Higher Intra-Abdominal Visceral Adipose Tissue Mass Is Associated With Lower Rates of Clinical and Endoscopic Remission in Patients With Inflammatory Bowel Diseases Initiating Biologic Therapy: Results of the Constellation Study

Safety and Effectiveness of Glucagon-like Peptide-1 Receptor Agonists in Inflammatory Bowel Disease

INTRODUCTION

The safety and effectiveness of glucagon-like peptide receptor agonists (GLP1-RA) in patients with inflammatory bowel disease (IBD) are poorly understood.

METHODS

Patients with IBD treated with GLP1-RA were retrospectively identified for outcomes of adverse events, weight change, and clinical, endoscopic, and biomarker response.

RESULTS

Among a total of 120 patients with IBD, gastrointestinal side effects being the most common (11.5%). Semaglutide showed the most significant weight reduction. C-reactive protein levels decreased after one year ( P = 0.005). No differences were observed in IBD-related hospitalizations or endoscopic scores.

DISCUSSION

GLP1-RA therapy appears safe and effective, with an associated C-reactive protein reduction, in patients with IBD.

Increased CT Attenuation of Pericolic Adipose Tissue as a Noninvasive Marker of Disease Severity in Ulcerative Colitis

OBJECTIVE

Accurate evaluation of inflammation severity in ulcerative colitis (UC) can guide treatment strategy selection. The potential value of the pericolic fat attenuation index (FAI) on CT as an indicator of disease severity remains unknown. This study aimed to assess the diagnostic accuracy of pericolic FAI in predicting UC severity.

MATERIALS AND METHODS

This retrospective study enrolled 148 patients (mean age 48 years; 87 males). The fat attenuation on CT was measured in four different locations: the mesocolic vascular side (MS) and opposite side of MS (OMS) around the most severe bowel lesion, the retroperitoneal space (RS), and the subcutaneous area. The fat attenuation indices (FAIMS, FAIOMS, and FAIRS) were calculated as the fat attenuation measured in MS, OMS, and RS, respectively, minus that of the subcutaneous area, and were obtained in the non-enhanced, arterial, and delayed phases. Correlations between the FAI and UC Endoscopic Index of Severity (UCEIS) were assessed using Spearman's correlation. Predictors of severe UC (UCEIS ≥7) were selected by univariable analysis. The performance of FAI in predicting severe UC was evaluated using the area under the receiver operating characteristic curve (AUC).

RESULTS

The FAIMS and FAIOMS scores were significantly higher than FAIRS in three phases (all P < 0.001). The FAIMS and FAIOMS scores moderately correlated with the UCEIS score (r = 0.474-0.649 among the three phases). Additionally, FAIMS and FAIOMS identified severe UC, with AUC varying from 0.77 to 0.85.

CONCLUSION

Increased CT attenuation of pericolic adipose tissue could serve as a noninvasive marker for evaluating UC severity. FAIMS and FAIOMS of three phases showed similar prediction accuracies for severe UC identification.

Obesity Is Associated with Inferior Clinical Treatment Outcomes in Inflammatory Bowel Disease: A Nationwide Dutch Registry Study

PURPOSE

To examine the impact of obesity on treatment outcomes in inflammatory bowel disease (IBD).

METHODS

Patients aged ≥ 16 years, with IBD, a documented baseline body mass index (BMI), and starting thiopurines and allopurinol, intravenous (iv) vedolizumab, subcutaneous (sc) vedolizumab, ustekinumab, ozanimod, filgotinib, or tofacitinib were selected from the Dutch Initiative on Crohn and Colitis (ICC) registry. Underweight patients (BMI < 18.5 mg/kg2) were excluded. The primary outcome was steroid-free clinical remission (i.e. Simple Clinical Colitis Activity Index (SCCAI) ≤ 2 for ulcerative colitis (UC) and IBD-unclassified (IBD-U), and Harvey Bradshaw Index (HBI) < 5 for Crohn's disease (CD)) at week 24. Remission rates were compared between normal weight (BMI 18.5-25 kg/m2), and overweight (BMI 25-30 kg/m2), and obese (BMI ≥ 30 kg/m2) patients using binary logistic regression analyses. Multivariable regression analysis was used to correct for possible confounders.

