An observational study in Crohn's Diseases, sponsored by University Hospital, Rouen. Not yet recruiting at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-13.
Sponsored by University Hospital, Rouen · Observational
Crohn's disease is a chronic inflammatory condition that can affect the entire digestive tract. The terminal ileum is the segment most frequently involved, and approximately one-third of patients present with disease limited to the ileum. In such cases, surgical resection to remove all inflammatory lesions may be performed. This procedure prevents recurrence in about 50% of patients within five years of surgery.
The post-operative setting offers a prime opportunity to study the early pathophysiological stages of Crohn's disease and the risk factors for recurrence. While smoking is a well-established risk factor for recurrence, the role of other factors-such as a fistulizing phenotype or a history of small-bowel resection-remains a subject of debate. Meanwhile, the role of the gut microbiota in this process remains largely unclear. Currently, the prevention of post-operative recurrence relies exclusively on smoking cessation and biologic therapies. However, the efficacy of these biologics-particularly anti-TNFα (Tumor Necrosis Factor alpha) agents-is reduced in patients who received prior treatment with these drugs before surgery. Notably, the proportion of such pre-treated patients has risen over the last two decades, reaching 50%. Consequently, there is a need to expand the range of strategies available to prevent post-operative recurrence. A better understanding of host-gut bacteria interactions could help prevent postoperative recurrence. To date, only *Faecalibacterium prausnitzii* and Adherent-Invasive *Escherichia coli* (AIEC) have been associated with a lower and higher risk of postoperative recurrence, respectively. However, a randomized controlled trial showed that antibiotic treatment aimed at eradicating AIEC was no more effective than a placebo in Crohn's disease. These trial results reinforce the value of a strategy based on identifying anti-inflammatory bacterial species that may play a protective role against postoperative recurrence.
*Pilosibacter rotomagensis* is a bacterial species recently isolated from humans by the INSERM U1073 team; it may play a key role in intestinal physiology. This species is distinguished by its high capacity to produce short-chain fatty acids-particularly butyrate-and by anti-inflammatory properties observed in various *in vitro* cellular models.
The hypothesis of this project is that carriage of *Pilosibacter rotomagensis* could play a protective role against postoperative recurrence in ileal Crohn's disease.
To explore this hypothesis, we will conduct a single-center, cross-sectional study investigating the association between *Pilosibacter rotomagensis* carriage and intestinal inflammatory activity following resection for isolated ileal Crohn's disease. Crohn's disease inflammatory activity will be assessed by measuring fecal calprotectin, a non-invasive inflammatory marker specific to intestinal inflammation that is used in routine clinical practice. Disease recurrence will be defined as the occurrence of any of the following events during the postoperative period: (1) endoscopic recurrence (defined by a Rutgeerts score ≥ 2); (2) a new surgical procedure related to Crohn's disease; or (3) the initiation or modification of biologic therapy at least 6 months after ileocecal resection. Furthermore, given the cross-sectional nature of the study, it would be difficult to establish a causal relationship-whether cause or consequence-between recurrence and bacterial carriage. Therefore, the association with inflammatory activity (fecal calprotectin) in the postoperative setting will be analyzed while adjusting for the following clinical parameters: smoking status at the time of sampling (non-smoker, former smoker, current smoker), complicated phenotype (defined as a history of fistulizing or stenosing complications during the course of Crohn's disease), and the time elapsed since surgery. The expected benefit of this study is to establish an initial clinical rationale regarding the role of this bacterium in the process of postoperative recurrence of Crohn's disease, by examining intestinal inflammation and its marker, fecal calprotectin. Consequently, this study could justify a multicenter, longitudinal, observational research protocol to investigate postoperative carriage of *Pilosibacter rotomagensis* and longitudinally track clinical recurrences of Crohn's disease. The ultimate goal of this line of research would be to pave the way for interventional studies aimed at preventing postoperative recurrence through oral supplementation with this bacterium. Finally, this study is part of a cross-disciplinary initiative to translate preclinical discoveries made by a research unit at the University of Rouen-a partner of the University Hospital-into clinical application.
1,923 studies on the registry are indexed under Crohn Disease; 467 are open to participants now.
This study's planned enrollment of 116 is below the median of 166 across 624 observational studies indexed under Crohn Disease.
