Study on the Mechanism of Gut Microbiota Mediating Restless Legs Syndrome Through Iron Metabolism

The goal of this observational study is to collect fecal and serum samples from patients with restless legs syndrome (RLS) and healthy controls for differential microbiota analysis to identify key bacterial species involved in the pathogenesis of RLS. Subsequently, metabolomic analysis will be performed on fecal and serum samples from RLS patients to identify key regulatory molecules in iron metabolism disorder pathways. Finally, correlation analysis will be used to determine which specific bacterial species and metabolites are involved in the pathogenesis of RLS. The main question it aims to answer is: i) Do RLS patients exhibit gut microbiota dysbiosis compared to healthy controls? ii) Which specific bacterial species and metabolites are linked to iron metabolism abnormalities and the pathogenesis of RLS?

Study Overview

• Status: Not yet recruiting
• Conditions: Restless Legs Syndrome (RLS)
• Intervention / Treatment: Other: Not applicable- observational study

• Study Type: Observational
• Enrollment (Estimated): 100

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

We will recruit 50 patients with restless legs syndrome from among those attending the Sleep Medicine Center of Chongqing Traditional Chinese Medicine Hospital during the period December 2025 to December 2026.

Description

Inclusion Criteria:

• ≥18 years old;
• The diagnostic criteria all meet the five diagnostic criteria for restless legs syndrome established by the International Committee for the Study of Restless Legs Syndrome (IRLSSG) (2014 revised version)

Exclusion Criteria:

• Suffering from serious physical illnesses, such as tumors, cardiovascular diseases, diabetes, stroke, etc.;
• Drug abuse, alcoholism, acute poisoning;
• Antibiotic use within the 4 weeks preceding sampling;
• Arobiotics or prebiotics use within the 4 weeks preceding sampling;
• Iron supplements use within the 4 weeks preceding sampling.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
There are differences in the abundance of gut microbiota between RLS and theThere are differences in the abundance of gut microbiota between RLS patients and the healthy controls.	1 year

Collaborators and Investigators

• Sponsor: Wenxia Jiang

Publications and helpful links

General Publications

• 1. Yan, F., Y. Cheng, and S. Feng, Association between serum GFAP, BDNF and NfL levels and clinical symptoms in restless legs syndrome: a case-control study. Sleep Med, 2025. 134: p. 106694. 2. Holland, M.T., et al., Adaptive spinal cord stimulation improves restless legs syndrome: Case report, literature review, and mechanistic hypothesis. Sleep Med, 2025. 134: p. 106664. 3. Takahara, I., et al., Prevalence of Restless Legs Syndrome in Patients with Inflammatory Bowel Disease. Dig Dis Sci, 2017. 62(3): p. 761-767. 4. Loosen, S.H., et al., Association between Inflammatory Bowel Disease and Subsequent Development of Restless Legs Syndrome and Parkinson's Disease: A Retrospective Cohort Study of 35,988 Primary Care Patients in Germany. Life (Basel), 2023. 13(4). 5. Hackethal, S., et al., Restless Legs Syndrome During Pregnancy and Puerperium. Sleep, 2025. 6. Elangovan, P., et al., Prevalence of Restless Leg Syndrome and Its Association With Iron Deficiency in Patients With Chronic Kidney Disease: A Cross-Sectional Observational Study. Cureus, 2025. 17(6): p. e86188. 7. Schormair, B., et al., Genome-wide meta-analyses of restless legs syndrome yield insights into genetic architecture, disease biology and risk prediction. Nat Genet, 2024. 56(6): p. 1090-1099. 8. Manconi, M., et al., Restless legs syndrome. Nat Rev Dis Primers, 2021. 7(1): p. 80. 9. Guo, X., et al., Clinical feature and alpha-synuclein level of restless legs syndrome with leucine-rich repeat kinase 2 encoding gene mutation. Parkinsonism Relat Disord, 2025. 138: p. 107944. 10. Earley, C.J., et al., Altered brain iron homeostasis and dopaminergic function in Restless Legs Syndrome (Willis-Ekbom Disease). Sleep Med, 2014. 15(11): p. 1288-301. 11. Mizuno, S., et al., CSF iron, ferritin and transferrin levels in restless legs syndrome. J Sleep Res, 2005. 14(1): p. 43-7. 12. Ferré, S., et al., New Insights into the Neurobiology of Restless Legs Syndrome. Neuroscientist, 2019. 25(2): p. 113-125.

Study record dates

Study Major Dates

• Study Start (Estimated): December 15, 2025
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: December 14, 2025
• First Submitted That Met QC Criteria: December 14, 2025
• First Posted (Estimated): December 29, 2025

Study Record Updates

• Last Update Posted (Estimated): January 2, 2026
• Last Update Submitted That Met QC Criteria: December 30, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Parasomnias; Restless Legs Syndrome
• Other Study ID Numbers: 2025-IIT-KS-23

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No