Effectiveness of Bile Acid Sequestrants in Microscopic Colitis and Utility of Bile Acid Testing: A Systematic Review and Meta-analysis.

INTRODUCTION: Bile acid sequestrants (BAS) are an option for microscopic colitis (MC) refractory or intolerant to budesonide. There are inconsistent data on the prevalence of bile acid malabsorption (BAM) and utility of bile acid testing in MC. The aim of this systematic review and meta-analysis was to evaluate these outcomes. METHODS: A systematic search of randomized control trials and observational studies of adults with MC treated with BAS was conducted using MEDLINE, Embase, Cochrane, and Scopus from inception to January 22, 2024. Data were extracted on (i) prevalence of BAM, (ii) clinical response and adverse events, and (iii) recurrence after BAS discontinuation. Data were pooled using random-effects models to determine weighted pooled estimates and 95% confidence intervals (CIs). RESULTS: We included 23 studies (1 randomized control trial, 22 observational), with 1,011 patients with MC assessed for BAM and 771 treated with BAS. The pooled prevalence of BAM was 34% (95% CI 0.26-0.42, I2 = 81%). The pooled response rate with BAS induction for all patients with MC, irrespective of BAM, was 62% (95% CI 0.55-0.70, I2 = 71%). There was a higher pooled response rate in patients with BAM compared with those without BAM ( P < 0.0001). The pooled rate of BAS-related adverse effects was 9% (95% CI 0.05-0.14, I2 = 58%). DISCUSSION: One-third of patients with MC had BAM, and almost two-thirds of all patients responded to BAS with limited side effects. Patients with MC and BAM were more likely to respond to therapy, supporting the value of bile acid testing.

Psychiatric disorders among 5800 patients with microscopic colitis: A nationwide population-based matched cohort study.

INTRODUCTION: Microscopic colitis (MC) is an inflammatory condition of the large intestine. Primarily diagnosed in middle-aged and older adults, the incidence of the disease has increased markedly during the past decades. While MC is associated with a reduced quality of life, large-scale studies on the association with future psychiatric disorders are lacking. METHODS: We conducted a nationwide matched cohort study in Sweden from 2006 to 2021. Through a nationwide histopathology database (the ESPRESSO study), we identified 5,816 patients with a colorectal biopsy consistent with MC. These patients were matched with 21,509 reference individuals from the general population, all of whom with no previous record of psychiatric disorders. RESULTS: From 2006-2021, 519 patients with MC (median age 64.4 years (interquartile range = 49.5-73.3)) and 1,313 reference individuals were diagnosed with psychiatric disorders (9.9 vs. 6.5 events per 1,000 person-years), corresponding to one extra case of psychiatric disorder in 29 patients with MC over 10 years. After adjustments, the hazard ratio (HR) for psychiatric disorders was 1.57 (95% confidence interval [CI]=1.42-1.74). We found significantly elevated estimates up to 10 years after MC diagnosis and a trend towards higher risk with increasing age. Specifically, we observed increased risks for unipolar depression, anxiety disorders, stress-related disorders, substance abuse, and suicide attempts.In sibling-controlled analysis the aHR was 1.76 (95%CI=1.44-2.15). CONCLUSION: Patients with MC are at increased risk of incident psychiatric disorders compared to the general population.

Prevalence of Comorbid Factors in Patients With Recurrent Clostridioides difficile Infection in ECOSPOR III, a Randomized Trial of an Oral Microbiota-Based Therapeutic.

BACKGROUND: Although comorbidities are risk factors for recurrent Clostridioides difficile infection (rCDI), many clinical trials exclude patients with medical conditions such as malignancy or immunosuppression. In a phase 3, double-blind, placebo-controlled, randomized trial (ECOSPOR III), fecal microbiota spores, live (VOWST, Seres Therapeutics; hereafter "VOS," formerly SER-109), an oral microbiota therapeutic, significantly reduced the risk of rCDI at week 8. We evaluated the efficacy of VOS compared with placebo in patients with comorbidities and other risk factors for rCDI. METHODS: Adults with rCDI were randomized to receive VOS or placebo (4 capsules daily for 3 days) following standard-of-care antibiotics. In this post hoc analysis, the rate of rCDI through week 8 was assessed in VOS-treated participants compared with placebo for subgroups including (i) Charlson comorbidity index (CCI) score category (0, 1-2, 3-4, ≥5); (ii) baseline creatinine clearance (<30, 30-50, >50 to 80, or >80 mL/minute); (iii) number of CDI episodes, inclusive of the qualifying episode (3 and ≥4); (iv) exposure to non-CDI-targeted antibiotics after dosing; and (v) acid-suppressing medication use at baseline. RESULTS: Of 281 participants screened, 182 were randomized (59.9% female; mean age, 65.5 years). Comorbidities were common with a mean overall baseline age-adjusted CCI score of 4.1 (4.1 in the VOS arm and 4.2 in the placebo arm). Across all subgroups analyzed, VOS-treated participants had a lower relative risk of recurrence compared with placebo. CONCLUSIONS: In this post hoc analysis, VOS reduced the risk of rCDI compared with placebo, regardless of baseline characteristics, concomitant medications, or comorbidities.

