SH-DS01 on Fecal Metagenomic Stability: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for SH-DS01 on Fecal Metagenomic Stability (NCT04598295), a randomized phase 2 study. The primary outcome is Safety and Tolerability of DS-01 Treatment vs Placebo.

2. Clinical Question

The central statistical question is therefore narrow: what do the reported adverse-event counts and the risk-difference summary say about the observed safety outcome in these enrolled participants? The posted record reports a risk difference of 0.0, with an interval from 0.0 to 0.0. Those figures describe the results as recorded, but they do not by themselves establish that the underlying event risks are identical or precisely known. The registry record does not post an analysis count or a p-value for this outcome.

3. Trial Design

The registry identifies this as a Phase 2, randomized, quadruple-masked, parallel-group study. It lists Beth Israel Deaconess Medical Center as the sponsor and gives the trial status as completed. The recorded enrollment is 48, with 24 participants assigned to microbial consortia (DS-01) and 24 assigned to placebo. The primary outcome timeframe is 12 weeks.

In the intervention description, DS-01 is a rationally defined microbial consortium comprising 24 strains across 12 species and polyphenolic and phenolic prebiotic bioactive compounds. Participants were instructed to take 2 capsules daily. The placebo capsules contained rice flour and were described as matched for color and texture, with an identical outer capsule shell; participants were also instructed to take 2 capsules daily. These are descriptions of the study arms, not evidence about adherence or actual exposure.

The record contains conflicting design descriptions. Its structured fields identify a Phase 2 study and enrollment of 48, whereas the brief summary calls it a Phase 1 study and describes a cohort of 100 participants, with 50 in each group. The structured arm records list 24 participants per arm. The registry record does not explain this mismatch, so the descriptions cannot be reconciled from the posted information alone.

The record gives a start date of 2020-10-20 and a primary completion date of 2022-10-17. It does not report the randomization sequence method, allocation concealment procedure, or which roles were covered by quadruple masking. It also does not give enough detail to establish whether all randomized participants completed follow-up. The available design information supports describing the study as randomized, masked, parallel, and placebo-controlled, but not filling in those unreported operational details.

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

Analysis population for the primary outcome, as defined in the registry: subjects who received DS-01 or matching placebo

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.

6. Primary Endpoint

The registry lists the primary outcome as Safety and Tolerability of DS-01 Treatment vs Placebo, measured over 12 weeks.

The primary endpoint is titled Safety and Tolerability of DS-01 Treatment vs Placebo. It is a count of participants, with the measure described as reported adverse events during the study period. The stated timeframe is 12 weeks, and the population is subjects who received DS-01 or matching placebo. The posted results show 0.0 participants with the outcome in the DS-01 arm and 0.0 in the placebo arm.

A participant count is a binary-outcome summary at the individual level: each person either contributes to the count as having a reported event or does not. The registry record does not provide a definition of which events qualified for this primary endpoint, how events were solicited or adjudicated, or whether a participant with multiple events was counted once or by event. Those details matter for interpreting what the count represents.

Safety and tolerability outcomes are used to describe reported harms and how they were observed over the study period. They answer a different question from outcomes of biological activity or clinical benefit. Although the official title refers to fecal metagenomic stability, gut barrier integrity, and metabolic output, the record posts one outcome measure, the safety and tolerability count. Results for those other topics are not reported in the registry record.

The endpoint is useful for describing the events recorded in the trial, but a zero count is not the same as proof that no events could occur. Its interpretation depends on follow-up, reporting, the endpoint definition, and the amount of information available. The registry record does not provide those details beyond the stated population and timeframe.

7. Results Posted in the Registry

• Microbial Consortia (DS-01): 0.0% (0/24) versus 0.0% (0/24) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0); unadjusted two-proportion z-test p = n/a.

8. Statistical Interpretation

9. Statistical Methods Explained

The posted outcome is a count of participants with a reported adverse event. For a binary outcome, the underlying individual-level information is whether each participant met the event definition during the stated timeframe. Arm-level event proportions can be compared, and the risk difference expresses the absolute difference between those proportions. Here, the registry reports a risk difference of 0.0 for DS-01 compared with placebo. Because the event counts are zero in both groups, the observed comparison is at the boundary of the possible range for event proportions.

