Randomised clinical trial of synbiotic therapy in elective surgical patients

Abstract

Background: It is possible to manipulate the composition of the gastrointestinal microflora by administration of pre- and probiotics. This may help to preserve gut barrier function and reduce the incidence of septic morbidity.

Aims: To assess the effects of a combination of pre- and probiotics (synbiotic) on bacterial translocation, gastric colonisation, systemic inflammation, and septic morbidity in elective surgical patients.

Patients: Patients were enrolled two weeks prior to elective abdominal surgery. Seventy two patients were randomised to the synbiotic group and 65 to the placebo group. Patients were well matched regarding age and sex distribution, diagnoses, and POSSUM scores.

Methods: Patients in the synbiotic group received a two week preoperative course of Lactobacillus acidophilus La5, Bifidobacterium lactis Bb-12, Streptococcus thermophilus, and Lactobacillus bulgaricus, together with the prebiotic oligofructose. Patients in the placebo group received placebo capsules and sucrose powder. At surgery, a nasogastric aspirate, mesenteric lymph node, and scrapings of the terminal ileum were harvested for microbiological analysis. Serum was collected preoperatively and on postoperative days 1 and 7 for measurement of C reactive protein, interleukin 6, and antiendotoxin antibodies. Septic morbidity and mortality were recorded.

Results: There were no significant differences between the synbiotic and control groups in bacterial translocation (12.1% v 10.7%; p = 0.808, chi(2)), gastric colonisation (41% v 44%; p = 0.719), systemic inflammation, or septic complications (32% v 31%; p = 0.882).

Conclusions: In this study, synbiotics had no measurable effect on gut barrier function in elective surgical patients. Further studies investigating the place of pre- and probiotics in clinical practice are required.

Figure 1

Serial C reactive protein (CRP) levels in the synbiotic and placebo groups. There was a significant postoperative rise in CRP in both groups (p<0.05, Wilcoxon signed rank) but no difference between the groups at any time point (p>0.05, Mann-Whitney U). Open circles, outliers (data points 1.5–3 box lengths from nearest quartile); *, extremes (data points >3 box lengths from nearest quartile).

Figure 2

Serial antiendotoxin core antibody (EndoCAb) levels in the synbiotic and placebo groups. There was a significant postoperative fall in EndoCAb in both groups (p<0.05, Wilcoxon signed rank) but no difference between the groups at any time point (p>0.05, Mann-Whitney U).