E-cigarette Use and Disease Outcomes in Inflammatory Bowel Diseases: A Case-Control Study.

INTRODUCTION: Traditional cigarette use adversely impacts disease outcomes in Crohn's disease (CD). There has been a worldwide increase in the use of e-cigarettes over the past decade. The impact of use of nicotine containing e-cigarettes on disease outcomes in CD or ulcerative colitis (UC) has not been well defined. METHODS: This was a retrospective case-control study of patients with CD or UC who were current users of nicotine containing e-cigarettes (cases). Each case was matched to two non-vaping controls. Our primary study outcome was a composite of new biologic initiation, switch of existing biologic therapy, or IBD-related hospitalization or surgery over 2 years. Multivariable models adjusting for relevant covariates were construction. RESULTS: The study consisted of 127 patients with IBD who were current e-cigarette users compared to 251 controls. Current e-cigarette users were younger than non-users and were more likely to have had an IBD-related surgery previously. On multivariable analysis among those with CD, current e-cigarette use was not associated with higher risk of study outcome (OR 0.82, 95% CI 0.36-1.87). No difference was observed separately among those who were current or former smokers. Similarly, in those with UC, current e-cigarette use was not associated with the primary outcome (OR 1.05, 95% CI 0.33-3.39). CONCLUSION: Current e-cigarette use was not associated with worse outcomes among patients with IBD. However, larger studies particularly of patients de novo initiating vaping are needed to draw robust conclusions. Patients should be discouraged from initiating vaping recognizing overall adverse health effects.

The CD4+ T cell response to a commensal-derived epitope transitions from a tolerant to an inflammatory state in Crohn's disease.

Reciprocal interactions between host T helper cells and gut microbiota enforce local immunological tolerance and modulate extra-intestinal immunity. However, our understanding of antigen-specific tolerance to the microbiome is limited. Here, we developed a systematic approach to predict HLA class-II-specific epitopes using the humanized bacteria-originated T cell antigen (hBOTA) algorithm. We identified a diverse set of microbiome epitopes spanning all major taxa that are compatible with presentation by multiple HLA-II alleles. In particular, we uncovered an immunodominant epitope from the TonB-dependent receptor SusC that was universally recognized and ubiquitous among Bacteroidales. In healthy human subjects, SusC-reactive T cell responses were characterized by IL-10-dominant cytokine profiles, whereas in patients with active Crohn's disease, responses were associated with elevated IL-17A. Our results highlight the potential of targeted antigen discovery within the microbiome to reveal principles of tolerance and functional transitions during inflammation.

Fecal microbiota transplantation: Uses, questions, and ethics.

Fecal microbiota transplantation (FMT) has rapidly grown in notoriety and popularity worldwide as a treatment for both recurrent and refractory C. difficile infection (CDI), as well as for a myriad of other indications, with varying levels of evidence to justify its use. At present, FMT use in the U.S. has not received marketing approval from the U.S. Food and Drug Administration (FDA), but is permitted under "enforcement discretion" for CDI not responding to standard therapy. Meanwhile, the rising interest in the gut microbiome throughout mainstream media has paved the way for "do-it-yourself" (DIY) adaptations of the procedure. This access and unregulated use, often outside any clinical supervision, has quickly outpaced the medical community's research and regulatory efforts. While some studies have been able to demonstrate the success of FMT in treating conditions other than CDI-studies on ulcerative colitis have been particularly promising-little is still known about the treatmen's mechanism of action or long-term side effects. Likewise, screening of donor stool is in its early stages in terms of protocol standardization. In this paper, we explore the regulatory and ethical concerns that arise from the need to balance access to a nascent but promising innovative treatment with the need for research into its efficacy, risk profile, and long-term impact.