Recent research leaves us in no doubt that the gut microbiome has a huge impact on immunity, mood, metabolism, and overall health. But what exactly are microbiome supplements, and do they work? Read on as we explore the science of using probiotics like L. Reuteri NCIMB 30242, spices, and fiber to target the microbiome.Disclaimer: This post is for informational purposes only. Please discuss your health concerns with your care provider and consult them before taking any supplements to avoid disease and drug interactions.
What are Microbiome Supplements?
Microbiome supplements are any supplements that have a potentially beneficial effect on the microbiome.
Most microbiome supplements are live probiotic bacteria or yeast. However, a broader definition of microbiome supplements also includes prebiotics, postbiotics, digestive enzymes, nutrients, and certain herbs, spices, and medicinal mushrooms that also boost microbiome health.
We don’t have only one microbiome, our whole body is made up of interconnected microbiomes—in our gut, on our skin, in our urogenital and reproductive organs, in breastmilk—that live in harmony with our cells.
Our whole-body microbiome grows with us from birth and our habits and genes continue to shape it throughout life (Rinninela et al., 2019).
The belief that our internal organs are “sterile” has long been debunked in science. In fact, living in ultra-sterile environments has a proven negative effect on our microbiome and increases the risk of chronic allergic and inflammatory disease (Levy et al., 2017; Gagliardi et al., 2018; Rinninela et al., 2019).
Out of all microbiomes in our body, the gut microbiome is the best researched. In this post, we’ll specifically focus on supplements that work on the gut microbiome.
The gut microbiome—also known as the human intestinal microbiota—is made up of trillions of bacteria and viruses that are considered to be beneficial to health. It plays an essential role in digestion, nutrient status, immunity, heart health, brain function, and overall well-being (Carding et al., 2015):
How Microbiome Supplements Work
Caveat: Probiotics Benefits are (Usually) Strain-Specific!
Probiotics are living beings, and they are extremely diverse. To date, there are more than 500 different kinds of probiotic species. Yet, not all are equally effective. This can create confusion when discussing their health benefits and effects on the microbiome.
To stay clear and evidence-based, any mention of the benefits of a probiotic needs to be specific. It should mention the probiotic genus, species, and strain. Many probiotic mechanisms of action are strain-specific and result in different health benefits (McFarland et al., 2018).
In line with this, clinical studies on our strain, Lactobacillus reuteri NCIMB 30242/LRC, apply only to it and not to other similar probiotics.
In one experiment, researchers screened over 127 different Lactobacillus strains and found only 3% had probiotic potential! (Domig et al., 2014).
In certain cases, studies don’t mention which strain they used, so we have to report on a probiotic species in general. This isn’t surprising as it wasn’t until 2010 that scientists realized that most probiotic benefits are strain-specific! (McFarland et al., 2018).
On the other hand, some health benefits may apply to the whole probiotic species (Lactobacillus reuteri/Limosilactobacillus reuteri) and genus (Lactobacilli).
For example, all lactobacilli produce lactic acid and are high in many traditionally consumed fermented foods. All lactobacillus probiotics seem to support a healthy immune system and gut and vaginal microbiome (Tannock, 2004; Mu et al., 2018).
1) Boost Overall Microbial Richness
Poor microbial richness—also called microbial diversity—is a common type of gut dysbiosis. It can be caused by antibiotics, toxins, bowel preparation, diet, and other lifestyle factors (Humphreys et al., 19 - Intestinal Permeability, Textbook of Natural Medicine, 2020).
Microbial diversity can take weeks to months to recover. Probiotic and prebiotic microbiome supplements are a promising way to facilitate this process (Grazul et al., 2016).
In one recent clinical study, the probiotic Bifidobacterium Tetragenous restored normal microbial richness in people undergoing bowel preparation for colonoscopy (Grazul et al., 2016).
Olive oil and medicinal mushrooms also help boost microbial richness. Extra virgin olive oil is a nutritious fat that promotes intestinal health and increases the diversity of the gut microbiome (Marcelino et al., 2019).
Edible medicinal mushrooms help balance and enrich the gut microbiome. Mushrooms act as prebiotics and are rich in immune-boosting active compounds. Sources include lion’s mane, reishi, shiitake, maitake, turkey tail, and others (Jayachandran et al., 2017; Diling et al., 2017).
2) Boost Potentially Beneficial Bacteria
The most common type of gut dysbiosis involves an overall reduction of known beneficial bacterial species like Lactobacilli and/or Bifidobacteria, especially Lactobacillus reuteri and Bacteroides fragilis. It may also include a reduction in butyrate-producing Firmicutes and other anti-inflammatory species (Levy et al., 2017; Humphreys et al., 19 - Intestinal Permeability, Textbook of Natural Medicine, 2020).
