Effects of the probiotic (PRO) Lactobacillus plantarum and of the combination of PRO and the prebiotic (PRE) inulin enriched with oligofructose (2%), and PRO with Lini oleum virginale (O) on counts of lactobacilli and coliforms and enzymatic activities in faeces of rats were studied. The rats (n = 60) were divided into 5 groups of 12 subjects. The animals were fed on a high fat diet (10%) for 8 weeks of experiment. Colon cancer was induced by the application of 1,2-dimethylhydrazine (DMH) twice a week in a dose of 20 mg/kg s.c. in groups G2-G5. The rats in group 1 (control 1) received a diet without any supplements. The rats in group 2 (control 2) received 1,2 DMH without any supplements. The rats in group 3 received PRO, group 4 PRO and PRE, and group 5 received PRO and O. A significant decrease (P < 0.05) of coliforms was found out after the application of PRO, PRO-O, and PRO-PRE in comparison with control group G2. Significantly higher (P < 0.05) counts of lactobacilli were determined after the application of PRO-O and PRO-PRE. Significantly lower (P < 0.001) activities of β-galactosidase, β-glucuronidase and α-glucosidase were observed in PRO, PRO-PRE and PRO-O, while in the case of the enzyme β-glucosidase the activity was lower only after the addition of PRO-O. The protective effect of lactobacilli was observed in the order PRO-O, PRO-PRE, and PRO. It was shown that combinations of PRO-O and PRO-PRE had a synergistic effect which was higher than the effect of administering only PRO.