Lactobacillus reuteri is a beneficial microorganism, classified as a probiotic bacterium, found within the human body. These microorganisms are live bacteria that, when administered in adequate amounts, can contribute to the host’s overall well-being. Understanding this bacterium involves recognizing its characteristics and natural presence in various bodily environments. This article explores its fundamental nature, how it interacts with the human system, its diverse contributions to health, and practical ways to incorporate it safely.
What is Lactobacillus reuteri?
Lactobacillus reuteri (formally Limosilactobacillus reuteri since April 2020) is a Gram-positive, rod-shaped, anaerobic bacterium belonging to the lactic acid bacteria group. These microorganisms typically arrange themselves in chains and do not form endospores. Its presence is widely observed across the animal kingdom, including the gastrointestinal tracts of humans, sheep, chickens, and pigs.
This bacterium was initially recorded in scientific classifications at the turn of the 20th century, though it was mistakenly grouped with Lactobacillus fermentum. Microbiologist Gerhard Reuter reclassified it in the 1960s, and significant differences led to its identification as a distinct species, L. reuteri, in 1980. It is a commensal organism, naturally coexisting within the human body, particularly found in the gut, breast milk, and oral cavity. Among its many variations, the strain DSM 17938 is frequently studied and utilized, especially in applications for children.
How Lactobacillus reuteri Interacts with the Body
Lactobacillus reuteri exerts its influence through several mechanisms within the host. One primary way it interacts is by producing antimicrobial substances. These include reuterin and reutericycline, which inhibit the growth of various undesirable microorganisms. Reuterin, for instance, is produced within the gastrointestinal tract, where it can hinder the proliferation of certain bacteria, such as Escherichia coli.
The bacterium also engages in direct competition with harmful bacteria for resources and attachment sites within the gut environment. By occupying these spaces and consuming available nutrients, L. reuteri can limit the ability of other microbes to establish and thrive. Beyond direct microbial interaction, L. reuteri modulates the host’s immune system. It can influence the production of various signaling molecules (cytokines) and supports the integrity of the gut barrier, which acts as a protective layer against external substances. Furthermore, this bacterium participates in regulating the metabolism of the gut microbiota, contributing to a balanced internal environment.
Diverse Roles of Lactobacillus reuteri in Health
Lactobacillus reuteri is associated with various aspects of human health, contributing to the body’s natural functions. In supporting digestive comfort, this bacterium helps maintain healthy digestion and assists during occasional digestive upset. Research indicates its involvement in reducing antibiotic-associated diarrhea and functional constipation. It has also been suggested to inhibit the growth of Helicobacter pylori, a bacterium linked to peptic ulcers.
For infant health, L. reuteri has been studied for its role in addressing infant colic. Studies indicate that daily administration of L. reuteri (at a dose of 10^8 colony-forming units) was associated with a reduction in crying time for breastfed infants experiencing colic symptoms. This bacterium can also be transferred from a mother’s breast milk to her infant’s gastrointestinal tract, supporting the early development of a balanced gut microbiome.
Regarding oral health, L. reuteri contributes to a healthy oral microbiome. It has been observed to reduce the presence of certain pathogenic bacteria in saliva, which in turn supports overall gum health. Beyond specific areas, L. reuteri provides general support for the body’s natural defenses. It aids in protecting the gut barrier and suppresses inflammatory responses, thereby contributing to the broader function of the immune system.
Sources and Safe Use of Lactobacillus reuteri
Lactobacillus reuteri is primarily introduced through probiotic supplements, as it is less commonly found in typical fermented foods compared to other probiotic strains. These supplements are available in various forms, including drops and capsules, providing a convenient method for consumption. Oral intake of L. reuteri can lead to colonization of the intestines, with levels establishing within days of consistent ingestion.
When using L. reuteri supplements, it is important to follow the dosage instructions provided on the product label. While generally well-tolerated, some individuals might experience mild digestive side effects, such as temporary gas or bloating, especially when first starting supplementation. For individuals with specific health conditions, or vulnerable populations such as infants or immunocompromised individuals, it is advisable to consult a healthcare professional before beginning any new supplement regimen. This ensures appropriate use and addresses any individual considerations.