Bifidobacterium animalis lactis

bacterianisin

What is it

Bifidobacterium animalis subsp. lactis is one of the most commonly used probiotic bacteria in commercial yogurts and supplements. It is notable for its robustness, surviving manufacturing, storage, and gastrointestinal transit better than many other Bifidobacterium species.

How it works

B. animalis subsp. lactis colonizes the colon transiently, where it ferments dietary fibers and other carbohydrates to produce short-chain fatty acids, primarily acetate. These acidify the colonic environment, support colonocyte energy supply, and create conditions less favorable for many pathogenic bacteria. It interacts with intestinal epithelial cells and the gut-associated immune system, supporting intestinal barrier function and modulating cytokine production. Some strains have been shown to improve transit time, which may underlie observed benefits for constipation and bowel regularity. The species is also notable for its bile salt hydrolase activity, which may influence lipid metabolism. Multiple strains have been extensively studied. BB-12 has the most published research, with applications in digestive health, immune function, and respiratory infections. DN-173 010 (used in some commercial yogurt brands) has been studied for constipation and bowel regularity. HN019 has been studied for digestive function and immunity in older adults. BL-04 has been studied for respiratory health.

Evidence for 5 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Constipation and bowel regularity

Grade B

Good evidence

Multiple trials of B. animalis subsp. lactis DN-173 010 and HN019 show modest improvement in stool frequency, consistency, and transit time in adults with functional constipation. Effect sizes are small but consistent.

Antibiotic-associated diarrhea prevention

Grade B

Good evidence

B. animalis subsp. lactis BB-12, often combined with Lactobacillus, reduces antibiotic-associated diarrhea incidence in both children and adults.

Gut microbiota modulation

Grade B

Good evidence

B. animalis subsp. lactis supplementation reliably increases fecal Bifidobacterium counts during use. This effect is transient and largely reverses after stopping supplementation.

Respiratory tract infections

Grade C

Moderate evidence

Trials of BB-12 and BL-04 in healthy adults suggest modest reduction in upper respiratory infection incidence or duration. Effect sizes are small.

Immune function in older adults

Grade C

Moderate evidence

Trials of BB-12 and HN019 in older adults show modest improvements in markers of innate immunity, including natural killer cell activity. Clinical translation to reduced infections varies by study.

4 commercial forms

B. animalis subsp. lactis BB-12

Robust acid and bile tolerance, well-studied

Most extensively researched strain in this species. Used in many branded yogurts and supplements globally.

B. animalis subsp. lactis DN-173 010

Studied for transit and constipation

Used in Activia and similar branded yogurts. Studied for bowel regularity in adults.

B. animalis subsp. lactis HN019

Studied for immunity and constipation

Used in adult and senior probiotic formulations targeting immune and digestive function.

B. animalis subsp. lactis BL-04

Studied for respiratory applications

Used in immune-targeted supplements, often with Lactobacillus strains.

Dosage

There is no RDA for probiotics. Clinical studies of B. animalis subsp. lactis typically use 1 to 100 billion CFU per day, with most trials in the 1 to 20 billion CFU range. BB-12 has been studied at 1 to 10 billion CFU daily. Commercial supplements commonly provide 1 to 20 billion CFU per dose; yogurts vary widely.

When and how to take it

B. animalis subsp. lactis can be taken with or without food. Taking with a small meal may improve survival through the stomach, though this strain is among the more robust probiotics. Consistency over weeks matters more than precise timing. For constipation or bowel regularity, allow 2 to 4 weeks of consistent use. Separate from antibiotic doses by at least 2 hours.

Food sources

Food	Amount	%DV
Activia yogurt (DN-173 010)	Approximately 10^9 to 10^10 CFU per serving	—
Other commercial yogurts with added BB-12	Variable; check label for live culture content	—
Kefir	Variable Bifidobacterium content	—

Safety

B. animalis subsp. lactis is generally well tolerated and has an excellent safety record from widespread use in fermented dairy products. Mild gas, bloating, or stool changes can occur initially. Serious adverse events are rare in healthy people. Immunocompromised individuals and critically ill patients face a small but documented risk of bacteremia. There is no established Tolerable Upper Intake Level.

Who should be cautious

Severely immunocompromised individuals, those with central venous catheters, and critically ill patients should consult their physician before taking live probiotic supplements. Premature infants should only receive probiotics under specialist supervision. Pregnant and breastfeeding women generally tolerate this species well.

Interactions

Antibiotics can kill probiotic organisms; separate doses by at least 2 hours. Immunosuppressive medications may increase the small risk of bacterial translocation. No well-documented interactions with most supplements or medications. Bile salt hydrolase activity could theoretically influence absorption of fat-soluble compounds, though clinically meaningful interactions are not documented.

Frequently asked questions

Why is BB-12 the most studied probiotic?⌄

BB-12 was one of the first commercially developed probiotic strains optimized for survival through manufacturing, storage, and digestion. Its long market presence has allowed for extensive research across many applications.

Is Activia yogurt actually effective for digestion?⌄

Trials of B. animalis DN-173 010 (used in Activia) show modest improvements in transit time and bowel regularity. Effects are small but real for many people, particularly those with mild constipation.

How quickly does B. animalis work for constipation?⌄

Trials typically show effects emerging over 2 to 4 weeks of consistent daily use. Effects reverse after stopping supplementation.

Can I take this with other probiotics?⌄

Yes. B. animalis subsp. lactis is commonly combined with Lactobacillus and other Bifidobacterium strains in multi-strain formulations.

Does it need to be refrigerated?⌄

Most B. animalis subsp. lactis supplements maintain potency at room temperature for the shelf life on the label, especially if encapsulated. Refrigeration generally extends viability.

References

ChEBI: nisin — ChEBI Database link
Wikidata: Bifidobacterium animalis subsp. lactis — Wikidata link

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.