Fecal microbiota transplantation: current challenges and future landscapes.

SUMMARYGiven the importance of gut microbial homeostasis in maintaining health, there has been considerable interest in developing innovative therapeutic strategies for restoring gut microbiota. One such approach, fecal microbiota transplantation (FMT), is the main "whole gut microbiome replacement" strategy and has been integrated into clinical practice guidelines for treating recurrent Clostridioides difficile infection (rCDI). Furthermore, the potential application of FMT in other indications such as inflammatory bowel disease (IBD), metabolic syndrome, and solid tumor malignancies is an area of intense interest and active research. However, the complex and variable nature of FMT makes it challenging to address its precise functionality and to assess clinical efficacy and safety in different disease contexts. In this review, we outline clinical applications, efficacy, durability, and safety of FMT and provide a comprehensive assessment of its procedural and administration aspects. The clinical applications of FMT in children and cancer immunotherapy are also described. We focus on data from human studies in IBD in contrast with rCDI to delineate the putative mechanisms of this treatment in IBD as a model, including colonization resistance and functional restoration through bacterial engraftment, modulating effects of virome/phageome, gut metabolome and host interactions, and immunoregulatory actions of FMT. Furthermore, we comprehensively review omics technologies, metagenomic approaches, and bioinformatics pipelines to characterize complex microbial communities and discuss their limitations. FMT regulatory challenges, ethical considerations, and pharmacomicrobiomics are also highlighted to shed light on future development of tailored microbiome-based therapeutics.

Comparative evaluation of a language model and human specialists in the application of European guidelines for the management of inflammatory bowel diseases and malignancies.

BACKGROUND: Society guidelines on colorectal dysplasia screening, surveillance, and endoscopic management in inflammatory bowel disease (IBD) are complex, and physician adherence to them is suboptimal. We aimed to evaluate the use of ChatGPT, a large language model, in generating accurate guideline-based recommendations for colorectal dysplasia screening, surveillance, and endoscopic management in IBD in line with European Crohn's and Colitis Organization (ECCO) guidelines. METHODS: 30 clinical scenarios in the form of free text were prepared and presented to three separate sessions of ChatGPT and to eight gastroenterologists (four IBD specialists and four non-IBD gastroenterologists). Two additional IBD specialists subsequently assessed all responses provided by ChatGPT and the eight gastroenterologists, judging their accuracy according to ECCO guidelines. RESULTS: ChatGPT had a mean correct response rate of 87.8%. Among the eight gastroenterologists, the mean correct response rates were 85.8% for IBD experts and 89.2% for non-IBD experts. No statistically significant differences in accuracy were observed between ChatGPT and all gastroenterologists (P=0.95), or between ChatGPT and the IBD experts and non-IBD expert gastroenterologists, respectively (P=0.82). CONCLUSIONS: This study highlights the potential of language models in enhancing guideline adherence regarding colorectal dysplasia in IBD. Further investigation of additional resources and prospective evaluation in real-world settings are warranted.

Microbiome changes under enteral deprivation are dynamic and dependent on intestinal location.

BACKGROUND: The microbiome has a pivotal role in intestinal health, and nutrition has a major role shaping its structure. Enteral deprivation, in which no oral/enteral nutrition is administered, is common in hospitalized/gastrointestinal patients. The dynamics that enteral deprivation exerts on the microbial community, specifically in the small intestine, are not well understood. METHODS: Enteral deprivation was modeled with exclusive parenteral nutrition (EPN) mice. Mice were allocated to receive either EPN or saline and chow (control) and euthanized after 0, 2, 4, or 6 days. DNA was extracted from jejunum, ileum, and colon content. 16S sequencing was used to compare changes in microbial communities between groups. Functional pathways were predicted using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States. RESULTS: EPN-treated mice showed community changes throughout the intestine. Beta diversity in colon showed clear separation between the groups (Bray-Curtis, P < 0.001). Time-dependent dynamics were seen in ileal but not jejunal samples. Alpha diversity was lower in the colon of EPN mice compared with control/baseline mice (Chao1, P < 0.01) but not in ileum/jejunum. Progressive loss of single-taxon domination was seen, most notably in the small intestine. This was accompanied by increases/decreases in specific taxa. A clear separation was seen in the functional capacity of the community between fed and enterally deprived mice at the ileum and colon, which was observed early on. CONCLUSIONS: Enteral deprivation disturbs the microbial community in a spatial and dynamic manner. There should be further focus on studying the effect of these changes on the host.

