Effects of products designed to modulate the gut microbiota on hyperlipidaemia

Fatalities due to heart and cerebrovascular diseases caused by uncontrolled hyperlipidaemia increase every year; on the other hand, lipid-lowering drugs are known to cause side effects. The gut microbiota has been thoroughly investigated by researchers and consumers, because they have unique functional properties and littler side effects. However, the effects of the gut microbiota remain controversial. We conducted a meta-analysis to assess the effects of products designed to modulate the gut microbiota on various hyperlipidaemias.

We systematically searched PubMed, Embase, Cochrane Library (Central), and Web of Science for randomized controlled trials (published before June 2017, and those only in English) to compare treatment (products designed to modulate the gut microbiota) versus placebo. Our main endpoints were total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in serum. We assessed pooled data using a fixed effects model.

Of 1337 identified studies, 21 were eligible and included in our analysis (n = 1436 participants). The combined estimate of effect size for the impact of products designed to modulate the gut microbiota on serum TC (WMD - 11.07 mg/dL, 95% CI - 13.72 to - 8.43, p < 0.001), LDL-C (WMD - 10.96 mg/dL, 95% CI - 13.37 to - 8.56, p < 0.001), and HDL-C (WMD 0.72 mg/dL, 95% CI 0.06-1.38, p = 0.032) were statistically significant, while no significant effect was found on TG concentrations (WMD - 0.56 mg/dL, 95% CI - 5.59 to 4.47, p = 0.828). Subgroup analysis showed parallel trials, probiotics, and long-term intervention had better effects on lowering blood lipid levels.

Products designed to modulate the gut microbiota results in changes of the plasma lipid concentrations and these changes may protect against cardiovascular disease.