That boundary case deserves care. General statistical explanation: when an outcome is rare or no events are observed, standard approximations can behave differently from calculations based on more balanced event information. The way an interval is calculated matters, particularly when counts are zero. The registry reports interval limits of 0.0 and 0.0 but does not identify the method used. It would be inappropriate to assume a method or to replace the posted result with an independently chosen interval.

The record posts a count-based endpoint rather than a continuous measure. Thus, concepts such as mean change and standard deviation do not describe this outcome. The registry also does not give a time-to-event analysis, event rates over person-time, or a measure of event severity for the primary endpoint. Its adverse-event summaries distinguish serious from other events, but they do not provide event-level timing or duration.

Randomization is intended, as a general design principle, to make treatment assignment independent of participant characteristics on average. It supports a fair comparison when the assigned groups are analyzed appropriately, but it does not guarantee that every possible source of bias is absent. The registry confirms randomized allocation and a parallel design. It does not report the sequence-generation method, concealment process, or analysis population, so those features cannot be evaluated from this entry.

Masking can, as a general principle, reduce the influence of expectations on care, reporting, and outcome assessment. The record labels masking as quadruple, but it does not say which participants, investigators, care providers, or assessors were masked. The placebo description says capsules were matched for color and texture and used an identical outer shell. Those details describe the intended comparator, but do not establish whether masking was maintained.

The record does not post an analysis count or a statistical analysis plan. It does not describe whether the comparison used a hypothesis test, an exact method, a regression model, or an adjustment strategy. It also does not state whether the comparison was prespecified in the protocol or whether it was conducted on an intention-to-treat or treated-participant basis. The posted risk difference and interval can be summarized as results, but not attributed to a particular analysis method.

General explanation: a confidence interval is a range constructed by a specified procedure to represent uncertainty around an estimate. Its meaning depends on the method and assumptions used. The interval printed has both limits equal to the point estimate. Without a reported construction method, the record does not allow a reader to check its coverage properties or understand how zero counts were handled. The displayed interval should not be taken as a guarantee that the true difference is exactly 0.0.

The sample-size section elsewhere on the page is a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation; its effect to detect is framed as a stated fraction of the observed effect. Such calculations are planning illustrations, not observed power and not a report of the trial's original design rationale. The registry record does not report the trial's own sample-size justification. When an observed effect is zero, illustrations anchored to that observed effect need particularly cautious interpretation; they do not establish that the study was adequately sized to assess safety.

Over-dispersion is a general concern when the variability in data exceeds what a statistical model assumes. It is especially relevant to some count models, where participants may have different underlying event tendencies. The posted primary measure is a participant count, and the registry does not report a model or dispersion estimate. There is therefore no basis to diagnose or adjust for over-dispersion in this analysis.

In short, the available record supports a basic descriptive reading of the event counts and the reported risk difference. It does not support reconstruction of the analysis, because key details—including the statistical plan, interval method, missing-data approach, and analysis population—are not reported in the registry record.

10. Confidence Intervals and Precision

Precision concerns how much uncertainty surrounds an estimated effect. The posted risk difference is 0.0, and the reported lower and upper interval limits are also 0.0. As displayed, the interval has no width. That is an unusual-looking presentation for an estimated difference based on participant counts and should not be read as demonstrating perfect precision.

The registry record does not report how the interval was constructed. It does not identify whether the limits come from a particular exact or approximate procedure, nor does it explain how the procedure handles zero events in both arms. Without this information, readers cannot evaluate the interval's statistical properties. The calculated display can present the posted limits, but it cannot supply a missing explanation of their derivation.

General explanation: a confidence interval is useful when interpreted together with its estimation method and assumptions. An interval that appears narrow may reflect substantial information, but it may also arise from a method or data representation that needs scrutiny. Here, the event counts are zero in each listed arm, so the observed data contain no event contrast. The collapsed interval should not be treated as evidence that all plausible underlying event risks are identical.

