Entry 21
Probiotic science page
Modulates gut transit time and immune cell activity to improve constipation and reduce infections, with RCT support.
Overview
B. animalis subsp. lactis HN019 is a commercially important probiotic strain. It was originally isolated from a yogurt source in New Zealand [1]. The New Zealand Dairy Research Institute developed it. It is now owned by DuPont (now IFF) under the Howaru Bifido brand [1,2]. HN019 has documented human RCT evidence for immune enhancement in the elderly, gut transit time improvement, and functional constipation [2,3].
Mechanism
HN019 enhances both innate and adaptive immune responses. It increases phagocytic activity of peripheral blood polymorphonuclear leukocytes and natural killer cell activity, as demonstrated in elderly populations [3,4]. The strain increases fecal concentrations of short-chain fatty acids (fuel for gut cells). It modifies the colonic microbiota composition. It consistently increases fecal bifidobacterial and lactobacilli counts [2,4]. Lab tests show HN019 sticks to cells lining the gut via mucus-binding proteins. It produces acetate, the primary energy source for colon cells [5].
Health Benefits
Gill et al. (2001) conducted a double-blind RCT (n=30 healthy elderly). They showed that 3-week HN019 supplementation significantly increased phagocytic capacity of PMN cells (P<0.05) and NK cell tumoricidal activity [3] [RCT]. Miller et al. (2017) conducted a systematic review and meta-analysis (pools results from multiple trials) covering four RCTs (n=204). They confirmed HN019 enhances cellular immune function in healthy elderly adults. Pooled effect sizes were significant for both phagocytic activity and NK cell activity [4] [systematic review + meta-analysis]. Waller et al. (2011) conducted an RCT (n=100). They demonstrated dose-dependent reduction in whole gut transit time (WGTT). The 1.7×10^10 CFU (colony-forming units, a live bacteria count)/day dose reduced WGTT from 49 to 36 hours (P=0.01) [2] [RCT]. Two large 2024–2025 RCTs (n=229 and n=237) confirmed HN019 efficacy for functional constipation in Chinese adults. They showed significant improvements in spontaneous bowel movement frequency [6,7] [RCTs]. Cheng et al. (2021) comprehensively reviewed HN019 gut health effects. These include constipation, gut transit, and microbiota modulation [1] [review].
Biology
Taxonomy: B. animalis subsp. lactis, per the Masco et al. (2004) reclassification [8]. It is Gram-positive, only grows without oxygen, non-motile, and non-spore-forming. It is a rod-shaped bacterium. It ferments glucose via fructose-6-phosphate phosphoketolase (bifid shunt). This produces acetate and L(+)-lactate. The strain was originally isolated from dairy culture. It is characterized by acid and bile tolerance suitable for gastrointestinal survival.
Bibliography
Cheng J, Laitila A, Ouwehand AC. (2021). Bifidobacterium animalis subsp. lactis HN019 Effects on Gut Health: A Review. Front Nutr. 8:790561. PMID: 34970580
Waller PA, Gopal PK, Leyer GJ, Ouwehand AC, Reifer C, Stewart ME, et al. (2011). Dose-response effect of Bifidobacterium lactis HN019 on whole gut transit time and functional gastrointestinal symptoms in adults. Scand J Gastroenterol. 46(9):1057-64. PMID: 21663486
Gill HS, Rutherfurd KJ, Cross ML, Gopal PK. (2001). Enhancement of immunity in the elderly by dietary supplementation with the probiotic Bifidobacterium lactis HN019. Am J Clin Nutr. 74(6):833-9. PMID: 11722966
Miller LE, Lehtoranta L, Lehtinen MJ. (2017). The Effect of Bifidobacterium animalis ssp. lactis HN019 on Cellular Immune Function in Healthy Elderly Subjects: Systematic Review and Meta-Analysis. Nutrients. 9(3):191. PMID: 28245559
D’Ambrosio S, Dabous A, Sadiq S, Casillo A, Schiraldi C, Cassese E, et al. (2024). Bifidobacterium animalis subsp. lactis HN019 live probiotics and postbiotics: production strategies and bioactivity evaluation for potential therapeutic properties. Front Bioeng Biotechnol. 12:1379574. PMID: 39055336
Cheng J, Gao C, Ala-Jaakkola R, Forssten SD, Saarinen M, Hibberd A, et al. (2024). Eight-Week Supplementation With Bifidobacterium lactis HN019 and Functional Constipation: A Randomized Clinical Trial. JAMA Netw Open. 7(10):e2436888. PMID: 39356506
Ala-Jaakkola R, Forssten SD, Cheng J, Griffon F, Metreau I, Sturm Y, et al. (2025). Effect of an 8-Week Bifidobacterium lactis HN019 Supplementation on Functional Constipation: A Multi-Center, Triple-Blind, Randomized, Placebo-Controlled Trial. Mol Nutr Food Res. 69(17):e70081. PMID: 40320938
Masco L, Ventura M, Zink R, Huys G, Swings J. (2004). Polyphasic taxonomic analysis of Bifidobacterium animalis and Bifidobacterium lactis reveals relatedness at the subspecies level: reclassification of Bifidobacterium animalis as Bifidobacterium animalis subsp. animalis subsp. nov. and Bifidobacterium lactis as Bifidobacterium animalis subsp. lactis subsp. nov. Int J Syst Evol Microbiol. 54(Pt 4):1137-1143. PMID: 15280282
Available Products
Howaru Bifido (DuPont/IFF) is supplied as frozen concentrate and freeze-dried powder for dietary supplements and functional foods. It is used in various multivitamin and mineral formulations, probiotic capsules, and fortified dairy products. These are primarily in Asia-Pacific and North American markets [1].