How a specific strain of Lactobacillus reuteri, NCIMB 30242, supports cardiovascular health
The relationship between increasing levels of LDL-cholesterol (LDL-C) and the risk of coronary artery disease (CAD) has long been established.[1] With CAD on the rise – not to mention the chest pain and heart attacks it can lead to – the importance of eating cleaner, exercising more, quitting smoking, decreasing inflammation, and fighting oxidative stress is on the radar of both integrative and traditional physicians and patients alike. There is likewise no shortage of pharmaceutical prescriptions written for cholesterol-lowering medications – in fact, these are among the most commonly prescribed drugs in America.[2]
What many don’t realize, however – and what scientists have only in recent years begun to unveil – is that the mix of bacteria, viruses, and fungi living in our intestines collectively known as the “microbiome” can exert powerful influence over our cardiovascular health.
How probiotics can help heart health
Given that gut health is so important for our health systemically, could an intervention as simple as taking a probiotic supplement help lower cholesterol levels? Researchers have asked this very question, and their findings suggest that yes, certain probiotics do seem to lower cholesterol levels – in particular the strain Lactobacillus reuteri NCIMB 30242.[3]
In a 2012 randomized, double-blind, placebo-controlled study, 127 participants were randomized to receive either a probiotic supplement containing L. reuteri NCIMB 30242 or placebo capsules daily for nine weeks.[4] At the end of the study, those who took L. reuteri NCIMB 30242 had better cholesterol panels than their counterparts in the control group: L. reuteri NCIMB 30242 reduced LDL-C, non-HDL-C, and apoB – all forms of harmful, or “bad” cholesterol – by 11.64%, 11.30%, and 8.41%, respectively.
Those who took L. reuteri NCIMB 30242 had better cholesterol panels than their counterparts in the control group.
The ratios of “bad” to “good” cholesterol (LDL-C/HDL-C) in the intervention group were also reduced – by 13.39%. Although triglycerides (the form of cholesterol highly influenced by blood sugar levels) were unchanged, high-sensitivity C-reactive protein (hs-CRP), a marker of inflammation, significantly decreased in the L. reuteri NCIMB 30242 group. The blood clot-forming protein fibrinogen also decreased by 14.25% relative to placebo. Similar results were observed in a study examining the effects of a yogurt formulation rich in L. reuteri NCIMB 30242,[5] and subsequent studies have shown both the capsule and yogurt containing L. reuteri NCIMB 30242 to have good safety profiles.[6],[7]
So… how does it work?
The liver / gallbladder / gut bacteria / cholesterol connection
It was first noted in the 1960s that germ-free animals (that is, animals without microorganisms living on them or in them, including their gut) have higher cholesterol levels than their conventionally raised counterparts.[8] The proposed explanation for this was that the intestinal microflora plays a role in the breakdown and elimination of cholesterol.[9]
Specifically, the intestinal microflora helps lower cholesterol levels by its interplay with the gallbladder, an unsung hero of digestion. The main function of the gallbladder is to eject bile (produced by the liver) into the intestine in order to break down fats. Similar to how soap and water wash olive oil off your hands much more effectively than water alone, bile salts act like soap, breaking down fats and oils in the digestive tract.
After the released bile acids finish up their fat-digesting work in the intestine, the bacteria found within a healthy intestinal microbiome help the “used up” bile acids to pass out of the body in the stool in a process known as “deconjugation.”[10]
Once the deconjugated bile acids have passed out the body, the liver uses cholesterol in the bloodstream to make new bile acids. In fact, the conversion of cholesterol to bile acids in the liver – and the subsequent fecal excretion of those bile acids – is a major route of cholesterol elimination.[11] And L. reuteri NCIMB 30242 may be a powerhouse of a probiotic that supports that very process.[12]
The conversion of cholesterol to bile acids in the liver – and the subsequent fecal excretion of those bile acids – is a major route of cholesterol elimination. L. reuteri NCIMB 30242 may be a powerhouse of a probiotic that supports that very process.
Germ-free animals have higher levels of bile acids in their intestines, yet have significantly lower levels of it in their stool, implying that those bile acids don’t get as efficiently eliminated.[13],[14] Furthermore, mice treated with antibiotics have been observed to have 70% less fecal output of bile acids – even after just three days of treatment![15] (Read more about how to bounce back after antibiotic use here.) Decreased elimination of bile acids can create negative consequences when it comes to cholesterol levels and heart health, but thankfully probiotic supplements, particularly those containing L. reuteri NCIMB 30242, may help undo this damage.[16]
In addition to improving general gastrointestinal health[17] and promoting the deconjugation of bile salts,[18],[19] L. reuteri NCIMB 30242 may further enhance cardiovascular health and reduce the risk of heart disease by increasing vitamin D levels.[20]
When it comes to cardiovascular health, the gut might just be the “heart” of the matter.