RESULTS

Among 1066 patients with IBD, 619 had normal weight, 303 were overweight, and 144 were obese. At week 24, obese patients achieved steroid-free clinical remission less frequently (35.3%, OR = 0.578, 95% CI: 0.380-0.879, p = 0.010), supported by multivariable analysis (OR = 0.537, 95% CI: 0.346-0.832, p = 0.005).

CONCLUSIONS

Obesity was associated with lower steroid-free clinical remission at week 24. Obese patients with IBD should be encouraged to lose weight not only to improve their overall health, but also to optimize their treatment outcomes.

GLP-1 Analog Use is Associated With Improved Disease Course in Inflammatory Bowel Disease: A Report from the Epi-IIRN

BACKGROUND AND AIMS

The growing use of glucagon-like peptide 1 (GLP-1) analogs for type 2 diabetes mellitus (DM2) and obesity necessitates studies about their use in patients with inflammatory bowel diseases (IBD).

METHODS

Data on patients with DM2 were retrieved from an Israeli nationwide cohort of patients with IBD (epi-IIRN), recording GLP-1 analog exposure for at least 6 months. The primary outcome was poor disease outcomes (ie, composite of steroid dependence, initiation of advanced IBD therapy, hospitalization, surgery, or death). Cox proportional hazard models with time-varying covariables were used to assess the impact of GLP-1 use on outcomes during follow-up.

RESULTS

We included 3737 patients (24 338 patient-years) with IBD and DM2 [50.4% ulcerative colitis (UC)], of whom 633 were treated with GLP-1 analogs. Accounting for demographics IBD/DM2 related variables, medication use, and laboratory measurements, GLP-1 analog use was associated with reduced composite outcome in the full cohort (adjusted hazard ratio [aHR] 0.74, 95% confidence interval [CI] 0.62-0.89) and in each subtype [UC (aHR 0.71, 95% CI 0.52-0.96) and Crohn's disease (aHR 0.78, 95% CI 0.62-0.99)]. Similar trends were seen in multivariate analyses of each individual outcome, although only hospitalization was significant (aHR 0.74, 95% CI 0.61-0.91). The protective effect of GLP-1 analogs was seen in patients with obesity (aHR 0.61, 95% CI 0.50-0.77), but not in non-obese (aHR 0.94, 95% CI 0.67-1.31).

CONCLUSIONS

GLP-1 analogs are associated with improved outcomes in IBD, specifically in patients with obesity. The mechanisms of these effects require further investigation as well as their role in patients without DM2.

Obesity Is Associated With Worsened Outcomes in Patients With Ulcerative Colitis on Advanced Therapies: A Propensity Matched Cohort Study From the U.S

BACKGROUND

Obesity has been linked to a more severe phenotype in patients with ulcerative colitis (UC).

AIM

To evaluate the impact of obesity on outcomes of advanced therapies in UC.

METHODS

We conducted a retrospective cohort study utilising the TriNetX database comparing the composite score of corticosteroid use, change in advanced therapy or colectomy within two years between two cohorts of patients with UC-those with obesity (BMI ≥ 30 kg/m2) and those without (BMI 18.5-24.9). The risk assessment was stratified to specific advanced therapies, including tumour necrosis factor α inhibitors (TNFi), vedolizumab, ustekinumab and Janus kinase inhibitors (JAKi). We performed 1:1 propensity score matching (PSM) for demographics, co-morbid conditions, laboratory values and IBD medications including corticosteroids.

