Dietary inflammatory potential mediated gut microbiota and metabolite alterations in Crohn's disease: A fire-new perspective

Background & aims: Pro-inflammatory diet interacting with gut microbiome might trigger for Crohn's disease (CD). We aimed to investigate the relationship between dietary inflammatory potential and microflora/metabolites change and their link with CD.

Methods: The dietary inflammatory potential was assessed using a dietary inflammatory index (DII) based on the Food Frequency Questionnaire from 150 new-onset CD patients and 285 healthy controls (HCs). We selected 41 CD patients and 89 HCs who had not received medication for metagenomic and targeted metabolomic sequencing to profile their gut microbial composition as well as fecal and serum metabolites. DII scores were classified into quartiles to investigate associations among different variables.

Results: DII scores of CD patients were significantly higher than HCs (0.56 ± 1.20 vs 0.23 ± 1.02, p = 0.017). With adjustment for confounders, a higher DII score was significantly associated with higher risk of CD (OR: 1.420; 95% CI: 1.049, 1.923, p = 0.023). DII score also was positively correlated with disease activity (p = 0.001). Morganella morganii and Veillonella parvula were increased while Coprococcus eutactus was decreased in the pro-inflammatory diets group, as well as in CD. DII-related bacteria were associated with disease activity and inflammatory markers in CD patients. Among the metabolic change, pro-inflammatory diet induced metabolites change were largely involved in amino acid metabolic pathways that were also observed in CD.

Conclusions: Pro-inflammatory diet might be associated with increased risk and disease activity of CD. Diet with high DII potentially involves in CD by mediating alterations in gut microbiota and metabolites.