Bacterial growth, flow, and mixing shape human gut microbiota density and composition

Area of Science:

• Microbiology
• Human Physiology
• Computational Biology

Background:

• The human gut microbiota is a complex and dynamic ecosystem.
• Host physiology and diet are known major drivers of microbial composition.
• Understanding these influences is crucial for gut health research.

Purpose of the Study:

• To develop a comprehensive modeling framework predicting microbiota composition changes.
• To integrate bacterial growth physiology with human physiological data.
• To elucidate the mechanistic links between host factors and gut microbial dynamics.

Main Methods:

• Integrated quantitative measurements of bacterial growth physiology.
• Reanalyzed published human physiological data.
• Developed a comprehensive modeling framework for predictive analysis.

Main Results:

• Hydrodynamic forces and colonic water absorption (transit time) significantly impact microbiota density and composition.
• These factors mechanistically influence colonic pH, affecting microbial competition for nutrients.
• Detailed analysis of luminal content mixing dynamics by wall contractions was performed.

Conclusions:

• Host physiological factors, particularly transit time, play a critical role in shaping gut microbiota.
• Colonic pH is a key mediator linking host physiology to microbial community structure.
• The developed modeling framework offers broader implications for gut microbiota research and understanding host-microbe interactions.