The enrollment record lists 24 participants per arm. Those counts provide the scale of the posted comparison, but they do not resolve uncertainty about outcomes that were not observed. In general, zero events in a finite group do not establish that the event is impossible in a wider population. The record does not provide a separate precision analysis or a method-specific uncertainty estimate that can be used to quantify this point.

The conflict between the brief summary's cohort description and the structured enrollment also matters when assessing how much information the record represents. The posted results list the structured arm counts, while the summary refers to a larger cohort; the relationship is not reported. Precision should therefore be discussed in relation to the posted outcome counts, without assuming that the larger cohort description contributed to these results.

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and no posted analyses. It does not describe a statistical analysis plan, a hierarchy of outcomes, or any strategy for controlling multiplicity. The official title refers to metagenomic stability, gut barrier integrity, and metabolic output, but the posted outcome count is one and the record does not post results for those biological domains. It is not possible to determine from this entry whether those outcomes were measured, planned, or analyzed elsewhere.

Multiplicity is a general issue when several outcomes, time points, subgroups, or comparisons are tested. Conducting many analyses can increase the chance of a seemingly noteworthy result arising by chance unless the analysis strategy accounts for that possibility. No such strategy is reported, so the reader should not infer that multiplicity was either present or controlled.

Missing-data handling is not reported in the registry record. The entry does not say whether there were missing safety assessments, how incomplete follow-up was handled, or whether participants who discontinued treatment remained in the outcome analysis. The primary endpoint population is described as subjects who received DS-01 or matching placebo, but this wording does not establish the detailed analysis set or how participants with incomplete information were treated.

The record also does not report a protocol-defined analysis population, per-protocol analysis, sensitivity analysis, or imputation procedure. These omissions matter because counts of reported events depend on observation and reporting during follow-up. The zero counts are the posted results, but the record does not provide enough information to evaluate whether all participants had complete and comparable ascertainment.

Accordingly, the safest statistical reading is limited to the figures recorded for the primary safety outcome and the separate adverse-event summaries. The absence of reported details should not be filled in with assumptions about a prespecified hierarchy, complete follow-up, or a particular missing-data method.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry's serious adverse-event summary lists 24 participants at risk in the DS-01 group and 0 affected; it lists 24 at risk in the placebo group and 0 affected. The other adverse-event summary likewise lists 24 at risk and 0 affected in each arm. The record lists 0 deaths in each group and no top serious-event terms.

These are counts in the posted safety tables. They are not, by themselves, evidence that no adverse events of any kind occurred outside the definitions or reporting represented in those tables. The primary outcome is described as reported adverse events, while the separate safety fields distinguish serious from other events. The registry record does not provide event definitions, collection procedures, adjudication details, or participant-level event listings.

General explanation: serious events and other adverse events are separate reporting categories, so they should not be conflated. A zero count in each category means no affected participants are listed in that category in the posted record. It does not demonstrate that the treatment has no potential risks, and it does not establish a comparative safety advantage. The figures should be interpreted within the recorded 12-week timeframe and the listed participants, not as a complete account of all possible outcomes.

13. What the Result Does, and Does Not, Mean

The result does mean that the registry's posted primary safety outcome records 0.0 participants with reported adverse events in each arm during the stated 12 weeks. The reported risk difference is 0.0, with interval limits of 0.0 and 0.0. The separate serious and other adverse-event summaries also list 0 affected participants in each arm, and no deaths are listed.

Those results are descriptive. They tell readers what was entered in the registry for this outcome and these groups. They do not prove that DS-01 and placebo have identical safety profiles, that adverse events cannot occur, or that the result would be the same in a different population or over a different duration. The registry does not report enough statistical detail to treat the collapsed interval as a reliable statement of certainty.

The result also does not answer the biological questions suggested by the trial's official title. The only posted outcome is the safety and tolerability count. Findings on fecal metagenomic stability, gut barrier integrity, or metabolic output are not reported in the registry record. Nor does this entry provide a posted efficacy outcome that could support a conclusion about symptom change.

