Risk of Inflammatory Bowel Disease Following Appendectomy in Adulthood

Prior Appendicectomy and Gut Microbiota Re-Establishment in Adults after Bowel Preparation and Colonoscopy

Emerging evidence suggests that the human vermiform appendix is not a vestigial organ but rather an immunological organ of biological relevance. It is hypothesised that the appendix acts as a bacterial 'safe house' for commensal gut bacteria and facilitates re-inoculation of the colon after disruption through the release of biofilms. To date, no studies have attempted to explore this potential mechanistic function of the appendix. We conducted a pre-post intervention study in adults (n = 59) exploring re-establishment of the gut microbiota in those with and without an appendix after colonic disruption via bowel preparation and colonoscopy. Gut microbiota composition was measured one week before and one month after bowel preparation and colonoscopy using 16S rRNA sequencing. We observed between group differences in gut microbiota composition between those with (n = 45) and without (n = 13) an appendix at baseline. These differences were no longer evident one-month post-procedure, suggesting that this procedure may have 'reset' any potential appendix-related differences between groups. Both groups experienced reductions in gut microbiota richness and shifts in beta diversity post-procedure, with greater changes in those without an appendix, and there were five bacterial genera whose re-establishment post-procedure appeared to be moderated by appendicectomy status. This small experimental study provides preliminary evidence of a potential differential re-establishment of the gut microbiota after disruption in those with and without an appendix, warranting further investigation into the potential role of the appendix as a microbial safe house.

Epidemiologic profile of inflammatory bowel disease in Eastern Mediterranean Region (EMRO) countries: a systematic review and meta-analysis

BACKGROUND

Inflammatory bowel disease (IBD) consists of two main types: Crohn's disease (CD) and ulcerative colitis (UC). The epidemiology of IBD patients has not been comprehensively studied in EMRO countries; therefore, we conducted this meta-analysis to study the epidemiology of this disease in these countries.

METHODS

We searched four international databases, namely Scopus, Web of Knowledge (ISI), Medline/PubMed, and ProQuest, from inception up to the end of May 2023. The Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guideline was used to carry out this systematic review and meta-analysis investigation. Using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist, the quality of the selected papers was assessed.

RESULTS

Based on the results of this study, the incidence of UC in EMRO countries was 2.65 per 100,000 (95% CI: 1.39-3.90), and the incidence of CD was 1.16 per 100,000 (95% CI: 0.73-1.59). The most commonly involved intestinal segment in CD was the terminal ileum (44.7%, 95% CI: 34.7-55.2), followed by the ileum (29.8%, 95% CI: 22.2-38.6), and colon (18.7%, 95% CI: 10.8-30.4). However, in UC patients, extensive colitis was the most common finding (32.3%, 95% CI: 26.4-38.8), followed by proctosigmoiditis (27.9%, 95% CI: 21.1-35.8), left-sided colitis (27.4%, 95% CI: 22.7-32.7), and proctitis (22.6%, 95% CI: 17.5-28.5).

CONCLUSION

As a result, we were able to establish the traits of IBD patients in EMRO nations. UC patients had a higher incidence than CD patients. The most common regions of involvement in CD and UC patients, respectively, were the colon and pancolitis. Compared to UC patients, CD patients had a higher history of appendectomy.

Laparoscopic ileocecal-sparing vs traditional right hemicolectomy for cancer of the hepatic flexure or proximal transverse colon: a dual-center propensity score-matched study

Background

Traditional right hemicolectomy (TRH) is the standard treatment for patients with nonmetastatic right colon cancer. However, the ileocecum, a vital organ with mechanical and immune functions, is removed in these patients regardless of the tumor location. This study aimed to evaluate the technical and oncological safety of laparoscopic ileocecal-sparing right hemicolectomy (LISH).

Method

Patients who underwent LISH at two tertiary medical centers were matched 1:2 with patients who underwent TRH by propensity score matching based on sex, age, body mass index, tumor location, and disease stage. Data on surgical and perioperative outcomes were collected. Oncological safety was evaluated in a specimen-oriented manner. Lymph nodes (LNs) near the ileocolic artery (ICA) were examined independently in the LISH group. Disease outcomes were recorded for patients who completed one year of follow-up.

Results

In all, 34 patients in the LISH group and 68 patients in the TRH group were matched. LISH added 8 minutes to the dissection of LNs around the ileocolic vessels (groups 201/201d, 202, and 203 LNs), without affecting the total operation time, blood loss, or perioperative adverse event rate. Compared with TRH, LISH had a comparable lymphadenectomy quality, specimen quality, and safety margin while preserving a more functional bowel. The LISH group had no cases of LN metastasis near the ICA. No difference was detected in the recurrence rate at the 1-year follow-up time point between the two groups.

Conclusion

In this dual-center study, LISH presented comparable surgical and oncological safety for patients with hepatic flexure or proximal transverse colon cancer.

Environmental and Microbial Factors in Inflammatory Bowel Disease Model Establishment: A Review Partly through Mendelian Randomization

Inflammatory bowel disease (IBD) is a complex condition resulting from environmental, microbial, immunologic, and genetic factors. With the advancement of Mendelian randomization research in IBD, we have gained new insights into the relationship between these factors and IBD. Many animal models of IBD have been developed using different methods, but few studies have attempted to model IBD by combining environmental factors and microbial factors. In this review, we examine how environmental factors and microbial factors affect the development and progression of IBD, and how they interact with each other and with the intestinal microbiota. We also summarize the current methods for creating animal models of IBD and compare their advantages and disadvantages. Based on the latest findings from Mendelian randomization studies on the role of environmental factors in IBD, we discuss which environmental and microbial factors could be used to construct a more realistic and reliable IBD experimental model. We propose that animal models of IBD should consider both environmental and microbial factors to better mimic human IBD pathogenesis and to reveal the underlying mechanisms of IBD at the immune and genetic levels. We highlight the importance of environmental and microbial factors in IBD pathogenesis and offer new perspectives and suggestions for improving experimental animal modeling. Our goal is to create a model that closely resembles the clinical picture of IBD.

