Inulin-Spirulina Co-intervention for Insomnia Disorder

May 15, 2026 updated by: Jing Lu, PhD, First Affiliated Hospital of Zhejiang University

Investigation of the Therapeutic Efficacy and Mechanistic Pathways of Inulin-Spirulina Co-intervention in Patients With Insomnia Disorder: A Randomized Controlled Trial

The goal of this clinical trial is to learn if inulin and spirulina, used alone or in combination, can improve insomnia disorder in adults aged 18 to 60 years with chronic insomnia disorder. It will also learn about the safety of these interventions. The main questions it aims to answer are:

Does inulin plus spirulina improve sleep quality, as measured by the reduction rate in Pittsburgh Sleep Quality Index (PSQI) score? Does the intervention improve sleep-related, mood, anxiety, and cognitive outcomes after 12 weeks? Researchers will compare an inulin group, a spirulina group, a combined inulin plus spirulina group, and a placebo group to see if the combined intervention provides greater benefit than either single intervention or placebo.

Participants will:

be randomly assigned to 1 of 4 groups: inulin, spirulina, inulin plus spirulina, or placebo; take the assigned study product once daily for 12 weeks; complete sleep, mood, anxiety, and cognitive assessments at baseline and week 12; undergo polysomnography and provide blood and stool samples at baseline and week 12; and be monitored for adverse events throughout the study.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This study is a single-center, prospective, randomized, double-blind, four-arm parallel-group clinical trial designed to evaluate the efficacy and safety of inulin and spirulina, administered alone or in combination, in adults with chronic insomnia disorder.

Insomnia disorder is associated with impaired sleep quality, emotional disturbances, and reduced cognitive function. Emerging evidence suggests that dysregulation of the gut microbiota and its metabolites may play an important role in the pathophysiology of sleep disorders through the gut-brain axis. Inulin, a prebiotic dietary fiber, and spirulina, a nutrient-rich microalga with anti-inflammatory and antioxidant properties, have both been shown to modulate gut microbiota composition and metabolic activity. Their combined use may produce synergistic effects on sleep regulation and related physiological processes.

In this study, eligible participants will be randomly assigned in a 1:1:1:1 ratio to receive inulin, spirulina, inulin plus spirulina, or placebo for 12 weeks. The interventions will be administered in powder form once daily, with identical appearance and packaging to ensure blinding of participants and study personnel.

The primary objective is to evaluate the effect of the interventions on sleep quality. Secondary objectives include assessing changes in sleep architecture, mood and anxiety symptoms, and cognitive function. In addition, this study aims to explore potential biological mechanisms by examining changes in gut microbiota composition before and after the intervention. Plasma samples collected at baseline and week 12 will be used for exploratory metabolomic analyses to further investigate potential biological pathways associated with treatment response.

Safety will be assessed throughout the study by monitoring adverse events. The findings of this study are expected to provide evidence on whether combined inulin and spirulina supplementation offers superior clinical benefits compared with single interventions or placebo, and to improve understanding of microbiota-related pathways involved in sleep regulation.

Study Type

Interventional

Enrollment (Estimated)

180

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Aged 18 to 60 years;
  2. Meet the ICSD-3 diagnostic criteria for chronic insomnia disorder;
  3. Pittsburgh Sleep Quality Index (PSQI) total score > 5;
  4. Willing to participate and provide written informed consent.

Exclusion Criteria:

