Modulating effect of a plant-based diet on the gut microbiota in Crohn's disease: A pilot study using DNA-based dietary monitoring

Background: Crohn's Disease (CD) is a chronic inflammatory condition characterized by dysbiosis and reduced microbial diversity in the gut. Emerging evidence suggests that dietary interventions, particularly a plant-based diet (PBD), may modulate gut microbiota and improve clinical outcomes in CD patients. Aim: This study aimed to evaluate the effects of a PBD on plant intake, microbial diversity, and clinical markers of inflammation in CD patients. Methods: Fifteen CD patients were enrolled in a 12-week dietary intervention study. Fecal samples were collected at baseline, week 4, and week 12. Plant diversity in feces was assessed using TrnL gene sequencing, while microbial diversity was analyzed through 16S rRNA sequencing. Dietary adherence was monitored through food diaries and fecal analysis for plant and animal residues. Clinical markers, including fecal calprotectin, were measured to evaluate inflammation. Results: The PBD led to a significant increase in plant diversity, as evidenced by a 1.4-fold rise in median plant genera intake by week 4. Microbial diversity also showed an upward trend, with notable increases in beneficial genera such as Faecalibacterium and Bacteroides. Fecal calprotectin levels decreased significantly, indicating reduced inflammation. These changes were more pronounced in patients with lower baseline plant intake, suggesting that initial dietary habits influence the response to dietary interventions. Conclusion: This study demonstrates that a PBD can effectively enhance microbial diversity, reduce inflammation, and improve dietary adherence in CD patients. These findings highlight the potential of dietary modifications as a therapeutic strategy for CD and provide a basis for further exploration of personalized dietary interventions in clinical practice.