RESULTS

There were 3904, 2025, 1150 and 477 patients on TNFi, vedolizumab, ustekinumab and JAKi, respectively, in the UC obesity cohort. After PSM, the UC obesity cohort was at an increased risk of the composite outcome of corticosteroid use, change in therapy and colectomy compared to the UC control cohort in patients on TNFi (aHR 1.37, 95% CI 1.29-1.49), vedolizumab (aHR 1.29, 95% CI 1.16-1.43), ustekinumab (aHR 1.1.26, 95% CI 1.10-1.44) and JAKi (aHR 1.38, 95% CI 1.13-1.69). Sub-group analysis based on the specific TNFi also showed an increased risk of composite outcome for infliximab (aHR 1.36, 95% CI 1.22-1.52) and adalimumab (aHR 1.26, 95% CI 1.11-1.42) within 2 years.

CONCLUSIONS

Obesity is associated with lower efficacy of several advanced therapies in patients with UC.

Obesity and Clinical Characteristics of Inflammatory Bowel Disease

INTRODUCTION

The frequency of obesity and possible correlations with characteristics and outcome of inflammatory bowel disease (IBD) are undefined. Primary aim was to assess the body mass index (BMI) distribution in IBD patients in follow-up. Secondary aim was to compare clinical characteristics and course of IBD in normal weight versus overweight or obese patients.

METHODS

Adult IBD patients in regular follow-up were prospectively enrolled and BMI was recorded during outpatient visits. Comparisons were assessed by the Student t-test, Mann-Whitney U test and Chi-square test, as appropriate.

RESULTS

In the 300 IBD patients enrolled (150 Crohn's disease [CD], 150 ulcerative colitis [UC]), BMI distribution included: 16 (5.3%) underweight, 170 (56.7%) normal weight, 92 (30.7%) overweight, 22 (7.3%) obese patients. For the secondary aim, the 16 underweight patients were excluded, thus leaving 284 patients for the analysis (141 [49.6%] CD; 143 [50.4%] UC). Among these, 114 (40.2%) were overweight/obese and 170 (59.8%) normal weight. CD group included 89 (63.1%) normal weight and 52 (36.9%) overweight/obese patients. Perianal disease and refractoriness to biologics were more frequent in overweight/obese than normal weight CD patients (9 [10.1%] vs. 12 [23%], p = 0.03; 0 [0%] vs. 4 [23.4%], p = 0.01). In UC group, there were 81 (56.6%) normal weight and 62 (63.4%) overweight or obese patients.

CONCLUSION

In IBD patients in follow-up, the proportion of underweight patients is low. Overweight and obese CD patients showed a higher frequency of perianal disease and refractoriness to biologics. BMI may influence phenotype and responsiveness to biologics in CD.

GLP-1 Receptor Agonists Confer No Increased Rates of IBD Exacerbation Among Patients With IBD

BACKGROUND

In patients with inflammatory bowel disease (IBD), multimorbidity with obesity and type 2 diabetes is common and increasing. Glucagon-like peptide 1 (GLP-1) receptor agonists are increasingly being prescribed for patients with IBD, yet their impact on patients with IBD is largely unknown. We aimed to assess the impact of GLP-1 receptor agonists on the course of IBD.

METHODS

We identified all IBD patients prescribed GLP-1 receptor agonists at a large academic healthcare network between 2009 and 2023. We analyzed demographics and IBD characteristics in the year pre- and post-GLP-1 receptor agonist prescription and matched them to non-IBD controls. Our primary outcome was IBD exacerbation in the year following GLP-1 receptor agonist initiation, measured as a composite of IBD-related hospitalization, corticosteroid prescription, medication escalation or changes, or IBD-related surgery. Secondary outcomes included change in metabolic risk factors.

RESULTS

Overall, 224 patients met inclusion criteria. At GLP-1 receptor agonist initiation, the median age was 54 years, 63% were female, 77% were White, and median BMI was 33.2 kg/m2. Compared to the 12-month period prior to GLP-1 receptor agonist initiation, in the 12 months post-GLP-1 receptor agonist initiation, there was no change in rates of IBD exacerbation, IBD-related hospitalization, steroids prescription, medication escalation or changes, or IBD-related surgery. There was a significant decrease in BMI in the year following GLP-1 receptor agonist initiation (median BMI 33.5 vs 31.6 kg/m2, P < .01), with rates of decrease comparable to non-IBD matched controls.

