Introduction

The phenotype and behavior of immune cells have been linked to cellular energy metabolisms, leading to the emergence of a new field of immunometabolism. The crucial role of the gut microbiota in immune system maturation and functions and the relatedness of mitochondria and bacteria suggest a role for the gut microbiota in intestinal epithelial and immune cell energy metabolism. The gut microbiota and its metabolites have a critical role in establishing and maintaining health and in the pathogenesis of diseases, including inflammatory bowel disease (IBD). Following an in vitro screening, we showed that indole-3-propionic acid (IPA) stimulates mitochondrial respiration of CD4+ T cells. IPA is a microbiota-derived tryptophan metabolite shown to be decreased in the feces of patients with IBD and which plays a crucial part in regulating intestinal immune tolerance, improving mucus barrier function and suppressing intestinal inflammation.

Aims & Methods

We aim at exploring the mechanisms involved in the anti-inflammatory effects of IPA. SCENITH technology (Single-cell energetic metabolism by profiling translation inhibition) was used to screen and identify the effect of metabolites on energy metabolism of specific subpopulations in mixed immune cell systems in both in vitro and in vivo. Seahorse, Mitotracker, metabolomics, proteomics experiments were used to explore the role of identified metabolites on energy metabolism in purified cells in vitro. Antibiotic-depleted gut microbiota, dextran sodium sulphate-induced colitis and adoptive reinfusion experiments in mice were used to evaluate the effects of metabolites on cellular energy metabolism and their anti-inflammation function in vivo.

Results

Using SCENITH technology on human blood mononuclear cells (PBMCs), we showed that IPA stimulates mitochondrial respiration of CD4+ T cells, by promoting fatty acid/amino acid oxidation rather than traditional glucose metabolism in the CD3/CD28 activation setting. Similar results were observed in mouse CD4+ T cells. In parallel with cellular energy reprogramming, IPA impacts CD4+ T cell behavior by favoring Treg over the Th17 phenotype in vitro. Blocking mitochondrial respiration with oligomycin or long-chain fatty acid metabolism with etomoxir inhibit IPA effects on T cells phenotype. IPA is a relatively weak Aryl hydrocarbon receptor (AhR) agonist. Using an AhR inhibitor (CH-223191) or AhR KO T cells, we showed that the effect of IPA on CD4+ T cell energy metabolism was not dependent on AhR. In microbiota-depleted mice, the alteration in mitochondrial respiration of small intestine and colon CD4+ T cells was rescued by IPA administration. In DSS-induced colitis, IPA administration increases mitochondrial respiration of CD4+ T cells by enhancing the oxidation of fatty acids and amino acids in the colon. Adoptive reinfusion of CD4+ T cells from IPA-treated mice into Rag2 KO mice induced protection against intestinal inflammation, confirming that IPA protective effects are mediated by CD4+ T cells.

Conclusion

Collectively, our study reveals from a whole new perspective that the anti-inflammatory effects of IPA are mediated by metabolic reprogramming of CD4+ T cells toward the enhancement of mitochondrial respiration, thereby leading to an anti-inflammatory phenotype and eventually protection in colitis context in mice. This study paves the way for the development of new therapeutic strategies in IBD.

Disclosure

Competing interests: HS report lecture fee, board membership, or consultancy from Carenity, AbbVie, Astellas, Danone, Ferring, Mayoly Spindler, MSD, Novartis, Roche, Tillots, Enterome, BiomX, Biose, Novartis,Takeda, Biocodex and is cofounder of Exeliom Biosciences.

Introduction

A wide range of relationships between the microbial community and various environmental or individual factors have been proposed. Monozygotic and dizygotic twins provide a unique model for assessing host-microbial interactions. The mycobiome has been increasingly implicated in the development of several diseases, but knowledge of the dynamics of the fungal community, particularly in twins, has not been addressed.

Aims & Methods

In this work, we investigated the fungal community in a twin cohort and explored its relationship with associated genetic and environmental factors through in-depth analysis.
The twin cohort consisted of 106 well-characterised and systematically studied monozygotic and dizygotic pairs (212 stool samples). DNA was extracted and PCR reactions were performed to sequence the lower gastrointestinal microbiome and the mycobiome community. The bacterial community was characterised using the V1-V2 region of the 16 rRNA gene and the fungal community was analysed using the ITS1-ITS2 region.

Results

The fungal community, represented by the sum of all fungal sequences, showed a significantly higher heterogeneity than the bacterial community. Several individual and genetic factors, such as the zygotic status of the twins (monozygotic vs. dizygotic), as well as sex, mode of birth, breast-feeding as newborns or living in the same household, were independent of the total number of fungal sequences. The bacterial community was significantly more abundant than the fungal community, the most common representatives of which were Candida and Geotrichum with sometimes very high abundances. Saccharomyces was also common in the cohort, but only in low abundance, other fungi with a wider distribution were Cladosporium or Penicillium. The environmental and individual factors mentioned above were also correlated with the individual fungal genera, but there were no significant correlations found here either. The next step was to correlate the bacterial and fungal communities with each other, and strong negative correlations were found with certain bacteria such as Prevotella.

