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Bacterium

Bifidobacterium animalis subsp. lactis

Common name: B. animalis

Beneficial Digestive Gut
Beneficial
Effect
Digestive
Impact
Gut
Location
Common
Prevalence
Last reviewed: March 18, 2026

Probiotic, immune support, lactose digestion

Overview

Bifidobacterium animalis subsp. lactis — commonly abbreviated B. animalis and still widely called Bifidobacterium lactis in the clinical and commercial literature — is among the most commercially important probiotic species in the genus Bifidobacterium. Multiple genetically distinct strains, including Bi-07, BB-12, HN019, and Bl-04, have been independently studied for applications ranging from lactose digestion and gastrointestinal symptom relief to innate immune function. Despite sharing highly similar genomes, these strains show meaningful differences in their clinical evidence profiles, reinforcing the principle that probiotic benefits must be evaluated strain-by-strain rather than extrapolated from species-level data.

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Documented Strains

Bi-07

Bifidobacterium animalis subsp. lactis Bi-07

Moderate research
ATCC SD-5220
Lactose intoleranceImmune defense in older adultsBloating and IBS symptoms

Key Findings

Lactose intolerance

Helped digest lactose as well as lactase supplements

Immune defense in older adults

Immune cells significantly more active against pathogens

The only B. animalis subsp. lactis strain tested head-to-head against commercial lactase supplements in clinical trials and shown to match lactase performance for lactose digestion — a clinically meaningful benchmark no other Bifidobacterium strain has cleared in published RCTs

BB-12

Bifidobacterium animalis subsp. lactis BB-12

Extensive research
DSM 15954

(1983)

Antibiotic-associated diarrheaBowel regularityRespiratory infections in infantsInfant colic

Key Findings

Antibiotic-associated diarrhea

Loose stools cut from 44% to 26% during antibiotic course

Bowel regularity

About 1.5 extra bowel movements per week in the largest probiotic bowel trial ever run

Respiratory infections in infants

Infection rate fell from 94% to 65% of infants over 7 months

Infant colic

Twice the reduction in daily crying episodes vs placebo

The world's most clinically documented probiotic Bifidobacterium — over 300 publications including positive RCTs across four distinct domains (AAD prevention, gut regularity, pediatric respiratory infections, and infant colic). No other B. animalis subsp. lactis strain has matched this breadth of independent clinical evidence.

A6

Bifidobacterium animalis subsp. lactis A6

Limited research
Perennial allergic rhinitis symptom reliefIL-13 (Th2) suppressionTotal IgE reduction

Key Findings

Perennial allergic rhinitis

Total nasal symptom score fell significantly more than placebo (Cohen's d=0.68)

Th2 cytokine suppression in allergy

IL-13 significantly reduced (p<0.01) and total IgE fell 54 kU/L vs placebo

The first B. animalis subsp. lactis strain tested in a dedicated perennial allergic rhinitis RCT — demonstrating a clinically meaningful TNSS reduction (Cohen's d=0.68) alongside significant IL-13 suppression and total IgE reduction in dust-mite allergic adults, representing the strongest allergy-specific clinical evidence of any B. animalis strain

B420

Bifidobacterium animalis subsp. lactis B420

Moderate research
DSM 32269
Weight managementBody fat reductionMetabolic syndromeGut barrier function

Key Findings

Body fat reduction

Total body fat mass reduced 4.0% vs placebo in 6-month RCT

Metabolic health

Energy intake reduced ~210 kcal/day (p=0.037)

Strongest published human clinical evidence among B. animalis subsp. lactis strains for abdominal fat reduction; effect amplified in combination with prebiotic fiber; mechanism linked to improved gut permeability via zonulin biomarker

CECT 8145

Bifidobacterium animalis subsp. lactis CECT 8145

Limited research
CECT 8145 DSM 25566
Abdominal obesityMetabolic healthPostbiotic applications

Key Findings

Abdominal obesity

Heat-killed form reduced visceral fat −7.01 cm² and increased Akkermansia

Unique in that its heat-killed (postbiotic) form demonstrated superior efficacy to live cells for visceral fat reduction; the Akkermansia-enhancing effect may underlie its metabolic benefits

Associated Conditions

Related Organisms

Frequently Asked Questions

What is Bifidobacterium animalis subsp. lactis?

