Research

Five connected threads, from statistical theory through open software to collaborative science.

Thread 01

Compositional data analysis

Relative abundances need a sampling fraction, not a normalization.

Sequencing gives us relative, not absolute, abundances. Ignoring that fact inflates false positives and can reverse the direction of an estimated effect. Our work on ANCOM-BC and ANCOM-BC2 estimates and corrects the sample-specific sampling fraction directly, delivering valid confidence intervals and controlled false discovery rates for differential abundance, extended to multiple groups, covariate adjustment, and repeated measures.

Thread 02

Multi-omics integration

Each assay is a partial view of one biology; the estimator has to link them.

Microbiome, metabolome, proteome, and clinical measurements each capture a partial view of the same biology. We develop correlation and latent-structure estimators that link these layers into a single coherent model; one example is SECOM, which recovers both linear and nonlinear taxa–taxa associations without the spurious correlations induced by compositionality.

Thread 03

Causal inference

Which features differ is a smaller question than which lie on a pathway.

Most omics studies are observational. We work on mediation analysis, confounding adjustment, and treatment-effect estimation tailored to high-dimensional, sparse, compositional exposures and mediators, asking not just which features differ, but which plausibly lie on a causal pathway.

Thread 04

Explainable AI

Accuracy on its own rarely changes clinical or regulatory practice.

Predictive accuracy alone rarely changes clinical or regulatory practice. We build machine-learning methods that pair competitive prediction with interpretable structure, uncertainty quantification, and feature attributions that hold up under the correlation patterns typical of omics data.

Thread 05

Translational collaboration

Methods are developed against real scientific questions, across six domains.

Methods are developed against real scientific questions. Current and past collaborations span:

  • Cancer: biomarker discovery and treatment response.
  • Infectious disease: gut microbiome, systemic inflammation, and HIV-1 acquisition.
  • Aging: longitudinal shifts in the microbiome and metabolome.
  • Maternal & child health: early-life exposures and developmental outcomes.
  • Environmental health: exposure–microbiome–outcome pathways.
  • Clinical trials: design and assessment of trial endpoints.