Bile Acid Sequestrants in Microscopic Colitis: Clinical Outcomes and Utility of Bile Acid Testing.

BACKGROUND & AIMS: Bile acid sequestrants (BAS) may be a treatment in microscopic colitis (MC), but efficacy data are limited. We evaluated the effectiveness of BAS in MC and assessed the utility of bile acid testing to predict response. METHODS: Adults with MC treated with BAS (2010-2020) at Mayo Clinic were identified. Bile acid malabsorption was defined by elevated serum 7⍺-hydroxy-4-cholesten-3-one or by fecal testing using previously validated cutoffs. Response was defined at 12 ± 4 weeks after BAS initiation as: complete (resolution of diarrhea), partial (≥50% improvement in diarrhea), nonresponse (<50% improvement), and intolerance (discontinuation due to side effects). Logistic regression was used to identify predictors of response to BAS. RESULTS: We identified 282 patients (median age, 59 years [range, 20-87 years]; 88.3% women) with median follow-up of 4.5 years (range, 0.4-9.1 years). Patients were treated with the following BAS: 64.9% cholestyramine, 21.6% colesevelam, and 13.5% colestipol. Clinical outcomes were: 49.3% complete response, 16.3% partial response, 24.8% nonresponse, and 9.6% intolerance. There were no differences in outcomes between those on BAS alone or BAS combined with other medications (P = .98). The dose of BAS was not associated with response (P = .51). Bile acid testing was done in 31.9% of patients, and 56.7% were positive. No predictors of response to BAS were identified. After BAS discontinuation, 41.6% had recurrence at a median of 21 weeks (range, 1-172 weeks). CONCLUSION: In one of the largest cohorts evaluating BAS treatment in MC, nearly two-thirds had a partial or complete response. Additional research is needed to determine the role of BAS and bile acid malabsorption in MC.

Reduction in urinary tract infections in patients treated with fecal microbiota transplantation for recurrent Clostridioides difficile infection.

We performed an updated study to investigate the rates of urinary tract infections (UTIs) in patients with recurrent Clostridioides difficile infection (CDI) who received fecal microbiota transplantation (FMT) for CDI. We found a significant reduction in number of UTIs after FMT compared to patients who received antibiotics for CDI treatment. After FMT, we also observed a trend towards reduction of antibiotic resistance in organisms causing UTI.

Outcomes of Fecal Microbiota Transplantation for C. difficile Infection in Inflammatory Bowel Disease : A Systematic Review and Meta-analysis.

BACKGROUND: Fecal microbiota transplantation (FMT) is a safe and effective therapy for recurrent Clostridioides difficile infection (CDI). Data on FMT for CDI in patients with underlying inflammatory bowel disease (IBD) are emerging but conflicting. We performed a systematic review and meta-analysis to describe the efficacy and safety of FMT for CDI in IBD and its impact on IBD outcomes. METHODS: A systematic search of multiple databases including Embase, Scopus, and Web of Science was performed. Our primary analysis focused on pooled rate of CDI resolution after single and multiple FMTs in IBD patients. Additional analyses included rates of IBD-associated outcomes (flare, surgery, symptom improvement) after FMT. The random-effects model was used to calculate pooled rates. RESULTS: Among 457 adult patients, 363 had CDI resolution after first FMT with a pooled cure rate of 78% [95% confidence interval (CI): 73%-83%; I2 =39%]. Overall pooled rate cure rate with single and multiple FMTs was 88% (95% CI: 81%-94%; I2 =73%). The pooled rate of an IBD flare after FMT was 26.8% (95% CI: 22.5%-31.6%; I2 =9%) and of colectomy was 7.3% (95% CI: 4.7%-10.5%; I2 =56%). Among 141 pediatric patients, 106 had CDI resolution after first FMT with pooled cure rate of 78% (95% CI: 58%-93%; I2 =59%). Overall pooled cure rate with single and multiple FMTs was 77% (95% CI: 50%-96%; I2 =63%). The pooled rate of an IBD flare after FMT was 10.8% (95% CI: 5.7%-18.5% I2 =43%), and of colectomy was 10.3% (95% CI: 2.1%-30.2% I2 =23%). CONCLUSIONS: FMT appears to be a highly effective therapy for preventing recurrent CDI in patients with IBD. Patients who fail a single FMT may benefit from multiple FMTs.

