Synbiotics and gut barrier function in surgical patients
The aim of this thesis was to study the effect of symbiotic administration on measurable parameters of gut-barrier function and clinical outcome in the following groups of surgical patients; Elective surgical admissions, Intensive Care patients, Irritable Bowel Syndrome sufferers and Crohn’s Disease patients. Each study was performed as a double blind, randomised and placebo controlled trial. The symbiotic preparation contained oligofructose and the probiotic bacteria Lactobacillus acidophilus La5, Bifidobacterium lactis Bb-12, Streptococcus thermophilus and Lactobacillus bulgaricus. The preoperative ingestion of synbiotics had no influence on the rate of bacterial translocation, endotoxin exposure or subsequent septic morbidity in elective surgical patients. Nasogastric colonisation by potentially pathogenic organisms was significantly reduced in the population of critically ill patients after symbiotic therapy, but was not associated with improved clinical outcome. Physical and psychological symptom scores improved in both the placebo and active symbiotic groups of irritable Bowel Syndrome patients, representing a significant placebo response. Synbiotic dietary supplementation had no significant effect on relapse rate, markers of disease activity or nutritional status in patients with Crohn’s Disease over a one year period. Synbiotic administration significantly altered nasogastric colonisation by potentially pathogenic bacteria, but had no effect on any other quantifiable measure of gut-barrier function. The clinical significance of this finding is uncertain, but warrants further investigation. To date, there is insufficient scientific evidence to recommend the routine use of synbiotics in surgical patients.