Microbiota-mediated effects of Parkinson's disease medications on Parkinsonian non-motor symptoms in male transgenic mice.

Parkinson's disease (PD) is characterized by motor symptoms and a loss of dopaminergic neurons, as well as a variety of non-motor symptoms, including constipation, depression, and anxiety. Recently, evidence has also accumulated for a link between gut microbiota and PD. Most PD patients are on dopamine replacement therapy, primarily a combination of L-DOPA and carbidopa; however, the effect of these medications on the microbiota and non-motor symptoms in PD is still unclear. In this study, we explored the effects of chronic oral treatment with L-DOPA plus carbidopa (LDCD) on the gut microbiota and non-motor symptoms in males of a transgenic mouse model of PD (dbl-PAC-Tg(SNCAA53T);Snca-/-). To further test whether the effects of these PD medications were mediated by the gut microbiota, oral antibiotic treatment (Abx; vancomycin and neomycin) was included both with and without concurrent LDCD treatment. Post-treatment, the gastrointestinal, motor, and behavioral phenotypes were profiled, and fecal, ileal, and jejunal samples were analyzed for gut microbiota composition by 16S sequencing. LDCD treatment was found to improve symptoms of constipation and depression in this model, concurrent with increases in Turicibacter abundance in the ileum. Abx treatment worsened the symptoms of constipation, possibly through decreased levels of short-chain fatty acids and disrupted gut barrier function. LDCD + Abx treatment showed an interaction effect on behavioral symptoms that was also associated with ileal Turicibacter levels. This study demonstrates that, in a mouse model, PD medications and antibiotics affect PD-related non-motor symptoms potentially via the gut microbiota.IMPORTANCEThe motor symptoms of Parkinson's disease (PD) are caused by a loss of dopamine-producing neurons and are commonly treated with dopamine replacement therapy (L-DOPA plus carbidopa). PD has also been associated with altered gut microbiota composition. However, the effects of these PD medications on PD-related non-motor symptoms and the gut microbiota have not been well characterized. This study uses a transgenic mouse model of PD to help resolve medication-induced microbiota alterations from those that are potentially disease relevant within a PD context, and explores how long-term treatment may interact with the gut microbiota to impact non-motor symptoms.

A personalized network framework reveals predictive axis of anti-TNF response across diseases.

Personalized treatment of complex diseases has been mostly predicated on biomarker identification of one drug-disease combination at a time. Here, we use a computational approach termed Disruption Networks to generate a data type, contextualized by cell-centered individual-level networks, that captures biology otherwise overlooked when performing standard statistics. This data type extends beyond the "feature level space", to the "relations space", by quantifying individual-level breaking or rewiring of cross-feature relations. Applying Disruption Networks to dissect high-dimensional blood data, we discover and validate that the RAC1-PAK1 axis is predictive of anti-TNF response in inflammatory bowel disease. Intermediate monocytes, which correlate with the inflammatory state, play a key role in the RAC1-PAK1 responses, supporting their modulation as a therapeutic target. This axis also predicts response in rheumatoid arthritis, validated in three public cohorts. Our findings support blood-based drug response diagnostics across immune-mediated diseases, implicating common mechanisms of non-response.

The Effect of Nutrient Deprivation on Early Life Small Intestinal Mucosal Microbiome and Host Proteome.

BACKGROUND: Nutrition plays a vital role in shaping the intestinal microbiome. However, many hospitalized children undergo periods of fasting during medical treatment. Changes to the small intestinal microbiota in early life in the setting of enteral deprivation have not been well described. OBJECTIVE: The aim of this study was to investigate the impact of enteral deprivation on the small intestinal mucosal microbiome and to identify factors that shape this interaction in infancy. METHODS: Intestinal biopsies were collected from proximal (fed) and distal (unfed) small bowel at the time of ostomy closure in children with a small intestinal enterostomy. Mucosal and luminal microbiome comparisons were performed including ß-diversity and differential abundance and correlations with clinical factors were analyzed. Host proteomics were compared between fed and unfed samples and correlated with microbiome parameters. Finally, microbial results were validated in another cohort of pediatric patients. RESULTS: Samples from 13 children (median age 84 d) were collected. Mucosal microbiome communities in the fed and unfed segments were strikingly similar [paired UniFrac distance (ß-diversity)], whereas luminal effluent differed significantly from fed samples (PERMANOVA, P = 0.003). Multivariate analysis revealed patient as the strongest predictor of the UniFrac distance. Environmental variables did not influence the intrapatient microbial dissimilarity. Host proteomics were similar intrapatient (paired fed-unfed Euclidian distance) and showed a correlation with the UniFrac distance (Spearman rho = 0.71, P < 0.001). Specific proteins and functional clusters were significantly different between paired samples, including lipid metabolism and intracellular trafficking, whereas no difference was seen in innate immune proteins. The microbiome results were validated in a different cohort with similar characteristics. CONCLUSION: We found the host to be the most dominant factor in the structure of the early life small intestinal mucosal microbiome. Nutrient deprivation was associated with specific changes in the host proteome. Further research is needed to better understand this host-microbe-nutrition interaction.