It is important to distinguish the trial description from the results. The record describes a Phase 2 randomized, quadruple-masked, parallel study, but its brief summary calls it Phase 1 and describes a cohort larger than the structured enrollment and arm listings. The entry does not explain the mismatch. It also does not report adherence, follow-up completeness, event ascertainment details, a statistical analysis plan, or how missing observations were handled.

Thus the appropriate conclusion is limited: no participants with the specified reported events appear in the posted summaries for either arm. This is not evidence of equivalence or proof of absence of risk. It is also not a basis for medical advice. It is a registry-level description whose uncertainty and scope are constrained by the information recorded.

14. Why This Trial Matters Statistically

This trial is statistically interesting because its posted safety comparison sits at the zero-event boundary: neither arm has reported affected participants. Such results illustrate why a point estimate alone is not enough. A risk difference of 0.0 describes no observed contrast, but the interpretation of uncertainty depends on the interval method, the event definition, and how completely participants were followed and assessed.

The registry reports interval limits equal to the estimate, but does not identify the calculation method. This makes the entry a useful example of the distinction between a displayed interval and an interpretable uncertainty analysis. Readers need to know how an interval was obtained before treating its apparent precision as meaningful. The record's silence on the method is consequential, particularly when both event counts are zero.

The entry also highlights the importance of consistent trial descriptions. The structured record lists a Phase 2 trial with enrollment of 48 and 24 participants per arm, while the brief summary describes Phase 1 and a cohort of 100 with 50 participants per arm. The record does not reconcile those descriptions. Clear alignment among the protocol summary, enrollment fields, and posted results helps readers understand which population the results represent.

Finally, the official title names several biological domains, but only a safety outcome is posted. This illustrates why readers should distinguish a trial's broad scientific aims from the outcomes with results available in a registry entry. Statistically, the posted information permits a narrow descriptive reading, but not a full assessment of the planned biological questions or the analysis choices behind them.

15. 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 outcome record is sparse. It reports a participant count and a 12-week timeframe, but does not define qualifying adverse events or describe how events were elicited, coded, or adjudicated. The separate safety summaries provide serious and other event counts, but no event-level terms are listed and no top serious-event terms are posted.

The comparison's reported interval is 0.0 to 0.0 around a risk difference of 0.0. The registry does not identify the interval method or explain the collapsed limits. There is no posted p-value, analysis count, or statistical analysis plan. Consequently, readers cannot verify the inferential procedure or assess whether it was prespecified.

The record does not describe the analysis population beyond saying that the endpoint concerns subjects who received DS-01 or matching placebo. It does not report adherence, withdrawals, completeness of follow-up, missing-data handling, or sensitivity analyses. Those omissions limit evaluation of whether the zero counts reflect complete, comparable ascertainment in both groups.

There is also an internal descriptive mismatch: the structured record lists Phase 2, enrollment of 48, and 24 participants per arm, while the brief summary says Phase 1 and describes a cohort of 100 with 50 per arm. The registry does not explain which summary best reflects the study conduct or how the accounts relate. The results should therefore be described using the posted structured counts while retaining that uncertainty about the record's descriptions.

Finally, the title refers to metagenomic stability, gut barrier integrity, and metabolic output, but results for those outcomes are not reported in the registry record. The posted safety result cannot substitute for evidence on those unreported measures.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: SH-DS01 on Fecal Metagenomic Stability — NCT04598295.
• Registry record last updated 2026-02-17; status last verified 2026-01.
• Results first posted 2026-02-17.
• 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.

19. Record Summary

The registry lists NCT04598295, titled SH-DS01 on Fecal Metagenomic Stability, as a completed randomized, quadruple-masked, parallel Phase 2 study sponsored by Beth Israel Deaconess Medical Center. The recorded enrollment is 48, with 24 participants in the DS-01 arm and 24 in the placebo arm. The primary safety outcome covers 12 weeks.

The posted primary results report 0.0 participants with adverse events in each arm and a risk difference of 0.0, with limits of 0.0 and 0.0. Separate summaries list no serious or other adverse events and no deaths in either group. No analyses are posted. The record does not explain the mismatch between the structured trial description and the brief summary, or report the statistical method behind the interval. Results for the biological outcomes named in the title are not reported in the registry record.