This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Beneficial Bacteria Treatment for Autism (NCT02504554), a non-randomized phase 1, phase 2 study. The primary outcome is Gastrointestinal Symptom Responsiveness Scale (GSRS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02504554 |
| Phase | Phase 1, Phase 2 |
| Condition | Gastrointestinal Problems, Autism Spectrum Disorders |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 18 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Arizona State University |
| Results posted | Yes |
2. Clinical Question
Population
Children with autism spectrum disorders and gastrointestinal problems. The registry record reports an enrollment of 18. The primary outcome description says results were reported for all participants, regardless of whether the initial dose of bacteria was administered orally or rectally.
Intervention
A combination therapy involving Vancomycin, MoviPrep, Prilosec, and processed, frozen human fecal material. Treatment included oral administration, with one group receiving all treatments orally and another receiving some treatments orally and some rectally.
Comparator
The registry record describes Oral and Rectal groups, but does not describe a randomized control group. Because allocation was non-randomized, these groups should not be treated as a like-for-like control comparison.
Primary question
How did gastrointestinal symptoms, measured by the Gastrointestinal Symptom Responsiveness Scale (GSRS), compare between baseline and the end of treatment at 10 weeks? The registry record does not report the GSRS results, so the direction and size of any change are not reported in the registry record.
3. Trial Design
This completed trial investigated a combination therapy for gastrointestinal problems in children with autism spectrum disorders. The registry lists the study as Phase 1 and Phase 2, with a parallel-group model, non-randomized allocation, and no masking. Enrollment was 18. The study began in 2014-07 and reached primary completion in 2016-04.
The two named groups were the Oral Group and the Rectal Group. Both were described as receiving a combination of Vancomycin, MoviPrep, Prilosec, and processed, frozen human fecal material. The Oral Group was to receive all treatments orally. The Rectal Group was to receive some treatments rectally and some orally. The registry record does not report the number of participants in each group.
The primary measure was the GSRS, assessed at baseline and 10 weeks, described as the end of treatment. Its outcome population included all participants, regardless of the route used for the initial bacterial dose. The registry also lists outcomes involving parent impressions, blood safety markers, autism-related rating scales, sensory profile, adaptive behavior, and daily stool records.
Non-randomized allocation and the absence of masking are important features when interpreting results. Without random assignment, group differences may reflect factors other than treatment route. Without masking, participants’ or assessors’ knowledge of treatment may affect subjective measurements. The registry record does not report further details about allocation procedures or masking of outcome assessment.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Oral Group | Rectal Group |
|---|---|---|
| STARTED | 12 | 6 |
| COMPLETED | 12 | 6 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: We report the data on all participants, regardless of how the initial dose of bacteria was administered (oral or rectal).
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: One of the participants in the oral group changed to the rectal group after nausea/vomiting with the initial oral dose. So, 13/5 changed to 12/6
| Characteristic | Unit | Oral Group | Rectal Group | Total |
|---|---|---|---|---|
| Participants analysed | 12 | 6 | 18 | |
| Age, Categorical: <=18 years | Participants | 12 | 6 | 18 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 1 | 1 | 2 |
| Sex: Female, Male: Male | Participants | 11 | 5 | 16 |
| Region of Enrollment: United States | participants | 12 | 6 | 18 |
6. Primary Endpoint
The registry lists the primary outcome as Gastrointestinal Symptom Responsiveness Scale (GSRS), measured over Baseline and 10 weeks (end of treatment).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was the Gastrointestinal Symptom Responsiveness Scale (GSRS), a measure of gastrointestinal symptoms. It includes 15 questions, each rated on a Likert scale from 1-7, with higher scores indicating worse symptoms. The reported outcome is an average across the questions, so the average also has a possible range of 1-7. Scores are expressed in units on a scale, with the mean and standard deviation specified.
The registry lists assessments at baseline and 10 weeks, the stated end of treatment. Repeated measurement can describe how scores differ over time within the study population. The registry’s outcome description says the analysis includes all participants, regardless of whether the initial dose of bacteria was given orally or rectally.
