Colectomy Rates Are Increasing Among Inpatients With Concomitant Ulcerative Colitis and Clostridioides difficile

The impact of gut microbiome enterotypes on ulcerative colitis: identifying key bacterial species and revealing species co-occurrence networks using machine learning

Ulcerative colitis (UC) is a chronic inflammatory intestinal disease affecting the colon and rectum, with its pathogenesis attributed to genetic background, environmental factors, and gut microbes. This study aimed to investigate the role of enterotypes in UC by conducting a hierarchical analysis, determining differential bacteria using machine learning, and performing Species Co-occurrence Network (SCN) analysis. Fecal bacterial data were collected from UC patients, and a 16S rRNA metagenomic analysis was performed using the QIIME2 bioinformatics pipeline. Enterotype clustering was conducted at the family level, and deep neural network (DNN) classification models were trained for UC and healthy controls (HC) in each enterotype. Results from eleven 16S rRNA gut microbiome datasets revealed three enterotypes: Bacteroidaceae (ET-B), Lachnospiraceae (ET-L), and Clostridiaceae (ET-C). Ruminococcus (R. gnavus) abundance was significantly higher in UC subjects with ET-B and ET-C than in those with ET-L. R. gnavus also showed a positive correlation with Clostridia in UC SCN for ET-B and ET-C subjects, with a higher correlation in ET-C subjects. Conversely, Odoribacter (O.) splanchnicus and Bacteroides (B.) uniformis exhibited a positive correlation with tryptophan metabolism and AMP-activated protein kinase (AMPK) signaling pathways, while R. gnavus showed a negative correlation. In vitro co-culture experiments with Clostridium (C.) difficile demonstrated that fecal microbiota from ET-B subjects had a higher abundance of C. difficile than ET-L subjects. In conclusion, the ET-B enterotype predisposes individuals to UC, with R. gnavus as a potential risk factor and O. splanchnicus and B. uniformis as protective bacteria, and those with UC may have ultimately become ET-C.

Early Flexible Sigmoidoscopy Improves Clinical Outcomes in Acute Severe Ulcerative Colitis

Objectives

Guidelines recommend performing a flexible sigmoidoscopy in patients hospitalized with acute severe ulcerative colitis (ASUC). However, it is unclear if time to sigmoidoscopy affects relevant clinical outcomes. We aimed to assess the impact of early sigmoidoscopy on clinical outcomes using a well-characterized cohort of patients with ASUC.

Methods

This is a single-center, retrospective study of all patients hospitalized with ASUC from January 1, 2012 to November 1, 2021. Early sigmoidoscopy was defined as occurring within 72 hours of admission while delayed sigmoidoscopy was defined as occurring >72 hours after admission. Primary outcomes were cumulative days of intravenous (IV) corticosteroid (CS) use, length of hospital stay, and colectomy rates. Secondary outcomes were time to infliximab (IFX) rescue and inpatient opioid medication use.

Results

A total of 112 patients hospitalized with ASUC who underwent sigmoidoscopy were included in the analysis. Eighty-seven patients (78%) had early sigmoidoscopy and 25 (22%) had delayed sigmoidoscopy. Patients in the early sigmoidoscopy group were exposed to significantly fewer days of IV CS (4.5 vs 9.2 days; P < .001), had shorter hospital stays (6.4 vs 19.3 days; P < .001), and shorter time to IFX rescue (3.5 vs 6.4 days; P = .004). Rates of colectomy in the early and delayed sigmoidoscopy groups were 17% versus 28%, respectively (P = .23). Longer time to sigmoidoscopy was associated with a 16% increased risk of colectomy (HR = 1.16, P = .002).

Conclusions

In this well-characterized cohort, early sigmoidoscopy in ASUC was associated with favorable clinical outcomes. These findings highlight the benefits of early sigmoidoscopy in patients with ASUC. Larger prospective studies are needed to corroborate these findings.