Browse Crohn Disease studies →University Hospital, Rouen is the lead sponsor of 416 studies on the registry; 105 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patient with a history of ileocecal resection for Crohn's disease.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
If the patient agrees to participate, the stool sample will be used for both fecal calprotectin analysis (standard care) and the analysis of gut microbiota and short-chain fatty acids (research protocol). The purpose of this stool collection is to address the primary and secondary objectives of the present study.
Association between intestinal inflammatory activity and the carriage rInvestigating the aate of *Pilosibacter rotomagensis
Investigating the association between intestinal inflammatory activity and the carriage rate of \*Pilosibacter rotomagensis following resection for isolated ileal Crohn's disease by measuring fecal calprotectin levels
Time frame: 1 day
Association between intestinal inflammatory activity and the relative abundance of Pilosibacter rotomagensis
Investigate the association between intestinal inflammatory activity and the relative abundance of Pilosibacter rotomagensis within the microbiota following resection for isolated ileal Crohn's disease by assessing the abundance of Pilosibacter rotomagensis in stool samples
Time frame: 1 day
Association between fecal carriage of Pilosibacter rotomagensis and clinical recurrence of Crohn's disease
Investigation of the association between fecal carriage of \*Pilosibacter rotomagensis\* and clinical recurrence of Crohn's disease following resection for isolated ileal Crohn's disease by determining the number of clinical recurrences of Crohn's disease
Time frame: 1 day
Association between intestinal inflammatory activity and fecal short-chain fatty acid abundance
Investigation of the association between intestinal inflammatory activity and fecal short-chain fatty acid abundance following resection for isolated ileal Crohn's disease by assessing the abundance of short-chain fatty acids in the stool.
Time frame: 1 day
Association between intestinal inflammatory activity and the relative abundance of F. prausnitzii in the microbiota
Investigation of the association between intestinal inflammatory activity and the relative abundance of F. prausnitzii in the microbiota following resection for isolated ileal Crohn's disease by Evaluation of the abundance of F. prausnitzii in stool
Time frame: 1 day
Association between intestinal inflammatory activity and the relative abundance of AIEC within the microbiota
Investigation of the association between intestinal inflammatory activity and the relative abundance of AIEC within the microbiota following resection for isolated ileal Crohn's disease by measuring the abundance of AIEC in the stool. AIEC stands for Adherent-Invasive Escherichia coli.
Time frame: 1 day
Association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota by evaluating alpha-diversity indices (observed richness,)
Time frame: 1 day
Association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota by evaluating Beta-diversity indices (Bray-Curtis dissimilarity index and Jaccard distance)
Time frame: 1 day
Association between intestinal inflammatory activity and the taxonomic composition of the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the taxonomic composition of the gut microbiota.by evaluating the relative abundance of the bacterial taxa making up the gut microbiota.
Time frame: 1 day
Association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota by evaluating alpha-diversity indices (Simpson Indice). The Simpson index is a measure of gut microbiota diversity. It therefore takes into account two elements: 1. richness: how many bacterial taxa are present; 2. evenness: how abundances are distributed among these taxa (in %).
Time frame: 1 day
Association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota by evaluating alpha-diversity indices (Shannon indice). The Shannon index is an alpha-diversity index used to measure gut microbiota diversity. It specifies how many types of bacteria are present and the extent to which their abundances are balanced (In %)
Time frame: 1 day
Association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota by evaluating alpha-diversity indices (Pielou indice). Pielou's index measures the evenness of a microbiota.It makes it possible to determine whether the various bacterial species are present in relatively balanced proportions. Pielou's index is calculated from the Shannon index: J = H' / log(S) where: H' = Shannon index; S = number of observed taxa (richness). The value generally ranges from 0 to 1: 1 → all species are present in equal proportions; close to 0 → one or a few species are strongly dominant.
Time frame: 1 day
Association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota by evaluating the beta-diversity index (Bray-Curtis dissimilarity index). Bray-Curtis is an index that measures the difference in composition between two microbiota. The two microbiota are identical → Bray-Curtis = 0. The microbiota are completely different → Bray-Curtis = 1.
Time frame: 1 day
Association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota.
Investigation of the association between intestinal inflammatory activity and the diversity of bacterial taxa constituting the gut microbiota by evaluating the beta-diversity index (Jaccard distance index). The Jaccard distance index is a measure of beta-diversity; it is used to compare the composition of two microbiota. The Jaccard distance generally ranges from 0 to 1: 0 → the two microbiota share the same taxa; 1 → no taxa in common.
Time frame: 1 day
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.