Multiple micronutrient deficiencies in early life cause multi-kingdom alterations in the gut microbiome and intrinsic antibiotic resistance genes in mice.

Globally, ~340 million children suffer from multiple micronutrient deficiencies, accompanied by high pathogenic burden and death due to multidrug-resistant bacteria. The microbiome is a reservoir of antimicrobial resistance (AMR), but the implications of undernutrition on the resistome is unclear. Here we used a postnatal mouse model that is deficient in multiple micronutrients (that is, zinc, folate, iron, vitamin A and vitamin B12 deficient) and shotgun metagenomic sequencing of faecal samples to characterize gut microbiome structure and functional potential, and the resistome. Enterobacteriaceae were enriched in micronutrient-deficient mice compared with mice fed an isocaloric experimental control diet. The mycobiome and virome were also altered with multiple micronutrient deficiencies including increased fungal pathogens such as Candida dubliniensis and bacteriophages. Despite being antibiotic naïve, micronutrient deficiency was associated with increased enrichment of genes and gene networks encoded by pathogenic bacteria that are directly or indirectly associated with intrinsic antibiotic resistance. Bacterial oxidative stress was associated with intrinsic antibiotic resistance in these mice. This analysis reveals multi-kingdom alterations in the gut microbiome as a result of co-occurring multiple micronutrient deficiencies and the implications for antibiotic resistance.

Multiple micronutrient deficiencies alter energy metabolism in host and gut microbiome in an early-life murine model.

Introduction: Micronutrients perform a wide range of physiological functions essential for growth and development. However, most people still need to meet the estimated average requirement worldwide. Globally, 2 billion people suffer from micronutrient deficiency, most of which are co-occurring deficiencies in children under age five. Despite decades of research, animal models studying multiple micronutrient deficiencies within the early-life period are lacking, which hinders our complete understanding of the long-term health implications and may contribute to the inefficacy of some nutritional interventions. Evidence supporting the Developmental Origins of Health and Disease (DOHaD) theory demonstrates that early-life nutritional deficiencies carry life-long consequences mediated through various mechanisms such as abnormal metabolic programming, stunting, altered body composition, and the gut microbiome. However, this is largely unexplored in the multiple micronutrient deficient host. Methods: we developed a preclinical model to examine undernutrition's metabolic and functional impact on the host and gut microbiome early in life. Three-week-old weanling C57BL/6N male mice were fed a low-micronutrient diet deficient in zinc, folate, iron, vitamin A, and vitamin B12 or a control diet for 4-weeks. Results: Our results showed that early-life multiple micronutrient deficiencies induced stunting, altered body composition, impaired glucose and insulin tolerance, and altered the levels of other micronutrients not depleted in the diet within the host. In addition, functional metagenomics profiling and a carbohydrate fermentation assay showed an increased microbial preference for simple sugars rather than complex ones, suggestive of a less developed microbiome in the low-micronutrient-fed mice. Moreover, we found that a zinc-only deficient diet was not sufficient to induce these phenotypes, further supporting the importance of studying co-occurring deficiencies. Discussion: Together, these findings highlight a previously unappreciated role of early-life multiple micronutrient deficiencies in shaping the metabolic phenome of the host and gut microbiome through altered glucose energy metabolism, which may have implications for metabolic disease later in life in micronutrient-deficient survivors.

Association of Antibiotic Use with Durability of Biologic Agents in Inflammatory Bowel Disease: a Report from the epi-IIRN.