CONCLUSIONS

In patients with IBD, GLP-1 receptor agonists are effective for weight loss and associated with few episodes of disease exacerbation.

Body mass index does not influence loss of response to tumor necrosis factor inhibitors in Crohn's disease

OBJECTIVES

Moderate to severe Crohn's disease (CD) treatment was revolutionized by introducing anti-tumor necrosis factor (TNF) agents, which is still a cornerstone of the treatment. It is speculated that adipose tissue may influence treatment response, especially for non-weight-adjusted agents.

PATIENTS AND METHODS

Research comparing the effectiveness of anti-TNFs between eutrophic and overweight patients may impact clinical management. We performed a retrospective analysis of a CD patient database. The primary endpoint was loss of response (LOR) after 54 weeks with infliximab (IFX) and adalimumab (ADA) in patients with body mass index (BMI) <25 and ≥25. Secondary endpoints were steroid-free remission and endoscopic remission rate.

RESULTS

One hundred seventy-nine CD patients were evaluated; 48.9% had LOR after 54 weeks of anti-TNF therapy. Fifty-four patients had a BMI ≥25, with 51 receiving IFX and 28 receiving ADA. The univariate analysis identified LOR in 56.5% of the patients with IFX and 34.9% in the ADA group (p=0.009). In the 54-week multivariate analysis, loss of response in the IFX group with BMI ≥25 had a relative risk of 1.04 [CI 0.60-1.80 (p=0.891)] compared to patients with BMI <25. Being overweight or obese led to a risk of 1.50 for LOR for ADA at 54-week time point [CI 0.60-3.74 (p=0.0387)]. Clinical remission at 54 weeks was similar between BMI groups.

CONCLUSIONS

Being overweight did not influence the LOR to treatment when IFX and ADA were compared, nor did it affect clinical and endoscopic remission after 54 weeks.

Myopenia and body fat distribution in hospitalized ulcerative colitis patients: correlations with clinical characteristics and response to vedolizumab

Background

Ulcerative colitis (UC) patients often suffer from impaired nutritional conditions. However, there are few studies focused on muscle loss in UC patients as well as its impact on therapeutic response. This study aimed to investigate the prevalence of myopenia in hospitalized patients with active UC, analyze the relationship between body composition including both skeletal muscle and fat with clinical characteristics, and explore the association between body composition and clinical response to vedolizumab.

Methods

A retrospective cohort study was conducted in hospitalized patients with active UC in Peking Union Medical College Hospital from November 2014 to October 2022. Computed tomography (CT) scans were used to measure skeletal muscle area, visceral fat area (VFA), subcutaneous fat area (SFA), and intramuscular fat infiltration at the third lumbar vertebrae (L3) level. These measurements were standardized by height (m) squared. Myopenia was defined as a skeletal muscle index (SMI) < 44.77 cm2/m2 for males and <32.50 cm2/m2 for females. The VFA/SFA ratio (VSR) served as an indicator of visceral obesity, while intramuscular fat infiltration was evaluated using the mean Hounsfield Unit (HU) value of the L3 skeletal muscle section.

Results

A total of 457 patients were enrolled. The prevalence of myopenia was 49.7% in this cohort. Female patients had significantly higher levels of subcutaneous fat and intramuscular fat but a lower level of visceral fat than male patients. SMI and mean HU showed positive correlations with serum albumin (ALB) and negative correlations with serum high-sensitivity C-reactive protein (hsCRP), whereas VSR showed the opposite trend. Among the 92 patients who received vedolizumab treatment, myopenia was significantly associated with a lower clinical response rate, and this association remained significant after adjusting for vedolizumab duration, ALB, and hsCRP (OR = 3.458, 95% CI 1.238-9.659, p = 0.018). Visceral obesity, defined as VSR ≥ 75th centile of gender-specific VSR, tended to diminish the clinical response rate but did not reach statistical significance.

