Bifidobacterium lactis BL-04
Also known as: B. lactis Bl-04, Bifidobacterium animalis subsp. lactis BL-04, Bl-04
Effective Dosage
No established dose from provided studies alone; study doses ranged from 10⁹ to 2×10¹⁰ CFU daily
What the Science Says
Bifidobacterium lactis BL-04 is a probiotic bacterium — a live microorganism meant to benefit gut and immune health when consumed in adequate amounts. Early clinical research suggests it may help modulate immune responses, including a faster antibody (IgG) rise after oral vaccination and potential reductions in inflammatory markers like TNF-α and IL-6, though these findings come from small studies and multi-strain blends where BL-04's individual contribution is unclear. It appears to survive the digestive tract reasonably well and is generally considered safe and well-tolerated in healthy adults.
What It Doesn't Do
Not proven to prevent or treat any disease on its own. Most studies use it in a cocktail of multiple probiotic strains, so you can't credit BL-04 alone for any result. No solid evidence it cures allergies, stops colds, or fixes gut disorders by itself. One rhinovirus challenge study found the probiotic had no measurable effect on T-cell responses. Don't expect dramatic immune protection from a single probiotic strain.
Evidence-Based Benefits
Bifidobacterium lactis BL-04 is a probiotic bacterium — a live microorganism meant to benefit gut and immune health when consumed in adequate amounts. Early clinical research suggests it may help modulate immune responses, including a faster antibody (IgG) rise after oral vaccination and potential reductions in inflammatory markers like TNF-α and IL-6, though these findings come from small studies and multi-strain blends where BL-04's individual contribution is unclear. It appears to survive the digestive tract reasonably well and is generally considered safe and well-tolerated in healthy adults.
Weak EvidenceEffective at: No established dose from provided studies alone; study doses ranged from 10⁹ to 2×10¹⁰ CFU daily
Source: auto-research
Absorption & Bioavailability
Moderate — one study specifically tested survival through simulated gastro-intestinal passage and found dose-dependent recovery, suggesting the strain can reach the colon alive, but real-world survival varies by product formulation and storage.
Red Flags to Watch For
- Nearly all clinical evidence comes from multi-strain probiotic blends — BL-04's individual contribution cannot be isolated from these studies
- Small study sizes (as few as 10–42 participants) limit confidence in any findings
- Open-label and unblinded study designs in several trials introduce significant bias
- Products containing BL-04 vary widely in CFU count, formulation, and storage conditions — label claims may not reflect viable bacteria at time of use
- Registered in over 1,000 supplement products (NIH DSLD), meaning quality control varies enormously across brands
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-11