The impact of an oral purified microbiome therapeutic on the gastrointestinal microbiome.
Bryant JA, Vulić M, Walsh EA, Allen EG Jr, Beauchemin NJ, Chafee ME, Diao L, Fenn K, Ford KA, Hasson BR, Litcofsky KD, Lombardo MJ, Martinez A, O'Brien EJ, Straub TJ, Sykes SM, Marshall LF, Winkler JA, McGovern BH, Ford CB, Wortman JR, Henn MR
- DOI
- 10.1038/s41591-025-04076-w
- Record issued
- 2026-08-15
- Engine
- 7.39.0
- Exported
- 2026-09-22
Prepared by Alpha1. This document is confidential: it is intended for the recipient it was shared with and must not be redistributed. The live record at alpha1science.com/verify/bc1e0967-cfa8-43be-a3f8-9ba307302ede is authoritative.
How this rating was calculated
- IntegrityIntegrity concern ×2−1★
- StatisticsStatistic did not reproduce−0.5★
- ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
- StatisticsPrinted percentage does not match its own count (capped)−0.25★
- ReportingData & code availability partially met−0.25★
- 01Printed percentage does not match its own count
66.7% is unattainable for n=28 (nearest: 64.3, 67.9%)
“66.7% female”
ResultsFind in source - 02Efficacy rests on an unvalidated surrogate endpoint
The primary efficacy claim is prevention of recurrent CDI, a hard clinical outcome, but the paper's main analyses focus on surrogate biomarkers (microbiome composition, engraftment, bile acids, fatty acids) as evidence of efficacy. While the phase 3 trial reported a hard clinical endpoint (recurrence), this manuscript's post hoc analyses use these surrogates to support the mechanism and efficacy. The paper does not establish a validated link between these surrogates and the clinical outcome beyond citing the phase 3 result, and target engagement is shown via engraftment but not linked to a validated surrogate-to-clinical-outcome relationship.
“In-depth phase 3 analyses revealed that VOS significantly altered microbial composition, significantly enriching the diversity and abundance of Firmicutes species and reducing the prevalence and abundance of C. difficile and opportunistic pathogens...…”
- 03Printed percentage does not match its own count
67.4% is unattainable for n=79 (nearest: 67.1, 68.4%)
“67.4% female”
ResultsFind in source - 04Other integrity concern
Trial NCT02437487 was first submitted to ClinicalTrials.gov on 2015-05-05, after the registered study start date of 2015-05. Retrospective registration means the protocol and outcomes were not on the public record before the study ran, which is what prospective registration exists to establish.
NCT02437487
reviewer’s wording
This Kaimen Rigor review uses Kaimen Rigor reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.
The paper is a rigorous post hoc analysis of a phase 3 randomized trial, with strong scientific premise, design, ethics, and reporting. The main weaknesses are incomplete data/code availability (no repository deposit or accession numbers) and some statistical reporting gaps (threshold p-values, unverified assumptions). Minor copyedit issues and a potential internal inconsistency in patient numbers should be addressed.
Both reviewers classified the study as observational (post hoc analysis of an RCT). The statistics verification covered only 3 tests, of which 2 were inconsistent but not decision errors; this is not sufficient to declare the statistics unsound. The citation check found no retracted or non-existent references. The integrity check flagged a potential internal contradiction in patient numbers and retrospective registration of one trial.
Numerical inconsistencies
3 findings · worst highValues that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.
- Summary statistic impossible for the stated N (GRIM/GRIMMER)Recomputed
- Printed percentage does not match its own countRecomputed
- Internal contradictions in the reported numbersAssessed
Recomputed 1 test: 1 consistent, 0 inconsistent; 1 via agent-written checks. 1 reported summary statistic mathematically impossible for the stated N (PERCENT). 1 printed percentage that does not match its own count.
- PERCENT66.7% is unattainable for n=28 (nearest: 64.3, 67.9%)
“66.7% female”
ResultsFind in source - PERCENT67.4% is unattainable for n=79 (nearest: 67.1, 68.4%)
“67.4% female”
ResultsFind in source
- CONSISTENTreported p < .001 · recomputed p = <.001Reviewer 1Relative risk of recurrence at week 8 in phase 3 (VOS vs placebo).