Conclusion

This study underscores the significance of assessing body composition in UC patients. Optimizing body composition should be considered an integral component of managing UC patients in the future.

Management of Overweight and Obesity in Patients With Inflammatory Bowel Disease

Increasing evidence has linked obesity to complications of inflammatory bowel disease (IBD); however, data are limited on the efficacy and impact of weight management strategies on the disease course. There are a strikingly limited number of interventional studies on weight management in patients with IBD, and the recent nutrition and IBD guidelines published in the United States do not mention weight management strategies. Overweight and obesity management in patients with IBD should follow a stepwise approach to assessment and treatment, including lifestyle modification, anti-obesity medications such as glucagon-like peptide-1 agonists, endobariatric procedures, and bariatric surgery (if deemed appropriate). This article reviews the management of overweight and obesity in patients with IBD, examines the efficacy of currently available interventions and their impact on the IBD course, and proposes a stepwise approach to the assessment and treatment of overweight or obesity for the IBD provider.

Heavy arch: from inflammatory bowel diseases to metabolic disorders

BACKGROUND

Metabolic disorders and inflammatory bowel diseases (IBD) have captured the globe during Westernisation of lifestyle and related dietary habits over the last decades. Both disease entities are characterised by complex and heterogeneous clinical spectra linked to distinct symptoms and organ systems which, on a first glimpse, do not have many commonalities in clinical practice. However, experimental studies indicate a common backbone of inflammatory mechanisms in metabolic diseases and gut inflammation, and emerging clinical evidence suggests an intricate interplay between metabolic disorders and IBD.

OBJECTIVE

We depict parallels of IBD and metabolic diseases, easily overlooked in clinical routine.

DESIGN

We provide an overview of the recent literature and discuss implications of metabolic morbidity in patients with IBD for researchers, clinicians and healthcare providers.

CONCLUSION

The Western lifestyle and diet and related gut microbial perturbation serve as a fuel for metabolic inflammation in and beyond the gut. Metabolic disorders and the metabolic syndrome increasingly affect patients with IBD, with an expected negative impact for both disease entities and risk for complications. This concept implies that tackling the obesity pandemic exerts beneficial effects beyond metabolic health.

Reviewing the impact of obesity on inflammatory bowel disease and considerations for optimizing management

PURPOSE OF REVIEW

This review examines the complex relationship between obesity and inflammatory bowel disease (IBD), encompassing their potentially shared pathogenesis, the impact of obesity on the natural history and treatment outcomes of IBD, and the management of obesity in the patient with IBD.

RECENT FINDINGS

Obesity represents a state of chronic inflammation that may not only contribute to IBD pathogenesis, but also influence disease progression, complications, and response to treatment. Increased visceral adiposity may carry negative prognostic implications for disease and treatment-specific outcomes. Antiobesity medications, endoscopic bariatric therapies, and even bariatric surgery may be effective and well tolerated in selected patients with IBD.

SUMMARY

The intersection of obesity and IBD presents a significant clinical challenge, with obesity influencing the natural history of IBD and potentially affecting treatment efficacy. As obesity prevalence among IBD patients rises, a tailored approach to management is crucial, taking into account the individualized risks and benefits of various treatment strategies, including lifestyle interventions, pharmacotherapy, endoscopic procedures, and bariatric surgery.

A High Visceral-to-Skeletal Muscle Area Ratio on Cross-Sectional Imaging Is Associated With Failure of Standard Ustekinumab Doses: A Multicenter Study

INTRODUCTION

Anti-interleukin 12/23 agents have shown greater durability in response compared with anti-tumor necrosis factor α agents. Data on the association between body composition (BC) or body mass index (BMI) and ustekinumab's therapeutic response is limited. We aimed to evaluate the impact of BC on time to failing standard doses of ustekinumab in patients with Crohn's disease (CD).

METHOD

Patients with CD aged 16 years and older from 2 tertiary centers were studied retrospectively. Included patients had abdominal imaging within 6 months of ustekinumab induction and were followed until April 30, 2022. An experienced abdominal radiologist blinded to the clinical information measured the area of visceral fat area and skeletal muscle area at the mid L3 vertebral level, with values corrected for height 2 to derive respective indices (visceral fat index [VFI], skeletal muscle index [SMI]) and the VFI:SMI ratio.

