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Bifidobacterium longum BL21

Also known as: Bifidobacterium longum BL21, BL21 strain of B. longum, Bifidobacterium longum subsp. longum BL21

Overview

Bifidobacterium longum BL21 is a specific probiotic strain isolated from infant feces, belonging to the beneficial gut microbiota genus Bifidobacterium. It is characterized by its genetic stability, resilience to gastrointestinal conditions, and a favorable safety profile, lacking virulence and antibiotic resistance genes. This strain is primarily investigated for its potential to modulate gut microbiota, regulate metabolism, and reduce inflammation. Emerging research suggests its therapeutic potential in metabolic and reproductive disorders such as polycystic ovary syndrome (PCOS) and type 2 diabetes. Its key characteristics include strong adhesion to intestinal cells, efficient carbohydrate metabolism, and mucin degradation capabilities, which contribute to its ability to colonize the gut and interact with host systems. While research is still in its early stages, preclinical and initial human studies support its probiotic properties and safety, positioning it as a promising candidate for dietary supplementation.

Benefits

Bifidobacterium longum BL21 demonstrates several evidence-based benefits, primarily in preclinical models. It has shown significant potential in mitigating metabolic abnormalities, particularly those induced by high-fat diets, and improving markers associated with type 2 diabetes through gut microbiota modulation. In models of PCOS, BL21 has been observed to reduce inflammation and correct sex hormone imbalances, leading to improved reproductive hormone profiles and increased neurotrophic factors. Secondary benefits include the enhancement of gut microbiota richness and diversity, promoting beneficial genera such as Bifidobacterium, Bacteroides, and Muribaculaceae, which are correlated with anti-inflammatory cytokines and improved hormonal balance. While specific quantitative effect sizes and confidence intervals are not yet well-established due to limited large-scale randomized controlled trial data, animal models consistently show statistically significant improvements in metabolic and inflammatory markers. These findings suggest particular benefit for individuals with metabolic syndrome, type 2 diabetes, and women with PCOS. Effects are typically observed after several weeks of administration, though long-term clinical data are still pending.

How it works

Bifidobacterium longum BL21 exerts its effects primarily by modulating the composition of the gut microbiota. It increases the abundance of beneficial bacteria while reducing pro-inflammatory taxa, which in turn influences systemic inflammation and metabolic pathways. This strain interacts with the gut-brain-ovary axis by modulating key inflammatory cytokines like TNF-α and IL-6, sex hormones such as testosterone, FSH, and estradiol, and neurotrophic factors like BDNF, all of which are crucial in the pathophysiology of conditions like PCOS. At a molecular level, BL21 adheres to intestinal epithelial cells and facilitates mucin degradation, promoting effective colonization and interaction with the host's immune responses. Its efficient carbohydrate metabolism further supports energy extraction and overall gut health. The strain's resilience to gastric acid and bile ensures its survival and bioavailability upon oral administration, allowing it to reach and colonize the intestines effectively.

Side effects

Bifidobacterium longum BL21 is generally considered safe for oral consumption. Genomic analysis has confirmed the absence of virulence or antibiotic resistance genes, and a 14-day oral toxicity study in animals reported no adverse effects. Due to the limited number of human clinical trials, common side effects have not been extensively documented, and no significant adverse events have been reported in preclinical studies. Currently, there are no known drug interactions or contraindications identified for BL21. However, caution is advised, and further clinical trials are needed to fully assess its safety profile, especially concerning potential interactions with medications or pre-existing conditions. For special populations, such as infants or immunocompromised individuals, additional research is required to confirm safety. As with any probiotic, individuals with severe underlying health conditions or compromised immune systems should consult a healthcare professional before use.

Dosage

Specific dosing guidelines for Bifidobacterium longum BL21 are not yet standardized due to the limited availability of human clinical trial data. However, based on general recommendations for other Bifidobacterium strains, a cautious extrapolation suggests a daily dosage range of 10^8 to 10^10 Colony Forming Units (CFU). The optimal timing of administration and the most effective formulation (e.g., capsule, powder) have not been detailed in the existing literature. The efficacy of BL21 is supported by its demonstrated resilience to gastric acid and bile, which are crucial for its survival and colonization in the gastrointestinal tract. No specific cofactors are reported to be required for BL21's efficacy. As more human clinical data become available, more precise and evidence-based dosing recommendations will be established. It is always advisable to follow product-specific instructions or consult a healthcare professional for personalized guidance.

FAQs

Is BL21 safe for daily use?

Current evidence from preclinical studies supports the short-term safety of BL21. However, long-term human studies are still needed to fully confirm its safety profile for daily, extended use.

How quickly does BL21 work?

Animal studies suggest that benefits from BL21 can be observed within several weeks of administration. The exact timeline for human effects is not yet clear and requires further clinical research.

Can BL21 be combined with other probiotics?

No contraindications have been reported regarding combining BL21 with other probiotics. While plausible, the effects of such combinations have not been specifically studied.

Does BL21 treat PCOS or diabetes?

BL21 shows promise as an adjunctive therapy for PCOS and diabetes by modulating gut microbiota and inflammation. However, it is not a standalone treatment and should complement conventional medical care.

Are there risks of antibiotic resistance?

Genomic analysis of BL21 indicates that it lacks antibiotic resistance genes, which minimizes the risk of contributing to antibiotic resistance.

Research Sources

https://journals.asm.org/doi/abs/10.1128/msphere.00887-24 – This preclinical animal study investigated Bifidobacterium longum BL21 in a DHT-induced PCOS mouse model. It found that BL21 modulated gut microbiota, reduced inflammation, improved sex hormone balance, and increased neurotrophic factors, suggesting its therapeutic potential in PCOS. While high-quality preclinical research, human data are still needed.
https://pubmed.ncbi.nlm.nih.gov/39505088/ – This research focused on the genomic and safety evaluation of Bifidobacterium longum BL21, including in vitro studies and a 14-day oral toxicity test in animals. The findings confirmed that BL21 is genetically stable, non-pathogenic, antibiotic-sensitive, and exhibits good adhesion and metabolic profiles, supporting its safety for oral use. This study provides foundational data for future clinical investigations.
https://pubmed.ncbi.nlm.nih.gov/39898662/ – This source likely refers to the same preclinical animal study as the first URL, focusing on the effects of Bifidobacterium longum BL21 in a PCOS mouse model. It reiterates findings that BL21 modulated gut microbiota, reduced inflammation, and improved hormonal and neurotrophic factors, highlighting its potential as a therapeutic agent for PCOS. The study emphasizes the need for human clinical confirmation.