Western diet is a risk factor for Crohn's disease.
Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is abnormally expressed in Crohn's disease patients.
This allows adherent-invasive Escherichia coli (AIEC) to colonize the gut mucosa and leads to inflammation.
Dr Nicolas Barnich and colleagues assessed the effects of a high fat/high sugar (HF/HS) Western diet on gut microbiota composition, barrier integrity and susceptibility to infection in transgenic CEABAC10 mice expressing human CEACAMs.
Colonic microbiota composition and susceptibility of CEABAC10 mice to AIEC LF82 bacteria infection were determined in mice fed a conventional or HF/HS diet.
Barrier function and inflammatory response were assessed by studying intestinal permeability, tight junction protein and mucin expression and localization, and by determining histological score and levels of cytokine release.
|The modifications led to a higher ability of AIEC bacteria to colonize the gut mucosa|
The team found that HF/HS diet led to dysbiosis in WT and transgenic CEABAC10 mice, with a particular increase in E coli population in HF/HS-fed CEABAC10 mice.
The research team observed that these mice showed decreased mucus layer thickness, increased intestinal permeability, induction of Nod2 and Tlr5 gene transcription, and increased TNFα secretion.
These modifications led to a higher ability of AIEC bacteria to colonize the gut mucosa and to induce inflammation.
Dr Barnich's team concludes, "Western diet induces changes in gut microbiota composition, alters host homeostasis and promotes AIEC gut colonization in genetically susceptible mice."
"These results support the multifactorial etiology of Crohn's disease, and highlight the importance of diet in Crohn's disease pathogenesis."