Enrichment of early enteral nutrition with lactic acid bacterium influences the innate immune system after major abdominal surgery

Background/aims

There is strong evidence that early enteral nutrition (EEN) enriched with probiotic bacteria may improve the clinical course of patients undergoing major abdominal surgery. Reduced bacterial translocation in the gut and resulting changes in innate immune response may be responsible for this phenomenon. The aim of this randomised, double-blind trial was to investigate changes of innate immunity of patients receiving EEN either enriched with lactic acid bacterium (LAB) or placebo before and after major abdominal surgery.

Patients and methods

Thirty-three patients undergoing either pylorus-preserving pancreaticoduode-nectomy or Whipple's operation were enrolled. EEN enriched with either LAB (n = 17) or placebo (n = 16) was supplied for a period of 5 days beginning on the day before surgery. Blood samples were taken before surgery as well as postperatively on day 1, 4 and 8. Flow cytometry analysis was performed immediately.

Results

Number of neutrophil granulocytes (PMNs), monocytes and total leukocytes increased significantly in both groups during the observation period. CD62L-positive PMNs decreased while CD62L-positive monocytes increased in both groups with significantly lower values in the verum-group. HLA-DR-positive monocytes decreased in both groups until day 1 but showed a significantly lower increase until day 8 in patients receiving LAB. Number of PMNs, monocytes, total leukocytes and CD62L-positive PMNs showed no significant differences between both groups.

Summary/conclusion

Numbers of PMNs, monocytes and total leukocytes as well as CD62L-positive PMNs showed well known changes after major surgery regardless of enrichment of EEN with LAB. In contrast, LAB supply seems to impair the expression of HLA-DR and CD62L on monocytes. Further investigations are necessary to evaluate the underlying mechanisms.