← All supplements
Moderate evidenceGut health

Bifidobacterium Lactis (BB-12/HN019)

One of the most studied probiotic species. HN019 speeds up gut transit in constipated adults in dose-ranging and multicenter trials; the effect is consistent but measured in hours, not days.

Where to buy

View on iHerb

Ships to 180+ countries · welcome discount for new customers

Referral link — this site may earn a commission on purchases.

What the science says

  • Faster colonic transit Moderate evidence

    A double-blind, randomized, dose-ranging trial found that 28 days of B. lactis HN019 shortened colonic transit time in adults with functional constipation and reduced some GI symptoms. A meta-analysis of randomized trials confirms that probiotic supplementation shortens intestinal transit by roughly half a day on average, with bifidobacteria among the better performers.

  • Functional constipation symptoms Moderate evidence

    A multi-center, triple-blind, randomized, placebo-controlled trial of 8 weeks of HN019 in functional constipation reported improvement in bowel habit outcomes, though effect sizes were modest.

  • Immune markers Limited evidence

    Trials in older adults report increases in phagocytic activity and other laboratory immune measures, without demonstrating fewer infections.

Dosage & safety

Studied doseTransit-time trials used 1.8 billion or 17.2 billion CFU per day of HN019, with both doses working. BB-12 products typically supply 1–10 billion CFU per day.
SafetyAmong the best-documented probiotics for safety, with adverse events comparable to placebo in systematic reviews. Mild gas at the start. Standard caution applies for severely immunocompromised or critically ill patients.

How to take it

TimingTiming does not matter.
With food?With a meal, which buffers stomach acid.
Worth knowingThe lower HN019 dose shortened transit as well as the higher one, so paying for a bigger count is optional.

Interactions

With medications

  • antibiotics

    Antibiotics kill the live organisms. separate by at least 2 hours and continue after the course

  • immunosuppressants and chemotherapy

    Live probiotics have caused bloodstream infections in severely immunocompromised patients. do not start without medical advice

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does Bifidobacterium lactis help constipation?

Yes, with moderate evidence: B. lactis HN019 shortened colonic transit time in adults with functional constipation and improved bowel habits in placebo-controlled trials, though effect sizes are modest.

How much Bifidobacterium lactis HN019 per day?

Transit-time trials used 1.8 billion or 17.2 billion CFU per day of HN019, and both doses worked, so paying for a bigger count is optional. BB-12 products typically supply 1–10 billion CFU per day.

Does Bifidobacterium lactis boost immunity?

The evidence is limited: trials in older adults show increases in lab immune measures such as phagocytic activity, without demonstrating fewer infections.

Is Bifidobacterium lactis safe?

B. lactis is among the best-documented probiotics for safety, with adverse events comparable to placebo and mild gas at the start. Standard caution applies for severely immunocompromised or critically ill patients.

Scientific references

Related in Gut health