As live “good” bacteria, probiotics should ideally travel to your colon and integrate into your gut microbiome. However, some probiotics don’t stick around but are forced to pass through—this is called colonization resistance.
Colonization resistance is when bacteria indigenous to your colon reject the new probiotic strain. It’s a big and common problem, and if it happens, the supplemented probiotic is removed with the stool without achieving its benefits (Yao et al., 2020; Zmora et al., 2018).
Preliminary studies suggest that polyunsaturated fatty acids (PUFA) and omega-3 fatty acids may help overcome colonization resistance. They help probiotics “stick” to the gut lining. Sources include wild-caught fish walnuts, sunflower seeds, and flaxseeds (Bomba et el., 2002; Bomba et al., 2003; Han et al., 2021).
3) Reduce Potentially Harmful Bacteria
Probiotic and prebiotic microbiome supplements work to rebuild the gut microbiome, which involves getting rid of unwanted bacteria.
Probiotics help suppress possibly harmful bacteria such as Enterobacteriaceae (Shigella and Escherichia). These bacteria are present in gut dysbiosis and may cause disease given the right conditions (Grazul et al., 2016; Levy et al., 2017; Humphreys et al., 19 - Intestinal Permeability, Textbook of Natural Medicine, 2020).
Prebiotic fiber is equally important. Gut dysbiosis often also involves an increase in putrefying/decay bacteria called Bacteroides. Putrefactive dysbiosis is usually a result of eating too much meat and unhealthy fats and not enough fiber (Gagliardi et al., 2018).
Curcumin—the main active ingredient in the spice turmeric—is another great microbiome supplement. Aside from being one of the best-researched natural anti-inflammatories, curcumin helps restore gut microbiome balance. Curcumin boosts the growth of beneficial probiotics while reducing the number of pathogenic gut bacteria. Plus, it helps strengthen the gut barrier, which might be helpful for people with leaky gut (Scazzocchio et al., 2020; Di Meo et al., 2019).
4) May Lower Inflammation
Chronic inflammation is a possible underlying factor in many common diseases, including heart disease, stroke, IBD, IBS, diabetes, mood disorders, anxiety, cancer, kidney disease, non-alcoholic fatty liver disease (NAFLD), and autoimmune and neurodegenerative conditions (Furman et al., 2019).
Many probiotics have been researched for their potential to reduce inflammation, but few quality clinical trials are available. Prebiotic and herbal microbiome supplements may also help lower chronic inflammation in the body, but more research is needed.
Here, we’ll focus on clinical studies that investigated the effects of probiotics on inflammatory markers, IBD, or IBS.
In one clinical trial of 127 people, Lactobacillus reuteri NCIMB 30242 lowered C-reactive protein (CRP) and fibrinogen compared to placebo. CRP is a marker of inflammation and heart disease severity, while fibrinogen may point to excessive blood clotting and atherosclerosis. Supplementation also reduced the heart disease risk categories in 27% of people with normal or high CRP (Jones et al., 2012).
Lactobacillus reuteri also improved oral health and soothed gum inflammation in a clinical trial of 38 adult patients. It worked by lowering several pro-inflammatory cytokines (Szkaradkiewicz et al., 2014).
An analysis of 21 IBS clinical trials concluded that the probiotic strains B. infantis 35624, and L. plantarum 299v may help. Another analysis of 13 IBD trials found evidence for VSL#3 mixture and S. boulardii I-745 (McFarland et al., 2018; McFarland et al., 2018).
L. reuteri NCIMB 30242 may also hold potential for IBD. This strain 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 research (Martoni et al., 2015; Stojanov et al., 2020).
5) Balance the Immune System
Most of your immune system is in your gut! Research confirms that probiotics stimulate the immune system and help maintain the normal activity of immune cells that fight off foreign invaders (Galdeano et al., 2019).
Certain probiotics may help the immune system fight off Candida, H. pylori, and viruses and bacteria that cause the common cold and flu (Yoo & Kim, 2016).
Additionally, probiotics may also help prevent immune system overactivity that can cause allergies, autoimmune problems, and food sensitivities. By reducing gut dysbiosis and intestinal leakage, probiotic supplementation may stop undigested food components from entering the blood and sending the immune system into overdrive (Galdeano et al., 2019).
6) Improve Nutrient Status
Microbiome supplements like probiotics, prebiotics, and digestive enzymes support healthy levels of nutrients like vitamin D, vitamin B12, and folate.
Vitamin D deficiency is a global public health issue that has even been recognized as a pandemic. About 1 billion people or 50% of the worldwide population have vitamin D deficiency (Sizar et al., 2021).