Conclusion

Genetic factors in twins are not associated with dynamics in the faecal fungal community and were the subject of high inter-individual variability. However, there is a strong association between bacterial and mycobial interaction, which requires further in-depth understanding of microbial interactions.

Disclosure

No conflict of interest to declare

Introduction

​​​​​Guselkumab (GUS) is a selective dual-acting IL-23p19 subunit inhibitor that potently blocks interleukin 23 (IL-23) and binds to CD64, a receptor on cells that produce IL-23¹. In patients with moderately to severely active Crohn’s disease (CD), the GALAXI-2 and GALAXI-3 Phase 3 studies established short- and long-term efficacy of GUS compared to placebo, and statistical superiority to ustekinumab (UST) in prespecified analyses of pooled data at Week (WK)48². We subsequently developed an endoscopic clustering method using Simple Endoscopic Score for Crohn's Disease (SES-CD) segmental scores in patients from GALAXI 2/3 which revealed higher endoscopic remission rates with GUS compared with UST at WK12 and WK48 in pts characterized by ileal disease and strictured right colon³. Here we report molecular differentiation of GUS compared with UST in isolated ileal disease based on serum pharmacodynamic (PD) markers and tissue transcriptomics in CD using pooled samples from the GALAXI studies.

Aims & Methods

Patients (pts) in GALAXI-2 (n=508) and GALAXI-3 (n=513) were randomized 2:2:2:1 to receive GUS 200mg IV q4w x3 → GUS 200mg SC q4w, GUS 200mg IV q4w x3→ GUS 100mg SC q8w, UST ⁓6mg/kg IV x1 → UST 90mg SC q8w or placebo IV q4w x3 (PBO). Serum biomarkers were measured in a subset of (n=50) pts per group at WK0, WK4 and WK12 using a proinflammatory panel and a high sensitivity IL-22 assay. Matched ileal and rectal biopsies were evaluated at WK0, WK12 and WK48 in a subset of 344 pts representative of the full study population. Transcriptional profiling was performed with bulk RNA sequencing (RNAseq) using transcriptional modules. Analysis of treatment effects was performed using molecularly inflamed samples (biopsy molecular inflammation score [bMIS]⁴ >0) from segments with SES-CD >0 at baseline. Serum proteins and transcriptional modules were evaluated for differential expression stratified by isolated ileal, isolated colonic and ileocolonic disease defined during screening.

Results

In pts with isolated ileal disease, GUS decreased serum protein levels of IL-22, IL-17A and IFNγ at WK12 while UST only reduced IFNγ. In ileal tissue, GUS significantly altered inflammatory modules at WK12 and WK48 including reductions in neutrophil, inflamed epithelium, IL-23/Th17 and inflammatory fibroblast biology compared with minimal changes observed with UST, which only significantly reduced neutrophil, plasma cell and macrophage modules at WK48. In contrast, in pts with isolated colonic or ileocolonic disease, both GUS and UST decreased IL-23-dependent serum proteins towards normal levels compared with an independent cohort of healthy control sera. In rectal tissue, both GUS and UST significantly altered key inflammatory transcriptional modules in rectal biopsies at WK12 and WK48. Overall, greater effects of GUS vs UST were observed in ileal tissue at WK12 and at WK48 in transcriptional modules associated with decreasing disease-related features and restoring epithelial health than UST.

Conclusion

GUS decreased IL-23-dependent serum proteins and improved tissue transcriptional profiles in pts with isolated ileal disease while UST only reduced serum IFNγ and had a minimal impact on IL-23-dependent transcriptional modules. These data suggest potential differences in IL-23 and IL-12 pathway enrichment in isolated ileal disease where inhibition of IL-23p19 subunit with GUS achieved greater molecular treatment effects early which were maintained through WK48 and associated with differential clinical outcomes in patients with isolated ileal disease.

References

1. Sachen K, Hammaker D, Sarabia I, et al. Guselkumab binding to CD64+ IL-23–producing myeloid cells enhances potency for neutralizing IL-23 signaling. Frontiers in Immunology. 2025; doi:10.3389/fimmu.2025.1532852
2. Panaccione R, Danese S, Feagan BE, et al. Efficacy and safety of guselkumab therapy in patients with moderately to severely active Crohn’s disease: results of the GALAXI 2 & 3 phase 3 studies. Gastroenterology. 2024; 5 (Supplement): p1057b
3. Richards D, Seridi L, Sohn, K, et al. Guselkumab shows higher endoscopic remission rates than ustekinumab in patients characterized by isolated ileal and srtictured right colon Crohn’s disease: Post-hos analysis of GALAXI 2/3 Ph3 trials. DDW 2025 Abs #4253526; poster.
4. Argmann C, Hou R, Ungaro, R, et al. A biopsy and blood-based molecular biomarker of inflammation in inflammatory bowel disease. Gut. 2022; 0:1-17.

