Lactobacillus reuteri is a well-studied probiotic bacterium, but the specific strain L. reuteri ATCC PTA 6475 represents a distinct entity. Probiotic science emphasizes that health benefits are strain-specific, meaning the effects observed for one strain may not apply to others. The alphanumeric code confirms the bacteria has been characterized and deposited in a culture collection. Understanding this specificity is paramount, as the unique properties of ATCC PTA 6475 are tied directly to its distinct genetic makeup and biological actions.
Identifying the Specificity of ATCC PTA 6475
The name Lactobacillus reuteri ATCC PTA 6475 is a highly specific designation that details the bacterial species, its former genus, and its unique archival identity. The first part, Lactobacillus reuteri, identifies the species, though it has recently been reclassified into the new genus Limosilactobacillus. The “ATCC” stands for the American Type Culture Collection, a global biological resource center that ensures the strain is standardized and traceable for researchers and manufacturers.
The “PTA 6475” is the specific accession number given to this strain upon its deposit, confirming its unique genetic fingerprint. This particular strain was originally isolated from the breast milk of a Finnish woman in 1997, which highlights its human origin. This precise naming convention allows clinical trials to be repeatable and ensures consumers receive the exact organism studied for its benefits.
Distinct Health Applications
Research has identified specific health outcomes linked to the consumption of ATCC PTA 6475, particularly related to inflammation and bone health. This strain supports bone mineral density in certain populations. In a randomized controlled trial involving older women with low bone mineral density, supplementation for one year reduced the rate of bone loss. Specifically, the loss of total volumetric bone mineral density in the distal tibia was nearly halved in the supplemented group compared to the placebo group.
This effect on bone density is relevant for age-related conditions, suggesting a strategy to reduce bone deterioration. Animal studies indicate that this strain may prevent bone loss associated with conditions like low estrogen levels or type 1 diabetes. The research also suggests that benefits may be more pronounced in individuals with higher baseline body mass index (BMI).
Beyond bone health, this strain is classified as immunosuppressive due to its anti-inflammatory properties, distinguishing it from other L. reuteri strains. It has been utilized in combination with another L. reuteri strain to address symptoms of Irritable Bowel Syndrome (IBS) in adults. The combination significantly reduced the severity of gastrointestinal symptoms and improved stool consistency. This suggests a role in modulating gut discomfort and localized inflammatory markers, such as fecal calprotectin concentration.
Understanding the Mechanism of Action
The unique health benefits of L. reuteri ATCC PTA 6475 stem from its immunomodulatory and metabolite-producing capabilities. Unlike other L. reuteri strains that focus on antimicrobial action, ATCC PTA 6475 is primarily recognized for suppressing inflammatory responses. It is classified as immunosuppressive because it secretes factors that inhibit the production of pro-inflammatory cytokines, specifically Tumor Necrosis Factor (TNF), by immune cells.
This anti-inflammatory effect is mediated by the production of histamine, a signaling molecule that acts on the host’s immune system. The histamine activates histamine receptor type 2 (H2) on myeloid cells, which suppresses the pro-inflammatory signaling pathway. This action helps temper excessive inflammation, which is implicated in conditions like bone loss and gastrointestinal distress.
In the context of bone health, the strain’s action is linked to the gut-bone axis, where it influences the regulation of bone-resorbing cells called osteoclasts. The mechanism involves modulating the immune system to exert beneficial effects on bone density. Specific compounds produced by the strain, such as lactobacillic acid, contribute to the suppression of osteoclast formation, protecting the bone from excessive breakdown. Furthermore, the strain’s influence on the gut environment results in metabolic changes, suggesting that the benefits are mediated through systemic metabolite signaling.
Dosage and Safety Considerations
For L. reuteri ATCC PTA 6475, the dosage used in clinical research and commercial products typically falls within a specific range of colony-forming units (CFU). Studies assessing its efficacy, particularly for bone health, have often utilized doses of \(1 \times 10^8\) CFU per day. In combination products targeting gastrointestinal issues, the total daily dose is sometimes higher, such as \(4 \times 10^8\) CFU per day. The viability of the bacteria is crucial for effectiveness.
The safety profile of this strain is generally favorable, even at doses significantly higher than the standard recommendation. Doses up to \(1 \times 10^{10}\) CFU per day have been shown to be well-tolerated in humans. The most commonly reported side effects are minor gastrointestinal changes, such as mild flatulence or alterations in bowel habits, which are common with many probiotic supplements.
To maintain the viability and efficacy of the live bacteria, products containing L. reuteri ATCC PTA 6475 are typically required to be kept refrigerated. Individuals with severe underlying medical conditions should consult a healthcare provider before beginning supplementation. The transient nature of L. reuteri colonization means that regular daily intake is necessary to maintain adequate levels in the gastrointestinal tract.