The gut microbiome as mediator between diet and its impact on immune function

Area of Science:

• Human health
• Immunology
• Microbiology

Background:

• Dietary habits significantly influence human inflammatory status.
• The gut microbiome (GM) processes dietary components and modulates the immune system, suggesting a mediating role in diet-inflammation relationships.

Purpose of the Study:

• To investigate the association between dietary patterns and inflammatory biomarkers.
• To explore the mediating role of the gut microbiome in diet-immune system interactions.

Main Methods:

• Cross-sectional analysis of 482 healthy participants.
• Dietary intake assessed via food questionnaires; inflammatory mediators and adipokines measured using immunoassays and ELISA.
• Gut microbiome composition analyzed from stool samples; statistical analyses included polychoric correlations, regression, and non-parametric entropy mediation.

Main Results:

• Three dietary patterns identified: 'high-meat', 'prudent diet', and 'high alcohol'.
• Prudent diet associated with higher adiponectin; high alcohol diet linked to increased pro-inflammatory markers (CRP, IL-6, VEGF).
• The gut bacterium Dialister invisus mediated the relationship between prudent diet and several immune biomarkers.

Conclusions:

• Dietary patterns impact chronic low-grade inflammation biomarkers; prudent diets show anti-inflammatory effects.
• The gut microbiome partially mediates the association between diet and immune function.
• Findings highlight the interplay between diet, gut microbiome, and immune system in maintaining health.