Computational Model Reveals How Stomach Motility Affects Pathogen Survival Against Gastric Acid
Researchers have developed an imaging-based computational model of the human stomach that tracks 10,000 simulated pathogen particles through a dynamic, realistic gastric environment. The model couples fluid flow, acid transport, and pathogen population kinetics to assess how stomach motility and tone affect the gastric acid barrier. The findings suggest that standard clinical metrics like average pH or emptying rate are insufficient to evaluate infection risk, and that impaired stomach motility significantly increases pathogen survival.
A new computational study published on arXiv introduces a stomach model that simulates the fate of ingested pathogens by tracking 10,000 massless particles through a spatially and temporally varying pH field driven by peristaltic mixing, acid secretion, and gastric tone. The model finds that motility is the dominant factor governing whether pathogens survive the gastric acid barrier: a hypomotile stomach retains nearly 50% of the initial pathogen population alive six minutes after ingestion, compared to fewer than 30% in healthy cases. Hypomotility also produces broader acid-dose distributions and more heterogeneous survival outcomes across the pathogen population. Counterintuitively, among healthy-motility scenarios, increased gastric tone was associated with delivering the highest concentration of viable pathogens into the duodenum, exposing a trade-off between faster transport and reduced time for acid-mediated inactivation. The authors argue that conventional metrics such as mean gastric pH or emptying rate fail to capture these dynamics, and that a coupled flow-transport-kinetics framework is necessary for a mechanistic understanding of gastric infection risk. The work has potential implications for understanding foodborne illness susceptibility in populations with gastric motility disorders.
What's missing
The model uses massless particles and does not account for pathogen-specific properties such as acid resistance, adhesion to mucus, or active motility, which vary substantially across species like H. pylori, Salmonella, or norovirus. The study has not yet undergone peer review. Validation against in vivo or ex vivo experimental data on actual pathogen survival in human stomachs is not reported, leaving the quantitative predictions unconfirmed. The model also focuses on liquid meals, and it is unclear how results would generalize to solid or mixed meals.
What different sources said
- arXiv physicsCenter
Flow-Mediated Regulation of Pathogen Survival in the Human Stomach
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