Introduction

Immune checkpoint inhibitors (ICIs) have marked a breakthrough in the management of a wide range of cancer types, leading to increased overall survival. However, this treatment is frequently associated with the onset of various immune-related adverse events (irAEs), including ICI-related diarrhea and colitis.¹ Current recommendations for patients with diarrhea or colitis grade 2 or higher (graded via CTCAE)² include the discontinuation of ICI and administration of immune suppressants (e.g. steroids or biologics), which may lead to worse outcomes in these patients.³ Therefore, alternative therapeutic strategies to manage irAEs are needed. The gut microbiota plays a pivotal role in the onset of gastrointestinal irAEs, but the role of its therapeutic modulation on these disorders is mostly unknown. ^4,5

Aims & Methods

Our aim was to evaluate the efficacy and safety of therapeutic microbiome modulation for gastrointestinal irAEs in cancer patients. We enrolled cancer patients affected by ICI-related diarrhea/colitis referred to our Microbiome Clinic from January 2023 to March 2025. After clinical evaluation, patients were stratified according to severity of diarrhea (graded via CTCAE)² and then received a microbiome-modulating therapy. Patients were followed-up for at least 8 week after the initiation of therapy. We collected data about patient demographics (age and gender), patient’s overall health status as assessed by the the Charlson Comorbidity Index (CCI)⁶, type of cancer, oncological therapy and its suspension, time in weeks from initiation of cancer therapy to onset of diarrhea, severity of diarrhea (graded via CTCAE)², time in weeks until resolution of diarrhea and resumption of oncological therapy

Results

We enrolled 42 patients in the study period (8 males, 34 females, mean age 58,3 years-old, mean CCI-index 5.8). All patients were treated with ICI (Pembrolizumab: n=25 , Dostarlimab: n=4, Nivolumab: n=4; Atezolizumab: n=3; Novulumab and Ipilumab: n=2, Cemiplimab: n=2; Mogamulizumab: n=1; Pertuzumab: n=1). Ten patients experienced G1 diarrhea (23,8%), 16 (38,1) G2, 15 (35,7%) G3 and one G4 (2,4%). As indicated by current European Guidelines³, 30 patients (71,4%) had to interrupt ICI due to diarrhea. Multi-strain probiotics were administered to 27 (64.3% ) patients, rifaximin to 22 (52,4%). Overall, 21 patients (50%) needed therapy with systemic steroids. Seven patients who experienced ICI-related colitis refractory to steroids and biologics were successfully treated with FMT. Twenty-eight patients (66.7% ) had a resolution of the diarrhea (G0) and 11 patients (26.2%) had diarrhea G1 at a mean time of 8 weeks. Upon resolution of diarrhea, nine of the 30 patients who had interrupted ICI (30%) were able to resume the treatment. None of the patients experienced any adverse event related to gut microbiota modulation as defined by CTCAE².

Conclusion

Therapeutic modulation of gut microbiota appears to be a promising safe and effective approach for treating ICI-related diarrhea and colitis. However, these preliminary findings need confirmation through more consolidated and well-designed studies.

References

1. Dougan M, Wang Y, Rubio-Tapia A, Lim JK. AGA Clinical Practice Update on Diagnosis and Management of Immune Checkpoint Inhibitor Colitis and Hepatitis: Expert Review. Gastroenterology. 2021;160(4):1384-1393. doi:10.1053/j.gastro.2020.08.063
2. Freites-Martinez A, Santana N, Arias-Santiago S, Viera A. Using the Common Terminology Criteria for Adverse Events (CTCAE - Version 5.0) to Evaluate the Severity of Adverse Events of Anticancer Therapies. Actas Dermosifiliogr. 2021;112(1):90-92. doi:10.1016/j.ad.2019.05.009
3. Haanen J, Obeid M, Spain L, et al. Management of toxicities from immunotherapy: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up. Ann Oncol. 2022;33(12):1217-1238. doi:10.1016/j.annonc.2022.10.001
4. Wang Y, Wiesnoski DH, Helmink BA, et al. Fecal microbiota transplantation for refractory immune checkpoint inhibitor-associated colitis. Nat Med. 2018;24(12):1804-1808. doi:10.1038/s41591-018-0238-9
5. Wang T, Zheng N, Luo Q, et al. Probiotics Lactobacillus reuteri Abrogates Immune Checkpoint Blockade-Associated Colitis by Inhibiting Group 3 Innate Lymphoid Cells. Front Immunol. 2019;10. doi:10.3389/fimmu.2019.01235
6. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: Development and validation. J Chronic Dis. 1987;40(5):373-383. doi:10.1016/0021-9681(87)90171-8

Disclosure

G.I. has received personal fees for acting as speaker for Biocodex, Danone, Sofar, Malesci, Metagenics and Tillotts Pharma, and for acting as consultant and/or advisor for Ferring Therapeutics, Giuliani, Malesci and Tillotts Pharma. A.G. reports personal fees for consultancy from Eisai Srl, 3PSolutions, Real Time Meeting, Fondazione Istituto Danone, SinergieSrl, Board MRGE and Sanofi SpA personal fees for acting as a speaker for Takeda SpA, AbbVie and Sandoz SpA and personal fees for acting on advisory boards for VSL3 and Eisai. G.C. has received personal fees for acting as advisor for Ferring Therapeutics. All other authors have no conflicts of interest to disclose.