BACKGROUND: Different antibiotic classes were reported to have variable effects on immunogenicity towards anti-tumour necrosis factor [TNF] agents. However, the impact of antibiotic administration on biologic treatment durability was not investigated. We aimed to assess the association between antibiotic treatment and persistence of different classes of biologic therapy in inflammatory bowel disease [IBD] patients. METHODS: Data from the epi-IIRN, a nationwide registry of all Israeli IBD patients were analysed. All patients who filled a prescription of either infliximab, adalimumab, vedolizumab, or ustekinumab, were included. Treatment cessation was defined as drug discontinuation of at least 6 months. Macrolides, cephalosporins, fluoroquinolones, and penicillins with beta-lactamase inhibitors were selected as primary exposure variables. Survival analysis was performed using marginal structural models for each drug separately. RESULTS: In all 13 513 IBD patients, with a total of 39 600 patient-years, were included. Significant differences of overall treatment persistence were demonstrated, with highest persistence rates for ustekinumab and the lowest for infliximab treatment. Macrolides were found to be significantly associated with reduced risk of infliximab cessation (adjusted hazard ratio [aHR] 0.72, 95% CI 0.62-0.89]. Fluoroquinolones and cephalosporins were associated with an elevated risk of adalimumab treatment cessation [aHR 1.33, 95% CI 1.22-1.46; and aHR 1.20, 95% CI 1.08-1.34, respectively]. No significant effects of the studied antibiotics were observed in ustekinumab and vedolizumab users. CONCLUSIONS: Specific antibiotic classes are associated with duration of anti-TNF treatment, but not with durability of vedolizumab or ustekinumab treatments. Further research is required to study the effect of specific antibiotics on response to biologics.

The Association Between Low Body-Mass Index and Serious Post-endoscopic Adverse Events.

BACKGROUND: Low body mass index (LBMI) was associated with longer colonoscopy procedure time and procedural failure, and commonly considered to be a risk factor for post-endoscopic adverse events, but evidence is lacking. AIM: We aimed to assess the association between serious adverse events (SAE) and LBMI. METHODS: A single center retrospective cohort of patients with LBMI (BMI ≤ 18.5) undergoing an endoscopic procedure was matched (1:2 ratio) to a comparator group (19 ≤ BMI ≤ 30). Matching was performed according to age, gender, inflammatory bowel disease or malignancy diagnoses, previous abdomino-pelvic surgery, anticoagulation therapy and type of endoscopic procedure. The primary outcome was SAE, defined as bleeding, perforation, aspiration or infection, following the procedure. The attribution between each SAE and the endoscopic procedure was determined. Secondary outcomes included each complication alone and endoscopy-attributed SAEs. Univariate and multivariate analyses were applied. RESULTS: 1986 patients were included (662 in the LBMI group). Baseline characteristics were mostly similar between the groups. The primary outcome occurred in 31/662 (4.7%) patients in the LBMI group and in 41/1324 (3.1%) patients in the comparator group (p = 0.098). Among the secondary outcomes, infections (2.1% vs. 0.8%, p = 0.016) occurred more frequently in the LBMI group. Multivariate analysis revealed an association between SAE and LBMI (OR 1.76, 95% CI 1.07-2.87), male gender, diagnosis of malignancy, high-risk endoscopic procedure, age > 40 years, and ambulatory setting. CONCLUSION: Low BMI was associated with higher post-endoscopic serious adverse events. Special attention is required when performing endoscopy in this fragile patient population.

Effects of Gut Microbiota Alterations on Motor, Gastrointestinal, and Behavioral Phenotype in a Mouse Model of Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) is a multi-system disorder consisting of not only classic motor symptoms but also a variety of non-motor symptoms including gastrointestinal (GI) dysfunction and mood disorders. The gut microbiota has been suggested to play a role in modulating PD motor and non-motor features, although the causality and mechanisms behind these proposed interactions remains largely understudied. OBJECTIVE: In this study, we aimed to provide in-depth characterization of an established mouse model of PD (transgenic (TG) SNCA A53T) and experimentally address how changes to the gut microbiota impact the PD-like phenotype. METHODS: We profiled the PD-like phenotype of transgenic mice through a panel of motor, GI, and behavioral tests. We then investigated how antibiotic treatment or gut microbial community transfer (via cohousing with wild-type mice) impacted the PD-like phenotype. RESULTS: We found that this mouse model demonstrated early (6 weeks of age) motor symptoms when compared to a wild-type control mouse strain. Transgenic mice also exhibited early GI dysfunction, as well as behavioral alterations, including reduced anxiety-like behavior, and increased depression-like and apathy-like behavior. Compared to wild-type mice, the transgenic fecal microbiota was less diverse and compositionally distinct. Interestingly, drastic alterations to the gut microbiota, through antibiotic treatment or cohousing with wild-type mice, had a minimal effect on the motor, GI, and behavioral phenotype of transgenic mice. CONCLUSION: We concluded that this mouse model effectively recapitulates motor and non-motor features of PD; however, the gut microbiota appears to exhibit a minor impact on the pathophysiology of this PD model.

