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

Genome-wide association studies (GWAS) have identified more than 250 risk variants linked to inflammatory bowel disease (IBD). Most genetic variants increase the risk of disease onset, and their impact on clinical presentation is limited.^1,2,3 Variants in NOD2 and IL23R not only modulate the risk of disease onset, but also influence disease behaviour and localisation. Their role in predicting treatment response remains unclear.^3,4
A variant in an intron of TNRC18 (rs7486781, allele frequency 3.6%) was recently identified as having a strong risk-increasing effect (OR 3.2, p=2.4x10-61) for IBD in the FinnGen biobank study. The same allele was also associated with a risk for ankylosing spondylitis (AS), uveitis and psoriasis.⁵ The functional effect of rs7486781 is not yet fully established.⁶

Aims & Methods

The FinnGen biobank study includes the genotype data of 520 000 individuals and their longitudinal register data from national health registers, including 11 298 individuals with verified diagnosis for IBD. The data also include drug purchases, procedure codes and laboratory measurements of the individuals.
Our aim was to study the impact of the TNRC18-variant on IBD phenotype, particularly disease behavior. We assessed established aspects of disease severity⁷: use of immunosuppressants and advanced therapies, necessity to switch medications, frequent use of corticosteroids and risk of procedures. We also evaluated the presence of extraintestinal manifestations (EIM) and other disease complications.

Results

Regarding disease severity, the use of therapies beyond 5-ASA was more common among variant carriers; the use of thiopurines and other immunosuppressants (OR 1.21-1.27, p-values 1.35x10^-5 - 0.00849), ustekinumab and other IL-inhibitors (OR 1.46-1.48, p-values 0.00324 - 0.00286) and TNF-α-inhibitors (OR 1.26, p=0.00753) was more frequent.
In addition, perianal and anal canal operations were more prevalent with TNRC18 variant carriers (OR 2.44, p=1.41x10^-4), indicating perianal disease.
Assessing EIM, we observed that diagnoses for AS and uveitis (OR 1.62-1.67, p=1.3x10^-5 - 1.55x10^-4) were more frequent within IBD in patients with rs7486781.
Interestingly, a reduced risk of primary sclerosing cholangitis (PSC) was implicated by lower number of cholangitis (K83.0) diagnoses (OR 0.617, p=0.00221) and fewer purchases of ursodeoxycholic acid (OR 0.55, p=2.83x10^-5), in addition to lower levels of ALP (mean 75 vs 82, p=0.00296), IgG4 (mean 0.45 g/l vs 0.81 g/l, p=4.81x10^-5) and IgM (0.12 vs 0.15, p=0.00115) among variant carriers. All events survived the false discovery rate–adjusted p threshold of 0.05.
Our results also suggest that the cumulative risk for IBD related procedures⁸ (patients with procedures n=2209) from diagnosis and birth were elevated in TNRC18 variant carriers (HR=1.12 and HR=1.14, p=0.050 and p=0.023, assuming additive effect) using a Cox regression model.
Finally, our results in ulcerative colitis indicate that TNRC18 variant carriers are at higher risk of transitioning from 5-ASA/immunomodulators to biologics/JAK-inhibitors (HR=1.38, p=0.016). Variant carriers receiving immunomodulators or advanced therapies were not, however, in increased risk of colectomy (HR~0.97-1.34, p~0.86-0.37).

Conclusion

TNRC18 variant was associated with greater risk of operative treatment, the need of more advanced medication and perianal disease. AS and uveitis were more common EIMs, but PSC appeared less infrequent. Our preliminary results indicate that TNRC18 variant carriers might benefit from early intervention with immunomodulators or advanced therapies.

References

1. Chang, J. T. Pathophysiology of Inflammatory Bowel Diseases. N Engl J Med 383, 2652–2664 (2020).

2. Cleynen, I. et al. Inherited determinants of Crohn’s disease and ulcerative colitis phenotypes: a genetic association study. Lancet 387, 156–167 (2016).

3. Atreya, R. & Neurath, M. F. Biomarkers for Personalizing IBD Therapy: The Quest Continues. Clin Gastroenterol Hepatol 22, 1353–1364 (2024).

