Tag: pilot study

A Short-Term Pacing Intervention in People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Study in Portugal

Abstract:

Background and Objectives: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) remains a disease without a curative treatment. Hence, patient healthcare is mostly based on symptom management and the application of coping strategies, such as pacing. In this strategy, patients learn how to plan their daily physical and cognitive activities according to their perceived energy reservoir (or envelop). However, there is currently no evidence for the feasibility of pacing in Portugal, where ME/CFS is not well recognized.

Materials and Methods: We implemented a 8-week pacing program in Portuguese patients with an official diagnosis of ME/CFS. We focused on recruitment feasibility, protocol adherence, and patient acceptability, with secondary exploratory analysis of pre- and post-intervention variations in the Chalder’s fatigue questionnaire and SF36 physical functioning scores.

Results: We were able to recruit thirteen patients for the study. The patients attended, on average, seven out of the eight sessions expected per participant, with the majority adhering to the research protocol (n=7;53.8%). In a post-intervention survey, the respondents (n=10) considered that the intervention addressed the specific needs of people living with ME/CFS. Concerning the outcome trends, the average fatigue score decreased from 27.5 at baseline to 17.7 after the intervention. The mean physical functioning score increased from 24.6 to 31.7.

Conclusions: This exploratory study supported the feasibility of benchmark studies in Portugal with increased sample size, longer interventions, and including a control group (e.g., specialized medical care), with which eventual placebo effects can be better accounted for.

Source: Ribeiro V, Azevedo P, Westermeier F, Sepúlveda N. A Short-Term Pacing Intervention in People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Study in Portugal. Medicina (Kaunas). 2026 Feb 6;62(2):331. doi: 10.3390/medicina62020331. PMID: 41752730. https://www.mdpi.com/1648-9144/62/2/331 (Full text)

Multi-Strain Probiotic Improves Tryptophan Metabolism and Symptoms in Chronic Fatigue Syndrome Patients with Co-Occurring Irritable Bowel Syndrome: An Open-Label Pilot Study

Simple Summary:

Chronic Fatigue Syndrome (CFS) is a debilitating condition often accompanied by gut health issues, but effective treatments are scarce. Recent research suggests that an imbalance in gut bacteria (dysbiosis) may contribute to CFS symptoms by producing harmful substances that affect the nervous system. We investigated whether a specific multi-strain probiotic (CDS22-formula) could improve symptoms in women with CFS and co-occurring IBS. Over 12 weeks, patients took a high-dose probiotic supplement. We monitored their fatigue levels and analyzed urine samples to track changes in tryptophan metabolism—a key pathway linking the gut to the brain. The results showed that the probiotic intervention was associated with an improved gut bacteria profile. Importantly, this coincided with a reduction in neurotoxic metabolites and a significant decrease in fatigue severity. Our findings suggest that targeting the gut microbiome can be a valuable strategy for managing chronic fatigue, potentially by modulating the production of metabolites that affect brain function.
Abstract:

Background/Objectives: Gut dysbiosis in Chronic Fatigue Syndrome (CFS) drives low-grade inflammation and shifts tryptophan metabolism toward neurotoxic pathways. The causal link between bacterial translocation, kynurenine pathway dysregulation, and symptom severity remains under-defined. We evaluated the impact of a high-concentration multi-strain probiotic on the “gut-kynurenine axis” and clinical status in CFS patients with co-morbid IBS-U and confirmed dysbiosis.
Methods: Forty female patients with confirmed dysbiosis (GA-map™ Dysbiosis Index > 2) received the CDS22 formula (450 billion CFU/day) for 12 weeks. We compared urinary tryptophan metabolite profiles (LC-MS/MS), gut dysbiosis markers (3-indoxyl sulfate), and fatigue severity (FSS) against 40 age-matched healthy controls.
Results: Baseline analysis revealed profound metabolic perturbations: elevated bacterial proteolytic markers (3-IS), substrate depletion (low tryptophan), and a neurotoxic signature (high quinolinic acid [QA], low kynurenic acid [KYNA]). Following the intervention, fatigue scores declined by 40.3%, with 97.5% of patients reaching the remission threshold (FSS < 36). Biochemically, 3-IS levels decreased to the range observed in healthy controls and attenuated xanthurenic acid levels. Although absolute QA concentrations remained elevated compared to controls, the neuroprotective KYNA/QA ratio increased significantly (+45%). Increased systemic tryptophan availability correlated directly with clinical symptom reduction (Spearman’s rho = −0.36, p = 0.024).
Conclusions: The CDS22 formulation was associated with a restoration of intestinal eubiosis and functional tryptophan partitioning. Clinical remission coincides with a metabolic shift favoring neuroprotection (increased KYNA/QA ratio), validating the gut–kynurenine axis as a modifiable therapeutic target. Peripheral metabolic improvement relative to the healthy baseline appeared sufficient for symptom relief in this specific phenotype, despite incomplete clearance of neurotoxic metabolites.
Source:

