ECCO Grant Final Report: Francesco Giudici, Edda Russo & Amedeo Amedei

Methodology that was used in the research (including deviations – if any – from originally proposed methodology/experiments)

Patients with ileal CD undergoing surgery were prospectively recruited. At surgery, we collected blood samples as well as CD and healthy tissue biopsies. For the “tissue level” study, we split the biopsy into different layers (mucosa, submucosa and serosa) in both damaged and healthy ileal tissue. We evaluated the cytokine profile of each layer. Furthermore, ileal tissue was used for microbiota analysis, assessing composition and community structure. For the “systemic-level” study, we evaluated the serum microRNA (miRNA) through quantitative real-time PCR amplification and free fatty acids (FFAs) using gas chromatography-mass spectroscopy.

Main findings/results of the research

We observed a distinct cytokine profile across the CD vs healthy ileal layers as well as a different distribution in first surgery vs relapse patients. In addition, the phylum Tenericutes, the family Ruminococcaceae, and the genera Mesoplasma and Mycoplasma were significantly enriched in the pathological setting. Moreover, significant microbiota differences were observed between relapse and first surgery conditions. At the systemic level, we observed a significant downregulation of some circulating inflammatory miRNAs, as well as several short chain fatty acids (SCFA), in recurrence compared to the first surgery patients. In addition, the concentration of caproic acid seems to act as a predictor of recurrence risk in CD patients.

Conclusions and perceived impact of the findings

We showed, for the first time, a dissimilarity of cytokine distribution and microbiota composition within CD and adjacent healthy ileal tissue layers and between first operation and surgical relapse. Moreover, at systemic level we observed a different regulation of the gut microbiota–immunity axis, involving circulating microbiota–related factors (SCFAs and miRNAs), at first surgery time and relapse conditions. In addition, we observed a potential involvement of microbiome patterns, associated to healthy ileal tissue, in triggering recurrence–linked determinants, suggesting that not only anti–inflammatory therapies but also eubiosis maintenance may be crucial for early treatment management . To conclude, we provided new insights into the dynamics of the gut microbiota-immunity axis in CD surgical recurrence, leading to detection of new microbial biomarkers. In addition, our results may pave the way for new diagnostics and therapeutics aimed not only at reducing inflammation but also at maintaining a general state of eubiosis in healthy tissue.

Plan of publication

The results of this project are published in the following original articles:

1. Russo E, Giudici F, Ricci F, Scaringi S, Nannini G, Ficari F, Luceri C, Niccolai E, Baldi S, D'Ambrosio M, Ramazzotti M, Amedei A. Diving into Inflammation: A Pilot Study Exploring the Dynamics of the Immune-Microbiota Axis in Ileal Tissue Layers of Patients with Crohn's Disease. J Crohns Colitis. 2021 Sep 25;15(9):1500-1516. doi: 10.1093/ecco-jcc/jjab034. PMID: 33611347

Impact factor: 10.020

1. Russo E, Cinci L, Di Gloria L, Baldi S, D'Ambrosio M, Nannini G, Bigagli E, Curini L, Pallecchi M, Andrea Arcese D, Scaringi S, Malentacchi C, Bartolucci G, Ramazzotti M, Luceri C, Amedei A, Giudici F. Crohn's disease recurrence updates: first surgery vs. surgical relapse patients display different profiles of ileal microbiota and systemic microbial-associated inflammatory factors. Front Immunol. 2022 Jul 29;13:886468. doi: 10.3389/fimmu.2022.886468. ECollection 2022. PMID: 35967326

Impact factor: 8.786