Efficacy and Safety of Vedolizumab and Tumor Necrosis Factor Inhibitors in the Treatment of Steroid-refractory Microscopic Colitis: A Systematic Review and Meta-analysis.

BACKGROUND: Tumor necrosis factor (TNF-α) inhibitors and the α4ß7 integrin antagonist, vedolizumab, have been investigated as treatment options for patients with steroid-refractory microscopic colitis. AIMS: To evaluate the benefit of vedolizumab and TNF-α inhibitors in patients with steroid-refractory microscopic colitis. METHODS: Retrospective studies and case series involving patients with steroid-refractory MC who either received vedolizumab, adalimumab, or infliximab were eligible for inclusion. Pooled proportional meta-analyses were used to calculate the rate of clinical remission at induction, clinical response, maintenance of remission, histologic remission, and overall medication related adverse effects. Statistical analysis was performed in R using the metafor and meta packages. RESULTS: A total of 14 studies involving 164 patients were included. Pooled analysis showed a clinical remission rate of 63.5% [95% CI (0.483; 0.776), I2=43% P=0.08], 57.8% [95% CI (0.3895; 0.7571), I2=0%, P=0.7541], and 39.3% [95% CI (0.0814; 0.7492), I2=66%, P=0.02] for vedolizumab, infliximab, and adalimumab, respectively. The maintenance of remission rates were 65.9% [95% CI (0.389; 0.889), I2=67%, P=0.02], 45.3% [95% CI (0.1479; 0.7747), I2=0%, P=0.36] and 32.5% [95% CI (0.000; 0.8508), I2=53%, P=0.14] in patients who received vedolizumab, infliximab, and adalimumab, respectively. Rate of biological-related adverse events warranting discontinuation of therapy was 12.2%, 32.9%, and 23.0% for the vedolizumab, infliximab, and adalimumab groups, respectively. CONCLUSION: Vedolizumab and anti-TNF-α agents demonstrated a clinical benefit in the treatment of steroid-refractory microscopic colitis and with a tolerable safety profile. Future randomized controlled trials are needed to compare vedolizumab with TNF-α inhibitors and examine treatment effect on patients' quality of life.

Fidaxomicin treatment for Clostridioides difficile infection in patients with inflammatory bowel disease.

BACKGROUND AND AIM: Although fidaxomicin is an effective first-line treatment for Clostridioides difficile infection, it has not been well studied in patients with inflammatory bowel disease. We aimed to assess the effectiveness of fidaxomicin for the treatment of C. difficile infection in patients with inflammatory bowel disease. METHODS: This was a multicenter retrospective study of adults with inflammatory bowel disease and C. difficile infection treated with fidaxomicin with at least 3 months of follow up. The primary outcomes were treatment response, defined as resolution of C. difficile infection-attributed diarrhea and/or negative C. difficile infection stool test, and time to C. difficile infection recurrence after fidaxomicin. RESULTS: Thirty-three patients (median age 42 years; 60.6% female) were included. Most patients had ulcerative colitis (26, 78.8%), were receiving treatment with a biologic or small molecule medication (19, 57.6%), and had a prior episode of C. difficile infection (26, 78.8%, median 2 episodes, range 0-15). Fidaxomicin led to resolution of C. difficile infection in 20 (60.6%) patients, with 6/20 (30.0%) developing a recurrence at a median of 55 days. Most patients who failed to respond to fidaxomicin underwent fecal microbiota transplantation (10/13, 76.9%) with resolution. CONCLUSIONS: In this cohort of patients with inflammatory bowel disease and C. difficile infection, 60.6% responded to treatment with fidaxomicin. Of those who did not respond, fecal microbiota transplantation was an effective therapy.

