Lactobacillus reuteri NCIMB 30242 is considered to be a “heart-healthy” probiotic because it helps lower LDL and total cholesterol. Plus, it’s the only probiotic strain that might give your vitamin D levels a boost. Can it also reset the gut microbiome in people with IBD? Read on for a breakdown of the complete research on its possible health benefits and side effects.
What is Lactobacillus reuteri NCIMB 30242?
Overview
Lactobacillus reuteri NCIMB 30242 was discovered in 2010 by a team of Canadian scientists. It was initially selected among other probiotic strains in the lab for safety and desired qualities before being tested in clinical trials [1].
Lactobacillus reuteri NCIMB 30242 was first called “Cardioviva” but is now trademarked “Microbiome Plus.”
It has been granted a GRAS (Generally Recognized As Safe) designation by the FDA. Interestingly, several Lactobacillus probiotics have GRAS status because they’re a normal part of our gut flora and have a long history of safe use in traditional fermented foods.
However, Lactobacillus reuteri NCIMB 30242 supplements have not been approved by the FDA for medical use and lack large-scale clinical research. Regulations set manufacturing standards for supplements but don’t guarantee that they’re safe or effective. Speak with your doctor before supplementing.
How It Works
Scientists think Lactobacillus reuteri NCIMB 30242 may work by helping the body take in less and get rid of more cholesterol.
L. reuteri NCIMB 30242 carries an important enzyme called bile salt hydrolase (BSH). This enzyme sets bile acids free from their bound form (deconjugating them) [2].
Bile acids conjugated into bile salts with the amino acids glycine or taurine have digestive action [3].
Free bile acids in the gut reduce the absorption of cholesterol in the gut that comes from both food and circulating bile. Unlike bound bile salts, free bile acids attach to cholesterol and get eliminated with the stool [4].
To make up for the loss, the liver increases the production of new bile acids. The body breaks down more cholesterol to keep up [4].
When free bile acids are released in the gut, mucin production also rises. Mucin is a gel-like layer that lies on top of the gut lining. It helps protect the gut lining, repair gut damage, and maintain a healthy gut microbiome. Low mucin has been implicated in inflammatory bowel disease (IBD) [2, 5].
On a cellular level, the BSH action of Lactobacillus reuteri NCIMB 30242 may turn “off” the farnesoid receptor (FXR). In turn, more cholesterol gets broken down and more bile acids get produced [4].
Scientists believe this mechanism may trigger liver cells to release more cholesterol by activating receptors called ABCG5 and ABCG8. Released cholesterol is flushed back into the gut and bile to be eliminated with the stool, which prevents cholesterol buildup [4].
Summary:
Potential Benefits of Lactobacillus reuteri NCIMB 30242
Possibly Effective for:
1) High Cholesterol
According to limited clinical evidence, L. reuteri NCIMB 30242 may be a good complementary strategy for lowering high blood cholesterol levels.
In a 2012 study, microencapsulated Lactobacillus reuteri NCIMB 30242 yogurt twice a day was tested against placebo in 114 adults with high cholesterol. It reduced LDL by ~9%, total cholesterol by ~5%, and non-HDL cholesterol by 6% over 6 weeks [6].
A limitation of this study is that it excluded people taking statins.
In a follow-up study of 127 people, researchers tested Lactobacillus reuteri NCIMB 30242 as capsules over 9 weeks and reported a stronger effect. This regimen reduced [7]:
- LDL cholesterol by ~11.6%
- Total cholesterol by ~9%
- Non-HDL cholesterol by ~11%
- LDL-C/HDL-C ratio by ~13%, and
- ApoB-100 by ~8% compared to placebo
Overall, it worked better than probiotics that are currently used for high cholesterol [6].
For example, a meta-analysis of 13 smaller probiotic clinical studies reported a mean reduction of LDL cholesterol by only ~3%. None included L. reuteri strains [8].
A more recent meta-analysis of 30 trials (including one Lactobacillus reuteri NCIMB 30242 trial) reported that probiotics in general lower LDL by only ~4% [9].
Cholesterol Hyperabsorbers
Probiotic supplementation might be better personalized in the future, according to some researchers.
