Lipids alter microbial transport through intestinal mucus

Area of Science:

• Gastroenterology
• Microbiology
• Biophysics

Background:

• The gastrointestinal mucus layer is crucial for regulating host-microbe interactions.
• Alterations in mucus barrier properties can influence gut homeostasis, inflammation, and pathogen invasion.
• Food components, such as lipids, can modify mucus characteristics and affect transport through it.

Purpose of the Study:

• To investigate the impact of dietary lipids on the transport of Escherichia coli (E. coli) through a model intestinal mucus.
• To analyze changes in mucus structure and E. coli swimming behavior in the presence of lipids.

Main Methods:

• Direct imaging of E. coli swimming patterns within a model intestinal medium mimicking a fed state.
• Analysis of mucus structure and E. coli track linearity and speed in the presence of triglycerides.
• Observation of physical interactions between E. coli and lipid emulsion droplets.

Main Results:

• Lipids in the model fed state intestinal contents significantly reduced E. coli speed and track linearity within the mucus.
• Lipid emulsion droplets remained intact within the mucus gel, potentially crowding the network.
• Physical interactions between E. coli and lipid structures were observed, impacting bacterial movement.

Conclusions:

• Dietary lipids alter mucus properties, impeding E. coli motility.
• Lipid-induced changes in mucus structure and direct bacterial-lipid interactions contribute to reduced bacterial speed.
• Lipid-based strategies could be explored to modulate the mucus barrier for controlling microbial interactions and preventing epithelial invasion.