RESULTS

Ninety-nine patients met inclusion criteria. The mean age at ustekinumab induction was 46.6 (±1.6) years. The median BMI (interquartile range) was 26.5 (22.6-30.8). Twenty-four patients (24.2%) did not respond or lost response to standard doses of ustekinumab over the follow-up duration. A younger age (hazard ratio 0.96, 95% confidence interval 0.94-0.99, P = 0.01) and a VFI:SMI ratio >1.6 (hazard ratio 4.65, 95% confidence interval 1.73-12.45, P = 0.002) were both associated with a shorter time to failing ustekinumab at standard doses on multivariate analysis. BMI, notably, had no association with the primary outcome.

DISCUSSION

A high VFI:SMI ratio is associated with an increased risk of failing standard doses of ustekinumab. BC measurements derived from cross-sectional imaging at the start of ustekinumab therapy is a useful indicator for therapeutic durability.

Challenges in IBD Research 2024: Pragmatic Clinical Research

Pragmatic clinical research is 1 of the 5 focus areas of the Challenges in IBD Research 2024, a multidisciplinary effort by scientists, clinicians, patients, and funders to identify priorities for patient-centric research. This summary provides a comprehensive overview of current gaps in inflammatory bowel disease (IBD) clinical research and actionable approaches to address them. This review is focused on identifying research that is needed to achieve the best outcomes for patients in clinical practice. Research gaps include understanding the needs of understudied patient groups and addressing barriers to care so all patients receive optimal care, validating and using biomarkers to enable early diagnosis and result in better outcomes for adults and children with IBD, and determining the optimal sequencing of treatments (medical, surgical, adjunct) in children and adults. Inclusive pragmatic research is needed to address these gaps and lead to improvements in patient care and outcomes for all populations of patients with IBD.

Quantification of Visceral Fat at the L5 Vertebral Body Level in Patients with Crohn's Disease Using T2-Weighted MRI

The umbilical or L3 vertebral body level is often used for body fat quantification using computed tomography. To explore the feasibility of using clinically acquired pelvic magnetic resonance imaging (MRI) for visceral fat measurement, we examined the correlation of visceral fat parameters at the umbilical and L5 vertebral body levels. We retrospectively analyzed T2-weighted half-Fourier acquisition single-shot turbo spin echo (HASTE) MR axial images from Crohn's disease patients who underwent MRI enterography of the abdomen and pelvis over a three-year period. We determined the area/volume of subcutaneous and visceral fat from the umbilical and L5 levels and calculated the visceral fat ratio (VFR = visceral fat/subcutaneous fat) and visceral fat index (VFI = visceral fat/total fat). Statistical analyses involved correlation analysis between both levels, inter-rater analysis between two investigators, and inter-platform analysis between two image-analysis platforms. Correlational analysis of 32 patients yielded significant associations for VFI (r = 0.85; p < 0.0001) and VFR (r = 0.74; p < 0.0001). Intraclass coefficients for VFI and VFR were 0.846 and 0.875 (good agreement) between investigators and 0.831 and 0.728 (good and moderate agreement) between platforms. Our study suggests that the L5 level on clinically acquired pelvic MRIs may serve as a reference point for visceral fat quantification.

Pre-operative visceral adipose tissue radiodensity is a potentially novel prognostic biomarker for early endoscopic post-operative recurrence in Crohn's disease

BACKGROUND

Evidence suggests inflammatory mesenteric fat is involved in post-operative recurrence (POR) of Crohn's disease (CD). However, its prognostic value is uncertain, in part, due to difficulties studying it non-invasively.

AIM

To evaluate the prognostic value of pre-operative radiographic mesenteric parameters for early endoscopic POR (ePOR).

