Acute Appendicitis and Microbiota - Etiology of Appendicitis and Antibiotic Therapy Effects

Appendicectomy has been the treatment of acute appendicitis for over a hundred years. Appendicectomy, however, includes operative and postoperative risks despite being a routine procedure. Several studies have proved promising results of the safety and efficiency of antibiotics in the treatment of acute uncomplicated appendicitis. The previous APPAC study by the investigators, published in 2015 in the Journal of American Medical Association, also proved promising results with 73% of patients with uncomplicated appendicitis treated successfully with antibiotics. None of the patients initially treated with antibiotics that later had appendectomy had major complications. The results of the APPAC trial suggest that CT proven uncomplicated acute appendicitis is not a surgical emergency and antibiotic therapy is a safe first-line treatment option. Reducing unnecessary appendectomies has also been shown to lead to significant economic savings. On the other hand, antibiotic therapies have been shown to have an effect on the normal gut microbiota and are considered an increasing global health threat underlining the importance of evaluating both short- and long-term effects of the antimicrobial treatment in old and new indications. The aims of this randomized prospective study are: 1. To evaluate the possible role and differences in the microbiological etiology of complicated and uncomplicated appendicitis. 2. To determine the effects of both antibiotic and placebo treatment on the composition of gut microbiota, and to evaluate how it recovers after the appendicitis-related antimicrobial treatment (AMT) 3. To evaluate the effects of the duration of the hospital stay on the AMR reservoir of the gut microbiota.