The 25-hydroxy vitamin D test is the best way to monitor vitamin D levels. Low levels have been associated with osteoporosis, cardiovascular disease, diabetes, autoimmune disease, infectious diseases, and cancer (Holick & Chen, 2008).
Lactobacillus reuteri NCIMB 30242 increased blood levels of 25-hydroxyvitamin D by 25.5% in a study of 123 people, compared to the placebo. This was the first study to report that an oral probiotic can improve vitamin D status (Jones et al., 2013)
Several Lactobacillus species, including L. reuteri strains, are also able to produce different types of vitamins, including vitamin B12 (cobalamin) and B9 (folate). Among these strains, L. reuteri CRL1098 (isolated from sourdough) and L. reuteri JCM1112 are the most studied (Mu et al., 2018).
Additionally, digestive enzyme supplements help improve nutrient status in people with low enzyme levels. Digestive enzymes break down fats, proteins, and carbs into nutrients your body can absorb—affecting the levels of all essential nutrients in your body (Ianiro et al., 2016).
Most digestive enzymes are normally made in the pancreas. Various metabolic and inflammatory diseases, as well as genetic factors, may reduce your digestive enzyme levels (Ianiro et al., 2016).
7) Reduce the Absorption of Cholesterol & Plant Sterols
One in three deaths in the U.S. is due to heart disease. High LDL or “bad” cholesterol can clog blood vessels and lead to atherosclerosis and heart disease—but so can plant sterols! (Gibbing et al., 2019).
You may think that margarine with plant sterols is good for you, but scientists have been warning against the mass fortification of foods with plant sterols since the 2000s. Recent research cautions that plant sterols may also build up in blood vessels, cause damage, and directly increase the risk of atherosclerosis (Makhmudova et al., 2021; Helgadottir et al., 2021; Helgadottir et al., 2020).
Therefore, the ideal microbiome supplement should aim to reduce both high cholesterol and high plant sterol levels. L. reuteri NCIMB 30242 is the only probiotic strain researched for maintaining normal levels of both cholesterol and plant sterols.
L. reuteri NCIMB 30242 is armed with an enzyme called bile salt hydrolase (BSH), which releases free bile acids from their bound or conjugated form. In the gut, free bile acids bind to cholesterol and plant sterols and reduce their absorption (Jones et al., 2012).
As a result, the liver produces more bile acids and breaks down more cholesterol. Meanwhile, the body increases the production of mucin, an anti-inflammatory gel that coats and protects the gut lining (Shirazi et al., 2000).
Lactobacillus reuteri and Lactobacillus plantarum seem to significantly reduce both total and LDL cholesterol, based on a focused analysis of 15 trials of Lactobacilli strains including close to 1k participants (Wu et al., 2017).
Lactobacillus reuteri NCIMB 30242 may also support blood sterol levels already in the normal range. In the clinical trial of 127 people, this strain decreased levels of several plant sterols in the blood (campesterol by 41.5%, sitosterol by 34.2%, and stigmasterol by 40.7%) (Jones et al., 2012).
8) Support Heart Health
Out of various Lactobacillus reuteri strains, only Lactobacillus reuteri NCIMB 30242 has been clinically researched for supporting markers of heart health.
One scientific review concluded that L. reuteri NCIMB 30242 best meets the requirements of a heart-healthy probiotic since it reduces cholesterol, improves inflammatory markers, and has "generally recognized as safe" (GRAS) status (DiRienzo, 2014).
In one study, Lactobacillus reuteri NCIMB 30242 yogurt taken twice a day for 6 weeks reduced LDL by ~9%, total cholesterol by ~5%, and non-HDL cholesterol by 6% compared to placebo in 114 adults with high cholesterol (Jones et al., 2012).
In another study, L. reuteri NCIMB 30242 capsules reduced LDL cholesterol by ~11.6%, total cholesterol by ~9%, and non-HDL cholesterol by ~11% compared to placebo in 127 people over 9 weeks. Supplementation also improved two other markers of heart health: the LDL-C/HDL-C ratio (by ~13%) and ApoB-100 (by ~8%) (Jones et al., 2012).
- Lactobacillus plantarum CECT 7527
- Lactobacillus plantarum CECT 7528
- Lactobacillus plantarum CECT 7529
- Lactobacillus plantarum ECGC 13110402 (may work similar to L. reuteri NCIMB 30242 but is less researched)
- Lactobacillus bulgaricus
- Lactobacillus sporogenes
- Bifidobacterium lactis HN019
More clinical research on the efficacy and safety of each of these strains is needed before they can be recommended to heart disease patients.