Risk Factors for Bacteremia After Endoscopic Procedures in Hospitalized Patients With a Focus on Neutropenia.

BACKGROUND: The risk for bacteremia following endoscopic procedures varies among studies. A low neutrophil count is considered as a risk factor. OBJECTIVE: To assess risk factors for bacteremia following endoscopic procedures, focusing on neutropenia. METHODS: This was a retrospective analysis of all inpatients undergoing endoscopic procedures between 2005 and 2018 with neutrophil count taken within 72 hours before the procedure in a tertiary center in Israel. The primary outcome was positive blood culture within 48 hours following the procedure of bacteria that was not cultured before. Risk factors for bacteremia were assessed and multivariate logistic regression models were built. In neutropenic patients, comparator groups were used to assess the risk related to the procedure and neutropenia. RESULTS: Of 13,168 patients included, postprocedural bacteremia was recorded in 103 (0.8%). Neutropenia, low albumin level, male gender, older age, preprocedure fever, and admitting department were associated with increased risk for bacteremia in both univariate and multivariate analyses. A multivariate model including these factors was found to be predictive of bacteremia (area under the curve 0.82; 95% confidence interval, 0.78-0.88). In neutropenic patients, the risk of postendoscopic bacteremia (4.2%) was not significantly different compared with neutropenic patients undergoing bronchoscopy (1.8%, P=0.14) or from the rate of bacteremia-to-neutropenic episodes ("background risk") in neutropenic patients in general (6.3%, P=0.33). CONCLUSIONS: Postendoscopic bacteremia is a rare event among inpatients. Although neutropenia was found to be a risk factor for bacteremia, it was not higher than the background risk in these patients. Models highly predictive of bacteremia were developed and should be validated.

The effect of indirect calorimetry guided isocaloric nutrition on mortality in critically ill patients-a systematic review and meta-analysis.

Indirect calorimetry (IC)-guided nutrition might positively affect the clinical outcome of critically ill patients. In this systematic review and meta-analysis, our objective was to assess the benefit of isocaloric nutrition guided by IC, compared to hypocaloric nutrition, for critically ill patients admitted to the intensive care unit (ICU). We performed a systematic review of all randomized controlled trials published through January 2021, assessing the benefit of isocaloric nutrition guided by IC. The primary outcome was 28-day all-cause mortality. Secondary outcomes were ICU and 90-day all-cause mortality, rate of nosocomial infections, and adverse events. Four trials evaluating 1052 patients were included. Patients treated with isocaloric nutrition had a lower 28-day mortality rate (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.63-0.99, P = 0.04). No between-group difference was found in ICU and 90-day mortality (RR 0.92, 95% CI 0.68-1.23, P = 0.56 and RR 0.88, 95% CI 0.72-1.07; P = 0.2, respectively) and in the rate of nosocomial infections (RR 1.15, 95% CI 0.77-1.72, P = 0.51). A pooled analysis of studies that evaluated the benefit of isocaloric nutrition guided by IC, for critically ill patients in the ICU, has shown reduced 28-day mortality. However, there was no difference in 90-day mortality and nosocomial infection rate.

Omitting Ciprofloxacin Prophylaxis in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation and Its Impact on Clinical Outcomes and Microbiome Structure.

