Enterocin (Ent) 4231, produced by non-rabbit origin strain Enterococcus faecium CCM 4231 was used in combination with sage plant extract in rabbits with the aim to check their antimicrobial activity against microbiota, their effect on immunological, biochemical blood parameters, values of volatile fatty acids in caecum, Eimeria sp. oocysts occurrence and selected parameters of rabbits meat. The animals were divided into three experimental groups (EG1-Ent 4231; EG2- sage; EG3- Ent 4231 with sage) and control group (CG); 24 rabbits in each. Natural substances (NS) were administered for 21 days. The experiment lasted for 42 days. The reduction of microbiota in faeces was observed in EG3 at day 21 by a decrease in the numer of coagulase-positive staphylococci (P<0.01) in comparison with that determined in CG. The bacterial counts in the caecum were lower than those found in faeces. A decrease in the numer of Pseudomonas-like sp. in caeca of the experimental groups was observed at days 21 and 42 (difference in range 0.40-1.87 log cycles) comparing with that determined in CG. At day 21, a significant increase in phagocytic activity (PA, P<0.001) was found in blood of rabbits from EG2 comparing with that observed in CG. At day 42, a significant increase in PA (P<0.001) was determined in all experimental groups in comparison with CG. At day 21, in caecal content of EG3 significantly higher values of lactic acid were observed (P<0.05) in comparison with those found in CG. The reduction of Eimeria sp. oocysts was demonstrated after application of each of NS. Addition of NS did not influence biochemical parameters, meat quality of the animals and does not influence negatively the health status of rabbits