Disclosure

DR, KS, MZ, RP, BM, NAT, MV, DC and PB are current or former employees of Janssen and may hold stock in Johnson & Johnson.
WR has served as a speaker for AbbVie, Celltrion, Ferring, Janssen, Galapagos Medice, MSD, Roche, Pfizer, Sobi, Takeda, as a consultant for AbbVie, Amgen, AOP Orphan, Boehringer Ingelheim, Bristol Myers Squibb, Calyx, Celltrion, Eli Lilly, Galapagos, Gilead, Index Pharma, Janssen, Medahead, Microbiotica, Pfizer, Takeda; as an advisory board member for AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celltrion, Galapagos, Janssen, Pfizer, and has received research funding from AbbVie, Janssen, Sandoz, Sanofi, Takeda.

Introduction

Chronic liver disease remains one of the most common causes for admission in the Gastroenterology department, with high morbidity and mortality rates. As quality-of-care gains traction in our clinical practice, chronic liver disease, particularly when regarding decompensated cirrhotic patients in the emergency department, remains without a standardized approach. Additionally, timely and adequate management within the first 24 hours of admission reduces morbidity and mortality in decompensated cirrhosis. In the United Kingdom, a standardized cirrhosis care bundle as been effectively applied.

Aims & Methods

We conducted a retrospective review to determine baseline management of patients with decompensated cirrhosis attending two Portuguese hospital centers, in 2021 and 2022.

Results

We included a total of 148 patients from 2 hospital centers, 141 were male (95.3%) and had a median age of 62 years at admission (IQR 15). Median Child-Pugh and Model for End-stage Liver Disease (MELD) -Na scores at admission were 9 (IQR 3) and 18 (IQR 10) points, respectively.
The most common decompensations were gastrointestinal bleeding in 33.1% of patients, ascites in 30.8% and hepatic encephalopathy in 25.6%. Sixty-five patients had more than 1 decompensation (43.9%). It was their first liver disease decompensation in 55 patients (37.2%). Regarding etiology, alcoholic liver disease was the most common, in 134 patients (90.5%). Median duration of admission was 8 days (IQR 6). The in-hospital mortality rate was 4.7% (7 patients) and mortality rate at 6 weeks after admission was 8.8% (13 patients). Forty-six patients were readmitted up to 3 months (31.1%).
In patients with ascites, 29 did not undergo paracentesis (33.3%). In patients with recent history of alcohol abuse, 5 did not receive thiamine (7.5%) and 6 did not undergo alcohol abstinence syndrome prevention therapy (9%). In suspected infection, 4 out of 38 patients did not receive empirical antibiotics in the first 24 hours of admission (10.5%). In acute renal lesion, 2 patients did not stop diuretics and/or nephrotoxic drugs (5.6%) and 4 did not receive fluids and/or albumin (12.1%). In 3 patients there was no diuresis monitoring (7.5%). At admission for gastrointestinal bleeding, 3 patients received a nonrestrictive approach regarding transfusions (5.5%), 18 did not undergo vasopressor therapy (32.1%) and in 5 prophylactic antibiotics were not administered (8.9%). Prophylactic lactulose was used in 25 patients (45.5%). Only 1 patient did not undergo upper endoscopy before 12 hours of admission (1.8%). In hepatic encephalopathy, the precipitating factor was recognized in 29 patients (69%), with infection as the most commonly identified (55.2%). Venous Thromboembolism prophylaxis was not administered (45.3%) in 67 patients and 88 patients did not undergo a nutritional evaluation during admission (59.5%).

Conclusion

We were able to identify several areas in need of improvement: one-third of patients with ascites did not undergo diagnostic ascitic taps, nearly on-third of patients did not start vasopressor therapy at admission and more than half had no nutritional evaluation.
Training and best practice policies are a priority in Gastroenterology nowadays, and the identification of poor performance areas is relevant for the betterment of our clinical practice. An adapted bundle for prospective application is underway in our centers as we hope to reduce overall hospital stay and mortality in decompensated cirrhosis.

References

Dyson JK, et al. Implementation of a ‘care bundle’ improves the management of patients admitted to hospital with decompensated cirrhosis. Aliment Pharmacol Ther 2016; 44: 1030–1038, doi:10.1111/apt.13806
McPherson S, et al. Decompensated Cirrhosis Care Bundle - First 24 Hours. Disponível em: https://www.bsg.org.uk/wp-content/uploads/2019/12/BSG-BASL-Decompensated-Cirrhosis-Care-Bundle-First-24-Hours.pdf