Abstract Background The gut microbiota has been implicated in the pathogenesis of Crohn’s disease (CD), and infliximab (IFX) is commonly being utilized as a therapeutic option for pediatric CD patients. However,it remains unclearwhether the fecal virome is modified during IFX treatment. This study aims to characterize the alterations in the fecal virome among pediatric patients with CD and to evaluate how IFX therapy affects these changes. Methods Metagenomic sequencing of fecal viral-like particles was applied todetermine the compositions of virome communities in fecal samples. The composition and function of the fecal virome were compared between CD patients(n = 60) and healthy controls(n = 25). Among these patients, 53 received at least three IFX treatments,and 41 of them achieved remission (IFX-R), while 12 did not (IFX-NR). Results Compared with controls, CD subjects exhibited significantly lower viral richness (measured by the Chao1 index). Patients in the baseline CD remission group (Baseline-R) demonstrated significantly elevated linear discriminant analysis (LDA) scores for Anelloviridae compared to other subjcets. Conversely, Microviridae manifested higher LDA scores in healthy control subjects, while Caudovirales displayed elevated LDA scores at the baseline level of the non-remission group (Baseline-NR). Following treatment with IFX, the IFX-R group exhibited a more diverse composition of dominant viral taxa, indicating potential remodeling of the gut virome during remission. Additionally, CD patients exhibited differences in various viral functions in terms of Gene Ontologyfunctions compared with healthy controls. Moreover, the combined fecal virome and bacterial markers demonstrated diagnostic potential for CD, with AUC of 89.3%. Conclusion Fecal virome in pediatric CD is characterized by a significant decrease in fecal viral diversity, changes in specific virus taxa, and a loss of multiple viral functions. Certain patterns in the fecal virome and fecal microbiome may be predictive for diagnosis of pediatric CD. Conflict of interest: Ge, Ting: No conflict of interest Ruan, Yangming: No conflict of interest Ye, Lin: No conflict of interest Xiao, Fangfei: No conflict of interest Prof. Dr. Zhang, Ting: No conflict of interest
Ge et al. (Thu,) studied this question.