Autonomic phenotyping, brain blood flow control, and cognitive-motor-integration in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome: A pilot study

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and the prolonged sequelae after COVID-19 (>3 months; Long COVID) have similar symptomology, are both associated with autonomic dysfunction, and a growing proportion of Long COVID patients are developing ME/CFS. We aimed to determine an autonomic phenotype of patients with ME/CFS vs Long COVID. We hypothesized that the groups would differ from controls yet be similar to one another.

We recruited sedentary controls (n = 10), mild/moderate ME/CFS patients (n = 12), and Long COVID patients (n = 9) to undergo 1) breathing 5 % CO2, 2) breathing 10 % O2, and 3) 5-minutes of 70° head-up tilt. Respiratory, hemodynamic, and cerebrovascular variables were measured throughout the 3 trials. Resting vascular function and cognitive-motor-integration were also assessed. ME/CFS and Long COVID were similar to the healthy controls and each other with regard to resting vascular function and the hemodynamic responses to hypoxia, hypercapnia, and head-up tilt (p > 0.05). However, in ME/CFS we observed a greater reduction of cerebrovascular resistance (p = 0.041) and impaired autoregulation (p = 0.042) during hypercapnia alongside impaired cognitive-motor integration (p < 0.02), and in Long COVID we observed reduced peripheral and end-tidal oxygen (p < 0.04) and less vagal withdrawal during tilt (p = 0.028).

Our findings suggest unique phenotypes when comparing ME/CFS and Long COVID whereby we have shown that Long COVID patients experience hypoxia while upright contributing to less vagal withdrawal, and ME/CFS patients experience impaired cerebrovascular control during potentially leading to reduced cognitive-motor integration. These differences could stem from disease severity/duration or some unique aspect of the COVID-19 virus.

Source: Badhwar S, Pereira TJ, Kerr K, Bray R, Tabassum F, Sergio L, Edgell H. Autonomic phenotyping, brain blood flow control, and cognitive-motor-integration in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome: A pilot study. Auton Neurosci. 2025 Oct 14;262:103358. doi: 10.1016/j.autneu.2025.103358. Epub ahead of print. PMID: 41138391. https://www.autonomicneuroscience.com/article/S1566-0702(25)00120-1/fulltext (Full text)

Stellate Ganglion Block reduces symptoms of SARS-CoV-2-induced ME/CFS: A prospective cohort pilot study

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating condition characterized by fatigue, orthostatic intolerance (OI), post-exertional malaise (PEM) and unrefreshing sleep. Our previous work has shown that modulating the autonomic nervous system can alleviate symptoms of Long COVID, which shares striking similarities with ME/CFS.

Objective: Determine the effect of stellate ganglion block (SGB) on symptoms of ME/CFS.

Methods: Subjects who met the WHO criteria for Long COVID and the Institute of Medicine criteria for ME/CFS were treated with sequential bilateral SGBs separated by 18–24 hours for three consecutive weeks (n = 10). At baseline, and at 2-weeks and 2-months post-treatment, we collected subjective assessments (SF-36 and DSQ2) of symptoms, objective assessments of orthostatic intolerance and cognitive performance, and saliva to measure morning cortisol. During the entire study period, a wearable device collected physiological data several nights a week to measure sleep parameters.

Results: DSQ2 measures of PEM, Unrefreshing Sleep, Cognitive Impairment, and OI improved significantly following treatment. SF-36 measures of Vitality, Physical Function, and Social Function improved significantly following treatment. Objective symptoms of POTS associated with infectious onset resolved following treatment. Objective measures of cognitive impairment were reduced following treatment, most notably in the areas of Immediate and Delayed Recognition. Morning cortisol and measures of sleep architecture did not change significantly following treatment.