[Clostridioides Infection in Patients with Inflammatory Bowel Disease]

Inflammatory bowel disease (IBD), comprising Crohn's disease and ulcerative colitis, is a chronic inflammatory condition of the gastrointestinal tract, which is often accompanied by altered gut microbial composition. Gut dysbiosis in IBD is considered to be the reason for the high risk of Clostridioides difficile infection (CDI) in patients with IBD. Therefore, CDI should be evaluated in IBD patients with a symptom flare. Medical treatment of non-severe CDI in IBD is similar to that in non-IBD patients and includes oral vancomycin or fidaxomicin. The risk of recurrent CDI in IBD is higher than in non-IBD patients and this could be mitigated by fecal microbiota transplantation. As CDI may worsen the clinical outcomes of IBD, patients should be carefully monitored and an escalation of IBD therapy needs to be considered when there is no improvement seen with the antimicrobial treatment of CDI. This review discusses the risk, pathophysiology, diagnosis, and management of CDI in IBD.

Risk of Gastrointestinal Infections After Initiating Vedolizumab and Anti-TNFα Agents for Ulcerative Colitis

GOALS

Characterize and compare the risk of Clostridioides difficile infection (CDI) and cytomegalovirus colitis (CMVC) after initiation of vedolizumab or anti-tumor necrosis factor (TNF)α agents for ulcerative colitis (UC).

BACKGROUND

Immunosuppression is a risk factor for gastrointestinal infections including CDI and CMVC among patients with UC; however, the risk according to the biological class is poorly understood.

STUDY

A retrospective cohort study of adults with UC involving the initiation of vedolizumab or anti-TNFα agents during June 1, 2014 to December 31, 2020 was conducted at a large academic health system. The primary outcomes for both CDI and CMVC analyses were first CDI or CMVC after biological initiation. The secondary outcome for the CDI analysis was severe CDI (>10,000 white blood cells or serum creatinine >1.5 mg/dL). Independent variables included demographics and UC history/severity factors. Inverse probability of treatment weighted Cox regression was performed to assess the hazard of CDI by biological group. Due to few outcomes, CMVC was reported descriptively.

RESULTS

A total of 805 UC patients initiated vedolizumab (n=195) or anti-TNFα agents (n=610). There were 43 CDIs and 11 severe CDIs over 1436 patient-years. The inverse probability of treatment weighted Cox regression demonstrated no association between CDI and vedolizumab versus anti-TNFα (hazard ratio 0.33, 95% confidence interval 0.05-2.03), but identified a significantly lower hazard of severe CDI for vedolizumab versus anti-TNFα (hazard ratio 0.10, 95% confidence interval 0.01-0.76). There were 5 cases of CMVC, all in the anti-TNFα group.

CONCLUSIONS

There was a lower adjusted risk of severe CDI but not total CDI associated with vedolizumab. CMVC was not observed after initiating vedolizumab. These findings may provide reassurance regarding the use of vedolizumab when also considering the risk of gastrointestinal infections.

Diagnosis and management of Clostridioides difficile infection in patients with inflammatory bowel disease

PURPOSE OF REVIEW

Clostridioides difficile infection (CDI) may complicate the course of ulcerative colitis and Crohn's disease. The clinical presentation of CDI in this population is often atypical, and patients may experience exacerbations of their underlying inflammatory bowel disease (IBD) secondary to C. difficile. In this review, we aim to review the risk factors, diagnosis, and management of CDI in the context of IBD.

RECENT FINDINGS

Patients with colonic involvement of their IBD are at higher risk for CDI and colonization may be more common than in the general population. Therefore, CDI is confirmed using a two-step approach to stool testing. Oral vancomycin or fidaxomicin are the preferred agents for nonfulminant disease, and oral metronidazole is no longer recommended as first-line therapy. For all patients with CDI recurrence, fecal microbiota transplant (FMT) should be considered, as this has been shown to be safe and effective. Among those who have worsening of their underlying IBD, retrospective research suggest that outcomes are improved for those who undergo escalation of immunosuppression with appropriate antimicrobial treatment of C. difficile, however prospective data are needed.

SUMMARY

CDI may complicate the course of IBD, however the presentation may not be typical. Therefore, all patients with worsening gastrointestinal symptoms should be evaluated for both CDI and IBD exacerbation. Providers should consider FMT for all patients with recurrent CDI as well as escalation of immunosuppression for patients who fail to improve with appropriate antimicrobial therapy.