Previous studies have indicated that supplementation with probiotic bacteria may improve lipid metabolism. The present study was aimed at investigating the effects of a mixture of three strains of Lactobacillus plantarum (CECT 7527, CECT 7528 and CECT 7529) on cholesterol-lowering efficacy in hypercholesterolaemic patients. A total of sixty volunteers (thirty participants in the placebo group and thirty counterparts in the L. plantarum group), aged 18–65 years old, participated in a controlled, randomised, double-blind trial. The study group received one capsule daily containing 1·2 × 10(9) colony-forming units of Lactobacillus strains in a unique dose; the placebo group consumed the same product without bacteria for 12 weeks. A significant reduction of 13·6 % in plasma total cholesterol (TC) levels was observed after 12 weeks of consumption in the L. plantarum group when compared with the placebo group. The lipidic outcomes were also analysed based on TC values at baseline: low initial values (LIV, 2000-2500 mg/l) v. high initial values (HIV, 2510–3000 mg/l). In the HIV group, the L. plantarum treatment showed a reduction after 12 weeks of consumption compared with the placebo group in TC, LDL-cholesterol (LDL-C) and oxidised LDL-C (17·4, 17·6 and 15·6 %, respectively). In the LIV, the L. plantarum treatment only showed a reduction after 12 weeks of consumption when compared with the placebo group in TC (9·4 %). The present results showed that the biofunctionality of L. plantarum (CECT 7527, CECT 7528 and CECT 7529) is proportional to the cardiovascular risk of the patient, having a better effect in patients with higher levels of cholesterol.