Oral antibiotics and mechanical bowel preparation for colorectal surgery: A prospective observational study of surgical site infection and microbial analysis.

PURPOSE: Surgical site infections (SSIs) are common in colorectal surgery. Mechanical bowel preparation (MBP) in conjunction with oral antibiotics (OABs) have been shown to reduce SSI rates. It however is still unclear which OABs to use, and how this can be implemented in practice. METHODS: This is a prospective observational study carried out in Swansea Bay University Health Board during 2019-2021, evaluating the introduction of OABs in a stepwise manner on the incidence of SSI in major colorectal surgery. A control group having MBP only was compared to two OAB groups: one group had MBP plus metronidazole only and the second MBP plus metronidazole and neomycin. A 30-day follow-up after surgery was ascertained via chart review and telephone contact. Logistic regression was performed to estimate the relation between OAB use and SSI, with adjustment for confounding. In a subset of patients, faecal samples were analysed through 16S rRNA amplicon sequencing before and after OAB treatment, depicting the impact of the gut microbiome. RESULTS: In total 160 patients were analysed: 46 patients had MBP only, whilst 76 patients had MBP plus metronidazole only and 38 patients had MBP with metronidazole/neomycin. The SSI rate in the entire cohort was 33.8%, whilst the adjusted ORs for the single- and dual-OAB groups were 0.76 (95% CI: 0.17-1.81) and 0.50 (95% CI: 0.17-1.52). The microbial analysis demonstrated that the relative abundance for many bacterial genera was changed before and after OAB treatment, but no link with SSI development could be shown. CONCLUSIONS: Introduction of OABs in conjunction with MBP in colorectal surgery is feasible, and may potentially lead to lower rates of SSI, as well as altering the community structure of the faecal microbiome. More research is needed, especially considering different OABs and mechanistic studies of the gut microbiome in the context of colorectal surgery.

Protocol for faecal microbiota transplantation in ulcerative colitis (FMTUC): a randomised feasibility study.

BACKGROUND: The interaction of the gut microbiota with the human host is implicated in the pathogenesis of inflammatory and immunological diseases including ulcerative colitis (UC). Faecal microbiota transplantation (FMT) as a method of restoring gut microbial diversity is of increasing interest as a therapeutic approach in the management of UC. The current literature lacks consensus about the dose of FMT, route of administration and duration of response. METHODS AND ANALYSIS: This single-blinded randomised trial will explore the feasibility of FMT in 30 treatment-naïve patients with histologically confirmed distal UC limited to the recto-sigmoid region (up to 40 cm from the anal verge). This study aims to estimate the magnitude of treatment response to FMT under controlled conditions. The intervention (FMT) will be administered by rectal retention enema. It will test the feasibility of randomising patients to: (i) single FMT dose, (ii) five daily FMT doses or (iii) control (no FMT dose). All groups will receive standard antibiotic gut decontamination and bowel preparation before FMT. Recruitment will take place over a 24-month period with a 12-week patient follow-up. Trial objectives include evaluation of the magnitude of treatment response to FMT, investigation of the clinical value of metabolic phenotyping for predicting the clinical response to FMT and testing the recruitment rate of donors and patients for a study in FMT. This feasibility trial will enable an estimate of number of patients needed, help determine optimal study conditions and inform the choice of endpoints for a future definitive phase III study. ETHICS AND DISSEMINATION: The trial is approved by the regional ethics committee and is sponsored by Abertawe Bro Morgannwg University's Health Board. Written informed consent from all patients will be obtained. Serious adverse events will be reported to the sponsor. Trial results will be disseminated via peer review publication and shared with trial participants. TRIAL REGISTRATION NUMBER: ISRCTN 58082603; Pre-results.