Effects of nVNS on Stress Reactivity in IBS
NCT07926945, Not applicable, Not yet recruiting, University of California, Los Angeles
Trial 10
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
| Field | Value | Source |
|---|---|---|
| Title | Effects of nVNS on Stress Reactivity in IBS | ClinicalTrials.gov |
| NCT number | NCT07926945 | ClinicalTrials.gov |
| Status | Not yet recruiting | ClinicalTrials.gov |
| Phases | Not applicable | ClinicalTrials.gov |
| Enrollment | 200 participants, estimated | ClinicalTrials.gov |
| Lead sponsor | University of California, Los Angeles | ClinicalTrials.gov |
| Conditions | Irritable Bowel Syndrome (IBS) | ClinicalTrials.gov |
| Interventions | Truvaga Plus | ClinicalTrials.gov |
| First posted | 2026-11-09 | ClinicalTrials.gov |
| Last updated | 2026-11-09 | ClinicalTrials.gov |
Registered outcomes 11
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description | Source |
|---|---|---|---|---|
| Primary | Change in IBS Severity Scoring System (IBS-SSS) | 8 weeks, from baseline to end of intervention | The IBS-SSS questionnaire is a validated measure of IBS symptom severity and has been shown to be responsive to treatment. The IBS-SSS assesses the severity of abdominal pain, frequency of abdominal pain, severity of abdominal distention, dissatisfaction with bowel habits, and interference of IBS with daily life over a 10-day period. Each of the five categories will receive a score from 0-100, and the total IBSSSS is calculated by taking the sum of these categories (range 0-500, 0 - no symptoms, 500 - very severe symptoms). | ClinicalTrials.gov |
| Primary | Change in Patient Health Questionnaire-15 (PHQ-15) | 8 weeks, from baseline to end of intervention | The PHQ-15 is a widely used measure of widespread somatic symptoms over 1 month that is sensitive to treatment effects. The PHQ-15 assess 15 different somatic symptoms (back pain, stomach pain, headaches, chest pain, trouble sleeping, etc.) rated by 0 - not bothered at all to 3 - bothered a lot. The scale is scored as follows: 0-4: Minimal somatic symptom severity, 5-9: Low somatic symptom severity, 10-14: Medium somatic symptom severity, 15-30: High somatic symptom severity. | ClinicalTrials.gov |
| Primary | Change in stress reactivity (SR)-related brain phenotypes. | 8 weeks, from baseline to end of intervention | SR-related brain phenotypes will be derived from prespecified MRI measures of brain structure, functional connectivity, and brain activity. MRI data will be collected at baseline and Week 8. The primary imaging analysis will compare baseline-to-Week-8 change in prespecified SR-related brain phenotypes between nVNS and Usual Care. | ClinicalTrials.gov |
| Secondary | IBS Severity Scoring System (IBS-SSS) responder rate | 8 weeks, from baseline to end of intervention | The proportion of participants with IBS who experience a ≥50-point reduction in IBS-SSS score from baseline will be compared between treatment groups. A reduction of at least 50 points represents a clinically meaningful improvement in IBS symptoms. The IBS-SSS questionnaire is a validated measure of IBS symptom severity and has been shown to be responsive to treatment. The IBS-SSS assesses the severity of abdominal pain, frequency of abdominal pain, severity of abdominal distention, dissatisfaction with bowel habits, and interference of IBS with daily life over a 10-day period. Each of the five categories will receive a score from 0-100, and the total IBSSSS is calculated by taking the sum of these categories (range 0-500, 0 - no symptoms, 500 - very severe symptoms). | ClinicalTrials.gov |
| Secondary | Biologic measures of Stress Reactivity - SNS-Immune gene expression profile | 8 weeks, from baseline to end of intervention | Changes in the sympathetic nervous system (SNS)-immune gene expression profile will be evaluated as a peripheral biologic measure of stress reactivity. Whole-blood SNS-immune gene expression will be measured using mRNA-targeted sequencing. Total RNA will be isolated from whole blood, converted to cDNA using Lexogen QuantSeq 3' FWD, sequenced using Illumina sequencing, mapped to the GRCh38 reference human transcriptome using STAR, and quantified as gene-specific reads per million mapped reads. Baseline-to-Week-8 changes will be compared between nVNS and Usual Care and examined in relation to clinical symptom change. Moderator analyses will also test whether baseline SNS-immune gene expression modifies the treatment response using an SNS-immune measure-by-treatment-by-time interaction. | ClinicalTrials.gov |
| Secondary | Biologic measures of Stress Reactivity - heart rate variability (HRV) | 8 weeks, from baseline to end of intervention | HRV will be evaluated as a peripheral autonomic measure of stress reactivity and compared over the treatment period. HRV will be derived from physiologic data collected using a Fitbit equipped with photoplethysmography sensors that estimate heart rate and intervals between successive beats. Participants will wear the device from baseline through the post-intervention assessment, including during sleep, to characterize longitudinal and circadian HRV. Changes in HRV will be compared between nVNS and Usual Care and correlated with symptom change. Moderator analyses will additionally test whether baseline HRV modifies treatment response through an HRV-by-treatment-by-time interaction. | ClinicalTrials.gov |