Introduction

Irritable Bowel Syndrome (IBS) is a prevalent and chronic gastrointestinal disorder that affects approximately 85 million Europeans. It predominantly impacts women and significantly impairs quality of life, presenting with recurrent abdominal pain and altered bowel habits in the absence of identifiable structural abnormalities. Beyond its gastrointestinal symptoms, IBS frequently co-occurs with mental and somatic conditions such as anxiety, depression, fibromyalgia (32.5%), and chronic fatigue syndrome (14%). Up to 60% of IBS patients experience mental comorbidities, highlighting the complex interplay between gut and brain—often referred to as dysregulation of the gut–brain axis. This dysregulation manifests in altered intestinal motility, increased gut permeability, visceral hypersensitivity, and significant shifts in gut microbiota composition.

Aims & Methods

We present the DISCOVERIE project (Development, dIagnostic and prevention of gender-related Somatic and mental COmorbitiEs in iRritable bowel syndrome In Europe), an international, multi-centre initiative aimed at characterizing IBS and its associated comorbidities, with a particular focus on sex- and gender-related differences. To this end, we generated a comprehensive multi-omics dataset from 743 individuals, including shotgun quantitative microbiome profiling and untargeted metabolomics. These molecular data were complemented by in-depth clinical phenotyping, capturing information on anxiety, depression, fibromyalgia, and chronic fatigue syndrome. Particular attention was given to age, sex/gender, lifestyle factors, and systemic inflammatory markers. Multivariate statistical models were applied, correcting for common microbiome confounders, to analyze the multi-omics layers and identify microbiome-related signatures and mechanistic links across IBS and its comorbid subgroups.

Results

Our microbiome analysis revealed that IBS subjects exhibit features of a dysbiotic bacterial community, characterized by an increased prevalence of the Bacteroides 2 enterotype (17–26% in IBS participants across comorbid groups vs. 17% in the general population and only 2% in the healthy control group; chi-squared test, FDR < 0.05), a reduced butyrate synthesis capacity, and increased levels of opportunistic taxa compared to non-IBS controls.
Interestingly, IBS individuals—regardless of comorbidities—showed enrichment of bacterial metabolic modules involved in the degradation of amino acids that serve as precursors for neurotransmitters. Specifically, we observed an increase in pathways associated with GABA degradation and a decrease in modules responsible for glutamate biosynthesis. This dysregulation of gut neurotransmitter metabolism may contribute to hallmark IBS symptoms.
Strikingly, pro-inflammatory IL-6 levels were strongly associated with specific bacterial genus (FDR < 0.05), as well as with a metabolic module responsible for the degradation of gamma-hydroxybutyric acid (GHB), a neurotransmitter and central nervous system depressant, suggesting a potential mechanistic link between low-grade inflammation and depressive symptoms in IBS.

Conclusion

The results from this large-scale, multi-center international study reveal a dysregulation of gut neurotransmitter metabolism that may contribute to IBS symptoms and associated comorbidities. These findings underscore a potential link between elevated IL-6 levels, microbial metabolism, and the gut–brain axis, offering new insights into the complex interplay between microbiota composition, host physiology, and IBS-related comorbidities.

Introduction

Eosinophilic esophagitis (EoE) is a chronic, progressive, esophageal disease driven by type 2 inflammation.

Aims & Methods

The aim of this analysis was to determine the histopathologic effect of dupilumab on esophageal inflammation in patients aged 1–11 years with eosinophilic esophagitis (EoE) from the phase 3 EoE KIDS trial. In Part A, patients were randomized to receive weight-tiered dupilumab or placebo for 16 weeks. In Part B, all patients received weight-tiered dupilumab for 36 weeks. Biopsies from proximal, mid, and distal esophageal regions were analyzed. Peak eosinophil count (PEC) and EoE Histologic Scoring System (HSS) grade/stage scores were assessed at baseline, Week 16, and Week 52.

