The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Lactobacillus reuteri is a strain of bacteria probiotic that is known for providing several benefits from improving gut health, fighting infection and a whole lot more. In this article, I’ll take you through exactly what Lactobacillus reuteri is and how it can help you. 

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

What is Lactobacillus Reuteri?

It’s a bit of a tongue-twister, isn’t it? Lactobacillus reuteri, or L. reuteri for short, is one of the most extensively studied probiotic bacteria strains and offers numerous health benefits. Basically, L. reuteri is a lactic acid bacteria strain that lives in the intestines, sometimes the stomach, in humans as well as other mammals and birds. It’s also found in the urinary tract, skin and breast milk.   

The name originates from the German microbiologist, Gerhard Reuter, who made the discovery in the 1960s.

Reuteri itself is actually categorized into sub-strains. Different strains of L. reuteri are associated with different effects and benefits. For example, the L. reuteri strain Primadophilus reuteri is known to support a strong immune system and healthy digestion. 

Although I said L. reuteri mainly lives in the intestines and is found in other sites around the body, not everyone has it. Back in the 1960s, 30-40% of the population had L. reuteri naturally occurring in their gut microbiome. Today, this isn’t the case and around only 10-20% of people have the bacteria strain in their gut. 

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Gut Colonization of L. reuteri 

L. reuteri colonizes in the gut of humans and animals. It’s thought that the reason it has such great probiotic properties is that it normally colonizes in the gastrointestinal (GI) tract. In order to provide the best environment for digestions and absorption, some sites of the GI system have developed harsh conditions for microorganism to colonize and thrive. 

In order to colonize in the gut in the first place, a microorganism has to survive in these sometimes tough conditions. A number of L. reuteri strains are resistant to bile salts and low pH levels, encouraging both survival and colonization in the gut.   

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

The Metabolite Production Profile of L. reuteri 

L. reuteri’s antimicrobial and immune boosting effects are linked to its metabolite production profile. A metabolite is a substance produced or used when the body breaks down food, chemicals or drugs. This process is called metabolism and makes energy needed for the body to grow, reproduce and maintain health. Here are four metabolites in L. reuteri that promote overall wellbeing. 

  • Reuterin

The majority of L. reuteri strains from humans and poultry are able to produce reuterin. Reuterin is an antimicrobial compound that works to kill microorganism or stop them from growing. The metabolite can inhibit a range of microorganism, mainly Gram-negative bacteria

The term Gram-negative bacteria is used to classify bacteria that turns a certain color after a chemical process known as Gram staining. Gram-negative infections include cholera, typhoid fever, plague, and salmonella. 

  • Histamine

Some strains of L. reuteri are able to convert the amino acid L-histidine into the biogenic amine histamine. Biogenic amines are a group of compounds that are derived from amino acids, the building blocks for protein. Histamine is the most well-known biogenic amine. It’s produced by the body and plays an important role in allergic reactions. 

One study found that histamine derived from the L. reuteri strain 6475 suppressed tumor necrosis factor (TNF). TNF refers to a protein in the body that causes inflammation. This suggests that certain strains of the bacteria could be very useful in treating or preventing inflammation in autoimmune diseases. 

  • Vitamins

There are 13 essential vitamins that you need as the human body isn’t able to synthesize them. Several strains of L. reuteri are actually able to produce different types of vitamins like B12 (cobalamin) and B9 (folate). B12 plays a vital role in the production of red blood cells and DNA, as well as keeping your nervous system in good working order. The vitamin is also essential in reuterin production. 

  • Exopolysaccharide (EPS)

Exopolysaccharides (EPS) are long-chain polymers that have been created and produced mainly by bacteria and microalgae. The EPS produced by L. reuteri is particularly important for biofilm formation and attachment of L. reuteri to surfaces within the body. 

A biofilm is a collection of one or more types of microorganisms that can grow on lots of different surfaces. Microorganisms that can form biofilms include fungi and bacteria. As well as this, the EPS created by L. reuteri is able to stop the adhesion of E. coli to epithelial cells.  

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Role of L. reuteri in Healing the Leaky Gut

If you’ve ever experienced digestive problems like stomach cramps or bloating and let’s face it who hasn’t, you know how uncomfortable it can feel. If you have a combination of digestive problems and acne or migraine, then you may be suffering from a leaky gut. 

Leaky gut, also known as increased intestinal permeability, is a digestive condition where bacteria and toxins are able to “leak” through the intestinal wall and into the body. Physical, biochemical and immunological barriers can all affect gut barrier function. If there are abnormalities in the intestinal barrier, the permeability may increase resulting in a leaky gut. 

