Microbiome 101
There is no doubt that heart disease poses a serious threat to human life. In fact, it is the leading cause of death for most racial and ethnic groups in the United States. One of the biggest contributors to the progression of heart disease is elevated cholesterol. And so in this article, we'll answer the question: do probiotics lower cholesterol?
A growing body of scientific evidence has linked the intake of probiotics to a wide range of beneficial effects, one of which is the potential ability to impact blood lipid management. In fact, a 2020 article in the American Journal of Preventive Cardiology included probiotics as part of the Top 10 dietary strategies for reducing risk of atherosclerosis, a plaque buildup in arteries caused over time by high cholesterol.
But the effect of probiotics on blood cholesterol level is not black and white: some reviewers of the evidence suggest a positive role, while others argue against it. The most reasonable conclusion at the current time: probiotic intake demonstrates an ability to improve total cholesterol and LDL levels in unhealthy subjects. More research is needed to determine how probiotics, looking at similar cardiovascular endpoints, affect healthy subjects.
Cholesterol 101
Although cholesterol is necessary for physiological functions — such as building healthy cell membranes, hormones, and fat-dissolving bile acids; and making vitamin D — high cholesterol is a well-established risk factor for cardiovascular disease (CVD). Low-density lipoprotein (LDL) is known as “bad” cholesterol, as it carries cholesterol to tissues and arteries. High-density lipoprotein (HDL cholesterol), known as “good” cholesterol, carries cholesterol from the tissues to the liver and leads to its excretion. Elevated total cholesterol level and LDL, or low HDL, are all associated with an increased risk for CVD. Intake of animal-based foods that are high in saturated fat can increase cholesterol, whereas foods that are loaded with fiber and healthy fats may reduce cholesterol.
Do probiotics lower cholesterol levels?
The World Health Organization (WHO) has officially defined probiotics as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.” Trillions of beneficial microbes naturally reside throughout the human body and are concentrated in the gut microbiome. Fermented foods such as yogurt, kefir, and sauerkraut contain probiotics, and regular consumption can help replenish good gut bacteria; or, they can be ingested as dietary supplements. Prebiotics, which you may also have heard of, are non-digestible, fermentable fibers that are essentially fuel for probiotics.
Beneficial probiotic gut microbes produce metabolites that help to promote digestive health, generate energy, and support immune health. In the gut, these good bacteria also work to strengthen the intestinal barrier, which can reduce inflammation and crowd out bad bacteria, so that the latter can’t produce endotoxins that can enter the bloodstream. Turns out that when there’s an imbalance in the gastrointestinal (GI) microbial community, known as gut dysbiosis, the result might not be just GI symptoms such as diarrhea, constipation, uncomfortable bloating and even pain, but also increased risk factors for CVD and other inflammatory conditions.
Several mechanisms have been proposed for how probiotics may influence cholesterol, yet further trials are needed to better elucidate and confirm them. Researchers believe that probiotics:
- Increase bile salt hydrolase activity, which increases the need for bile acids that play a role in reducing cholesterol.
- Produce short-chain fatty acids (SCFAs) that lower hepatic cholesterol synthesis and regulate cholesterol metabolism.
- Reduce the amount of cholesterol that is absorbed by binding it in the small intestine.
- Modulate the trimethylamine N-oxide (TMAO) pathway. Gut bacteria generate TMAOs when foods such as red meat are consumed, and TMAOs may lead to cholesterol buildup in the arteries.
What the research says about probiotics and cholesterol
Clinical trials and several large meta-analyses have verified a cholesterol-lowering role for probiotics, yet some researchers argue that those analyses were flawed due to limitations on quantity and quality of studies, use of unhealthy (hypercholesterolemic) subjects, or other variables.