4. Kayali, S. et al. NOD2 and Crohn’s Disease Clinical Practice: From Epidemiology to Diagnosis and Therapy, Rewired. Inflamm Bowel Dis 31, 552–562 (2025).

5. Kurki, M. I. et al. FinnGen provides genetic insights from a well-phenotyped isolated population. Nature 613, 508–518 (2023).

6. Rahimov, F. et al. A genome-wide CRISPR screen supported by human genetics identifies the TNRC18 gene locus as a novel regulator of inflammatory signaling. bioRxiv 2023.10.04.560902 (2023) doi:10.1101/2023.10.04.560902.

7. Swaminathan, A. et al. The Disease Severity Index for Inflammatory Bowel Disease Is a Valid Instrument that Predicts Complicated Disease. Inflamm Bowel Dis 30, 2064–2075 (2024).

Disclosure

Anna Aarni: Speaker fee from Abbvie, Clinic visit: travelling expenses from Tillots Pharma

Pauliina Molander: Speaker, consultancy and advisory board member fees from Abbvie, Johnson & Johnson, Lilly, Pfizer and Takeda. Clinic visit: traveling expenses from Tillots Pharma

Jukka Koskela: Pfizer-FinnGen genetic advisory board, traveling, clinic and congress visits: FinnGen partners, Tillots Pharma, Takeda, consulting: Pfizer

Introduction

Prospective evidence of the long-term efficacy of endoscopic submucosal dissection (ESD) for T1 colorectal cancer (CRC) is insufficient.

Aims & Methods

We aimed to evaluate long-term ESD outcomes for T1 CRC, focusing on the risk stratification criteria and necessity of additional surgery.
This large-scale, multicenter, prospective cohort study was conducted by Hiroshima GI Endoscopy Research Group. All consecutive patients who underwent colorectal ESD between January 2014 and December 2018 were included, and those with pathologically confirmed T1 CRC were analyzed. Patients were classified into low-risk and high-risk groups based on histopathological risk factors for lymph node metastasis in JSCCR guidelines. High-risk patients were categorized into those who underwent additional surgery (surgery group) and those who were followed up without surgery (follow-up group).

Results

Among 2357 patients who underwent ESD for 2478 early colorectal neoplasms, 431 were diagnosed with T1 CRC. Ten recurrences (2.6%) and five T1 CRC-associated deaths (1.3%) occurred in the high-risk group, with none in the low-risk group. Five-year cumulative overall and local recurrence rates were significantly higher in the follow-up versus surgery group (7.7% and 1.9%; P=0.019 versus 6.4% and 0%; P<0.001), with no local recurrence in the surgery group. Five-year overall survival was significantly worse in the follow-up group (79.5% and 95.2%; P<0.001), while no significant difference was found in 5-y disease-specific survival (98.5% and 98.5%; P=0.447).

Conclusion

No recurrence or mortality occurred in the low-risk group, suggesting that intensive surveillance may be unnecessary for these patients after curative ESD. Additional surgery could prevent local recurrence for high-risk T1 CRC, supporting a risk-based treatment approach.

Introduction

Corpus atrophic gastritis (CAG) requires endoscopic-histological surveillance due to the risk of developing gastric neoplastic lesions (GNL). This study aimed to identify variables associated with GNL development at long-term follow-up using a feature ranking method based on a novel One-Class Support Vector Machine (SVM) model.

Aims & Methods

A dataset containing clinical, endoscopic, and histological variables from consecutive CAG patients (2001-2023) adhering to a surveillance program was considered. GNL presence at the longest available follow-up was recorded. Gastric biopsies and histological evaluations were conducted according to the updated Sydney system. CAG patients with any missing data or a GNL diagnosis at the baseline gastroscopy were excluded from the final analysis. A Fisher score-based feature ranking method and One-Class SVM were used to select the optimal subset of baseline variables associated with GNL development, aiming to achieve average sensitivity (Se) and specificity (Sp) above 80%.

