Nutrient competition predicts gut microbiome restructuring under drug perturbations.

Area of Science:

• Microbiology
• Systems Biology
• Pharmacology

Background:

• Human gut bacteria face various stresses, making community-level responses to external factors like drugs unpredictable.
• Understanding microbial community dynamics is crucial for predicting drug efficacy and side effects.

Purpose of the Study:

• To investigate the impact of clinically relevant drugs on human gut bacterial communities.
• To determine the role of nutrient competition in shaping microbial community responses to drug exposure.

Main Methods:

• Screened stool-derived in vitro communities against 707 clinically relevant drugs.
• Analyzed compositional and metabolomic changes across approximately 5,000 community-drug conditions.
• Utilized consumer-resource models to predict species abundance changes.

Main Results:

• Nutrient competition was a primary driver of community composition and metabolic shifts, with species expanding by outcompeting suppressed competitors.
• Most compositional changes resulted from species extinction, often reversible by reintroduction, though some drugs induced persistent alternative community states.
• Drug resistance emergence was infrequent despite significant selective pressures.

Conclusions:

• Nutrient competition quantitatively tunes microbial species abundances and provides a predictive framework for gut microbiome drug responses.
• This framework can help anticipate and potentially mitigate unintended drug side effects on the human gut microbiota.