“only 12% of VOS-treated patients versus 40% of placebo patients recurred by week 8 (relative risk 0.32, P < 0.001)”
Taken as given: The 12% and 40% are recurrence rates in VOS and placebo arms, respectively.; The total number of patients in each arm is 100 (since percentages are given).; The p-value is from a chi-square test of the 2x2 table.Method: Recomputed Pearson chi-square p-value from the 2x2 table (12/88 vs 40/60) using pChi2x2.How we recomputed it: pChi2x2(12, 88, 40, 60)
- lowinternal contradictionThe abstract states 86.7% (26/30) recurrence-free in phase 1b, but the results section reports engraftment data for 28 patients in phase 1b, which is inconsistent with the 30 patients mentioned.
86.7% (26/30) of patients with recurrent CDI did not experience a subsequent recurrence over 8 weeks in an open-label phase 1b study ... metagenomics data from 273 samples from 28 patients in the phase 1b trial
Abstractreviewer’s wording
Overstated conclusions
2 findings · worst highConclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.
- Efficacy rests on an unvalidated surrogate endpointAssessed
- Conclusions only partially backed by the presented evidenceAssessed
9 major claims checked against the paper's own evidence: 1 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.
- partialReviewers 1, 2The findings underscore the importance of rapidly restoring key protective functions of the microbiome to achieve durable prevention of recurrence.The paper shows associations between engraftment, metabolite changes, and clinical outcomes, but does not directly demonstrate causality or durability beyond 24 weeks.Evidence: Engraftment and metabolite changes are associated with reduced recurrence, but no direct mediation analysis is performed.
“Engraftment of drug species is a critical step in driving the pharmacodynamic changes needed to prevent rCDI.”
Discussion ¶1Find in source - supportedReviewer 1Higher VOS dose in phase 3 is associated with improved engraftment compared to phase 2.The paper provides cross-trial engraftment comparisons showing higher engraftment in phase 3 than phase 2.Evidence: Figure 1b and Extended Data Table 2 show engraftment comparisons across trials.
“Engraftment in the phase 3 trial was also higher than that observed in patients who received the fixed low-dose regimen in the phase 2 study at all timepoints shared”
ResultsFind in source - supportedReviewer 1VOS treatment significantly alters microbial composition, enriching Firmicutes and reducing C. difficile and opportunistic pathogens.The paper presents taxonomic analyses showing increased Firmicutes and decreased Proteobacteria and C. difficile in VOS arm.Evidence: Figures 4 and 5 show relative abundances and prevalence of phyla and genera.
we observed a jump in the relative abundance of Firmicutes ... significantly less C. difficile in the VOS arm relative to the placebo arm
Resultsreviewer’s wording - supportedReviewer 1VOS treatment leads to changes in metabolites relevant to C. difficile life cycle, including depletion of primary bile acids and enrichment of secondary bile acids and fatty acids.Targeted and global metabolomics show significant changes in bile acids and fatty acids in VOS arm.Evidence: Figure 6 and Extended Data Fig. 5 show metabolite changes.
concentrations of the primary bile acids cholic acid and chenodeoxycholic acid (CDCA) were highest at baseline and remained elevated in the placebo arm relative to the VOS arm through week 2 ... secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA) were low at baseline and increased rapidly in the VOS arm
Resultsreviewer’s wording - supportedReviewer 1In vitro, VOS batches produce C. difficile-inhibiting metabolites.In vitro experiments show that VOS dose material produces DCA, LCA, butyrate, valerate, and hexanoate, and that these fatty acids inhibit C. difficile growth.Evidence: Extended Data Fig. 7 and 6 show metabolite production and growth inhibition.
“All five batches displayed the anticipated bile acid and fatty acid metabolic activities”
ResultsFind in source - supportedReviewer 2The higher, efficacious phase 3 dose is associated with improved pharmacokinetics, assessed by VOS engraftment.The paper provides cross-trial comparisons showing higher engraftment in phase 3 compared to phase 2, supporting the claim.Evidence: Figure 1b and Extended Data Table 2 show engraftment comparisons across trials.
“across-trial comparisons confirmed that the higher, efficacious phase 3 dose is associated with improved pharmacokinetics, assessed by VOS engraftment”
AbstractFind in source - supportedReviewer 2VOS significantly altered microbial composition, enriching Firmicutes and reducing C. difficile and opportunistic pathogens.The paper presents taxonomic analyses showing increased Firmicutes and decreased Proteobacteria and C. difficile in VOS-treated patients.Evidence: Figures 4 and 5 show relative abundances and prevalence of taxa.