Signs and symptoms of a leaky gut include depression, anxiety, stomach cramps and bloating. To find out more about leaky gut, I discuss everything you need to know about leaky gut from what causes it to testing for it and starting the healing process. 

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Various probiotics are known for their abilities to improve mucosal barrier function, in turn, strengthening the intestinal wall. One of the most well-studied examples of this is the probiotic L. reuteri. This little bacteria helps to promote the healing of leaky gut by repairing the holes in the gut lining that caused the condition.   

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Role of L.reuteri on Candida

Candida is a type of yeast that is usually found in small amounts in the body like in the mouth and intestines and on the skin. At normal levels, it doesn’t cause a problem. However, when Candida begins to get out of control, it can cause an infection known as candidiasis. Candida is the most common cause of fungal infections in humans.  

Research suggests that L. reuteri may have antifungal properties suggesting it could stop the growth and eventually kill off various species of Candida.

In a study investigating the antifungal potential of the bacteria, two L. reuteri strains, DSM 17938 and ATCC PTA 5289, completely inhibited the growth of some Candida species including Candida albicans. Candida albicans is one of the most common types of Candida that live in the gut flora. Types of Candida albicans infections include urinary yeast infection, oral thrush, and genital yeast infection. 

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Role of L. reuteri in Babies with Colic ( L. reuteri found in breastmilk)

Have you got a colicky baby? When distressed parents find their breastfed infant won’t stop crying, there might be a surprising remedy, probiotics.

The probiotic L. reuteri is naturally contained in human breastmilk. Research suggests that the presence of lactobacilli may be a good marker for a healthy milk microbiota that hasn’t been altered by antibiotics. Breast milk contains several components and harbours a unique set of bacteria which may serve as a source of colonizing bacteria for a newborn.   

Colic is classed as inconsolable crying in an infant that usually starts around the second week of life and can last up until about three months old. Colic affects up to 28% of infants, understandably causing considerable stress for both parents and healthcare providers. In the first three months of a baby’s life, crying is the No.1 reason for pediatric visits.  

Over the years, there have been similar recommendations for breastfeeding mothers. However, studies suggest that low numbers of intestinal Lactobacillus may play a role in colic and studies have documented improved symptoms after treatment with Lactobacillus compared with a treatment of simethicone. Simethicone is an anti-gas medication that’s used to help with bloating and allows for gas to pass more easily. 

In a randomized study, 50 breastfed colicky babies aged between 2 to 16 weeks received either L. reuteri DSM 17 938 or placebo daily for 21 days. At all stages in the study, crying time for the treatment group was significantly less than the placebo group. By day 21, the number of infants who cried for more than three hours a day was noticeably lower in the treatment group. 

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Role of L. reuteri Preventing Infant Allergies

Over the last several decades, the prevalence of allergic diseases has risen and are now recognized as a burden to public health. Almost 20% of the Australian population has an allergic disease and that percentage is increasing. 

Different strains of probiotics have been used in allergy prevention trials. But, why use probiotics to help prevent childhood allergies?

Well, the increasing prevalence of allergies in affluent countries may actually be caused by reduced microbial stimulation. Probiotics may be used to increase microbial stimulation, enrich the gut and promote a balanced immune system. L. reuteri has demonstrated potential in preventing allergies early on in life. 

One study using L. reuteri supplementation showed promise in preventing allergy-induced eczema. The supplement was given to pregnant women daily from 36 weeks of pregnancy, the infants then continued with the same supplement until 12 months of age.

The study found that there was less IgE-associated eczema at two years of age when both the infant and mother took the supplement. IgE is a type of antibody that plays a major role in response to allergens such as anaphylactic drugs and bee stings. 

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

Role of L. reuteri in Fighting Viral Infections

There has been a considerable amount of research into the effects of L. reuteri on viral infections. There is evidence showing that the bacteria may help to fight against rotavirus, papillomaviruses, and circoviruses.

Experts believe that L. reuteri works to fight infection and make it better by regulating the microbiota and secreting metabolites that contain antiviral properties. The gut microbiota refers to the microbe population that lives in your intestine.

The benefits of Lactobacillus Reuteri 

Lactobacillus Reuteri has several benefits from helping to fight infection to boosting vitamin D levels. Here are seven benefits that the bacteria brings. 

  • Anti-Inflammatory Effects

Low levels of L. reuteri have been linked to an increase in the number of cases of inflammatory diseases. Some strains of the bacteria can also reduce the production of pro-inflammatory cytokines. Cytokines are regulators in the body’s response to certain things like infection or immune infections. Whereas some cytokines reduce inflammation and promote healing, pro-inflammatory cytokines look to make disease worse.   