Results

At Week 16, dupilumab vs placebo treatment resulted in significantly greater improvements in PEC (least squares mean percent change -86.09% vs 20.98%, respectively; P<0.0001) and improvements from baseline were observed in EoE-HSS grade and stage total scores, and inflammatory and architectural sub-scores (Table). Improvements were maintained at Week 52 with continued dupilumab. For those who switched from placebo at Week 16, improvements were observed at Week 52. Improvements in individual component scores were also observed.

Table. Mean percent change from Part A baseline in EoE-HSS scores at Weeks 16 and 52.

Conclusion

Dupilumab treatment improved a range of histopathologic aspects of EoE through 52 weeks versus placebo in children aged 1–11 years with EoE.

Disclosure

Collins MH: Arena, Pfizer, AstraZeneca, Calypso Biotech, EsoCap Biotech, GSK, Receptos, Celgene, Bristol Myers Squibb, Regeneron Pharmaceuticals Inc., Robarts Clinical Trials Inc. Alimentiv, Inc., Sanofi, Shire, a Takeda company – advisory board/consultancy fees.
Lerner D: Regeneron Pharmaceuticals Inc. – educational board fees.
Pesek RD: Regeneron Pharmaceuticals Inc. – advisory board/consultancy fees.
Zevit N: AstraZeneca, Rafa Inc., Regeneron Pharmaceuticals Inc., Sanofi, Takeda – advisory board/consultancy fees. Adare Pharmaceuticals, Dr. Falk Pharma – advisory board/consultancy fees. Dr. Falk Pharma, Rafa Inc., Regeneron Pharmaceuticals Inc., Sanofi – speaker fees. Rome Foundation – honoraria.
Xia C, Raphael BP, Radwan A: Regeneron Pharmaceuticals Inc. – employees and shareholders.
Zaghloul S, Angello JT: Sanofi – employees, may hold stock and/or stock options in the company.

Introduction

Irritable bowel syndrome (IBS) is defined as a disorder of gut-brain interaction (DGBI) and is characterised by intestinal immune activation, increased intestinal permeability, and structural and functional brain alterations. DGBI patients have a higher prevalence of psychological comorbidities. Nevertheless, the exact pathophysiological link between these factors and the sequence of events is unknown. Gut alterations have been suggested to induce brain neuroinflammation in DGBI, but scientific evidence is lacking.

Aims & Methods

The present study aims to assess whether GI alteration induces brain neuroinflammation, alters brain function, and, consequently, induces psychological comorbidities. A unique longitudinal study was conducted from 30 to 220 days of age to establish the chronological sequence of intestinal and neurological changes. For this, we utilised the BioBreeding diabetes-prone (BBDP) rat model, which spontaneously develops intestinal inflammation, increased permeability, and colonic hypersensitivity^{1, 2}and has been employed as a model of DGBI. The BioBreeding diabetes-resistant (BBDR) was used as control. Anxiety-like behaviour was assessed using the elevated plus maze. Intestinal permeability was assessed in vivo by measuring the passage of 4 kDa and 70 kDa dextrans into the blood, thereby evaluating paracellular and transcellular permeability, respectively. The appearance of red colour, given by the mixture of the dextrans in the stools, was used to assess overall intestinal motility. The blood-brain barrier (BBB) integrity and brain metabolic profile were assessed using contrast-enhanced magnetic resonance imaging (0.25 mL/100g weight of 0.05 mM, gadolinium) and proton magnetic resonance spectroscopy, respectively.

Results

BBDP rats exhibit an increased colonic permeability starting from 90 days, and reduced GI motility at 90 and 160 days. Interestingly, this increased permeability is accompanied by an increased BBB permeability at 220 days only in the anterior cingulate cortex (ACC) but not in the hippocampus, insula, amygdala, or thalamus. BBDP rats showed a slight increase in total choline and myoinositol concentrations in the ACC and the insula at late time points, which may indicate increased neuroinflammation. BBDP rats also have higher concentrations of glutamine-glutamate in the insula and N-acetyl aspartate in the ACC. Moreover, BBDP rats develop anxiety-like behaviour at 160 and 220 days.

Conclusion

The BBDP rat model supports the current hypothesis that increased gut permeability can lead to brain neuroinflammation, altered function, and, consequently, to psychological comorbidities.
EU-funded DISCOvERIE project (No. 848228).

References

1. Meleine M, Accarie A, Wauters L, et al. Colonic hypersensitivity and low-grade inflammation in a spontaneous animal model for functional gastrointestinal disorders. Neurogastroenterol Motil 2019;31:e13614.
2. Vanuytsel T, Vanormelingen C, Vanheel H, et al. From intestinal permeability to dysmotility: the biobreeding rat as a model for functional gastrointestinal disorders. PLoS One 2014;9:e111132.