“VOS significantly altered microbial composition, significantly enriching the diversity and abundance of Firmicutes species and reducing the prevalence and abundance of C. difficile and opportunistic pathogens”
AbstractFind in source - supportedReviewer 2Significant changes in key bioactive metabolites were observed, including depletion of primary bile acids and enrichment of secondary bile acids and fatty acids.Targeted and global metabolomics data show these changes in VOS-treated patients.Evidence: Figure 6 and Extended Data Fig. 5 show bile acid and fatty acid changes.
“significant changes in key bioactive metabolites were observed, including depletion of conjugated and deconjugated primary bile acids, enrichment of secondary bile acids and increases in short-chain and medium-chain fatty acids.”
AbstractFind in source - supportedReviewer 2In vitro, VOS batches produced these C. difficile-inhibiting metabolites.In vitro experiments show that VOS dose material produces DCA, LCA, butyrate, valerate, and hexanoate.Evidence: Extended Data Fig. 7 shows metabolite production in dose material cultures.
“In vitro, VOS batches produced these C. difficile -inhibiting metabolites.”
AbstractFind in source
Premise concern: surrogate not validated for clinical benefit.
- INADEQUATESurrogate endpointThe primary efficacy claim is prevention of recurrent CDI, a hard clinical outcome, but the paper's main analyses focus on surrogate biomarkers (microbiome composition, engraftment, bile acids, fatty acids) as evidence of efficacy. While the phase 3 trial reported a hard clinical endpoint (recurrence), this manuscript's post hoc analyses use these surrogates to support the mechanism and efficacy. The paper does not establish a validated link between these surrogates and the clinical outcome beyond citing the phase 3 result, and target engagement is shown via engraftment but not linked to a validated surrogate-to-clinical-outcome relationship.
“In-depth phase 3 analyses revealed that VOS significantly altered microbial composition, significantly enriching the diversity and abundance of Firmicutes species and reducing the prevalence and abundance of C. difficile and opportunistic pathogens... Consistent with these taxonomic changes, significant changes in key bioactive metabolites were observed, including depletion of conjugated and deconjugated primary bile acids, enrichment of secondary bile acids and increases in short-chain and medium-chain fatty acids.”
- ADEQUATEEffect sizeThe primary clinical effect size is reported as a relative risk of 0.32 (12% vs 40% recurrence) in the phase 3 trial, which is a large and clinically meaningful reduction. The manuscript also reports engraftment and metabolite changes, but the key efficacy claim is anchored to this hard clinical outcome with a clear magnitude.
“In phase 3, only 12% of VOS-treated patients versus 40% of placebo patients recurred by week 8 (relative risk 0.32, P < 0.001).”
Data authenticity concerns
1 finding · worst mediumAn adversarial read for patterns associated with data that may not be genuine: results that look too clean, implausibly large effects, duplicated data or images, and methods that do not match the results reported.
- Other integrity concernAssessed
2 integrity concerns flagged (0 high).
- mediumotherTrial NCT02437487 was first submitted to ClinicalTrials.gov on 2015-05-05, after the registered study start date of 2015-05. Retrospective registration means the protocol and outcomes were not on the public record before the study ran, which is what prospective registration exists to establish.
NCT02437487
reviewer’s wording
Reporting gaps
1 finding · worst mediumRequired detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.
- Data/code availability incompleteAssessed
The introduction cites prior research on bile acid and fatty acid mechanisms, the phase 1b/2/3 trials, and the hypothesis of suboptimal dosing. The rationale for the post hoc analysis is clearly linked to the discordant phase 2 results and the need to understand VOS pharmacology. Limitations of prior work (e.g., phase 2 failure) are addressed by the higher dose in phase 3.
“Microbe-mediated conversion of conjugated primary bile acids to secondary bile acids is inhibitory to C. difficile spore germination and growth”
“A follow-up pharmacological assessment led to the hypothesis that these markedly discordant results were due to differences in VOS dosing titer and frequency”
“An approximately 10-fold higher dose was given over 3 days in the phase 3 trial”
“Microbe-mediated conversion of conjugated primary bile acids to secondary bile acids is inhibitory to C. difficile spore germination and growth”
“we compared the pharmacokinetics of the phase 3 trial to the phase 1b and phase 2 trials to address the hypothesis that different dosing regimens across the VOS clinical development program led to different clinical results.”
“These discordant outcomes were hypothesized to be due to suboptimal dosing.”