Conclusions: Symptoms of ME/CFS were reduced after treatment with SGBs in this small prospective cohort pilot study. Given the lack of FDA-approved treatments for ME/CFS, replication of results in a large clinical trial is warranted.

Source: Duricka, D. L., & Liu, L. D. (2025). Stellate Ganglion Block reduces symptoms of SARS-CoV-2-induced ME/CFS: A prospective cohort pilot study. Fatigue: Biomedicine, Health &amp; Behavior, 13(2), 97–114. https://doi.org/10.1080/21641846.2025.2455876 https://www.tandfonline.com/doi/full/10.1080/21641846.2025.2455876#d1e276 (Full text)

Virtual reality education on myalgic encephalomyelitis for medical students and healthcare professionals: a pilot study

Abstract:

Introduction: Myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS) is a chronic condition which may be characterised by debilitating fatigue, post-exertional malaise, unrefreshing sleep, and cognitive difficulties. ME/CFS has significant negative impact on quality of life for those living with the condition. This may be exacerbated by a lack of knowledge within healthcare regarding the condition. Previous research has found that immersive virtual reality (VR) educational experiences within healthcare education can increase knowledge and empathy.

Methods: The present study employed a quasi-experimental pre-test-post-test design to investigate the impact of a short immersive VR educational experience on knowledge of ME/CFS and empathy for those living with the condition. The VR experience placed participants into a virtual scene which told real life stories of the experience of people living with ME/CFS and their families. 43 participants completed in this pilot study: 28 medical students and 15 primary care health professionals. Participants completed measures of knowledge of ME/CFS and empathy before and after engagement with the experience.

Results: A statistically significant increase was found for levels of knowledge (p < .001, d = 0.74) and empathy (p < .001, d = 1.56) from pre-VR experience levels to post-VR experience levels with a medium and large effect size, respectively. Further analysis revealed no statistically significant difference between baseline levels of knowledge of ME/CFS between healthcare professionals and medical students.

Discussion: The present study is the first to explore the use of this short immersive VR experience as an education tool within healthcare to increase knowledge of ME/CFS, and empathy for those living with the condition. Findings allude to the previously established lack of knowledge of ME/CFS within healthcare although promisingly the increases in knowledge and empathy found suggest that this immersive VR experience has potential to address this. Such changes found in this small-scale pilot study suggest that future research into the use of VR as an educational tool within this setting may be beneficial. Use of a control group, and larger sample size as well as investigation of retention of these changes may also enhance future research.

Source: Anderson T, Duffy G, Corry D. Virtual reality education on myalgic encephalomyelitis for medical students and healthcare professionals: a pilot study. BMC Med Educ. 2024 Sep 17;24(1):1018. doi: 10.1186/s12909-024-05990-2. PMID: 39289650; PMCID: PMC11409778. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11409778/ (Full text)

Herbal Medicines for Long COVID: A Phase 2 Pilot Clinical Study

Abstract:

Background: Infections of Coronavirus Disease-2019 (COVID-19) can cause long-term effects known as long COVID. This pilot study aimed to evaluate the feasibility of a clinical study as well as the efficacy and safety of traditional East Asian herbal medicines in alleviating fatigue and cognitive dysfunction “brain fog” in patients with long COVID.

Methods: This prospective pilot study investigated the use of three types of herbal medicines, Bojungikki-tang (BIT), Kyungok-go (KOG), and Cheonwangbosim-dan (CBD), for a 12-week period as potential treatments for fatigue and cognitive dysfunction in patients with long COVID. Forty-five patients with long COVID were recruited, and one of three drugs was given based on the patient’s symptoms and pattern identification. The effect of herbal medications on fatigue and cognitive function outcomes was assessed over a 36-week period, with patient adherence closely monitored.

Results: After 12 weeks of herbal drug administration, fatigue symptoms improved significantly across all groups, with treatment success rates of 80%, 53.33%, and 46.67% in the BIT, KOG, and CBD groups, respectively. However, “brain fog” symptoms showed less improvement, with treatment success rates of 40%, 46.67%, and 13.33% in the BIT, KOG, and CBD groups, respectively. All adverse events reported were mild and unrelated to the medication. The study design was found to be feasible with high medication adherence.

Conclusions: This study demonstrated the feasibility of conducting a clinical trial with three herbal medicines to treat long COVID symptoms like fatigue and “brain fog.”