  1. Use of prebiotics, probiotics, high-fiber supplements, or microbiota-related products within the past 8 weeks;
  2. Diagnosis of psychiatric disorders other than insomnia based on DSM-5 criteria, assessed using the Mini-International Neuropsychiatric Interview (MINI);
  3. Regular use of sedative or hypnotic medications within the past 4 weeks, or frequent intermittent use (e.g., benzodiazepines, non-benzodiazepine receptor agonists, melatonin receptor agonists, sedating antihistamines);
  4. Severe hepatic or renal dysfunction, hematologic disorders, or respiratory diseases;
  5. Severe gastrointestinal diseases or malnutrition;
  6. Pregnancy or breastfeeding;
  7. Apnea-hypopnea index > 10, or periodic limb movement index > 15/hour on polysomnography;
  8. Known allergy or intolerance to inulin, spirulina, or maltodextrin;
  9. Participation in another clinical trial within the past 3 months.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Inulin plus Spirulina
Participants receive 15 g inulin plus 5 g spirulina dissolved in warm water, taken orally once daily after breakfast for 12 weeks.
Dietary supplement: Inulin
Inulin is a prebiotic dietary fiber used in this study to modulate gut microbiota and metabolic activity.
Other Names:
  • Fructooligosaccharide
Dietary supplement: Spirulina
Spirulina is a nutrient-rich microalga with antioxidant and anti-inflammatory properties, used in this study as a dietary supplement.
Other Names:
  • Arthrospira platensis
Experimental: Inulin
Participants receive 15 g inulin plus 5 g maltodextrin dissolved in warm water, taken orally once daily after breakfast for 12 weeks.
Dietary supplement: Inulin
Inulin is a prebiotic dietary fiber used in this study to modulate gut microbiota and metabolic activity.
Other Names:
  • Fructooligosaccharide
Dietary supplement: Maltodextrin
Maltodextrin is used as a placebo control in this study and is matched in appearance and administration to the active interventions.
Other Names:
  • Placebo
Experimental: Spirulina
Participants receive 5 g spirulina plus 15 g maltodextrin dissolved in warm water, taken orally once daily after breakfast for 12 weeks.
Dietary supplement: Spirulina
Spirulina is a nutrient-rich microalga with antioxidant and anti-inflammatory properties, used in this study as a dietary supplement.
Other Names:
  • Arthrospira platensis
Dietary supplement: Maltodextrin
Maltodextrin is used as a placebo control in this study and is matched in appearance and administration to the active interventions.
Other Names:
  • Placebo
Placebo Comparator: Placebo
Participants receive 20 g maltodextrin dissolved in warm water, taken orally once daily after breakfast for 12 weeks.
Dietary supplement: Maltodextrin
Maltodextrin is used as a placebo control in this study and is matched in appearance and administration to the active interventions.
Other Names:
  • Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Pittsburgh Sleep Quality Index (PSQI) Score
Time Frame: Baseline to Week 12
The primary outcome is the change in Pittsburgh Sleep Quality Index (PSQI) total score from baseline to week 12. The PSQI is a validated self-reported questionnaire assessing sleep quality, with higher scores indicating worse sleep. The outcome will be analyzed as the difference between baseline and post-intervention scores.
Baseline to Week 12

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Total Sleep Time Assessed by Polysomnography
Time Frame: Baseline, Week 2, Week 4, Week 8, and Week 12
Change in total sleep time measured by overnight polysomnography. Total sleep time will be reported in minutes.
Baseline, Week 2, Week 4, Week 8, and Week 12
Change in Sleep Latency Assessed by Polysomnography
Time Frame: Baseline, Week 2, Week 4, Week 8, and Week 12
Change in sleep latency measured by overnight polysomnography. Sleep latency will be reported in minutes.
Baseline, Week 2, Week 4, Week 8, and Week 12
Change in Wake After Sleep Onset Assessed by Polysomnography
Time Frame: Baseline, Week 2, Week 4, Week 8, and Week 12
Change in wake after sleep onset measured by overnight polysomnography. Wake after sleep onset will be reported in minutes.
Baseline, Week 2, Week 4, Week 8, and Week 12
Change in Hamilton Depression Rating Scale-24 (HAMD-24) Total Score
Time Frame: Baseline, Week 2, Week 4, Week 8, and Week 12
Change in Hamilton Depression Rating Scale-24 total score from baseline to week 12. The Hamilton Depression Rating Scale-24 is a clinician-rated scale for depressive symptom severity with a total score range of 0 to 76, where higher scores indicate worse depressive symptoms.
Baseline, Week 2, Week 4, Week 8, and Week 12
Change in Hamilton Anxiety Rating Scale (HAMA) Total Score
Time Frame: Baseline, Week 2, Week 4, Week 8, and Week 12
Change in Hamilton Anxiety Rating Scale total score from baseline to week 12. The Hamilton Anxiety Rating Scale is a clinician-rated scale for anxiety severity with a total score range of 0 to 56, where higher scores indicate worse anxiety symptoms.
Baseline, Week 2, Week 4, Week 8, and Week 12
Change in MATRICS Consensus Cognitive Battery (MCCB) Overall Composite T Score
Time Frame: Baseline, Week 2, Week 4, Week 8, and Week 12
Change in MATRICS Consensus Cognitive Battery overall composite T score from baseline to week 12. The MATRICS Consensus Cognitive Battery assesses cognitive performance across multiple cognitive domains. Higher scores indicate better cognitive performance.
Baseline, Week 2, Week 4, Week 8, and Week 12
Change in Relative Abundance of Gut Microbiota Taxa Assessed by 16S rRNA Sequencing
Time Frame: Baseline, Week 2, Week 4, Week 8, and Week 12
Change in relative abundance of gut microbiota taxa in stool samples from baseline to week 12, assessed by 16S rRNA sequencing.
Baseline, Week 2, Week 4, Week 8, and Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

First Affiliated Hospital of Zhejiang University

Investigators

  • Principal Investigator: Jing Lu, PhD, Zhejiang University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

May 1, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

April 30, 2027

Study Registration Dates

First Submitted

April 6, 2026

First Submitted That Met QC Criteria

April 12, 2026

First Posted (Actual)

April 17, 2026

Study Record Updates

Last Update Posted (Actual)

May 19, 2026

Last Update Submitted That Met QC Criteria

May 15, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IIT20250259C-R2

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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