The phase 3 trial was randomized, double-blind, and placebo-controlled, with randomization stratified by age and antibiotic. Blinding of patients, site staff, and sponsor is stated. The primary and preplanned exploratory endpoints are defined. However, the randomization method (e.g., computer-generated) is not described, and the power analysis is not reported in this paper (likely in the primary publication). Inclusion/exclusion criteria are described. Outlier handling is not explicitly discussed, but sample exclusions are detailed.
“Patients were randomly assigned 1:1 to VOS (approximately 3 × 10 7 spore colony-forming units) or matching placebo administered as four oral capsules once daily over three consecutive days . All patients, site staff and the sponsor were blinded to treatment assignment.”
“eligible adults 18 years of age or older with three or more CDI episodes within 12 months, inclusive of the qualifying acute episode, were enrolled”
“Some patient samples were not available due to missing specimens, protocol deviations or low sequencing read depth.”
“Patients were randomly assigned 1:1 to VOS (approximately 3 × 10 7 spore colony-forming units) or matching placebo administered as four oral capsules once daily over three consecutive days”
“All patients, site staff and the sponsor were blinded to treatment assignment.”
“eligible adults 18 years of age or older with three or more CDI episodes within 12 months, inclusive of the qualifying acute episode, were enrolled.”
Sex and age are reported for the phase 3 trial (59.9% female, mean age 65.5 years) and for phase 1b/2. Demographics are referenced to primary publications. The paper states that sex was not considered in the study design but that a treatment effect did not differ between males and females, justifying the lack of sex-based microbiome analyses. Age and antibiotic stratification are described. Health status (CDI episodes) is reported.
“One hundred and eighty-two patients were randomized in the phase 3 trial (59.9% female, mean age 65.5 years; Extended Data Table ).”
“A treatment effect of lower CDI recurrence in VOS versus placebo did not differ between males and females. Therefore, sex-based microbiome analyses were not executed.”
“A full description of patient demographics and baseline characteristics, including sex and age, is available in Feuerstadt et al. and Cohen et al.”
“One hundred and eighty-two patients were randomized in the phase 3 trial (59.9% female, mean age 65.5 years; Extended Data Table ).”
“The cohort had an average age of 30 years and an average body mass index of 23 kg m −2 and was 44% female.”
The paper states that the institutional review board for each study site reviewed and approved the protocol, and all patients provided written informed consent. This is reported for both the phase 3 trial and the healthy cohort. Regulatory compliance is implied by following CONSORT and GCP, though not explicitly named for all aspects.
“The institutional review board for each study site reviewed and approved the protocol and applicable amendments, and all patients provided written informed consent at screening”
“The institutional review board for each study site reviewed and approved the protocol, and all patients provided written informed consent.”
“The trial followed the CONSORT reporting guideline.”
“The institutional review board for each study site reviewed and approved the protocol and applicable amendments, and all patients provided written informed consent at screening”
“The institutional review board for each study site reviewed and approved the protocol, and all patients provided written informed consent.”
The investigational product VOS is described with its composition and manufacturing. Software tools are named with versions (MetaPhlAn2, StrainPhlAn version 4, vegan version 2.5-6, etc.). Reagents such as the Omega Mag-Bind Universal Pathogen Kit are identified with vendor. However, catalog numbers for some reagents and software are not provided, and the healthy cohort is described but not fully identified.
“VOS comprises purified Firmicutes bacterial spores, manufactured by processing fecal matter from rigorously screened heathy donors with ethanol to kill organisms that are not spores”
“DNA was extracted in-house from patient stool and drug materials using the Omega Mag-Bind Universal Pathogen Kit (Norcross).”
“All experiments were carried out with three different C. difficile ribotypes (RT-001, C lostridioides difficile American Type Culture Collection (ATCC) 9689; RT-060, C lostridioides difficile ATCC 43593; RT-087, Clostridioides difficile ATCC 43255)”
“DNA was extracted in-house from patient stool and drug materials using the Omega Mag-Bind Universal Pathogen Kit (Norcross).”
Statistical tests are named (Mann-Whitney U, PERMANOVA, Fisher's exact, etc.) and software is identified. Effect sizes with confidence intervals are reported in some cases (e.g., relative risk 0.32). However, many p-values are reported as thresholds (e.g., P < 0.001) rather than exact values, and assumptions are not explicitly verified. Data presentation includes box plots with defined error bars and sample sizes. Mathematical plausibility checks were not possible for most analyses due to lack of raw data.