VE303, a Defined Bacterial Consortium, for Prevention of Recurrent Clostridioides difficile Infection: A Randomized Clinical Trial.

Importance: The effect of rationally defined nonpathogenic, nontoxigenic, commensal strains of Clostridia on prevention of Clostridioides difficile infection (CDI) is unknown. Objective: To determine the efficacy of VE303, a defined bacterial consortium of 8 strains of commensal Clostridia, in adults at high risk for CDI recurrence. The primary objective was to determine the recommended VE303 dosing for a phase 3 trial. Design, Setting, and Participants: Phase 2, randomized, double-blind, placebo-controlled, dose-ranging study conducted from February 2019 to September 2021 at 27 sites in the US and Canada. The study included 79 participants aged 18 years or older who were diagnosed with laboratory-confirmed CDI with 1 or more prior CDI episodes in the last 6 months and those with primary CDI at high risk for recurrence (defined as aged ≥75 years or ≥65 years with ≥1 risk factors: creatinine clearance <60 mL/min/1.73 m2, proton pump inhibitor use, remote [>6 months earlier] CDI history). Interventions: Participants were randomly assigned to high-dose VE303 (8.0 × 109 colony-forming units [CFUs]) (n = 30), low-dose VE303 (1.6 × 109 CFUs) (n = 27), or placebo capsules (n = 22) orally once daily for 14 days. Main Outcomes and Measures: The primary efficacy end point was the proportion of participants with CDI recurrence at 8 weeks using a combined clinical and laboratory definition. The primary efficacy end point was analyzed in 3 prespecified analyses, using successively broader definitions for an on-study CDI recurrence: (1) diarrhea consistent with CDI plus a toxin-positive stool sample; (2) diarrhea consistent with CDI plus a toxin-positive, polymerase chain reaction-positive, or toxigenic culture-positive stool sample; and (3) diarrhea consistent with CDI plus laboratory confirmation or (in the absence of a stool sample) treatment with a CDI-targeted antibiotic. Results: Baseline characteristics were similar across the high-dose VE303 (n = 29; 1 additional participant excluded from efficacy analysis), low-dose VE303 (n = 27), and placebo (n = 22) groups. The participants' median age was 63.5 years (range, 24-96); 70.5% were female; and 1.3% were Asian, 1.3% Black, 2.6% Hispanic, and 96.2% White. CDI recurrence rates through week 8 (using the efficacy analysis 3 definition) were 13.8% (4/29) for high-dose VE303, 37.0% (10/27) for low-dose VE303, and 45.5% (10/22) for placebo (P = .006, high-dose VE303 vs placebo). Conclusions and Relevance: Among adults with laboratory-confirmed CDI with 1 or more prior CDI episodes in the last 6 months and those with primary CDI at high risk for recurrence, high-dose VE303 prevented recurrent CDI compared with placebo. A larger, phase 3 study is needed to confirm these findings. Trial Registration: ClinicalTrials.gov Identifier: NCT03788434.

Long-term Safety of Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection.

BACKGROUND: Fecal microbiota transplantation (FMT) is highly effective for treating recurrent Clostridioides difficile infection (CDI), with emerging data on intermediate and long-term safety. METHODS: A prospective survey-based study was conducted (September 2012-June 2018) in patients undergoing FMT for recurrent CDI. Data on demographics and comorbidities were abstracted from medical records. Patients were contacted at 1 week, 1 month, 6 months, 1 year (short-term), and ≥2 years post-FMT (long-term). Symptoms and new medical diagnoses were recorded at each time point. Data were weighted to account for survey nonresponse bias. Multivariate logistic regression models for adverse events were built using age (per 10-year increment), sex, time of survey, and comorbidities. P < .05 was considered statistically significant. RESULTS: Overall, 609 patients underwent FMT; median age was 56 years (range, 18-94), 64.8% were women, 22.8% had inflammatory bowel disease (IBD). At short-term follow-up (n = 609), >60% of patients had diarrhea and 19%-33% had constipation. At 1 year, 9.5% reported additional CDI episodes. On multivariable analysis, patients with IBD, dialysis-dependent kidney disease, and multiple FMTs had higher risk of diarrhea; risk of constipation was higher in women and lower in IBD (all P < .05). For long-term follow-up (n = 447), median time of follow-up was 3.7 years (range, 2.0-6.8). Overall, 73 new diagnoses were reported: 13% gastrointestinal, 10% weight gain, 11.8% new infections (all deemed unrelated to FMT). Median time to infections was 29 months (range, 0-73) post-FMT. CONCLUSION: FMT appears safe with low risk of transmission of infections. Several new diagnoses were reported, which should be explored in future studies.