Source:Kim, T.; Yoon, J.; Kim, S.; Kang, B.; Kang, J.W.; Kwon, S. Herbal Medicines for Long COVID: A Phase 2 Pilot Clinical Study. Preprints 2024, 2024011605. https://doi.org/10.20944/preprints202401.1605.v1 https://www.preprints.org/manuscript/202401.1605/v1 (Full text available as PDF file)

Phenotypic characteristics of peripheral immune cells of Myalgic encephalomyelitis/chronic fatigue syndrome via transmission electron microscopy: A pilot study

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex chronic multi-systemic disease characterized by extreme fatigue that is not improved by rest, and worsens after exertion, whether physical or mental. Previous studies have shown ME/CFS-associated alterations in the immune system and mitochondria.

We used transmission electron microscopy (TEM) to investigate the morphology and ultrastructure of unstimulated and stimulated ME/CFS immune cells and their intracellular organelles, including mitochondria. PBMCs from four participants were studied: a pair of identical twins discordant for moderate ME/CFS, as well as two age- and gender- matched unrelated subjects-one with an extremely severe form of ME/CFS and the other healthy.

TEM analysis of CD3/CD28-stimulated T cells suggested a significant increase in the levels of apoptotic and necrotic cell death in T cells from ME/CFS patients (over 2-fold). Stimulated Tcells of ME/CFS patients also had higher numbers of swollen mitochondria. We also found a large increase in intracellular giant lipid droplet-like organelles in the stimulated PBMCs from the extremely severe ME/CFS patient potentially indicative of a lipid storage disorder. Lastly, we observed a slight increase in platelet aggregation in stimulated cells, suggestive of a possible role of platelet activity in ME/CFS pathophysiology and disease severity.

These results indicate extensive morphological alterations in the cellular and mitochondrial phenotypes of ME/CFS patients’ immune cells and suggest new insights into ME/CFS biology.

Source: Jahanbani F, Maynard RD, Sing JC, Jahanbani S, Perrino JJ, Spacek DV, Davis RW, Snyder MP. Phenotypic characteristics of peripheral immune cells of Myalgic encephalomyelitis/chronic fatigue syndrome via transmission electron microscopy: A pilot study. PLoS One. 2022 Aug 9;17(8):e0272703. doi: 10.1371/journal.pone.0272703. PMID: 35943990. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0272703 (Full text)

Hydrogen water as a treatment for myalgic encephalomyelitis/chronic fatigue syndrome: a pilot randomized trial

Abstract:

Background: Given the absence of effective medical treatments for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), the testing of a new intervention that may ameliorate potentially pathologic levels of oxidative stress, sympathetic arousal, and inflammation may yield symptomatic improvements.

Objective: To explore in a pilot study, the possible beneficial effect of molecular hydrogen (H2) for the symptoms and functional limitations of ME/CFS.

Methods: Twenty-three subjects were randomized to H2 or active placebo which involved drinking up to five glasses daily of hydrogen-enriched water or placebo water for 28 days. Assessments included: (i) self-report fatigue, physical function, and stress; (ii) salivary C-Reactive Protein (inflammation), Uric Acid (antioxidant status), and Alpha-Amylase (sympathetic function); and (iii) heart rate variability (parasympathetic activity). Data were analysed with Wilcoxon rank-sum tests.

Results: Completion rate for the primary outcome measure of fatigue severity was 100% for the 11 hydrogen participants and 91.7% (n = 11) for placebo participants. No significant changes were found on self-report or biological variables in the active vs. placebo treatment conditions. A small, but significant reduction in fatigue was found in the placebo condition. Adverse effects led to treatment discontinuation in 27.2% of H2 subjects. All severe- and moderate-intensity effects were found in the active treatment condition. Adverse effects were not significantly associated with any demographic or symptom variable.

Conclusions: Therapeutic molecular hydrogen did not yield improvement on any biological or symptom measure in individuals with ME/CFS. Dosage reduction might benefit any future trial of hydrogen therapy in this illness.