“Differences in genus prevalence across arms were assessed using Fisherʼs exact tests adjusted for multiple hypothesis testing by controlling the false discovery rate (FDR) with the Benjamini−Hochberg procedure.”
“only 12% of VOS-treated patients versus 40% of placebo patients recurred by week 8 (relative risk 0.32, P < 0.001)”
“the strain-based approach showed significantly greater numbers of dose strains in the VOS arm compared to the placebo arm (Extended Data Fig. ; MWU, P < 0.001)”
“two-sided Mann−Whitney U -test (MWU), P < 0.01”
“MWU, P < 0.001”
“R 2 values at week 1: VOS: 0.64, placebo: 0.13”
The data availability statement says data may be requested by contacting an email, with review by a legal team, but does not specify a repository or platform. This is reported_but_inadequate. No code is shared, and no accession numbers are provided for sequencing data. The statement is concrete enough to be a managed access route, but lacks details on conditions and timeframe.
“Metabolomics, sequencing and individual-level patient data may be requested for non-commercial purposes by contacting NHScdatarequests@us.nestle.com.”
“Metabolomics, sequencing and individual-level patient data may be requested for non-commercial purposes by contacting NHScdatarequests@us.nestle.com. All requests will be reviewed by a member of the Nestlé Health Science legal team to ensure alignment with applicable patient consent agreements and regulatory requirements.”
Methods are detailed. Trial registration numbers are provided. CONSORT guideline is mentioned. All outcomes are reported, including negative results. Limitations are explicitly discussed. Conclusions are proportional. Funding and COI are disclosed.
“ClinicalTrials.gov: NCT03183128”
“Limitations of this study include the limited number of CDI recurrences in the VOS arm, preventing examination of associations between engraftment or metabolites and clinical outcome.”
“The trial followed the CONSORT reporting guideline.”
“Limitations of this study include the limited number of CDI recurrences in the VOS arm, preventing examination of associations between engraftment or metabolites and clinical outcome.”
Registered (2 IDs: ClinicalTrials.gov). Reporting guideline cited: CONSORT.
Broken references and links
None foundReferences checked against Crossref, OpenAlex and Retraction Watch for retractions and resolvability, plus declared data and code links probed for whether they resolve to content matching the paper.
Checked — nothing surfaced.
Checked 60 references by DOI: 59 verified — 1 no DOI (shown, not verified).
- NO DOIEfficacy and safety of investigational microbiome drug SER-109 for treatment of recurrent Clostridioides difficile infectionNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
4 data/code links checked; 4 live.
- datahttps://clinicaltrials.gov/study/NCT02437487LIVEHTTP 200Resolves, but the content could not be matched to the paper.
- datahttps://clinicaltrials.gov/study/NCT03183128LIVEHTTP 200Resolves, but the content could not be matched to the paper.
- datahttps://clinicaltrials.gov/ct2/show/NCT02437487LIVEHTTP 200Resolves, but the content could not be matched to the paper.
- datahttps://clinicaltrials.gov/ct2/show/NCT03183128LIVEHTTP 200Resolves, but the content could not be matched to the paper.
Copyediting
6 minorWording, consistency and formatting errors that need correcting before submission.
No major wording or formatting errors. 6 minor suggestions below.
6 copyedit issues flagged: mostly typo, consistency, clarity.
- MINORtypoIntroduction, paragraph 3“heathy donors”→ healthy donorsTypographical error.
- MINORconsistencyAbstract and Results“phase 1b”→ phase 1b consistentlyInconsistent use of 'phase 1b' vs 'phase 1'.
- MINORclarityMethods, Statistical analyses“The evaluation of engraftment, changes in species composition and bile acid concentrations presented herein are post hoc analyses consistent with the preplanned statistical analysis with the following deviations.”→ Consider rephrasing for clarity.Sentence is long and could be split.
- MINORtypoAbstract“heathy donors”→ healthy donorsTypographical error in the introduction.
- MINORconsistencyMethods, Statistical analyses“betadisper”→ betadisper (or betadisp)The function name may be misspelled; the correct vegan function is 'betadisper'.
- MINORclarityResults, VOS engraftment confirmed using strain-based methods“R 2 values at week 1: VOS: 0.64, placebo: 0.13”→ R² values at week 1: VOS: 0.64, placebo: 0.13Use superscript for squared notation.