One study found that L. reuteri stopped NF-kB, which is important when reducing whole-body inflammation. Another study showed that L. reuteri increased levels of oxytocin, the feel-good hormone, which is known to have anti-inflammatory effects. L. reuteri has also been shown to increase Treg cells in the body. Regulatory T cells or Tregs, control the immune response and help to prevent autoimmune disease. 

  • Aids Gut Health

The gut is incredibly complex and important to our overall health. L. reuteri has been shown to switch the body’s primary food source from sugar to tryptophan. This is important as gut bacteria need to consume tryptophan in order to produce serotonin and keep the gut in proper working order. 

By encouraging the gut bacteria to consume tryptophan, it helps to protect the gut from infection and lessen your susceptibility to problems such as IBS. L. reuteri has also been found to help constipation and increase the frequency of bowel movements, all of which contribute towards a healthy gut.

One study found that L. reuteri increased the number of bowel movements, going from 3.89 to 5.28 bowel movements per week. The bacteria has been shown to stop diarrhea in children as well as reduce gut lining inflammation in children with active ulcerative colitis.  

  • Boosts Vitamin D

Vitamin D, also known as the sunshine vitamin, is produced by the body in response to sun exposure. It can also be taken in a supplement. It’s essential for a healthy immune system, nervous system, brain, teeth, and bones. Evidence suggests that a large chunk of the population is vitamin D deficient. 

In one study, taking L. reuteri has been shown to increase levels of vitamin D by 25.5%. This study was the first to show that oral probiotic supplements may increase levels of the sunshine vitamin. As more human studies are carried out in this field, no doubt more detail on the precise mechanism of how the bacteria affects vitamin D levels will come to light. 

  • Increases Vitamin B12 and B9 (Folate)

Several strains of L. reuteri are able to produce vitamins such as vitamin B12 and B9. B vitamins support many vital functions throughout the body and are essential for maintaining good health. There are at least four strains of L. reuteri that can produce vitamin B12. Some specific strains of L. reuteri have also been found to produce folate as well including L. reuteri JCM1112.    

  • Helps Prevent Infections

L. reuteri can help to prevent and fight infection mainly due to its antimicrobial properties. It has the ability to produce antimicrobial molecules like lactic acid, acetic acid, and reuterin. It’s this antimicrobial activity that allows L. reuteri to stop the colonization of harmful microbes. The bacteria may help to prevent a number of infections mainly from Gram-negative bacteria. 

Some strains can stop the growth of Candida in the vagina. Research shows that L. reuteri has the power to completely eradicate H. pylori from the intestine. H. pylori, or Helicobacter pylori, is a type of bacteria that can infect your stomach. It’s a common cause of peptic ulcers. Lactobacillus reuteri may also help prevent salmonella and E-coli. 

  • Autism

Evidence suggests that exposure to maternal obesity during pregnancy increases the chance of the child developing neurodevelopmental disorders such as autism. In an animal study, maternal high-fat diets (MHFD) were shown to induce social deficits in their offspring. The levels of L. reuteri were reduced nine-fold in the gut microbiome of the offspring on a high-fat diet compared to those on a regular diet. What’s more, supplementing L. reuteri led to significant improvements in sociability. 

  • Fertility

Probiotics may help to improve fertility by encouraging a healthy vaginal microbiota. Research suggests that an abnormal vaginal microbiota may negatively affect pregnancy rate in both IVF and natural parents. One study of 130 women undergoing IVF found that those with an abnormal vaginal microbiota had a tougher time getting pregnant. 

Further animal research shows that eating probiotic yoghurt can cause more acidic conditions in the mouth, skin, and vagina. Evidence suggests that an acidic pH in the vagina is linked to peak fertility, which is estimated to be around age 25. 

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health


The probiotic bacteria Lactobacillus reuteri is one of the most well-studied probiotics with astounding health benefits. The gut is a complex environment and the type of bacteria you encourage to thrive can have a massive impact on your overall health. By understanding how crucial L. reuteri is, you can boost both your health and that of your babies. 

If you are interested in discovering whether this is the best probiotic for you, you may want to consider having a gut microbiome test.

Alternatively, get in touch to find out how you can try L. reuteri for yourself or your kids 🙂 

I hope you enjoyed the article, as always, feel free to ask any questions in the comments and please share the article with anyone you feel could benefit!

The Vital Role Lactobacillus Reuteri Plays in Your (and your babies) Health

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