Bifidobacterium animalis subsp. lactis is a bacterium found in the human microbiome.

Where is Bifidobacterium animalis subsp. lactis found in the body?

Bifidobacterium animalis subsp. lactis is primarily found in the Gut.

What are the health impacts of Bifidobacterium animalis subsp. lactis?

Bifidobacterium animalis subsp. lactis primarily impacts Digestive and is beneficial for human health.

Research References

  1. Rasinkangas P, Forssten SD, Marttinen M, et al.. Bifidobacterium animalis subsp. lactis Bi-07 supports lactose digestion in vitro and in randomized, placebo- and lactase-controlled clinical trials. American Journal of Clinical Nutrition. 2022. doi:10.1093/ajcn/nqac264
  2. Maneerat S, Lehtinen MJ, Childs CE, et al.. Consumption of Bifidobacterium lactis Bi-07 by healthy elderly adults enhances phagocytic activity of monocytes and granulocytes. Journal of Nutritional Science. 2013. doi:10.1017/jns.2013.31
  3. Ringel-Kulka T, Palsson OS, Maier D, et al.. Probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 versus placebo for the symptoms of bloating in patients with functional bowel disorders: a double-blind study. Journal of Clinical Gastroenterology. 2011. doi:10.1097/MCG.0b013e31820ca4d6
  4. Leyer GJ, Li S, Mubasher ME, Reifer C, Ouwehand AC. Probiotic effects on cold and influenza-like symptom incidence and duration in children. Pediatrics. 2009. doi:10.1542/peds.2008-2666
  5. Merenstein D, Fraser CM, Roberts RF, et al.. Bifidobacterium animalis subsp. lactis BB-12 Protects against Antibiotic-Induced Functional and Compositional Changes in Human Fecal Microbiome. Nutrients. 2021. doi:10.3390/nu13082814
  6. Eskesen D, Jespersen L, Michelsen B, Whorwell PJ, Müller-Lissner S, Morberg CM.. Effect of the probiotic strain Bifidobacterium animalis subsp. lactis, BB-12®, on defecation frequency in healthy subjects with low defecation frequency and abdominal discomfort: a randomised, double-blind, placebo-controlled, parallel-group trial. British Journal of Nutrition. 2015. doi:10.1017/S0007114515003347
  7. Taipale T, Pienihäkkinen K, Isolauri E, et al.. Bifidobacterium animalis subsp. lactis BB-12 in reducing the risk of infections in infancy. British Journal of Nutrition. 2011. doi:10.1017/S0007114510003685
  8. Nocerino R, De Filippis F, Cecere G, et al.. The therapeutic efficacy of Bifidobacterium animalis subsp. lactis BB-12® in infant colic: A randomised, double blind, placebo-controlled trial. Alimentary Pharmacology & Therapeutics. 2020. doi:10.1111/apt.15561
  9. Costabile A, Buttarazzi I, Kolida S, et al.. Effects of Bifidobacterium animalis subsp. lactis BB-12® on the lipid/lipoprotein profile and short chain fatty acids in healthy young adults: a randomized controlled trial. Nutrition Journal. 2017. doi:10.1186/s12937-017-0261-6
  10. Wang L, Gao X, Li Y, et al.. Bifidobacterium animalis subsp. lactis A6 supplementation improves symptoms of perennial allergic rhinitis: a randomized, double-blind, placebo-controlled trial. Clinical and Translational Allergy. 2025. doi:10.1002/clt2.70064
  11. Stenman LK, Lehtinen MJ, Meland N, et al.. Probiotic With or Without Fiber Controls Body Fat Mass, Associated With Serum Zonulin, in Overweight and Obese Adults — Randomized Controlled Trial. EBioMedicine. 2016. doi:10.1016/j.ebiom.2016.10.036
  12. Cano PG, Aguero G, Perdigon G, et al.. Effect of a probiotic and a postbiotic of Bifidobacterium animalis subsp. lactis on body adiposity and metabolic biomarkers in abdominally obese subjects. International Journal of Obesity. 2019. doi:10.1038/s41366-018-0220-0