Results

Overall, 355 CAG patients were initially considered. Of these, 36 were excluded due to the presence of GNL at baseline gastroscopy, and 216 for missing data. Thus, a total of 103 patients were considered and grouped into: CAG patients with [22 patients (F 68.1%), median age 68 (35-83) years] and without GNL at follow-up [81 patients (F 72.8%), median age 59(26-84) years]. After a median follow-up of 60 (12-192) months, 13 epithelial GNL (gastric adenocarcinoma or high/low-grade dysplasia) and nine type-1 gastric-neuroendocrine-tumors (T1gNET) were recorded. Parietal-cell-antibodies and pepsinogen-I < 30 μg/l were associated with both epithelial GNL and T1gNET. Antral inflammation and age > 60 were linked to epithelial GNL, while anti-thyroperoxidase-antibodies, smoking, and dyspeptic symptoms at CAG diagnosis were linked to T1gNET. Low-dose aspirin and H. pylori eradication therapy showed inverse associations with epithelial GNL and T1gNET, respectively.

Conclusion

This is the first study in which an AI model simultaneously considers clinical, endoscopic, and histological characteristics from a dataset of CAG patients, showing good sensitivity and specificity in identifying those variables associated with developing GNL. Nonetheless, we acknowledge the need for improved variable standardization and data balancing between groups to enhance model performance further.

Introduction

Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely related to the metabolic syndrome of chronic liver disease and its pathogenesis involves a variety of cell types of metabolic disorders and inflammatory response, however, treatment is limited. Mas is a G protein-coupled receptor highly expressed by myeloid cells. It may play a key role in regulating myeloid-associated inflammation and metabolic homeostasis in the process of MASLD. However, its specific mechanism of action in MASLD remains unclear.

Aims & Methods

This study aims to explore the regulatory mechanism of MAS in myeloid cells in the occurrence and development of MASLD. In this study, liver tissues of patients with MASLD and animal models of MASLD induced by high-fat diet (HFD) were analyzed. In this study, myeloid-specific Mas1 knockout (Lysm^creMas1^f/f) mice were constructed. Single-cell RNA sequencing and multi-omics analysis were used to explore the role and mechanism of myeloid Mas in HFD-induced MASLD mice.

Results

The study found that the expression of MAS protein on myeloid cells in the livers of MASLD patients and MASLD animal models was significantly increased. Mononuclear phagocyte system（MPs）undergo metabolic disorders in the MASLD model, with elevated glycolysis levels, increased lactic acid production, and at the same time, the expression of cellular senescence markers (such as p16 and p21) is upregulated, and the secretion of inflammatory factors is increased. Single-cell multi-omics analysis revealed that myeloid MAS1 knockout activated the FN1⁺CCR2⁺monocytes first. Pseudo-temporal analysis showed that the FN1⁺CCR2⁺ monocytes had spatiotemporal metabolic responses with the macrophages, significantly involving the activation of glycolysis and inflammatory senescence by myeloid MAS. Non-target metabolomics of MASLD patients also revealed elevated glycolytic metabolism and increased lactic acid secretion. Mass spectrometry revealed that Mas specifically bound to the key glycolytic protein pyruvate kinase M2 (PKM2) and activated the lactylation of transcription factor Spi1-K208 site mediated by PKM2. The lactylation of Spi1-K208 promoted the transcription of senescence-associated secretory phenotype (SASP) -related proteins. Myeloid Mas1 knockout inhibited the nuclear translocation of PKM2 and blocked the lactylation of Spi1, inhibiting the transcriptional initiation of SASP. Screening of over 100,000 small molecule compounds through a virtual drug library revealed that Theaflavin 3,3'-digallate (TFDG) might reduce the protein expression of Mas and PKM2, and block the binding of the MAS-PKM2 complex. We synthesized macrophage membrane to encapsulat PLGA nanoparticles loaded with TFDG (MM@NP-TFDG) and found that MM@NP-TFDG effectively reduced the expression level of Mas-PKM2 complex protein expression in the MASLD mouse model, inhibited the glycolytic - inflammatory senescence axis of FN1⁺CCR2⁺ monocytes and macrophages, and alleviated liver inflammation and tissue damage. While the lipid deposition in the liver is reduced and the fatty acid oxidation is enhanced.

Conclusion

This study reveals that myeloid MAS1 protein participates in the occurrence and development of MASLD by regulating PKM2-mediated Spi1 lactylation and reprogramming the metabolic-inflammatory senescence axis of MPs during the process of MASLD. This discovery provides new potential targets for the treatment of MASLD patients and is expected to offer new clinical treatment strategies for MASLD patients.