Limited evidence points to a greater benefit of Lactobacillus reuteri NCIMB 30242 in cholesterol hyperabsorbers: people who absorb too much cholesterol but produce little. This subgroup tends to respond poorly to statins and better to Zetia [10, 11].
Upcoming studies should investigate Lactobacillus reuteri NCIMB 30242 in this group. They should also test it as an add-on or alternative to statins and other cholesterol-lowering drugs in more people, taking into account their genetics and labs.
Summary:
Insufficient Evidence for:
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of Lactobacillus reuteri NCIMB 30242 for any of the below-listed uses.
2) High Plant Sterols
In the clinical trial of 127 people, Lactobacillus reuteri NCIMB 30242 capsules taken over 9 weeks decreased three plant sterols in the blood [7]:
- Campesterol by 41.5%
- Sitosterol by 34.2%, and
- Stigmasterol by 40.7%
Your blood sterol levels reflect how much dietary cholesterol your body absorbs. This can help your doctor determine whether you’re a cholesterol hyperabsorber (hint: look into sterols testing). About one in four people are hyperabsorbers [12, 10].
Besides, excessively high plant sterols in the blood can be dangerous. We know this from sitosterolemia, a rare genetic disorder that causes a massive buildup of plant sterols in the body, fatty growths under the skin, and heart complications [13].
Common genetic mutations (ABCG5, ABCG8) can also raise blood sterols levels above the normal range. Possible consequences include abnormal red blood cells, anemia, giant platelets, increased bleeding, and adrenal and ovarian failure [13, 14].
Additional clinical studies on the effects of Lactobacillus reuteri NCIMB 30242 on plant sterol levels and health are required.
Summary:
3) Heart Health & Inflammation
If you’re looking to improve heart health, you’ve probably heard about the TLC (Therapeutic Lifestyle Changes) diet. It was created by the National Institute of Health (NIH)’s National Cholesterol Education Program as a way to reduce cholesterol.
According to one review and based on the existing evidence, L. reuteri NCIMB 30242 is a probiotic that best meets TLC dietary requirements. The authors say that’s because it:
- Reduced LDL and total cholesterol similar to existing TLC dietary options
- Seemed to improve other heart disease risk factors (inflammatory markers)
- Has GRAS status.
They suggest adding L. reuteri NCIMB 30242 to NIH’s list of TLC dietary recommendations [15].
Also, in a study of 127 people, Lactobacillus reuteri NCIMB 30242 lowered two markers of heart disease and inflammation: CRP and fibrinogen. It reduced the heart disease risk categories in 27% of people whose CRP values were normal or high (compared with 1.7% of people on placebo) [7].
According to a review from the scientists behind the main studies, the future of this strain is likely in combination therapies with already existing treatment options [16].
Plus, other researchers discovered that some strains of Lactobacilli produce small, active peptides. These peptides are hypothesized to mimic angiotensin-converting enzyme (ACE) inhibitors–the mainstay drugs for high blood pressure [17].
Whether or not L. reuteri NCIMB 30242 acts similar to ACE inhibitors hasn’t yet been tested, though.
Summary:
4) Healthy Vitamin D Levels
Taking Lactobacillus reuteri NCIMB 30242 increased blood levels of vitamin D3 by 25.5% compared to placebo in a Canadian study of 123 people. All participants had similar dietary vitamin D intake and sun exposure, ruling out these factors as confounders [18].
This is the first study to report an oral probiotic can increase blood levels of vitamin D3.
The authors hypothesize that Lactobacillus reuteri NCIMB 30242 may do this in two ways. First, by boosting lactic acid production in the gut, which helps absorb more vitamin D. Second, by increasing the production of a compound (7-DHC) that the liver can transform into vitamin D [18].
These mechanisms have yet to be confirmed.
And although the findings are promising, this purported benefit remains unproven until additional, large-scale clinical trials come out.
Summary:
5) Gut Health, Diarrhea, IBS & IBD
Poor gut health has been linked with an unhealthy gut microbiome, inflammation, bile acid imbalances, and disrupted gut-brain communication [19].
In a clinical trial of 127 people, Lactobacillus reuteri NCIMB 30242 improved general gastrointestinal health and diarrhea, compared to placebo [2].
According to one study, people with IBD may have more bound bile acids in the stool. An imbalanced gut microbiome may reduce the breakdown of bile salts, lowering free bile acids. This contributes to inflammation and IBD symptoms [20, 21].