In general, a symptom scale can translate several reported experiences into a structured measure that can be compared across assessment times. The scale’s meaning depends on its scoring direction: for this measure, a higher average represents worse symptoms. The registry record does not report the baseline mean, the 10-week mean, their variability, or a statistical comparison. Therefore, the posted record does not establish whether GSRS scores changed, how large any change was, or how precisely it was estimated.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a completed study with 18 participants enrolled and identifies the GSRS at baseline and 10 weeks as the primary outcome. However, it does not report the GSRS results. In particular, the record does not give the mean at either assessment, a change estimate, a standard deviation for the outcome, a confidence interval, or a p-value. The direction, magnitude, and statistical precision of the primary outcome are therefore not reported in the registry record.
The design also limits what can be inferred from a comparison of the Oral and Rectal groups. Allocation was non-randomized, and the registry record explicitly cautions that the arms are not a like-for-like control comparison. Any difference between those groups could be associated with factors other than administration route; the record does not report enough information to assess or adjust for such factors. The stated primary outcome population combines all participants regardless of initial administration route, so it is not described as a randomized comparison between the groups.
Absence of masking is another relevant design feature, particularly for outcomes based on reported symptoms or ratings. In general, expectations or knowledge of treatment can influence how subjective outcomes are reported or assessed. The registry record does not specify whether any outcome assessor was masked.
These limitations do not mean that the study’s observations have no value. A completed, open-label trial can describe the treatment procedures and the measurements collected in its enrolled participants. But without the posted primary outcome results, the registry record does not permit a statistical assessment of observed GSRS change. It also does not provide a basis for concluding that the combination therapy did or did not alter gastrointestinal symptoms.
The listed secondary outcomes indicate that the study collected or planned to assess a range of measures, including safety markers and behavioral or functional scales. Their results are not reported in the registry record. No conclusions about those outcomes can be drawn from their names alone. The distinction is between a registered measurement plan and reported results: identifying an endpoint does not itself show what happened on that endpoint.
9. Statistical Methods Explained
Statistical methods help clarify what a study’s measurements can support, but the registry record does not report a detailed statistical analysis plan or the primary outcome estimates. The explanations below are general and should not be read as a description of analyses confirmed to have been performed.
What does a mean and standard deviation describe?
The primary outcome is described as a mean GSRS score with standard deviation. In general, a mean describes the average score in a group, while the standard deviation describes how spread out individual scores are around that average. The mean gives a concise summary, but it does not show the full distribution of responses. The standard deviation describes participant-level variability; it is not the same thing as the uncertainty around the mean.
For this scale, higher scores mean worse gastrointestinal symptoms, and the average score has a possible range of 1-7. To interpret a reported mean, a reader would need to know the assessment time and the participants included. To interpret change, the baseline and follow-up results or a direct change estimate would be needed. Those GSRS values are not reported in the registry record.
What would a confidence interval add?
In general, a confidence interval gives a range of values compatible with an estimate under the method used to calculate it. It communicates uncertainty more directly than a point estimate alone. A narrow interval indicates greater precision than a wide interval, though precision alone does not determine whether an effect is important. The registry record does not report a confidence interval for the primary endpoint.
A confidence interval for a change would be interpreted in relation to the direction of the scale and the comparison being estimated. Because higher GSRS scores represent worse symptoms, the sign and definition of a change estimate would matter. The registry record does not state a primary change estimate or the convention used for its direction.
Why does the non-randomized design matter?
In general, random allocation helps make treatment groups comparable with respect to measured and unmeasured characteristics, on average. Non-randomized allocation does not provide that protection. If the Oral and Rectal groups differ in outcome, the difference may reflect baseline characteristics, treatment choices, or other factors as well as route. Statistical adjustment can sometimes address measured differences, but cannot automatically remove confounding, and the registry record does not report an adjustment method.
The record also states that the primary outcome population includes all participants regardless of initial bacterial administration route. That pooled description may summarize change across the enrolled participants, but it does not isolate a causal effect of one route versus another. The allocation structure and the analysis population need to be considered together when interpreting any estimate.
What is the role of the sample-size illustration?
In general, a sample-size calculation estimates how many participants a future study would need to detect a specified effect under stated assumptions. The registry record’s planning description refers to a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a stated fraction of an observed effect. These are planning assumptions, not evidence that a study had a particular probability of finding a result.