Fluoroquinolone prophylaxis during allogeneic hematopoietic stem cell transplantation (allo-HSCT) reduces bloodstream infections. However, this practice affects the gut microbiome and potentially increases dysbiosis, which is closely related to transplantation outcomes, and lower gastrointestinal (GI) tract acute graft-versus-host disease (GVHD). This study assessed the impact of omitting ciprofloxacin prophylaxis on GI GVHD, clinical outcomes, and microbiome composition in patients undergoing allo-HSCT. In this single-center, retrospective study comprising recipients of allo-HSCT performed between 2018 and 2020, routine ciprofloxacin prophylaxis (the exposure variable) was stopped in December 2018. The primary outcome was acute lower GI GVHD within 100 days post-transplantation; secondary outcomes were 1-year overall survival, nonrelapse mortality, relapse, and overall acute GVHD. Outcomes were compared using univariate and multivariate analyses and Kaplan-Meier/competing-risk analyses. Sequential stool samples were collected prospectively from a subpopulation of recipients, and the microbiome composition was analyzed. Seventy-five of the 129 patients (58.1%) received prophylactic ciprofloxacin treatment. Baseline characteristics did not differ between the 2 study groups: patients with ciprofloxacin prophylaxis and those without ciprofloxacin prophylaxis. The rate of lower GI GVHD also did not differ between the 2 groups (24% versus 18.5%; P = .597). None of the secondary outcomes was significantly different between the 2 groups in univariate, multivariate, and time-to-event analyses. In addition, microbiome analysis in a subpopulation of 22 patients did not reveal any significant between-group difference in alpha or beta diversity. Omitting prophylactic ciprofloxacin during allo-HSCT did not affect microbiome composition, lower GI-GVHD rate, or other significant clinical outcomes. The use of prophylactic antibiotics in this setting should be evaluated further.

Differential Serum-intestinal Dynamics of Infliximab and Adalimumab in Inflammatory Bowel Disease Patients.

BACKGROUND AND AIMS: Therapeutic drug monitoring is used to guide anti-tumour necrosis factor [TNF] therapy. However, the associations between serum drug levels [SDL], TNF-bound, and free anti-TNF in the target tissue are incompletely defined. We aimed to assess the interactions between these parameters in inflammatory bowel disease [IBD] patients. METHODS: ENZYME-LINKED IMMUNOSORBENT: assays [ELISA assays] were used to detect free drug and TNF-drug complexes in intestinal tissues. Concurrent SDL, anti-drug antibodies [ADA], pharmacotherapy, clinical response, endoscopic appearance, and histological severity were determined. Comparisons between anti-TNFs and paired inflamed/non-inflamed tissue were performed. Variables were correlated and potential interactions detected using multivariate analysis. RESULTS: A total of 95 biopsies taken from 49 anti-TNF treated IBD patients [26 receiving infliximab and 23 adalimumab] were studied. Free drug levels were higher in inflamed compared with non-inflamed paired specimens. Tissue free-drug and TNF-drug complexes levels were higher in adalimumab-treated patients. In adalimumab-treated patients, SDL were correlated with free drug, but not TNF-drug complex levels, in both inflamed and non-inflamed segments. In infliximab-treated patients, higher SDL were associated with the presence of tissue free drug in both inflamed and non-inflamed segments, whereas TNF-drug complexes were mostly detected in non-inflamed but not in inflamed tissue. In the presence of ADA, neither free drug nor TNF-infliximab complexes were measured in the tissue. Tissue levels did not correlate well with clinical, endoscopic, or histological scores. CONCLUSIONS: SDL correlated with tissue free drug levels; however, different dynamics were observed for TNF-drug complex levels. Infliximab and adalimumab tissue drug dynamics differ. Better understanding of these interactions may allow future therapeutic optimisation.

Oral Capsulized Fecal Microbiota Transplantation for Eradication of Carbapenemase-producing Enterobacteriaceae Colonization With a Metagenomic Perspective.

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) infections lead to considerable morbidity and mortality. We assessed the potential of fecal microbiota transplantation (FMT) to eradicate CPE carriage and aimed to explain failure or success through microbiome analyses. METHODS: In this prospective cohort study, all consenting eligible CPE carriers received oral capsulized FMT for 2 days. Primary outcome was CPE eradication at 1 month, defined by 3 consecutive negative rectal swabs, the last also negative for carbapenemase gene by polymerase chain reaction. Comprehensive metagenomics analysis of the intestinal microbiome of donors and recipients before and after FMT was performed. RESULTS: Fifteen CPE carriers received FMT, 13 of whom completed 2 days of treatment. CPE eradication at 1 month was successful in 9/15 and 9/13, respectively. Bacterial communities showed significant changes in both beta and alpha diversity metrics among participants who achieved CPE eradication that were not observed among failures. Post-FMT samples' beta-diversity clustered according to the treatment outcome, both in taxonomy and in function. We observed a significant decrease in beta diversity in participants who received post-FMT antibiotics. Enterobacteriaceae abundance decreased in post-FMT samples of the responders but increased among failures. Functionally, a clear demarcation between responders (who were similar to the donors) and failures was shown, driven by antimicrobial resistance genes. CONCLUSIONS: Our study provides the biological explanation for the effect of FMT against CPE carriage. Decolonization of CPE by FMT is likely mediated by compositional and functional shifts in the microbiome. Thus, FMT might be an efficient strategy for sustained CPE eradication. CLINICAL TRIALS REGISTRATION: NCT03167398.

