Systematically assessing microbiome-disease associations identifies drivers of inconsistency in metagenomic research

Braden T Tierney1,2,3,4, Yingxuan Tan1, Zhen Yang2,3,4

  • 1Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America.

Plos Biology
|March 2, 2022
PubMed

Insights

Statistical models for the gut microbiome often yield inconsistent results. This study evaluated millions of strategies, finding many published microbe-disease links, especially for diabetes, lack robustness and are contradictory.

Area of Science:

  • Microbiome research
  • Statistical modeling
  • Human health and disease

Background:

  • Reliable statistical associations are crucial for understanding the human gut microbiome's role in disease.
  • Previous studies have identified numerous microbe-disease associations, but their consistency is often unverified.

Purpose of the Study:

  • To evaluate the robustness and consistency of microbiome-based disease indicators across multiple statistical models and cohorts.
  • To develop a method for discriminating between robust and non-robust findings in microbiome association studies.

Main Methods:

  • Applied millions of different association modeling strategies to analyze 6 prevalent phenotypes across 15 public cohorts (2,343 individuals).
  • Assessed the consistency of taxon-disease associations, including previously reported findings.
  • Quantified the influence of potential confounders (e.g., sequencing depth, BMI, glucose, cholesterol) on identified associations.

Main Results:

  • Many different statistical models produced contradictory associations (positive vs. negative correlations) for the same microbe-disease pair.
  • 1 in 3 previously reported microbe-disease associations showed substantial inconsistency in the direction of the association.
  • >90% of published findings for type 1 diabetes (T1D) and type 2 diabetes (T2D) were found to be particularly non-robust.
  • Confounders significantly influenced the perceived correlation between specific microbes (e.g., Faecalibacterium prausnitzii) and health status.

Conclusions:

  • A significant proportion of microbiome-disease associations, particularly for diabetes, lack robustness and consistency across different analytical approaches.
  • The proposed method can help prioritize reliable findings from microbiome association studies.
  • Increased confidence in prioritizing microbiome findings is achievable through rigorous evaluation of analytical consistency.