Such planning illustrations are not observed power. Observed power is not a substitute for the estimate and its uncertainty after results are collected. The registry record does not report the primary outcome effect needed to interpret a calculation tied to a fraction of that effect. Any sample-size figures should therefore be understood as hypothetical planning quantities, not as observed findings or proof that the trial could reliably detect a clinically meaningful change.
Why can over-dispersion matter?
In general, over-dispersion occurs when observed variability is greater than a statistical model assumes. If a method assumes less variability than the data contain, standard errors may be understated and confidence intervals too narrow. This concept is most relevant when the outcome and model involve a variance assumption, and it should not be presumed to apply to this trial. The registry record does not report a model assessment or a finding of over-dispersion.
For a continuous measure such as the GSRS, the choice of model and how it handles repeated measurements can affect the estimate and its uncertainty. The registry record identifies the measure and its assessment times but does not report the model, covariance assumptions, or a detailed method for analyzing repeated scores. Those analysis details are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists several secondary outcomes: Parent Global Impressions-Revised, blood chemistry and complete blood count safety markers, the Childhood Autism Rating Scale, the Social Responsiveness Scale, the Short Sensory Profile, the Vineland Adaptive Behavior Scale, and the Daily Stool Record. It also records eight outcome measures and six analyses. These listings indicate multiple measurements or analyses, but do not explain how they were prioritized or interpreted together.
When many outcomes or analyses are examined, the chance of obtaining at least one apparently notable result can increase. In general, statistical methods can address multiplicity through prespecified primary outcomes, adjustment procedures, or a clearly exploratory interpretation. The registry record does not report a multiplicity adjustment or a detailed plan for handling multiple comparisons. It would be inappropriate to assume that an adjustment was or was not performed.
The registry record also does not report the GSRS estimates or results for the listed secondary outcomes. Missing results in a record are not the same as evidence that an outcome was measured and found unchanged. The record does not explain whether any measurements were missing, how missing observations were handled, or whether participants withdrew from particular assessments.
The primary outcome description states that data are reported on all participants regardless of initial administration route. It does not specify the analysis method, how incomplete follow-up was handled, or the exact analysis population beyond that description. The registry record does not report an intention-to-treat approach, a per-protocol population, imputation, or a sensitivity analysis. These details are not reported in the registry record, so the potential effect of missing data or analysis choices cannot be evaluated from the record alone.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| All Groups | 0 | 18 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| All Groups | 0 of 18 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| All Groups | 12 of 18 |
Most frequent non-serious adverse event terms
| Event term | Organ system | All Groups |
|---|---|---|
| hyperactivity and/or irritability | Nervous system disorders | 12 of 18 |
| rash | Skin and subcutaneous tissue disorders | 1 of 18 |
| nausea/vomiting | Gastrointestinal disorders | 1 of 18 |
The safety summary lists 18 participants at risk for serious adverse events, 0 affected by serious adverse events, and 0 deaths. It also lists 18 participants at risk for other adverse events and 12 affected by other adverse events. These are the registry’s all-groups figures; the record does not provide group-specific safety counts in the registry record.
In general, “at risk” identifies the group used as the denominator for a safety category, while “affected” is the count recorded for that category. The serious-event figure is a count for this study record, not a guarantee that no serious events could occur in other participants or settings. The registry lists no serious-event terms, so the nature of serious events is not reported in the registry record.
The other-adverse-event count should not be conflated with the serious-adverse-event count. The record reports 12 participants affected by other adverse events, but does not list their terms or severity in the registry record. These figures describe what was recorded in the trial; they do not, by themselves, establish whether an event was caused by a treatment. The registry record does not report an attribution assessment or further detail about event timing.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed, open-label, non-randomized study enrolled 18 participants and assessed gastrointestinal symptoms using the GSRS at baseline and 10 weeks. It describes two administration groups and a combination treatment involving oral medicines and processed, frozen human fecal material. It also lists a range of secondary measures and summarizes serious and other adverse events.
