The effect of a probiotic milk product on plasma cholesterol: a meta-analysis of short-term intervention studies

Abstract

Introduction: Certain fermented dairy milk products may have beneficial effects on plasma cholesterol levels. However, a number of studies have produced conflicting results as to whether dietary supplementation by a probiotic dairy product containing the bacteria culture Causido® reduces plasma cholesterol.

Objective: To conduct a meta-analysis of intervention studies to evaluate the effect of the Causido® culture on plasma total cholesterol and low-density lipoprotein (LDL)-cholesterol.

The probiotic milk product: The yoghurt product Gaio® is fermented with Causido®, composed of one strain of Enterococcus faecium (human species) with the proposed cholesterol-lowering effect, and two strains of Streptococcus thermophilus.

Study inclusion and data extraction: Six studies were identified from a literature search and from the yoghurt producer. All studies met the inclusion criteria. Summary data for plasma concentrations of total cholesterol and LDL-cholesterol were extracted from the original publications or by personal request to the authors. Data from 4–8 weeks of treatment duration was used.

Statistical analysis: We performed a traditional meta-analysis where mean differences between intervention and control of the pre–post changes in total cholesterol and LDL-cholesterol were calculated, as well as 95% confidence intervals (CIs).

Results: In the six studies included in the meta-analysis, the Gaio® interventions produced changes in total cholesterol above those of the control groups ranging from −0.02 to −1.02 mmol/l and in LDL-cholesterol ranging from −0.02 to −1.15 mmol/l. After inclusion of an open-label study, the meta-analysis of the double-blind studies showed that Gaio® as compared to the control group changed total cholesterol by −0.22 mmol/l (95% CI: −0.35 to −0.08, P<0.01) and LDL-cholesterol by −0.20 mmol/l (95% CI: −0.33 to −0.06, P<0.005). The outcome was essentially the same if all studies were included.

Conclusions: The present meta-analysis of controlled short-term intervention studies shows that the fermented yoghurt product produced a 4% decrease in total cholesterol and a 5% decrease in LDL-cholesterol when the open-label study is excluded. To demonstrate sustained effects on blood lipids, long-term studies are required.

Sponsorship: MD Foods A/S, Denmark.

European Journal of Clinical Nutrition (2000) 54, 856–860