- In a randomized trial of 127 people with elevated cholesterol, subjects taking L. reuteri for a 9-week study period had significantly lowered total cholesterol (9%) and LDL (12%). The results were attributed to probiotics' role in reducing cholesterol absorption through deconjugation of bile acid. Another randomized study with 114 hypercholesterolemic subjects who consumed yogurt containing L. reuteri twice daily for 6-weeks also suggested that this strain may be efficacious for lowering LDL and total cholesterol.
- A 2014 review of two meta-analyses and 26 clinical trials reported lowered LDL and inflammatory markers with multiple probiotic strains, with the most significant effect from yogurt or oral capsules containing L. reuteri and E. faecium.
- A 2015 meta-analysis of 30 randomized controlled trials (RCTs) in which 1,624 participants (both healthy and hypercholesterolemic) were given probiotics for 3 to 12 weeks showed that the test group had lower total cholesterol and LDL compared with those treated with placebo. Strains associated with significant reductions in total and LDL cholesterol included L. acidophilus, a combination of L. acidophilus and B. lactis, and L. plantarum. Positive effects were linked to probiotic consumption for more than 4-weeks.
- A 2018 meta-analysis of 32 RCTs with a total of 1,971 patients found that when compared to control groups, serum total cholesterol was significantly reduced in those given probiotics. The authors suggested that, in line with previous studies, a probiotic intervention could reduce cholesterol. However, further randomized clinical trials were suggested to elicit a better understanding for probiotic use in management of cardiovascular risk.
- Counter to the positive analyses described above, a 2019 review of 14 studies with 942 healthy subjects who consumed probiotics for 15-150 days found insufficient evidence to conclude a beneficial effect on blood lipid levels. The researchers suggested that the lack of evidence could be due to inclusion of both healthy and unhealthy subjects in previous reviews, giving a greater opportunity for improvements in lipid profiles.
Key takeaways
Mainstream medicine has embraced research indicating that probiotic intake is consistently linked to a healthy balance of gut microflora and the ability to ease GI distress. Research into the mechanism of action for and use of probiotics in managing cholesterol levels is at an earlier stage. Collectively, findings from clinical trials, reviews, and meta-analyses suggest that probiotic intake results in an improvement in total cholesterol and LDL levels in unhealthy subjects. However, conclusions regarding the influence of probiotics (including specific strain, dosing frequency, etc.) on reducing blood cholesterol in healthy adults will require considerably more research and larger clinical trials, although some of the initial results are encouraging.
Supplementing with Eden’s Synbiotic
Eden’s Synbiotic Superblend combines probiotics, prebiotics and polyphenols in a formulation designed to optimize functioning of the gut microbiome and address a range of metabolic parameters involving glycemic regulation, lipid control, immune health, satiety, and digestive comfort. As a synbiotic, the probiotic, prebiotic and polyphenol components work in concert to develop and fuel select health-promoting probiotic bacteria. Learn more: What is a synbiotic?
The probiotics in Eden’s that may benefit heart health include:
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Bacillus coagulans (B. coagulans): In a recent double-blind trial, six weeks after supplementation with this probiotic, the study group had significantly lower triglyceride levels compared to the placebo group.
- Lactobacillus paracasei (LPC-37): This strain of robust good bacteria has been suggested to positively impact lipid levels, along with its other documented benefits of strengthening the intestinal mucosal barrier, support for immune health, support for a healthy stress response, and improvement in nutrient absorption.
Certain of the Eden’s selected prebiotic fibers and polyphenols also exhibit support for decreasing CVD risk factors:
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Locust bean gum: This soluble fiber has been linked to reduced total and LDL (the bad kind) cholesterol, along with well-documented benefits for glucose management and digestive health.
- Lychee/green tea extract: One of the polyphenols in Eden’s, Oligonol (essentially 85% lychee and 15% green tea) has been shown to reduce serum triglyceride concentrations.
Perhaps of greater significance than these aforementioned individual ingredient studies, results from a non-randomized pilot study in 20 participants who consumed Eden's synbiotic, for 28-days, indicated a 9% increase in HDL, a cardiovascular benefit worth noting. Get Eden's here.