Microscopic Colitis and Risk of Colon Adenomas: A Multicenter Retrospective Cohort Study.

Microscopic colitis (MC) is a common cause of chronic watery diarrhea, with the highest incidence in women over age 50.1 Cross-sectional studies have suggested that patients with MC have a lower incidence of adenomatous colon polyps compared with those without MC.2-4 The existing literature is limited by cross-sectional design, small sample sizes, lack of longitudinal follow-up, and the use of average-risk patients, rather than those with chronic diarrhea, as controls. We aimed to explore the association between MC and colon adenomas.

The Epidemiology of Microscopic Colitis in Olmsted County, Minnesota: Population-Based Study From 2011 to 2019.

BACKGROUND & AIMS: Epidemiologic studies from Europe and North America have reported an increasing incidence of microscopic colitis (MC) in the late 20th century, followed by a plateau. This population-based study assessed recent incidence trends and the overall prevalence of MC over the past decade. METHODS: Residents of Olmsted County, MN, diagnosed with collagenous colitis (CC) or lymphocytic colitis (LC) between January 1, 2011, and December 31, 2019 were identified using the Rochester Epidemiology Project. Clinical variables were abstracted by chart review. Incidence rates were age- and sex-adjusted to the 2010 US population. Associations between incidence and age, sex, and calendar periods were evaluated using Poisson regression analyses. RESULTS: A total of 268 incident cases of MC were identified with a median age at diagnosis of 64 years (range, 19-90 y); 207 (77%) were women. The age- and sex-adjusted incidence of MC was 25.8 (95% CI, 22.7-28.9) cases per 100,000 person-years. The incidence of LC was 15.8 (95% CI, 13.4-18.2) and CC was 9.9 (95% CI, 8.1-11.9) per 100,000 person-years. A higher MC incidence was associated with increasing age and female sex (P < .01). There was no significant trend in age- and sex-adjusted incidence rate over the study period (P = .92). On December 31, 2019, the prevalence of MC, LC, and CC (including cases diagnosed before 2011) was 246.2, 146.1, and 100.1 per 100,000 persons, respectively. CONCLUSIONS: The incidence of MC and its subtypes was stable between 2011 and 2019, but its prevalence was higher than in previous periods. The incidence of MC continues to be associated with increasing age and female sex.

Budesonide Maintenance in Microscopic Colitis: Clinical Outcomes and Safety Profile From a Population-Based Study.

INTRODUCTION: Outcomes and safety of budesonide maintenance therapy in microscopic colitis (MC) are not well known. METHODS: Adult residents of Olmsted County, Minnesota, diagnosed with MC (2002-2019) and treated with budesonide were identified using the Rochester Epidemiology Project. Response was assessed at 12 ± 4 weeks after initiation of therapy and defined as complete (resolution of diarrhea), partial (≥50% improvement in the number of bowel movements), nonresponse (<50% improvement), and intolerance (discontinued because of side effects). For safety outcomes, cases (budesonide maintenance) and MC controls (no budesonide therapy) were matched by sex and age at diagnosis (±2 years). RESULTS: A total of 450 patients were identified, of whom 162 (36.0%) were treated with budesonide for induction of clinical remission (median age 67 [23-91] years and 126 women [77.8%] ). Clinical outcomes for induction were as follows: 130 (80.2%) complete response, 22 (13.6%) partial response, 8 (4.9%) no response, and 2 (1.2%) intolerance. After induction, 96 (63.2%) had recurrence after discontinuation, of whom 27 (28.1%) required further budesonide induction treatment without maintenance, 56 (58.3%) required long-term budesonide maintenance, and 13 (13.5%) were treated with other therapies. Of those receiving budesonide maintenance, all responded (55 [98.2%] complete and 1 [1.8%] partial). No patient stopped maintenance from adverse events. The median duration of follow-up was 5.6 years (0.3-18.9). There was no significant difference between cases and controls in the incidence of osteopenia/osteoporosis, diabetes mellitus, hypertension, glaucoma, or cataracts. DISCUSSION: The long-term use of budesonide in MC seems to be effective and generally well tolerated with limited adverse effects.

Management of Acute and Chronic Pouchitis.