Source: Fred Friedberg & Dennis Choi (2022) Hydrogen water as a treatment for myalgic encephalomyelitis/chronic fatigue syndrome: a pilot randomized trial, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2022.2038519

Modification of Immunological Parameters, Oxidative Stress Markers, Mood Symptoms, and Well-Being Status in CFS Patients after Probiotic Intake: Observations from a Pilot Study

Abstract:

The present study discusses about the effects of a combination of probiotics able to stimulate the immune system of patients affected by Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). To this purpose, patients diagnosed according to Fukuda’s criteria and treated with probiotics were analyzed by means of clinical and laboratory evaluations, before and after probiotic administrations.

Probiotics were selected considering the possible pathogenic mechanisms of ME/CFS syndrome, which has been associated with an impaired immune response, dysregulation of Th1/Th2 ratio, and high oxidative stress with exhaustion of antioxidant reserve due to severe mitochondrial dysfunction. Immune and oxidative dysfunction could be related with the gastrointestinal (GI) chronic low-grade inflammation in the lamina propria and intestinal mucosal surface associated with dysbiosis, leaky gut, bacterial translocation, and immune and oxidative dysfunction.

Literature data demonstrate that bacterial species are able to modulate the functions of the immune and oxidative systems and that the administration of some probiotics can improve mucosal barrier function, modulating the release of proinflammatory cytokines, in CFS/ME patients. This study represents a preliminary investigation to verifying the safety and efficacy of a certain combination of probiotics in CFS/ME patients. The results suggest that probiotics can modify the well-being status as well as inflammatory and oxidative indexes in CFS/ME patients.

No adverse effects were observed except for one patient, which displayed a flare-up of symptoms, although all inflammatory parameters (i.e., cytokines, fecal calprotectin, ESR, and immunoglobulins) were reduced after probiotic intake. The reactivation of fatigue symptoms in this patient, whose clinical history reported the onset of CFS/ME following mononucleosis, could be related to an abnormal stimulation of the immune system as suggested by a recent study describing an exaggerated immune activation associated with chronic fatigue.

Copyright © 2019 Letizia Venturini et al.

Source: Venturini L, Bacchi S, Capelli E, Lorusso L, Ricevuti G, Cusa C. Modification of Immunological Parameters, Oxidative Stress Markers, Mood Symptoms, and Well-Being Status in CFS Patients after Probiotic Intake: Observations from a Pilot Study. Oxid Med Cell Longev. 2019 Nov 23;2019:1684198. doi: 10.1155/2019/1684198. eCollection 2019. https://www.hindawi.com/journals/omcl/2019/1684198/ (Full study)

Open Trial of Vitamin B12 Nasal Drops in Adults With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Comparison of Responders and Non-Responders

Abstract:

Introduction: A recent study reported a favorable effect of vitamin B12 injections/oral folic acid support in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients. Recently, vitamin B12 nasal drops were developed as an alternative to the vitamin B12 injections. As no data are available on efficacy of this formulation, we studied vitamin B12 serum levels, the physical activity scale of the RAND-36, the number of steps on an activity meter, and the fatigue and concentration scales of the CIS20r questionnaires, before and after 3 months of treatment in ME/CFS patients.

Methods and Results: Fifty-one patients completed all measurements. Forty-four were female. Mean age was 42 years, and mean disease duration was 16 years. Median vitamin B12 levels before treatment were 328 (244-429) pmol/l, and 973 (476-1,476) pmol/l after treatment.

Thirty-four patients reported a favorable response to treatment. In the non-responders, only a small but significant increase in vitamin B12 levels was observed. In contrast, in responders, the number of steps, the physical activity scale of the RAND-36, and the vitamin B12 serum levels increased significantly. The CIS20r fatigue scale decreased significantly, and the CIS20r concentration scale was unchanged.

Conclusions: Nasal drop vitamin B12 administration resulted in a significant increase in vitamin B12 serum levels and therefore may be effective. This pilot study suggest that the nasal drops may be used as an alternative to injections because two thirds of ME/CFS patients reported a positive effect, accompanied by an increased number of steps, improvement of the RAND-36 physical functioning scale and the CIS20r fatigue scale, and a significant increase in serum vitamin B12 levels.Copyright © 2019 van Campen, Riepma and Visser.

Source: van Campen CLM, Riepma K, Visser FC. Open Trial of Vitamin B12 Nasal Drops in Adults With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Comparison of Responders and Non-Responders. Front Pharmacol. 2019 Sep 20;10:1102. doi: 10.3389/fphar.2019.01102. eCollection 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6764214/ (Full article)