The aim of this study was to determine the beneficial effect of natural substances – enterocin M (Ent M; the proteinaceous substance produced by Enterococcus faecium CCM8558) and sage plant ( Salvia officinalis L.) extract on the production of mucus in the rabbits small intestine and caecum. Sixty four post-weaned rabbits (meat line M91) were divided into three experimental groups (EG – Ent M; SG – sage extract; ESG – combination Ent M with sage extract) and control group (CG). The experiment lasted for 35 days, the natural substances were administered during the first 21 days, Ent M in EG/ESG, sage extract in SG/ESG. The beneficial effect on mucus production quantity occured in the duodenum (p<0.001) and jejunum (p<0.01) in ESG compared to that found in CG on day 21, the prolonged effect in EG in the duodenum (p<0.001) compared to that observed in CG at the end of the experiment and to that in EG on day 21. The novelty of the study is in the application and monitoring the effect of non-rabbit-derived probiotic strain ( Enterococcus faecium CCM8558) bacteriocin – Enterocin M and sage plant extract on mucus quantity (expressed in gram) in different segments of the rabbit small intestine as well as the caecum. The results obtained indicate that supplementation of selected natural substances in the feed has the potent stimulatory effects on mucus production in the rabbit small intestine.