BACKGROUND: Restorative proctocolectomy with IPAA is the procedure of choice when colectomy is needed for medically refractory ulcerative colitis. Pouchitis is one of the most common complications among patients who have undergone IPAA and represents a spectrum of disease varying in both phenotype and clinical course. OBJECTIVE: This study aimed to assist clinicians and surgeons in the treatment of both acute and chronic pouchitis, including newer therapies and future directions. DIAGNOSIS AND MANAGEMENT: Diagnosis is made by endoscopy of the pouch with biopsy because other conditions may produce similar symptoms such as increased stool frequency, abdominal cramps, and urgency. Pouchitis is classified by duration (acute versus chronic), disease pattern (infrequent, relapsing, and continuous), and response to antibiotics (responsive, dependent, and refractory). The Pouchitis Disease Activity Index may be used to measure disease activity. The management of pouchitis is guided by the disease phenotype. Acute episodes are treated with an initial 2-week course of antibiotics (typically ciprofloxacin or metronidazole), although patients with relapsing or chronic pouchitis may require long-term antibiotic treatment or the cycling of different antibiotics. Certain probiotics may also be used for maintenance therapy in those with chronic symptoms. For patients with chronic antibiotic refractory pouchitis, oral budesonide, immunosuppressive agents (azathioprine), or biologic therapy (infliximab, adalimumab, vedolizumab, and ustekinumab) may be required for both induction and maintenance with close monitoring for potential side effects. In rare cases, diverting ileostomy or pouch excision may be required. CONCLUSION: Pouchitis represents a spectrum of disease phenotypes, ranging from acute antibiotic responsive pouchitis to chronic antibiotic refractory pouchitis. The management of pouchitis is primarily directed by the disease phenotype.

Postinfection Irritable Bowel Syndrome Following Clostridioides difficile Infection: A Systematic-review and Meta-analysis.

BACKGROUND: Postinfection irritable bowel syndrome (PI-IBS) affects ~14% patients after acute bacterial enterocolitis. AIM: The aim of this study was to conduct a systematic review and meta-analysis to find the prevalence of PI-IBS following Clostridioides difficile infection (CDI). METHODS: We systematically searched Medline, Embase, and Web of Science from inception through January 20, 2020 for cohort studies assessing PI-IBS following CDI. Primary outcome was pooled prevalence calculated using inverse variance heterogeneity model [MetaXL (v. 5.3)]. A priori subgroup analyses were done [by irritable bowel syndrome (IBS) diagnostic criteria-Rome vs. others, time of IBS diagnosis-<6 or >6 mo, exclusion or inclusion of pre-existing IBS and CDI treatment-antibiotic with fecal microbiota transplantation vs. antibiotic only]. Heterogeneity was considered substantial if I2>50%. RESULTS: From 2007 to 2019, 15 studies were included (10 prospective, 5 retrospective; 9 full-text, 6 abstracts). Data from 1218 patients were included in the quantitative analysis. Risk of bias was low in 7, medium in 4 and high in 4 studies. Pooled prevalence of PI-IBS was 21.1% (95% confidence interval, 8.2%-35.7%), I2=96%. Common PI-IBS subtypes were diarrhea-predominant in 46.3% (50) patients, and mixed in 33.3% (36) patients. Subgroup analyses by IBS diagnostic criteria, time of IBS diagnosis or CDI treatment did not significantly change the primary outcome (all P>0.05), nor decrease heterogeneity. Funnel plot analysis revealed publication bias. CONCLUSIONS: Over 20% of patients develop PI-IBS after CDI. Factors such as diagnostic criteria for IBS and CDI treatment did not affect prevalence, though small numbers limit the confidence in these conclusions. Larger, well conducted studies are needed to study PI-IBS in CDI.

Abnormal findings on abdominopelvic cross-sectional imaging in patients with microscopic colitis: a retrospective, multicenter study.