The published work is largely robust, but an informed reader should weigh the incomplete data/code availability and the minor statistical reporting gaps. The internal inconsistency in patient numbers (26/30 vs 28) warrants clarification or an erratum. The retrospective registration of NCT02437487 is a transparency concern but does not invalidate the findings.
- 1.HIGHreportingReconcile the discrepancy between the abstract's 26/30 recurrence-free in phase 1b and the results section's 28 patients with engraftment data; clarify the correct denominator.An internal contradiction in patient numbers undermines the paper's credibility and could warrant an erratum.
- 2.HIGHdata codeDeposit sequencing data in a public repository (e.g., SRA) with accession numbers, if patient consent allows, and update the data availability statement accordingly.Providing accession numbers enhances reproducibility and is expected for data-driven papers.
- 3.HIGHdata codeShare custom analysis code in a public repository (e.g., GitHub) with a DOI, or state explicitly why code is not shared.Code sharing is critical for reproducibility of the bioinformatics analyses.
- 4.MEDIUMstatisticsProvide exact p-values for all comparisons currently reported as thresholds (e.g., P < 0.001) in the Results and figures, or state that exact values are in supplementary tables.Exact p-values improve transparency and allow readers to assess the strength of evidence.
- 5.MEDIUMstatisticsAdd a statement on how statistical assumptions (normality, equal variance) were verified or why non-parametric tests were used.Explicitly addressing assumptions strengthens the statistical rigor.
- 6.MEDIUMreportingInclude a power analysis or sample size justification for the microbiome endpoints, or reference the primary trial's power calculation.Power analysis is important for interpreting negative results and study design adequacy.
- 7.MEDIUMreportingReport all pre-specified outcomes, including safety outcomes, or reference where they are reported.Complete outcome reporting is required for transparency and to avoid selective reporting.
- 8.MEDIUMreportingClarify the randomization method (e.g., computer-generated sequence) in the Methods section.Describing the randomization method is a standard requirement for clinical trials.
- 9.MEDIUMreportingDescribe the handling of missing data in more detail, including the number of samples excluded for each reason.Detailed missing data handling improves transparency and reproducibility.
- 10.LOWcopyeditFix the typo 'heathy donors' to 'healthy donors' in the Introduction and Abstract.Correcting typos improves professionalism.
- 11.LOWcopyeditEnsure consistent use of 'phase 1b' vs 'phase 1' throughout the manuscript.Consistent terminology avoids confusion.
- 12.LOWcopyeditRephrase the long sentence in Methods, Statistical analyses for clarity.Clearer writing improves readability.
- 13.LOWcopyeditUse superscript for R² notation in the Results section.Proper notation is a minor formatting issue.
- 14.LOWreportingProvide catalog numbers or RRIDs for key reagents and software tools.Catalog numbers and RRIDs enhance resource identification and reproducibility.
- 15.LOWreportingAdd a statement about the validation of the proprietary species marker database used for taxonomic profiling.Validation of the marker database is important for the reliability of taxonomic assignments.
The star rating is the report’s one-glance summary. Every paper starts at 5★ and loses stars for the concrete problems the review finds — so a rating is never a vague average, it’s a running total you can read line by line under “How this rating was calculated.”
- Reporting — 8 dimensionseach dimension that fully fails−½★
- each dimension partially met−¼★
- Statistics · Integrity · Claimseach serious problem−1★
- each medium problem−½★
- Citationseach retracted or unverifiable reference−¼★
- Copyeditonly when the manuscript needs a full edit−½★
The rating never drops below 1★, and a demonstrable critical failure (an impossible statistic, a proven ethics violation) caps it at 1★ on its own — so the stars can never look healthy when the verdict is CRITICAL.
The rating draws on a panel of agents. Three independent Kaimen Rigor reviewers grade the eight dimensions below across several independent passes (the shown verdict is their majority vote — steadier than any single run), isolate the paper’s major claims and check its own evidence backs them, and flag integrity concerns. Alongside them, a citation agent resolves every reference against Crossref, OpenAlex, and Retraction Watch; a statistics agent recomputes reported tests; and rule-based checks verify that declared data/code links actually resolve. Full text is required — an abstract-only submission is not analyzed.
Graded against NIH, MDAR, ARRIVE 2.0, CONSORT, EQUATOR, and RRID guidelines. A dimension that doesn’t apply to the study type is skipped, never penalized.
This Kaimen Rigor review is model-assisted and is not a substitute for formal expert review. It complements human evaluation by surfacing potential methodological concerns — verify each finding against the source.