| Secondary | Biologic measures of Stress Reactivity - fecal microbial stress index | 8 weeks, from baseline to end of intervention | Changes in the fecal microbial stress index will be evaluated as a peripheral biologic measure of stress reactivity. The fecal microbial stress index will be derived from stool samples collected at baseline and Week 8 using shotgun metagenomic sequencing. Microbial sequencing data will undergo species-level taxonomic and functional characterization. Baseline-to-Week-8 changes in the microbial stress index will be compared between nVNS and Usual Care and correlated with clinical symptom change. | ClinicalTrials.gov |
| Secondary | Biologic measures of Stress Reactivity - fecal metabolite stress index | 8 weeks, from baseline to end of intervention | Changes in the fecal metabolite stress index will be evaluated as a peripheral biologic measure of stress reactivity. The fecal metabolite stress index will be derived from stool metabolomic data obtained using LC-MS/MS-based profiling. Baseline-to-Week-8 changes in the metabolite stress index will be compared between nVNS and Usual Care and correlated with clinical symptom change. Moderator analyses will additionally test whether the baseline metabolite stress index modifies treatment response through a metabolite stress index-by-treatment-by-time interaction. | ClinicalTrials.gov |
| Secondary | Brain changes associated with IBS severity, comorbid symptom scores, and peripheral biologic measures of SR | 8 weeks, from baseline to end of intervention | Examine associations between changes in scores on the SR-related brain phenotype signatures and changes in IBS severity, comorbid symptom scores, and peripheral biologic measures of SR. General linear models will examine associations between baseline-to-Week-8 changes in SR-related brain phenotype signature scores and corresponding changes in IBS-SSS, PHQ-15, HRV, SNS-immune gene expression, and microbial and metabolite stress indices, with adjustment for relevant covariates. Alternative approaches may be used to examine multivariate associations between changes in symptom severity, stress reactivity, comorbidity, and brain connectivity. | ClinicalTrials.gov |
| Secondary | Change in extraintestinal symptoms in nVNS compared to Usual Care | 8 weeks, from baseline to end of intervention | Predict response (Pre-Post change in extraintestinal symptoms) in nVNS compared to Usual Care. General linear model-based moderator analyses will evaluate whether baseline SR-related brain phenotype scores predict pre- to post-treatment change in extraintestinal symptom severity differently in participants assigned to nVNS versus Usual Care. Models will include baseline SR brain phenotype score, treatment group, the brain phenotype-by-treatment interaction, and prespecified covariates. A significant interaction will indicate differential prediction of treatment response. | ClinicalTrials.gov |
| Other | Exploratory outcome - Sex differences | 8 weeks, from baseline to end of intervention | Examine whether females with IBS with higher comorbid symptom scores will present with greater changes in SR-related brain signatures following the nVNS intervention compared to male IBS. Exploratory models will examine whether females with IBS with greater baseline comorbid symptom burden demonstrate greater baseline-to-Week-8 changes in SR-related brain signatures following nVNS compared with males with IBS. The moderator analysis includes the comorbid symptom score-by-group interaction, with adjustment for age, BMI, and diet. | ClinicalTrials.gov |
Outcomes 0
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as | Source |
|---|
Results by group 0
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units | Source |
|---|
Participant flow 0
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted | Source |
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Adverse events 0
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events | Source |
|---|
Adverse event totals 0
The totals the trial posted for each group.
| Total | Group | Affected | At risk | Source |
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Papers 10
The papers the trial lists on ClinicalTrials.gov.
Grants 0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
| Project | Title | Principal investigators | Organization | Funder | Fiscal years | Source |
|---|
Trial comparisons 0
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
| Comparison | Source |
|---|
Tests 0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
| Test | Named as | Source |
|---|
Source 5
| Field | Value | Source |
|---|---|---|
| Release | trials-2026-11-12-0.4.0 | ClinicalTrials.gov |
| Release manifest SHA-256 | 0f4a8d8c48aee2a7573ae0fa94ecbeab70c1adbe449bbc95c424bc7d3e97b9d4 | ClinicalTrials.gov |
| Registry capture | 2026-11-12 | ClinicalTrials.gov |
| Results copy, AACT | 2026-03-23 | ClinicalTrials.gov |
| NIH clinical studies file | 2026-11-13 | ClinicalTrials.gov |
Release trials-2026-11-12-0.4.0
ClinicalTrials.gov's posted results, through CTTI's AACT: ClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299 ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
ClinicalTrials.gov: none stated ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
NIH RePORTER's clinical studies and project files: Public domain (NIH RePORTER)