METHODS

We conducted a retrospective cohort study of CD subjects ≥ 12 years who underwent ileocecal or small bowel resection between 1/1/2007 to 12/31/2021 with computerized tomography abdomen/pelvis ≤ 6 months pre-operatively and underwent ileocolonoscopy ≤ 15 months post-operatively. Visceral adipose tissue (VAT) volume (cm3), ratio of VAT:subcutaneous adipose tissue (SAT) volume, VAT radiodensity, and ratio of VAT:SAT radiodensity were generated semiautomatically. Mesenteric lymphadenopathy (LAD, largest lymph node > 10 mm) and severe vasa recta (VR) engorgement (diameter of the VR supplying diseased bowel ≥ 2 × VR supplying healthy bowel) were derived manually. The primary outcome was early ePOR (Rutgeert's score ≥ i2 on first endoscopy ≤ 15 months post-operatively) and the secondary outcome was ePOR severity (Rutgeert's score i0-4). Regression analyses were performed adjusting for demographic and disease-related characteristics to calculate adjusted odds ratio (aOR) and 95% confidence interval (CI).

RESULTS

Of the 139 subjects included, 45% of subjects developed early ePOR (n = 63). VAT radiodensity (aOR 0.59, 95%CI: 0.38-0.90) and VAT:SAT radiodensity (aOR 8.54, 95%CI: 1.48-49.28) were associated with early ePOR, whereas, VAT volume (aOR 1.23, 95%CI: 0.78-1.95), VAT:SAT volume (aOR 0.80, 95%CI: 0.53-1.20), severe VR engorgement (aOR 1.53, 95%CI: 0.64-3.66), and mesenteric LAD (aOR 1.59, 95%CI: 0.67-3.79) were not. Similar results were observed for severity of ePOR.

CONCLUSION

VAT radiodensity is potentially a novel non-invasive prognostic imaging marker to help risk stratify CD patients for POR.

Integrated multi-omics reveal gut microbiota-mediated bile acid metabolism alteration regulating immunotherapy responses to anti-α4β7-integrin in Crohn's disease

Gut microbiota and related metabolites are both crucial factors that significantly influence how individuals with Crohn's disease respond to immunotherapy. However, little is known about the interplay among gut microbiota, metabolites, Crohn's disease, and the response to anti-α4β7-integrin in current studies. Our research utilized 2,4,6-trinitrobenzene sulfonic acid to induce colitis based on the humanized immune system mouse model and employed a combination of whole-genome shotgun metagenomics and non-targeted metabolomics to investigate immunotherapy responses. Additionally, clinical cases with Crohn's disease initiating anti-α4β7-integrin therapy were evaluated comprehensively. Particularly, 16S-rDNA gene high-throughput sequencing and targeted bile acid metabolomics were conducted at weeks 0, 14, and 54. We found that anti-α4β7-integrin therapy has shown significant potential for mitigating disease phenotypes in remission-achieving colitis mice. Microbial profiles demonstrated that not only microbial composition but also microbially encoded metabolic pathways could predict immunotherapy responses. Metabonomic signatures revealed that bile acid metabolism alteration, especially elevated secondary bile acids, was a determinant of immunotherapy responses. Especially, the remission mice significantly enriched the proportion of the beneficial Lactobacillus and Clostridium genera, which were correlated with increased gastrointestinal levels of BAs involving lithocholic acid and deoxycholic acid. Moreover, most of the omics features observed in colitis mice were replicated in clinical cases. Notably, anti-α4β7 integrin provided sustained therapeutic benefits in clinical remitters during follow-up, and long-lasting remission was linked to persistent changes in the microbial-related bile acids. In conclusion, gut microbiota-mediated bile acid metabolism alteration could play a crucial role in regulating immunotherapy responses to anti-α4β7-integrin in Crohn's disease. Therefore, the identification of prognostic microbial signals facilitates the advancement of targeted probiotics that activate anti-inflammatory bile acid metabolic pathways, thereby improving immunotherapy responses. The integrated multi-omics established in our research provide valuable insights into potential mechanisms that impact treatment responses in complex diseases.