Li Lab

What We Do

Research

We build computational methods and apply them alongside experimental collaborators to establish mechanistic causality at the host-microbe interface — identifying the enzymes, metabolites, and spatial programs through which microbes shape host physiology.

Gut bacteria enzymatically converting cholesterol to coprostanol, with an accompanying fall in serum cholesterol

Gut Microbial Metabolism & Cardiometabolic Health

Most microbiome–cardiometabolic studies rest on cross-sectional snapshots. We use six years of paired fecal metagenomes and LC-MS/MS metabolomes from the Framingham Heart Study to ask how microbial metabolism tracks with host cardiometabolic trajectories — work that began with our discovery of Oscillibacter as a cholesterol-metabolizing genus.

  • Temporal stability of the microbial metabolic landscape over six years
  • Deconvolving microbial metabolic contributions from cohort data
  • Cholesterol and steroid transformation by gut bacteria
  • Prioritizing microbial enzymes as therapeutic targets
An intestinal Swiss roll — the gut coiled into a flat spiral for spatial transcriptomics, labelled proximal at the centre and distal at the outer end

Spatial Biology of the Intestine

Our "Swiss-roll" spatial transcriptomic map of the mouse intestine revealed a microbially triggered ILC2–goblet cell axis in the mid-colon. We are extending the method to ask how the gut responds to a high-fat diet imposed just after weaning, and whether early-life dietary stress reshapes tissue identity reversibly.

  • High-resolution expression maps along the full intestinal axis
  • Diet-induced disruption of epithelial–immune crosstalk
  • Plasticity and reversibility of early-life exposures
  • Systemic validation in LDL-receptor-deficient models
An undifferentiated cloud of sepsis patients resolving, via serum metabolomics, into three distinct endotype clusters

Decoding Sepsis Heterogeneity

Sepsis lacks effective treatment largely because patient responses are so diverse. We think the serum metabolome encodes the logic of its sub-phenotypes, and are building methods to characterize that "metabolomic dark matter" and resolve it into cell-type-specific pathways using single-cell references.

  • Explainable models of sepsis sub-phenotypes
  • Cell-type deconvolution of untargeted serum metabolomics
  • Biomarkers for predicting clinical outcome
  • Supported by a Broad CISID New Investigator Award
A microbial community on the left and a mass spectrum on the right, linked by arrows in both directions: production flow from microbes to metabolites, and source tracing back again

Methods for Microbial Ecology & Metabolomics

Method development runs through everything we do, building on BEEM and BEEM-Static, our algorithms for recovering absolute abundances from compositional data. We are extending it in three directions: spatiotemporal dynamics from fecal metagenomes, annotation of uncharacterized LC-MS and MS/MS features, and linking metabolites to the microbes that produce them.

  • Spatiotemporal dynamics inferred from fecal metagenomic data
  • Metabolite annotation from LC-MS and MS/MS spectra
  • Linking metabolites to their microbial and enzymatic sources
  • Protein language models for enzyme function prediction

Approaches & Data Types

🔭Shotgun metagenomics
🧬Strain-resolved & comparative genomics
⚗️Untargeted metabolomics (LC-MS/MS)
🗺️Spatial transcriptomics
📊Single-cell RNA sequencing
🧵Long-read & nanopore sequencing
🤖Protein language models
📈Ecological & statistical modeling
💻Reproducible workflows on HPC & cloud