Bratislava Medical Journal Vol.117, No.12, p.734-737, 2016

OBJECTIVES AND BACKGROUND: Oleuropein is a phenolic compound of olive leaves. Enteric bacterial flora is very important for human health and diet is a directly affecting factor of enteric bacterial flora composition. In this study, it was hypothesized that oleuropein could reduce total aerobic bacterial count in rat caecal flora.
METHODS: Twenty adult, male, Wistar albino rats were randomly divided into two groups. Group C (n=10) was fed with standard rat chow and water for 30 days. Group O (n=10) received olive leaf extract 20 mg/kg/day by intragastric gavage in addition to standard rat chow and water for 30 days. One gram of caecal content was collected from each rat and then consecutive 10-fold serial dilutions were prepared with a final concentration of 10–8. Then 0.1 ml of each dilution were spread onto the surfaces of Plate Count Agar and Violet Red Bile Glucose Agar to enumerate the aerobic enteric bacteria.
RESULTS: Total aerobic bacterial counts of Group O were significantly lower than of Group C in all agar plates inoculated with ceacal samples for every dilution (p<0.05).

CONCLUSION: Adding oleuropein to enteral feeding solutions of critically ill patients may be adventageous in the presence of clinical conditions predisposing to bacterial translocation by reducing enteric bacterial counts (Tab. 1, Ref. 32).