OBJECTIVES: Patients with microscopic colitis may have subtle macroscopic findings on colonoscopy such as erythema, edema, or altered vascular pattern; however, radiographic abnormalities on cross-sectional imaging have not been investigated. We aimed at identifying the abdominopelvic radiographic abnormalities in patients with microscopic colitis, as well as possible correlation with endoscopic findings and the need for extended duration of treatment. MATERIALS AND METHODS: This was a retrospective study of patients with biopsy-proven microscopic colitis at two tertiary centers between 1 January 2010 and 30 April 2020. Patients underwent computed tomography scan or magnetic resonance imaging within 30 days of a diagnostic flexible sigmoidoscopy or colonoscopy. Patients with colon ischemia and other causes of colitis were excluded. Radiographic abnormalities from imaging reports included bowel wall thickening, mucosal hyperenhancement and mesenteric fat stranding. Univariate and multivariable logistic regression models were used to identify predictors of radiographic abnormalities. RESULTS: 498 patients with microscopic colitis underwent abdominopelvic cross-sectional imaging within 30 days of flexible sigmoidoscopy/colonoscopy. Lymphocytic colitis was diagnosed in 54.6% of patients, and collagenous colitis in 45.4%. Endoscopic and radiographic abnormalities were identified in 16.1% and 12.4% of patients, respectively. Radiographic abnormalities were associated with the need for budesonide therapy (p = .029) and budesonide therapy long-term (p = .0028). Budesonide therapy long-term (p = .047) was associated with radiographic abnormalities in multivariate analysis. CONCLUSIONS: Radiographic abnormalities may be present on abdominopelvic cross-sectional imaging in a minority of patients with biopsy-proven microscopic colitis, suggesting cross-sectional imaging has low clinical value in the evaluation and treatment of this disease.

Clinical Characteristics and Treatment Response in Microscopic Colitis Based on Age at Diagnosis: A Multicenter Retrospective Study.

BACKGROUND: Microscopic colitis (MC) primarily affects older adults; thus, data in younger patients are scarce. AIMS: To compare clinical characteristics and treatment response by age at diagnosis. METHODS: This retrospective cohort study was performed at Mayo Clinic and Massachusetts General Hospital. Patients were chosen consecutively using established databases. Patients were 'younger' if age at diagnosis was ≤ 50 years and 'older' if age > 50 years. Treatment outcomes were captured for induction (12 ± 4 weeks), based on the total number of daily stools, and defined as remission (complete resolution), response (≥ 50% improvement), non-response (< 50% improvement), and intolerance. Patients were considered 'responders' if they had remission or response and 'non-responders' if they had non-response or intolerance. RESULTS: We included 295 patients (52 younger, 243 older). There were no differences in sex, race, MC subtype, and diarrhea severity between groups (all P > 0.05). Younger patients were more likely to have celiac disease (17.3% vs. 5.8%, P = 0.01), while older patients had higher BMI (mean 25.0 vs. 23.8 kg/m2, P = 0.04) were more likely smokers (53.9% vs. 34.6%, P = 0.01) and use NSAIDs (48.6% vs. 15.4%, P < 0.01) and statins (22.6% vs. 3.8%, P < 0.01). Overall treatment response was highest for budesonide (88.3%) and did not differ when comparing older to younger patients (90.6% vs. 77.8%, P = 0.12) or by MC subtype (LC, 81.5% vs. CC, 92.9%, P = 0.07). CONCLUSIONS: There are no significant differences in MC treatment response based on age or disease subtype. These findings support treating patients with MC based on symptom severity rather than age.

Durability of Response to Fecal Microbiota Transplantation After Exposure to Risk Factors for Recurrence in Patients With Clostridioides difficile Infection.

BACKGROUND: Fecal microbiota transplantation (FMT) is highly effective for preventing recurrent Clostridioides difficile infection (CDI). Durability (no recurrence despite additional risk factor exposure) of FMT protection is largely unknown. We studied the durability of FMT in patients with recurrent CDI. METHODS: We conducted a retrospective study of adults undergoing FMT for recurrent CDI. Data collected included demographics, CDI risk factors (comorbidities, healthcare exposure, non-CDI antibiotic use, acid suppressant medications), and future CDI episodes. Durable response to FMT was defined as lack of CDI episodes within 1 year post-FMT despite risk factor exposure. RESULTS: Overall, 460 patients were included (median age, 57 years [18-94]; 65.2% female). Comorbidities included chronic liver disease, 12.8% (n = 59); cancer, 11.7% (n = 54); chronic kidney disease, 3.9% (n = 18); and inflammatory bowel disease, 21.9% (n = 101). Overall, 31.3% (n = 144) received antibiotics, 21.7% (n = 100) received acid suppressants, and 76.8% (n = 350) had healthcare exposure after FMT. Of 374 patients with risk factor exposure, 78.1% (95% confidence interval [CI], 72.7%-84.0%) had durable response to FMT at 1 year. On multivariable analysis, antibiotic use was independently associated with decreased durability of FMT (hazard ratio, 0.27; 95% CI, .15-.49; P < .001). CONCLUSIONS: The majority of patients had a durable response to FMT despite exposure to CDI risk factors. Antibiotic exposure after FMT independently predicted loss of durability of FMT. Larger studies are needed to define predictors of durable response in patients with and without exposure to antibiotics.