New-Onset of Crohn's Disease Is Associated with Antistreptolysin O Positive Titers.

OBJECTIVE: Different infectious agents have been presumed to be candidates acting as an etiologic factor or trigger of Crohn's disease (CD). Group A Streptococcus (GAS) is a common human infection agent that can also trigger post-infectious immune-mediated conditions. The current study aimed to examine whether the immunogenic activity induced by GAS may trigger new-onset of CD. METHODS: Data for antistreptolysin O (ASO) level, throat culture for GAS, and history of streptococcal infection were collected from 91 patients with CD that were divided into three groups including; new-onset CD, CD in remission and active CD. The data were compared with the control group. RESULTS: All participants had negative results of throat culture for GAS and had no history of documented streptococcal infection in the past year. Our results indicate that new-onset CD, but not CD in remission or active CD, is associated with significantly increased positive ASO compared to controls. Half of the patients in the new-onset CD group were ASO positive, which was significantly higher compared to the control group in a univariant (OR: 4.00; 95% CI 1.27-12.58; P=0.02) and multivariant analysis (OR: 4.41; 95% CI 1.35-14.37; P=0.014). CONCLUSION: Our study is the first to focus on ASO levels in patients with CD and to demonstrate a significant association between ASO and new-onset of CD. Large prospective randomized controlled studies are needed to confirm the validity of this data and to further clarify the clinical significance of our findings.

Does early corticosteroid therapy affect prognosis in IBD patients hospitalized with Clostridioides difficile infection?

BACKGROUND: Corticosteroids (CS) therapy to Clostridioides difficile infection (CDI) in inflammatory bowel disease (IBD) flares may worsen CDI outcomes. AIM: Assess the impact of early CS exposure on outcomes of IBD patients diagnosed with CDI. METHODS: Retrospective study of IBD patients admitted with first-time CDI between 2002 and 2018. Comparisons were made based on CS exposure 48 h from admission. Patients were further subdivided to 5 groups based on CS-antibiotics temporal exposure. The primary outcome was all-cause mortality or colectomy within 3 months. Secondary outcomes were colectomy and mortality rates at 1 year, length of stay, readmissions, bacteremia, and diarrhea improvement by day 7/discharge. Cox proportional hazard model and Kaplan-Meier curves were used to assess the effects on survival. Logistic and ordinal regressions were used to assess primary and secondary outcomes. RESULTS: One hundred thirteen patients (64 CD, 46 UC, and 3 IBDU) were included, 82 (72.5%) received early CS. At baseline, CRP was significantly lower and albumin was higher in the group not exposed to early CS. At 3 months, 4 (4.8%) patients required colectomy and 6 (5.8%) died (p = NS). Length of stay was significantly reduced among patients not exposed to early CS. All other endpoints were not associated with CS exposure. In subgroup analysis, the primary outcome was not significantly different among the sub-groups. Mortality rate at 1 year was significantly lower in patients who did not receive antibiotics for CDI. CONCLUSION: Early CS therapy in IBD patients hospitalized with CDI is not associated with worse clinical outcomes. However, additional prospective research is required.

Infliximab-Tumor Necrosis Factor Complexes Elicit Formation of Anti-Drug Antibodies.