9) Contribute to Good Metabolism
Probiotics contribute to good metabolic health, while gut microbiome dysbiosis and disruption have been linked with obesity and diabetes. Many metabolic diseases that are on the rise are thought to be a result of an impoverished gut microbiome and hormonal imbalances due to the growing number of chemicals in the environment (Aguilera et al., 2020).
Our modern, sedentary lifestyle involves increased exposure to microbiome disruptors like antibiotics, hormones, various drugs, chemical pollutants, electronic waste, processed food, alcohol, and diets low in fiber and nutrients (Gagliardi et al., 2018; Rinninela et al., 2019).
In one placebo-controlled clinical trial, taking L. reuteri JBD301 for 12 weeks significantly reduced body weight in overweight adults (Mu et al., 2018).
According to one analysis of 11 clinical trials, probiotic supplements may help maintain healthy sugar levels in people with diabetes. More research is needed, though (Sun et Bays, 2016).
10) Balance Hormones & Combat Endocrine Disruption
Microbiome disruptors are also endocrine disruptors. They can trigger hormonal imbalances that may affect sex hormones, thyroid hormones, and other hormones in the body (Velmurugan et al., 2017).
Research suggests that probiotic microbiome supplements may help the body better detoxify endocrine-disrupting chemicals and become more resilient to them (Sevim & Kara, 2021).
A healthier gut microbiome may be more efficient at deactivating and flushing chemicals from the body. It also helps keep the gut lining strong, preventing any chemical “leaks” into the blood. Plus, a balanced gut microbiome means efficient digestion, which reduces the amount of time these toxic chemicals spend in the intestines (Snedeker & Hay, 2012).
In turn, microbiome supplements may help prevent endocrine disruption or contribute to re-establishing hormonal balance in the body.
Studies on aging mice also reveal that Lactobacillus reuteri ATCC 6475 may boost testosterone levels and restore normal testicle size. It’s hypothesized to help with male-pattern baldness and libido, but clinical trials are lacking (Levkovich et al., 2013)
11) Improve Brain Function
Limited research suggests that probiotics and prebiotics can improve psychological well-being and cognition, but more clinical studies are needed (Ansari et al., 2020).
Probiotics and prebiotics are being researched for their potential to help with mental health disorders like anxiety, schizophrenia, depression, and autism. Scientists have even coined the term “psychobiotic” to describe their effects (Ansari et al., 2020).
Animal studies suggest that Lactobacillus reuteri probiotics may increase sociability by boosting oxytocin (the “love hormone”) in the hypothalamus. Human studies are lacking to confirm this, though (Buffington et al., 2016).
According to another animal experiment, Lactobacillus reuteri may also speed up wound healing by supporting natural oxytocin production via stimulating the vagus nerve (Poutahidis et al., 2013).
Limited research also points to the potential role of probiotic supplements in neurodegenerative diseases like Alzheimer’s. According to one theory, gut dysbiosis in the elderly can cause leaky gut, which may result in silent systemic inflammation and promote neuroinflammation that’s common in early Alzheimer’s disease (Leblhuber et al., 2018).
Lastly, probiotics are being used as an alternative and complementary therapy in children with autism, but more clinical research is needed to establish their safety and effectiveness. The results so far have been inconclusive (Sivamaruthi et al., 2020).
You don’t need to supplement your microbiome, but research strongly suggests that you may well benefit from it.
Microbiome supplements are a broad category that includes any natural compound that may beneficially affect your microbiome.
The best-researched microbiome supplements are probiotics. Microbiome supplements can also be prebiotics, postbiotics, nutrients, digestive enzymes, and even foods like olive oil, turmeric, and medicinal mushrooms.
The health benefits of probiotics are often strain-specific. Certain probiotic strains may help you achieve specific health goals, like supporting heart health, immune function, normal vitamin D levels, or mental health.
Microbiome Plus+ L. Reuteri NCIMB 30242 has been through several clinical trials for supporting already normal LDL cholesterol, total cholesterol, C-reactive protein, vitamin D, and fibrinogen levels—factors that promote cardiovascular and immune health. It also supports healthy gut microbiome diversity.
- Lactobacillus Reuteri Probiotic Benefits & Clinical Studies
- Foods that actively lower cholesterol
- How to Take Prebiotics and Probiotics Together for Best Results
- What's the Difference Between Probiotics and Prebiotics?
Ana Aleksic, MSc (Pharmacy)
Ana is an integrative pharmacist and scientist with many years of medical writing, clinical research, and health advising experience. She loves communicating science and empowering people to achieve their optimal health. Ana has edited 800+ and written 200+ posts, some of which reached over 1 million people. Her specialties are natural remedies, drug-supplement interactions, women’s health, and mental health. She is also a birth doula and a strong advocate of bridging scientific knowledge with holistic medicine.