Entry 23
Probiotic science page
Uses competitive pathogen exclusion and immune modulation to reduce infections and allergy symptoms, with RCT support.
Overview
B. longum BB536 is a probiotic strain isolated from the feces of a healthy breastfed infant by Morinaga Milk Industry (Japan) in 1969 [1]. It is one of the longest continuously marketed probiotic strains worldwide. It has over 100 clinical studies and regulatory recognition including GRAS status (FDA) and Qualified Presumption of Safety (EFSA) [1,2]. Primary clinical applications include improvement of defecation frequency and bowel habits in elderly constipation and tuning of the immune system [1,3].
Mechanism
BB536 activates plasmacytoid dendritic cells (pDCs) in peripheral blood. This promotes type-1 interferon responses and enhances innate antiviral immunity [3]. The strain modifies intestinal microbiota composition. It increases production of short-chain fatty acids (fuel for gut cells), primarily acetate. It also increases fecal butyrate concentrations via cross-feeding interactions [1,2]. BB536 produces extracellular polysaccharides and pili-like structures. These facilitate sticking to cells lining the gut and exclusion of harmful enteric bacteria [1]. Viability studies confirm BB536 survives gastrointestinal transit. Viable cells are recovered in feces [2].
Health Benefits
Takeda et al. (2023) conducted a double-blind RCT (n=84, elderly with chronic constipation). They showed BB536 supplementation significantly increased spontaneous bowel movement frequency from 3.3 to 4.8 per week. Placebo only increased from 3.3 to 3.6 per week (P<0.05) [1] [RCT]. Sato et al. (2024) conducted an RCT (n=90). They demonstrated that 12-week BB536 + B. breve MCC1274 supplementation reduced visceral fat area in normal and overweight adults vs. placebo (P<0.05) [4] [RCT]. Li et al. (2023) conducted an RCT (n=98). They showed BB536 activated pDCs in peripheral blood with increased IFN-alpha production capacity compared to placebo [3] [RCT]. Miraglia Del Giudice et al. (2017) conducted an RCT (n=40 children) using a three-strain Bifidobacterium mixture containing BB536. They reported significant reduction in allergic rhinitis symptom scores (P<0.05) [5] [RCT, multi-strain]. Inoue et al. (2018) conducted an RCT (n=38 healthy elderly). They found combined BB536 supplementation with resistance training improved cognitive function scores [6] [RCT]. Sen et al. (2025) confirmed viable BB536 detection in fecal samples after oral administration. They used molecular and cultivation methods [2].
Biology
Taxonomy: B. longum subsp. longum, following the Mattarelli et al. (2008) reclassification [7]. It is Gram-positive, only grows without oxygen, non-motile, and non-spore-forming. It is a rod with characteristic bifid morphology (Y-shaped or bifid forms). It metabolizes carbohydrates via fructose-6-phosphate phosphoketolase (bifid shunt). This produces acetate and L(+)-lactate in a theoretical 3:2 ratio. Habitat: infant gastrointestinal tract. It is a human milk-associated species.
Bibliography
Takeda T, Asaoka D, Nojiri S, Yanagisawa N, Nishizaki Y, Osada T, et al. (2023). Usefulness of Bifidobacterium longum BB536 in Elderly Individuals With Chronic Constipation: A Randomized Controlled Trial. Am J Gastroenterol. 118(3):561-568. PMID: 36216361
Sen A, Kimura M, Ejima R, Arai S, Mitsuyama E, Kaneko H, et al. (2025). Probiotic viability in the gastrointestinal tract in a randomised placebo controlled trial: combining molecular biology and novel cultivation techniques. Benef Microbes. 16(3):271-280. PMID: 39814039
Li Y, Arai S, Kato K, Iwabuchi S, Iwabuchi N, Muto N, et al. (2023). The Potential Immunomodulatory Effect of Bifidobacterium longum subsp. longum BB536 on Healthy Adults through Plasmacytoid Dendritic Cell Activation in the Peripheral Blood. Nutrients. 16(1):42. PMID: 38201872
Sato S, Arai S, Kato K, Yoshida K, Iwabuchi N, Sagami T, et al. (2024). Effects of Bifidobacterium longum BB536 and Bifidobacterium breve MCC1274 on Body Composition in Normal and Overweight Adults in Randomized Placebo-Controlled Study. Nutrients. 16(6):815. PMID: 38542727
Miraglia Del Giudice M, Indolfi C, Capasso M, Maiello N, Decimo F, Ciprandi G. (2017). Bifidobacterium mixture (B longum BB536, B infantis M-63, B breve M-16V) treatment in children with seasonal allergic rhinitis and intermittent asthma. Ital J Pediatr. 43(1):25. PMID: 28270216
Inoue T, Kobayashi Y, Mori N, Sakagawa M, Xiao JZ, Moritani T, et al. (2018). Effect of combined bifidobacteria supplementation and resistance training on cognitive function, body composition and bowel habits of healthy elderly subjects. Benef Microbes. 9(6):843-853. PMID: 30198326
Mattarelli P, Bonaparte C, Pot B, Biavati B. (2008). Proposal to reclassify the three biotypes of Bifidobacterium longum as three subspecies: Bifidobacterium longum subsp. longum subsp. nov., Bifidobacterium longum subsp. infantis comb. nov. and Bifidobacterium longum subsp. suis comb. nov. Int J Syst Evol Microbiol. 58(Pt 4):767-72. PMID: 18398167
Available Products
Morinaga supplies BB536 as freeze-dried powder (BB536 Probiotic Cultures) to manufacturers worldwide. It is marketed in functional foods including yogurt (Morinaga Bifidus Yogurt) and dietary supplements in Japan. It is also available as dietary supplement capsules in North America and Europe, and in functional foods throughout Asia [1].