathophysiology and multifaceted aspects of brain disorders.

Fibromyalgia and Irritable Bowel Syndrome Interaction: A Possible Role for Gut Microbiota and Gut-Brain Axis

Fibromyalgia (FM) is a serious chronic pain syndrome, characterised by muscle and joint stiffness, insomnia, fatigue, mood disorders, cognitive dysfunction, anxiety, depression and intestinal irritability. Irritable Bowel Syndrome (IBS) shares many of these symptoms, and FM and IBS frequently co-exist, which suggests a common aetiology for the two diseases. The exact physiopathological mechanisms underlying both FM and IBS onset are unknown. Researchers have investigated many possible causes, including alterations in gut microbiota, which contain billions of microorganisms in the human digestive tract. The gut-brain axis has been proven to be the link between the gut microbiota and the central nervous system, which can then control the gut microbiota composition. In this review, we will discuss the similarities between FM and IBS. Particularly, we will focus our attention on symptomatology overlap between FM and IBS as well as the similarities in microbiota composition between FM and IBS patients. We will also briefly discuss the potential therapeutic approaches based on microbiota manipulations that are successfully used in IBS and could be employed also in FM patients to relieve pain, ameliorate the rehabilitation outcome, psychological distress and intestinal symptoms.

Pain-resolving immune mechanisms in neuropathic pain

Interactions between the immune and nervous systems are of central importance in neuropathic pain, a common and debilitating form of chronic pain caused by a lesion or disease affecting the somatosensory system. Our understanding of neuroimmune interactions in pain research has advanced considerably. Initially considered as passive bystanders, then as culprits in the pathogenesis of neuropathic pain, immune responses in the nervous system are now established to underpin not only the initiation and progression of pain but also its resolution. Indeed, immune cells and their mediators are well-established promoters of neuroinflammation at each level of the neural pain pathway that contributes to pain hypersensitivity. However, emerging evidence indicates that specific subtypes of immune cells (including antinociceptive macrophages, pain-resolving microglia and T regulatory cells) as well as immunoresolvent molecules and modulators of the gut microbiota-immune system axis can reduce the pain experience and contribute to the resolution of neuropathic pain. This Review provides an overview of the immune mechanisms responsible for the resolution of neuropathic pain, including those involved in innate, adaptive and meningeal immunity as well as interactions with the gut microbiome. Specialized pro-resolving mediators and therapeutic approaches that target these neuroimmune mechanisms are also discussed.

Investigating the association between the symptoms of women with Fibromyalgia, Digestive function, and markers of the microbiota of the Gastrointestinal Tract (The FIDGIT Study): study protocol

BACKGROUND

Fibromyalgia a common idiopathic condition affecting around 1.4% of adults globally. Its signature symptom is chronic widespread pain, with a constellation of somatic and psychological symptoms. Fibromyalgia is associated with significant reductions in quality of life, yet to date there is no biochemical marker for its diagnosis. Previous studies have indicated a strong association with gastrointestinal dysfunction, and more recently, alterations to the gut microbiome. No studies have examined the inter-relationship between fibromyalgia, gastrointestinal dysfunction, and the microbiome. This prospective observational case-controlled study will gather data on gastrointestinal function, dietary intake, fermentation patterns of ingested carbohydrates, and symptoms commonly associated with fibromyalgia. These will be evaluated alongside human gene expression and metatranscriptomic analysis of the oral and faecal microbiome.

METHODS

Adult women aged ≥18 years diagnosed with fibromyalgia and/or meeting ACR 2016 criteria, and healthy family or age-matched controls will be recruited from the community. From consenting participants, we will collect detailed survey information and samples of blood, urine, stool, saliva, and breath.

DISCUSSION

This is the first prospective study examining interactions between digestive function, human gene expression, and the gut microbiome together with general, and fibromyalgia-specific, symptoms experienced by New Zealand women. This exploration will allow an in-depth understanding of clinically relevant factors that are associated with fibromyalgia and will guide further research and contribute to improved management of this poorly understood condition.

TRIAL REGISTRATION

The study was approved by the New Zealand Health and Disability Committee (HDEC) (ref: 20/CEN/197) and registered with the Australia and New Zealand Clinical Trials Registry (ANZCTR), registration number ACTRN12620001337965. Written consent will be obtained after providing participants with detailed information about the procedures. Access to data will be restricted to the immediate research team, and all samples and survey data will be deidentified and coded before analysis.

Enhanced Patient-Centricity: How the Biopharmaceutical Industry Is Optimizing Patient Care through AI/ML/DL

Technologies utilizing cutting-edge methodologies, including artificial intelligence (AI), machine learning (ML) and deep learning (DL), present powerful opportunities to help evaluate, predict, and improve patient outcomes by drawing insights from real-world data (RWD) generated during medical care. They played a role during and following the Coronavirus Disease 2019 (COVID-19) pandemic by helping protect healthcare providers, prioritize care for vulnerable populations, predict disease trends, and find optimal therapies. Potential applications across therapeutic areas include diagnosis, disease management and patient journey mapping. Use of fit-for-purpose datasets for ML models is seeing growth and may potentially help additional enterprises develop AI strategies. However, biopharmaceutical companies often face specific challenges, including multi-setting data, system interoperability, data governance, and patient privacy requirements. There remains a need for evolving regulatory frameworks, operating models, and data governance to enable further developments and additional research. We explore recent literature and examine the hurdles faced by researchers in the biopharmaceutical industry to fully realize the promise of AI/ML/DL for patient-centric purposes.