BACKGROUND & AIMS: Some patients develop anti-drug antibodies (ADAs), which reduce the efficacy of infliximab, a monoclonal antibody against tumor necrosis factor (TNF), in the treatment of immune-mediated diseases, including inflammatory bowel diseases. ADAs arise inconsistently, and it is not clear what factors determine their formation. We investigated features of the immune system, the infliximab antibody, and its complex with TNF that might contribute to ADA generation. METHODS: C57BL/6 mice were given injections of infliximab and recombinant human TNF or infliximab F(ab')2 fragments. Blood samples were collected every 2-3 days for 2 weeks and weekly thereafter for up to 6 weeks; infliximab-TNF complexes and ADAs were measured by enzyme-linked immunosorbent assay (ELISA). Intestinal biopsy and blood samples were obtained from patients having endoscopy who had received infliximab therapy for inflammatory bowel diseases; infliximab-TNF complexes were measured with ELISA. Infliximab-specific plasma cells were detected in patient tissue samples by using mass cytometry. We studied activation of innate immune cells in peripheral blood mononuclear cells (PBMCs) from healthy donors incubated with infliximab or infliximab-TNF complexes; toll-like receptors (TLRs) were blocked with antibodies, endocytosis was blocked with the inhibitor PitStop2, and cytokine expression was measured by real-time polymerase chain reaction and ELISAs. Uptake of infliximab and infliximab-TNF complexes by THP-1 cells was measured with confocal microscopy. RESULTS: Mice given increasing doses of infliximab produced increasing levels of ADAs. Blood samples from mice given injections of human TNF and infliximab contained infliximab-TNF complexes; complex formation was associated with ADA formation with an area under the curve of 0.944 (95% confidence interval, 0.851-1.000; P = .003). Intestinal tissues from patients, but not blood samples, contained infliximab-TNF complexes and infliximab-specific plasma cells. Incubation of PBMCs with infliximab-TNF complexes resulted in a 4.74-fold increase in level of interleukin (IL) 1ß (IL1B) messenger RNA (P for comparison = .005), increased IL1B protein secretion, and a 2.69-fold increase in the expression of TNF messenger RNA (P for comparison = 0.013) compared with control PBMCs. Infliximab reduced only IL1B and TNF expression. Antibodies against TLR2 or TLR4 did not block the increases in IL1B or TNF expression, but endocytosis was required. THP-1 cells endocytosed higher levels of infliximab-TNF complexes than infliximab alone. CONCLUSIONS: In mice, we found ADA formation to increase with dose of infliximab given and concentration of infliximab-TNF complexes detected in blood. Based on studies of human intestinal tissues and blood samples, we propose that infliximab-TNF complexes formed in the intestine are endocytosed by and activate innate immune cells, which increase expression of IL1B and TNF and production of antibodies against the drug complex. It is therefore important to optimize the infliximab dose to a level that is effective but does not activate an innate immune response against the drug-TNF complex.

Cell-centred meta-analysis reveals baseline predictors of anti-TNFα non-response in biopsy and blood of patients with IBD.

OBJECTIVE: Although anti-tumour necrosis factor alpha (anti-TNFα) therapies represent a major breakthrough in IBD therapy, their cost-benefit ratio is hampered by an overall 30% non-response rate, adverse side effects and high costs. Thus, finding predictive biomarkers of non-response prior to commencing anti-TNFα therapy is of high value. DESIGN: We analysed publicly available whole-genome expression profiles of colon biopsies obtained from multiple cohorts of patients with IBD using a combined computational deconvolution-meta-analysis paradigm which allows to estimate immune cell contribution to the measured expression and capture differential regulatory programmes otherwise masked due to variation in cellular composition. Insights from this in silico approach were experimentally validated in biopsies and blood samples of three independent test cohorts. RESULTS: We found the proportion of plasma cells as a robust pretreatment biomarker of non-response to therapy, which we validated in two independent cohorts of immune-stained colon biopsies, where a plasma cellular score from inflamed biopsies was predictive of non-response with an area under the curve (AUC) of 82%. Meta-analysis of the cell proportion-adjusted gene expression data suggested that an increase in inflammatory macrophages in anti-TNFα non-responding individuals is associated with the upregulation of the triggering receptor expressed on myeloid cells 1 (TREM-1) and chemokine receptor type 2 (CCR2)-chemokine ligand 7 (CCL7) -axes. Blood gene expression analysis of an independent cohort, identified TREM-1 downregulation in non-responders at baseline, which was predictive of response with an AUC of 94%. CONCLUSIONS: Our study proposes two clinically feasible assays, one in biopsy and one in blood, for predicting non-response to anti-TNFα therapy prior to initiation of treatment. Moreover, it suggests that mechanism-driven novel drugs for non-responders should be developed.