Mucus-penetrating microbiota drive chronic low-grade intestinal inflammation and metabolic dysregulation

Area of Science:

• Microbiology
• Gastroenterology
• Metabolic Health

Background:

• Metabolic syndrome is linked to gut microbiota changes, including bacterial encroachment in the colon's mucus layer.
• Dietary emulsifiers, carboxymethylcellulose (CMC) and polysorbate-80 (P80), may promote these gut alterations and metabolic dysfunction.

Purpose of the Study:

• To investigate the role of mucus microbiota versus fecal microbiota in mediating the effects of CMC and P80.
• To determine if changes in the mucus microbiome drive low-grade inflammation and metabolic syndrome.

Main Methods:

• Mice were fed CMC or P80, and their fecal and mucus microbiomes were analyzed.
• Gut microbiota composition and bacterial encroachment were assessed.
• Germfree mice received fecal or mucus microbiota transplants from CMC/P80-fed mice.

Main Results:

• CMC and P80 significantly altered the mucus microbiome composition, distinct from fecal changes.
• Microbiota transfer from CMC/P80-fed mice induced bacterial encroachment, low-grade inflammation, and metabolic syndrome features in recipient mice.
• Mucus microbiota, not fecal microbiota, were responsible for transferring these detrimental effects.

Conclusions:

• The gut mucus microbiome plays a critical role in regulating intestinal inflammation.
• Alterations in mucus-associated bacteria are key drivers of metabolic syndrome.
• Dietary emulsifiers impact host metabolism through their effects on the mucus microbiome.