REVISITING DIET AND APPENDICITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS renatopitesa@gmail.com

342-03

REVISITING DIET AND APPENDICITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

4

New Zealand

Oral or Poster

Understanding of the aetiology of acute appendicitis (AA) has yet to converge on a single unifying theory. Low-fibre western dietary patterns (WDP) have long been thought to increase risk of AA, yet the strength and consistency of the evidence has not been quantified.

A systematic review was conducted following PRISMA guidelines (PROSPERO CRD420251024372). All human studies published in CENTRAL, MEDLINE, Embase, and Scopus from inception to December 2024 were retrieved. The primary outcome investigated was incidence of AA, dietary patterns and the association between the two. Secondary outcomes included severity of AA and appendiceal microbiome changes. Risk of Bias was assessed using the ROBINS-E tool. Studies with insufficient standardised data for meta-analysis or regression were synthesised narratively.

Twenty-one studies (eight case-control, eight epidemiological, four cross-sectional, one cohort) met the inclusion criteria. Most studies were deemed to have high risk of bias. A meta-analysis of four case-control studies showed lower fibre intake in AA patients (MD -4.53 g/day [95%CI -8.50; -0.56] p = 0.02). A meta-regression of epidemiological studies (15 subgroups, 3 variance-weighted studies) suggested each additional gram of fibre daily was associated with a 34% reduction in AA incidence. A narrative synthesis of the remaining studies consistently linked low-fibre, high-meat, or sugar-dense WDPs with higher AA risk.

The available evidence, although largely observational, supports an inverse association between dietary fibre and AA, while meat- and sugar-rich WDPs appear to increase AA risk.