Treatment Effects of Natural Products on Inflammatory Bowel Disease In Vivo and Their Mechanisms: Based on Animal Experiments

Inflammatory bowel disease (IBD) is a chronic, non-specific inflammatory disease of the intestine that can be classified as ulcerative colitis (UC) and Crohn's disease (CD). Currently, the incidence of IBD is still increasing in developing countries. However, current treatments for IBD have limitations and do not fully meet the needs of patients. There is a growing demand for new, safe, and highly effective alternative drugs for IBD patients. Natural products (NPs) are used in drug development and disease treatment because of their broad biological activity, low toxicity, and low side effects. Numerous studies have shown that some NPs have strong therapeutic effects on IBD. In this paper, we first reviewed the pathogenesis of IBD as well as current therapeutic approaches and drugs. Further, we summarized the therapeutic effects of 170 different sources of NPs on IBD and generalized their modes of action and therapeutic effects. Finally, we analyzed the potential mechanisms of NPs for the treatment of IBD. The aim of our review is to provide a systematic and credible summary, thus supporting the research on NPs for the treatment of IBD and providing a theoretical basis for the development and application of NPs in drugs and functional foods.

A Review on Inflammatory Bowel Diseases: Recent Molecular Pathophysiology Advances

Inflammatory bowel diseases are considered immune disorders with a complex genetic architecture involving constantly changing endogenous and exogenous factors. The rapid evolution of genomic technologies and the emergence of newly discovered molecular actors are compelling the research community to reevaluate the knowledge and molecular processes. The human intestinal tract contains intestinal human microbiota consisting of commensal, pathogenic, and symbiotic strains leading to immune responses that can contribute and lead to both systemic and intestinal disorders including IBD. In this review, we attempted to highlight some updates of the new IBD features related to genomics, microbiota, new emerging therapies and some major established IBD risk factors.

Genes vs environment in inflammatory bowel disease: an update

INTRODUCTION

Inflammatory bowel diseases (IBDs) are known to be caused by a combination of genetic and environmental factors that vary in their influence on the development of the disease. Environmental exposures seem to influence IBD susceptibility, whereas genetic background is thought to modulate the impact of the environment on disease course and phenotype.

AREAS COVERED

A broad review of the involvement of genes and the environment in IBD pathogenesis was performed, and information regarding the main genetic and environmental factors - categorized into lifestyle factors, drugs, diet, and microbes - was updated. Monogenic very early onset IBD (VEO-IBD) was also discussed.

EXPERT OPINION

In the upcoming years, better understanding of gene-environment interactions will contribute to the possibility of a better prediction of disease course, response to therapy, and therapy-related adverse events with the final goal of personalized and more efficient patient management.

Validity of Diagnostic Algorithms for Inflammatory Bowel Disease in Japanese Hospital Claims Data

Inflammatory bowel disease (IBD) diagnoses are increasing in Japan. Some patients have symptoms that are difficult to control, and further research on IBD is needed. Claims databases, which have a large sample size, can be useful for IBD research. However, it is unclear whether the International Classification of Diseases, Tenth Revision (ICD-10) codes alone can correctly identify IBD. We aimed to develop algorithms to identify IBD in claims databases. We used claims data from the Department of Gastroenterology, Tohoku University Hospital from 1 January 2016 to 31 December 2020. We developed 11 algorithms by combining the ICD-10 code, prescription drug, and workup information. We had access to the database which contains all the information for Crohn’s disease and ulcerative colitis patients who visited our department, and we used it as the gold standard. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value for each algorithm. We enrolled 19,384 patients, and among them, 1012 IBD patients were identified in the gold standard database. Among 11 algorithms, Algorithm 4 (ICD-10 code and ≥1 prescription drugs) showed a strong performance (PPV, 94.8%; sensitivity, 75.6%). The combination of an ICD-10 code and prescription drugs may be useful for identifying IBD among claims data.

Appendix and Ulcerative Colitis: a Key to Explaining the Pathogenesis and Directing Novel Therapies?

The vermiform appendix is generally considered a redundant organ, but recent evidence suggests that the appendix could contribute to the pathogenesis of inflammatory bowel diseases, in particular ulcerative colitis (UC), and may even have a therapeutic role; however, mechanisms of the appendix involvement remain unclear. Here, we highlight current evidence on the link between the appendix and UC and consider plausible therapeutic implications. A literature search was conducted using PubMed and PubMed Central from inception to Nov 2021 using the terms "Appendix", "UC", "Appendix & UC," "Appendectomy", and "Peri-appendicular patch," including only articles published in English. Reference lists from the selected studies were manually searched and reviewed to gather additional related reports. Inflammation around the appendix ("peri-appendicular patch") has been frequently observed in UC patients without other cecal involvement, and this inflammation can even precede the onset of UC. Epidemiologic studies propose that appendectomy reduces the risk of developing UC or even the risk of flare after UC is diagnosed, although this remains controversial. We reviewed studies showing altered host-microbe interactions in the appendix in UC, which suggest that the appendix could act as a priming site for disease via alterations in the immune response and changes in microbiota carried distally to the colon. In summary, recent literature suggests a possible role for microbes and immune cells within the appendix; however, the role of the appendix in the pathogenesis of UC remains unclear. Further research could clarify the therapeutic potential related to this organ.