Introduction

Chronic intestinal pseudo-obstruction (CIPO) is a rare disease where impaired propulsive activity of the gut leads to bowel dilatation without an anatomical obstruction. There is no single assessment that comprehensively assesses the severity of symptoms and their impact on patients. Our aim was to develop a CIPO-specific electronic patient-reported outcome (ePRO), the CIPO Daily Diary^© (CIPO eDD), for clinical trials.

Aims & Methods

The CIPO eDD was developed per FDA guidelines^1,2 in a noninterventional, cross-sectional, qualitative interview study. This multi-stage process started with a targeted literature review and GAP analysis, with subsequent input from experts and patients. Literature reviews identified key signs and symptoms, and outcomes previously used in CIPO. Interviews with 3 clinicians experienced in diagnosing and treating CIPO, and insights from a steering committee that included the 3 clinicians and 2 external consultants, identified draft elements for the CIPO eDD. The draft CIPO eDD underwent iterative (4 rounds) hybrid concept elicitation (CE)/cognitive interviews and usability testing (CIUT) with patients from the USA (aged 18–80 years) with physician-confirmed CIPO diagnosis. For CE, patients answered open-ended questions about their CIPO experiences. CIPO signs, symptoms and impacts (concepts) emerged spontaneously from the responses. For CIUT, patients completed the CIPO eDD and reviewed the comprehensiveness, relevance and clarity of items. Textual analysis of interview transcripts guided amendments to the CIPO eDD items based on patient feedback. Following the initial CE/CIUT interviews, the same patients answered follow-up questions about the draft CIPO eDD to refine the items and to obtain qualitative and preliminary quantitative evidence for the potential revision or removal of items.

Results

Overall, 14 patients (female, n=10; mean [SD] age and time since diagnosis, 55.3 [15.5] and 4.3 [4.0] years, respectively) were interviewed. Concept saturation was reached after 3 rounds of CE/CIUT, with 15 of the 25 unique CIPO signs and symptoms included in the CIPO eDD (Table). Based on feedback from follow-up interviews (12 patients), no changes were made to items in the draft CIPO eDD. Minor changes were made to four items (vomiting, regurgitation, early satiety and CIPO episodes) suggested by qualitative data and the steering committee to improve clarity; the order of the nausea and vomiting items was switched. The sorting exercise did not identify any items for addition/removal or revision based on the qualitative evidence, with most patients indicating that all items should remain in the diary.

Conclusion

We have developed a de novo CIPO-specific ePRO per established FDA guidelines.^1,2 A final scoring system of the CIPO eDD based on the 15 items is in development. Ongoing quantitative assessment and psychometric validation of the CIPO eDD will enable its use in monitoring CIPO severity in clinical trials, thus supporting the development of effective therapies.

Table. Final items for the CIPO Daily Diary, and amendments from patient interviews

References

1. FDA. Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims. 2009. Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/patient-reported-outcome-measures-use-medical-product-development-support-labeling-claims (Accessed April 15, 2025).
2. FDA. Patient-Focused Drug Development: Collecting Comprehensive and Representative Input. 2009. Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/patient-focused-drug-development-collecting-comprehensive-and-representative-input (Accessed April 15, 2025).

Disclosure

MG has received research support from Alexza Pharmaceuticals, Alfasigma, Donga and Takeda; and is an advisory board member for Alfasigma, Ardelyx and Evoke Pharma.
ViS is an advisory board member and/or speaker for Alfasigma, Bayer, Bromatech, Falck and GE Healthcare; and receives research support from Alfasigma.
JT has given scientific advice to Aclipse, Adare Pharma Solutions, Alfasigma, Clasado, Danone, Dr Falk Pharma, FitForMe, Ironwood, Kyowa Kirin, Menarini, PRO.MED.CS, Recordati, Takeda, Truvion Healthcare, Tsumura and Zealand Pharmaceuticals; receives research support from BIOHIT Healthcare, Kyowa Kirin, ProMed, Sofar and Takeda; and is a speaker for Abbott, Biocodex, Mayoly, Menarini, ProMed, Reckitt Benckiser, Schwabe, Takeda, Thai Meiji Pharmaceutical and Truvion Healthcare.
SM, EP and VaS are employees of Alfasigma S.p.A.
This study was sponsored by Alfasigma S.p.A.
The authors would like to thank all of the Alfasigma team who were involved in this study for their contributions to study conceptualization, study design, methodology, data curation, formal analysis, data interpretation and endorsement of the study design. In addition, the authors would like to thank the external consultants for their time and expertise, and the principal investigators at the collaborating sites for patient recruitment and data collection.
Medical writing support for the development of this abstract was provided by Hannah Stephens, PhD, of PharmaGenesis London, London, UK, and was funded by Alfasigma S.p.A.