Bifidobacterium lactis BL-04

EVIDENCE: MIXED

Also sold as: B. lactis BL-04, Bifidobacterium animalis subsp. lactis BL-04, Bl-04, Danisco/IFF Bl-04

B. lactis BL-04 is an identified probiotic strain with human respiratory-immune research at two billion CFU daily. Periodontal trials cited for B. lactis used another strain, HN019. Their findings cannot automatically be applied to BL-04.

Compiled by iSupplementReviews editorial team ·Updated 2026-10-13 · 4 sources

Type: Probiotic — named commercial strain
Studied dose: 2×10⁹ CFU/day (the respiratory-immunity RCTs)
Best form: BL-04 is itself the 'best form' — a named strain means the evidence can be matched; the question is whether the product delivers a studied CFU count
Our rating: MIXED — Some human evidence, inconsistent or indirect

What is Bifidobacterium lactis BL-04?

BL-04 is an identified probiotic strain of Bifidobacterium animalis subspecies lactis, supplied by IFF, formerly Danisco/DuPont. Naming the strain makes it possible to compare a label with its specific research. Species-level names do not provide the same match.

Other names and forms it’s sold as

BL-04 / Bl-04: the IFF/Danisco strain code
Bifidobacterium animalis subsp. lactis: the species name (also written B. lactis)
Distinct from HN019, Bi-07, BB-12: other commercial B. lactis strains with separate evidence bases

Where does it come from?

Industrial culture collections. BL-04 is manufactured at scale for the supplement and food industry; its origin matters less than its registry: it’s the same defined organism across products.

How does it work in the body?

The documented mechanism is innate-immune modulation: BL-04 increased nasal and systemic markers of immune vigilance in trial work, which is the plausible pathway behind its respiratory-illness findings. For oral outcomes there’s laboratory pathogen work, but no human dental trial has tested BL-04 specifically.

What is it claimed to do?

In oral-probiotic marketing: “balance of mouth bacteria,” respiratory-tract support, and immune maintenance. The respiratory/immune framing is the half; it’s where the actual human data lives.

What does the research show?

Claim	Evidence	Dose studied	Verdict
Reduced upper-respiratory-illness risk	One positive trial (N=465) + one finding of no benefit challenge trial (N=334)	2×10⁹ CFU/day	Mixed — modest effect at best
Oral/gum benefit	No BL-04 human oral trial; related strain HN019 has periodontal trials	6.75×10⁹ CFU/day (HN019)	Extrapolated — strain mismatch
Immune support	Mechanistic markers in trials	2×10⁹ CFU/day	Plausible

One positive, one finding of no benefit — the trial record

West et al. (Clin Nutr, 2014, N=465): healthy active adults taking 2×10⁹ CFU/day of BL-04 had a 27% lower hazard of upper respiratory illness over ~5 months (HR 0.73, p=0.022): a real, independent-sized effect. The rhinovirus-challenge trial (EClinicalMedicine, 2021, N=334): same dose for 28 days before deliberate virus exposure found no effect on cold incidence (56% vs 50%, p=0.34), and this trial was manufacturer-funded. Meanwhile, the periodontitis evidence that gets cited for B. lactis, Invernici et al. (J Clin Periodontol, 2018) showing better pocket-depth outcomes after cleaning, used HN019, not BL-04.

That’s the complete picture: a real strain with real human data for a neighboring outcome, being cited with another strain’s dental results.

What dose was studied?

Goal	Dose	Form/route	Duration
Respiratory-illness risk	2×10⁹ CFU/day	oral powder/capsule	~5 months
Rhinovirus challenge (no benefit found)	2×10⁹ CFU/day	sachet	28 days

Side effects

None material at studied doses; standard probiotic class profile (transient digestive adjustment at most).

Drug interactions

Antibiotics: space doses or take after the course
Immunosuppressants: standard class caution for the severely immunocompromised

Who should not take it?

Severely immunocompromised or critically ill patients. No population-level restrictions otherwise.

What the authorities say

ISAPP’s strain-specificity consensus cuts both ways here: BL-04’s naming is a genuine transparency credit, but the same rule means HN019’s periodontal results can’t be claimed for BL-04. The strain ID that makes this ingredient checkable is also what exposes the evidence mismatch.

What to know about Bifidobacterium lactis BL-04

BL-04’s human trials concern respiratory and immune outcomes, with mixed results at two billion CFU daily. The cited periodontal evidence belongs to HN019, a different strain. Check both the strain and live-bacteria count before applying trial findings to a product.

Frequently asked questions about Bifidobacterium lactis BL-04

What is Bifidobacterium lactis BL-04?

A specific, commercially registered strain of B. lactis owned by IFF (formerly Danisco). Unlike species-only labels, 'BL-04' names the actual organism, so its trial record can be checked directly.

Does BL-04 help gums and teeth?

Not directly demonstrated. The B. lactis periodontal trials (reduced pocket depth as a cleaning adjunct) used strain HN019, a different organism. BL-04's human evidence is for upper-respiratory-illness risk, which is an immune outcome, not a dental one.

What did the BL-04 respiratory trials find?

One positive and one finding of no benefit: a 465-person trial found 2×10⁹ CFU/day cut upper-respiratory-illness risk (hazard ratio 0.73), while a 334-person rhinovirus-challenge trial found no effect on cold incidence. mixed evidence: real but modest.

Is BL-04 safe?

Yes; a food-grade strain used in commercial probiotics for years. Standard class caution applies only to severely immunocompromised patients.

References

Products we reviewed containing Bifidobacterium lactis BL-04

Based on recorded labels or seller-described formulas. Inclusion does not establish a match to the strains, preparations or amounts studied here; check each review's disclosure limits.

ProDentim