RBX7455, a Non-frozen, Orally Administered Investigational Live Biotherapeutic, Is Safe, Effective, and Shifts Patients' Microbiomes in a Phase 1 Study for Recurrent Clostridioides difficile Infections.

BACKGROUND: Recurrent Clostridioides difficile infections (rCDI) are a global public health threat. To reduce rCDI, microbiota-restoring therapies are needed, particularly standardized, easy-to-administer formulations. METHODS: This phase I open-label trial assessed the safety, efficacy in preventing rCDI recurrence, and intestinal microbiome effects of RBX7455, a room temperature-stable, orally administered investigational live biotherapeutic. Adult participants with 1 or more prior episodes of rCDI received: 4 RBX7455 capsules twice daily for 4 days (group 1); 4 RBX7455 capsules twice daily for 2 days (group 2); or 2 RBX7455 capsules twice daily for 2 days (group 3). For all groups, the first dose was administered in clinic, with remaining doses self-administered at home. Adverse events were monitored during and for 6 months after treatment. Treatment success was defined as rCDI prevention through 8 weeks after treatment. Participants' microbiome composition was assessed prior to and for 6 months after treatment. RESULTS: Nine of 10 group 1 patients (90%), 8 of 10 group 2 patients (80%), and 10 of 10 group 3 patients (100%) were recurrence-free at the 8-week endpoint with durability to 6 months. Seventy-five treatment-emergent adverse events were observed in 27 participants with no serious investigational product-related events. Prior to treatment, participants' microbiomes were dissimilar from the RBX7455 composition with decreased Bacteroidia- and Clostridia-class bacteria, whereas after treatment, responders' microbiomes showed increased Bacteroidia and Clostridia. CONCLUSIONS: Three dosing regimens of RBX7455 were safe and effective at preventing rCDI. Responders' microbiomes converged toward the composition of RBX7455. These results support its continued clinical evaluation. CLINICAL TRIALS REGISTRATION: NCT02981316.

SER-109, an Investigational Microbiome Drug to Reduce Recurrence After Clostridioides difficile Infection: Lessons Learned From a Phase 2 Trial.

BACKGROUND: Recurrent Clostridioides difficile infection (rCDI) is associated with loss of microbial diversity and microbe-derived secondary bile acids, which inhibit C. difficile germination and growth. SER-109, an investigational microbiome drug of donor-derived, purified spores, reduced recurrence in a dose-ranging, phase (P) 1 study in subjects with multiple rCDIs. METHODS: In a P2 double-blind trial, subjects with clinical resolution on standard-of-care antibiotics were stratified by age (< or ≥65 years) and randomized 2:1 to single-dose SER-109 or placebo. Subjects were diagnosed at study entry by PCR or toxin testing. Safety, C. difficile-positive diarrhea through week 8, SER-109 engraftment, and bile acid changes were assessed. RESULTS: 89 subjects enrolled (67% female; 80.9% diagnosed by PCR). rCDI rates were lower in the SER-109 arm than placebo (44.1% vs 53.3%) but did not meet statistical significance. In a preplanned analysis, rates were reduced among subjects ≥65 years (45.2% vs 80%, respectively; RR, 1.77; 95% CI, 1.11-2.81), while the <65 group showed no benefit. Early engraftment of SER-109 was associated with nonrecurrence (P < .05) and increased secondary bile acid concentrations (P < .0001). Whole-metagenomic sequencing from this study and the P1 study revealed previously unappreciated dose-dependent engraftment kinetics and confirmed an association between early engraftment and nonrecurrence. Engraftment kinetics suggest that P2 dosing was suboptimal. Adverse events were generally mild to moderate in severity. CONCLUSIONS: Early SER-109 engraftment was associated with reduced CDI recurrence and favorable safety was observed. A higher dose of SER-109 and requirements for toxin testing were implemented in the current P3 trial. CLINICAL TRIALS REGISTRATION: NCT02437487, https://clinicaltrials.gov/ct2/show/NCT02437487?term=SER-109&draw= 2&rank=4.