What the record does not establish is the observed primary outcome result. The GSRS means, variability, change estimate, confidence interval, and p-value are not reported in the registry record. Without those results, it is not possible to say from the posted information whether scores changed, in what direction, by how much, or with what precision. The endpoint’s existence is not evidence of a particular outcome.
The design also cannot support a simple causal interpretation of differences between the Oral and Rectal groups. Allocation was non-randomized, and the registry record states that the arms are not a like-for-like control comparison. The pooled primary outcome population is described as including participants regardless of initial route; it is not presented as a randomized route comparison.
In general, an observed before-and-after change in an open-label study can be informative as a description of participants’ measurements, but it does not by itself isolate the effect of the treatment from other explanations. Here, even that descriptive change cannot be assessed because the primary result is absent from the registry record. The appropriate conclusion is therefore limited: the registry documents the study design, planned or listed measures, and safety counts, but does not report the numerical primary outcome needed to interpret GSRS change.
13. Why This Trial Matters Statistically
This trial is statistically notable because it combines a continuous symptom measure assessed over time with a non-randomized, unmasked, parallel-group design. Each feature shapes the interpretation. The GSRS provides a structured measure with a stated scoring direction and range, while the design means that comparisons between administration groups cannot be assumed to have the protections of random allocation.
The distinction between a treatment description and an outcome estimate is especially important. The registry describes multiple components and routes of administration, but a treatment description cannot establish an outcome. For the primary endpoint, the registry identifies baseline and 10-week assessment times but does not report the corresponding results. Consequently, precision, direction, and magnitude cannot be evaluated from the registry record.
The record also illustrates why reporting the analysis population matters. The primary endpoint description includes all participants irrespective of initial route. That pooled population addresses a different descriptive question from a comparison of Oral and Rectal groups. Keeping those questions separate helps avoid attributing differences to route when allocation was non-randomized.
Finally, the safety summary distinguishes serious events from other adverse events and reports both categories separately. That distinction matters for statistical reading, but counts alone do not provide event descriptions or attribution. Taken together, the record is useful for understanding the study’s structure and the limits of its reported evidence. It also demonstrates why clear outcome estimates, uncertainty measures, analysis methods, and missing-data information are necessary for a full statistical interpretation.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary limitation for interpreting results is that the registry record does not report the primary GSRS outcome values. No baseline or 10-week mean, standard deviation, change estimate, confidence interval, or p-value is given. The size, direction, and precision of any change therefore cannot be evaluated.
The study was non-randomized and unmasked. The registry record cautions that the Oral and Rectal groups are not a like-for-like control comparison. Group differences may be confounded, and the record does not report an adjustment method or details about allocation. The absence of masking may also matter for symptom ratings and other subjective measures; assessor masking is not reported in the registry record.
The registry lists multiple secondary outcomes, but does not report their results or a plan for multiplicity. It also does not report how missing measurements were handled, whether participants discontinued, or what analysis populations beyond the primary outcome description were used. These gaps prevent assessment of potential bias from incomplete data or analytic choices.
The safety summary provides counts but no serious-event terms and no descriptions of the other adverse events in the registry record. The registry record does not report event attribution or group-specific safety results. Finally, the enrollment of 18 is the total reported enrollment; group sizes are not reported in the registry record. The sample-size planning assumptions do not replace observed outcome estimates or establish the precision of this completed study.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Beneficial Bacteria Treatment for Autism — NCT02504554.
- Registry record last updated 2025-09-12; status last verified 2025-08.
- Results first posted 2019-12-18.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT02504554 is a completed Phase 1 and Phase 2, open-label, non-randomized, parallel-group trial sponsored by Arizona State University. It enrolled 18 children with autism spectrum disorders and gastrointestinal problems. The Oral and Rectal groups received a combination involving Vancomycin, MoviPrep, Prilosec, and processed, frozen human fecal material, with different administration routes.
The primary endpoint was mean GSRS score at baseline and 10 weeks. The registry record does not report its results. The safety summary lists 0 serious adverse events and 0 deaths, with 12 participants affected by other adverse events. Secondary outcomes include parent ratings, blood safety markers, autism-related measures, adaptive behavior, sensory profile, and stool records. Detailed analysis methods, missing-data handling, and results for these outcomes are not reported in the registry record.