The experiment was conducted to determine the effects of the inoculation of the probiotic and enterocin A-producing strain Enterococcus faecium EK13 on selected parameters of metabolic profile, gut microflora, growth, and health in newborn piglets of Slovak White Improved. Piglets for study were divided into two groups: one group (EK13 group, n=8) received strain EK13 per os once daily for 7 days (2ml per piglet, 10(9)CFU/mL of saline buffer). The control group of piglets (n=7) was given placebo-saline buffer. The experiment lasted 14 days. After 7 days, strain EK13 reached 9.8 log(10) CFU/g in faeces of E. faecium EK13 treated piglets while counts of Escherichia coli were significantly lower (P<0.01) than in piglets of the control group. The concentrations of total serum protein, calcium, haemoglobin, haematocrit, red blood cell count and index of phagocytic activity of leukocytes were significantly higher after application of strain EK13. On the other hand, cholesterol was significantly lower in the EK13 group of animals. On day 14, piglets were killed and samples of intestinal contents were taken. Total counts of bacteria in the intestinal contents (jejunum, ileum, caecum, colon) were not significantly influenced. The pH value was significantly lower (P<0.05) only in duodenum of piglets receiving E. faecium EK13. There was a significant higher concentration of lactic acid (P<0.01) and propionic acid in the colon (P<0.001) of the EK13 group. Application of E. faecium EK13 did not influence the daily body weight gain significantly.