Gut microbiome link to Complex Regional Pain Syndrome

Role of the Gut Microbiome in Complex Regional Pain Syndrome

Observational Washington University School of Medicine · NCT03612193

This study will test whether differences in the gut microbiome relate to how severe CRPS symptoms are and whether people recover, in adults with CRPS and their household controls.

Quick facts

Study typeObservational
Enrollment140 (estimated)
Ages18 Years and up
SexAll
SponsorWashington University School of Medicine Academic / other
Locations1 site (St Louis, Missouri)
Trial IDNCT03612193 on ClinicalTrials.gov

What this trial studies

This prospective observational project has two parts: a cross-sectional arm comparing gut microbiota composition with symptom severity and chronicity in adults with current or past CRPS, and a longitudinal arm following people newly diagnosed (<6 months) to see if microbiome features predict recovery. Stool samples, clinical symptom measures, and tests of cognitive flexibility will be collected, with household cohabitants serving as controls. People who live alone, follow a vegan diet, are pregnant or lactating, or cannot stop probiotics for one week are excluded. All procedures are conducted at Washington University School of Medicine in St. Louis.

Who should consider this trial

Good fit: Adults diagnosed with CRPS by the Budapest criteria — current or past cases for the cross-sectional arm or diagnoses within 6 months for the longitudinal arm — and willing household cohabitants as controls who speak English and can provide consent and stool samples.

Not a fit: People who live alone, are pregnant or lactating, follow a vegan diet, do not speak English, or cannot stop probiotic use for one week would be ineligible and unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the findings could help develop microbiome-based markers to predict prognosis and point to new treatment approaches for people with CRPS.

How similar studies have performed: Related research has found preliminary links between the gut microbiome and chronic pain or neuroinflammatory conditions, but longitudinal predictive studies specifically in CRPS are largely novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Study A: Cross-sectional study

Inclusion criteria, cases:

* Adults over the age of 18
* Current (\< 1 year duration) or former (\> 1 year) diagnosis of Complex Regional Pain Syndrome by the Budapest criteria
* English as primary language
* able to consent

Inclusion criteria, controls

* Adults over age of 18
* Cohabitant of person with current or former diagnosis of CRPS

Study B: Longitudinal Study

Inclusion criteria, cases:

* Adults over the age of 18
* Recent diagnosis (\<6 months) of Complex Regional Pain Syndrome by the Budapest criteria
* English as primary language
* able to consent

Inclusion criteria, controls

* Adults over age of 18
* Cohabitant of person with diagnosis of CRPS

Study A and B: Exclusion criteria, cases and controls:

* Unwilling to participate in the study
* Lives alone
* Current use of probiotics and unwilling to stop for 1 week prior to stool sample
* Pregnant or lactating
* Vegan diet

Where this trial is running

St Louis, Missouri

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Complex Regional Pain Syndromes
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.