Disclosure

The authors declare no conflict of interest.

Introduction

Chronic pouchitis is a common complication following ileal pouch-anal anastomosis (IPAA), with limited effective treatment options.¹ Antibiotics remain the first-line therapy; however, in cases of chronic pouchitis, prolonged antibiotic use contributes to increased antimicrobial resistance within the ileal pouch microbiome.² Fecal microbiota transplantation (FMT) has been proposed as a means of restoring microbial balance. Nevertheless, randomized placebo-controlled trials have demonstrated that, although FMT can alter the microbiome, it does not confer clinical benefits compared to placebo.^3–5

Aims & Methods

Given the lack of efficacy of FMT using stool from healthy donors, the present study aims to characterize the microbiome of a healthy ileal pouch and to evaluate the impact of high antibiotic exposure in patients with chronic pouchitis.
In this cohort study, stool samples were collected from four groups: patients with a normally functioning IPAA, patients with chronic pouchitis, patients with ulcerative colitis, and healthy controls. Microbiome composition and antibiotic resistance genes were analyzed across these groups. Fecal samples underwent metagenomic sequencing, and metagenome-assembled genomes (MAGs) were reconstructed. For Escherichia coli MAGs, the antibiotic resistance gene (ARG) profiles and plasmid content were specifically examined.

Results

This study included 197 participants. A clear pattern emerged in the microbial composition, revealing that reduced alpha diversity is directly associated with declining gut function and clinical health. Both species richness and Shannon diversity were lowest in patients with chronic pouchitis and highest in healthy individuals, with intermediate levels observed in the other groups. Notably, the ileal pouch microbiome of many chronic pouchitis patients was dominated by E. coli. Given the potential clinical implications of high E. coli abundance, we further investigated the ARG profiles and plasmid content of E. coli MAGs. E. coli MAGs from chronic pouchitis patients exhibited a significantly higher frequency of single nucleotide polymorphisms (SNPs) associated with resistance to fluoroquinolones—an antibiotic uniformly used among this patient group—compared to MAGs from the normally functioning IPAA and healthy control cohorts. Furthermore, E. coli MAGs from chronic pouchitis patients harbored a greater number of plasmids, with an increased presence of plasmid-borne ARGs conferring resistance to antibiotics commonly administered in this group, relative to the other cohorts.

Conclusion

These findings demonstrate that the composition of the ileal pouch microbiome—both in chronic pouchitis and normally functioning IPAA—differs significantly from that of individuals with normal gut physiology. This suggests that the microbiome of a normally functioning IPAA may serve as a more appropriate baseline for comparative studies than the healthy gut microbiome. Additionally, our results indicate that antibiotic use exerts increased selective pressure on E. coli strains carrying antibiotic resistance genes, directly correlating with the types of antibiotics administered.

References

1. Hata K, Ishihara S, Nozawa H, et al. Pouchitis after ileal pouch-anal anastomosis in ulcerative colitis: Diagnosis, management, risk factors, and incidence. Dig Endosc 2017;29:26–34.
2. Shen B, Kochhar GS, Rubin DT, et al. Treatment of pouchitis, Crohn’s disease, cuffitis, and other inflammatory disorders of the pouch: consensus guidelines from the International Ileal Pouch Consortium. Lancet Gastroenterol Hepatol 2021;7:69–95.
3. Herfarth H, Barnes EL, Long MD, et al. Combined Endoscopic and Oral Fecal Microbiota Transplantation in Patients with Antibiotic-Dependent Pouchitis: Low Clinical Efficacy due to Low Donor Microbial Engraftment. Inflamm Intest Dis 2019;4:1–6.
4. Karjalainen EK, Renkonen-Sinisalo L, Satokari R, et al. Fecal Microbiota Transplantation in Chronic Pouchitis: A Randomized, Parallel, Double-Blinded Clinical Trial. Inflamm Bowel Dis 2021;27:1766–1772.
5. Kousgaard SJ, Cold F, Halkjær SI, et al. The effect of non-pooled multi-donor faecal microbiota transplantation for inducing clinical remission in patients with chronic pouchitis: Results from a multicentre randomised double-blinded placebo-controlled trial (MicroPouch). J Crohn’s Colitis 2024;18:1753–1766.