Many clinicians recommend probiotics to patients with functional bowel diseases like IBS and inactive IBD, but it was never clear why they might help.
Now we know that higher levels of free bile acids may reduce gut inflammation and strengthen the gut lining (via FXR activation) [2].
In a study, L. reuteri NCIMB 30242 increased free bile acids, total bile acids, and the ratio of Firmicutes to Bacteroidetes gut bacteria in 10 healthy people over 4 weeks. People with IBD often have a decreased Firmicutes to Bacteroidetes ratio, according to studies [22, 23].
Also, the study found a link between higher bile acid levels and a protein called FGF-19 (fibroblast growth factor-19). Low FGF-19 seems to play a role in inflammation in Crohn’s disease (a type of IBD) and some forms of diarrhea [24, 25].
Large clinical trials are needed to further investigate this potential health benefit.
Summary:
Research Limitations
Have in mind that some probiotic health effects are strain-specific while others apply to the whole probiotic species (Lactobacillus reuteri) or genus (Lactobacilli).
For example, all lactobacilli produce lactic acid and likely support gut health, vaginal health, and immune balance. They’re abundant in fermented foods [26, 27].
Scientists say that probiotics in general also have a wide potential for fighting infections, soothing allergies, and improving our mood and cognitive function.
So, although this post focuses only on the potential benefits based on Lactobacillus reuteri NCIMB 30242 research, other, more general health benefits might apply to this strain too.
Summary:
Lactobacillus reuteri NCIMB 30242 Dosage & Side Effects
Side Effects
Fortunately, Lactobacillus reuteri NCIMB 30242 clinical studies used standardized, well-defined formulations. This makes determining dosage and side effects easier.
A study of 131 people testing the clinical safety and toxicology of supplement capsules containing L. reuteri NCIMB 30242 vs. placebo didn’t report any side effects [28].
There were no significant differences between L. reuteri NCIMB 30242 and placebo side effects in other trials either [29, 7].
Also, no adverse effects have been associated with Lactobacillus reuteri strains in general in clinical trials.
However, L. reuteri NCIMB 30242 supplementation may increase the ratio of Firmicutes to Bacteroidetes gut bacteria. Although this is seen as desirable in people with IBD, it might not be good in people who are overweight or obese and already have a high ratio.
That doesn’t mean Lactobacillus reuteri NCIMB 30242 can worsen weight gain, but we advise caution in people who struggle with obesity until more studies rule this out [22, 23].
Some Lactobacillus reuteri users have reported bloating or an increase in stomach gas.
Larger trials should investigate the long-term side effects.
Synergy
Prebiotic fiber can boost the effects of probiotics and vice versa. For this reason, synbiotic products that contain both a prebiotic and a probiotic are thought to be most effective [30, 31, 32].
Dosage & Formulation
The dosage used in clinical trials was 2.9×10⁹ CFU L. reuteri NCIMB 30242 per capsule, twice daily for 9 weeks. One study used 5 ×1010 CFU microencapsulated L. reuteri NCIMB 30242 in yogurt, twice per day for 6 weeks [29, 7].
Microencapsulation makes Lactobacillus reuteri NCIMB 30242 resistant to stomach acid, which protects probiotic bacteria until they reach the colon where they become active [33].
Commercially available Lactobacillus reuteri NCIMB 30242 (branded Microbiome Plus) contains 3.5×10⁹ CFU per capsule. It’s also available as a synbiotic (L. Reuteri NCIMB 30242 & prebiotic scFOS fiber).
Takeaway
Lactobacillus reuteri NCIMB 30242 is a relatively new probiotic strain. It was selected by scientists for its ability to release free bile acids in the body, helping to lower total and bad “LDL” cholesterol.
Solid evidence supports its use in people with high cholesterol. Lactobacillus reuteri NCIMB 30242 might work best for those who absorb cholesterol in excess. Plus, this strain may reduce high plant sterol levels.
According to a couple of small studies, Lactobacillus reuteri NCIMB 30242 might support heart health, normal vitamin D levels, digestion, and gut health. Research on its effects on IBS and IBD is promising but limited. More clinical trials are needed.
No side effects were reported in clinical trials compared to placebo. Some users report bloating.
