Emeritus Professor Ross Barnard

Independent Review

Common Probiotic Strains


The following is an independent review of probiotic strains conducted by Emeritus Ross Barnard, on behalf of PERKii. The information presented is general and based on publicly available research for educational purposes. It is not intended to be a reflection of the specific benefits of consuming PERKii products.

About Emeritus Professor Ross Barnard:

Ross has a BSc(hons) in microbiology and microbial genetics (Melb./Monash), a PhD in Physiology and a Higher Doctorate (in diagnostics development) from the University of Queensland. He was an NHMRC C.J. Martin fellow at the University of California and held a National Health and Medical Research Council RD Wright Fellowship between 1993 – 1996.

He was a Senior Research Fellow at the Collaborative Research Centre for Diagnostic Technologies and nucleic acids diagnostics program leader at PanBio Ltd before returning to in 2000, to direct the Biotechnology teaching program. He is a Fellow of the Australian Society for Microbiology and a Fellow of the American Association for Clinical Chemistry.

Ross’s research focus has been in the endocrinology of growth, the development of new diagnostic technologies to detect infectious disease agents, and antibody engineering for diagnostic and therapeutic applications in infectious disease and cancer.

Lactobacillus casei CRL431 and Bifidobacterium animalis BB-12: a review of reported health benefits, with a focus on human clinical trials

Lactobacillus and Bifidobacterium species colonize the gastrointestinal tract and the urogenital tract of humans. They are found in a wide variety of food products and fermented products. They are listed as GRAS (generally recognized as safe) by the United States Food and Drug Administration (FDA), and they are listed as QPS (qualified presumption of safety) by the European Food Safety Authority (Hill et al., 2018; Jungersen et al., 2014).

Based on the summarised studies below, probiotic strains LC431 and BB12 may support the body’s immune function.

In infants, faecal levels of total IgA and anti-poliovirus IgA during intake of a formula containing Bifidobacterium lactis BB-12 were significantly higher than those before intake.The increase in local IgA levels resulting from ingestion of the probiotic formula may contribute to enhancement of the mucosal resistance against gastrointestinal infections (Fukushima et al., 2011).

Van Baarlen et al. (2011) suggested on the basis of their clinical trial results, that consumption of L. casei CRL-431 may promote a shift in the Th1/Th2 balance towards a Th2 type and/or Th17 type, the latter consistent with the observed up-regulation of IL-17D (syn. IL-22) and IL-21. IL-15, IL-17D (IL-22), and IL-21 which are also involved in development of natural killer cells.

Note: Th1 type immune responses are more effective against intracellular pathogens (viruses and bacteria). Th2 responses are more effective against extracellular bacteria and parasites, and are involved in class switching of B-cell production of immunoglobulins to IgA, IgG1 and IgE. IgA is the immunoglobulin most important for protection of mucosal surfaces.

The study by Zhang et al (2018) utilised Lactobacillus casei CRL 431 in combination with two other strains of Lactobacillus and reported that subjects who consumed probiotics demonstrated a significantly higher level of IFN-γ in the serum (p < 0.001) and sIgA in the gut (p < 0.010) as compared to the placebo group and a significant higher level of serum IFN-γ (p < 0.001) and gut sIgA (p < 0.001) compared to their baseline test results. The authors reported that the study demonstrated that probiotics were safe and effective for fighting the common cold and influenza-like respiratory infections by boosting the immune system.

Research using four strains of Lactobacillus ( L. casei CRL431 was not tested) demonstrated that IL-1β expression was induced by L. helveticus and L. casei, but not by two other species of Lactobacillus.. IL-1 β plays an important role in the costimulation of T lymphocytes. This result is indicative of differences between strains in relation to effects on the immune system. Phagocytosis and bactericidal activity of cultured human macrophages against various pathogens, such as S. aureus, S. typhimurium, and E. coli, were increased by pretreatment with Lactobacillus (Rocha-Ramirez et al., 2017).

Bifidobacterium BB-12 has been reported by Meng et al., (2017) to reduce pro-inflammatory cytokines in healthy adults. The delivery matrix influences the immunomodulatory properties of BB-12, with the effects only observed when BB-12 was added to yoghurt after fermentation.

Mohan et al. (2008) conducted a double blind, placebo controlled randomized clinical study was performed on 69 preterm infants. In the probiotic group, orally treated with Bifidobacterium BB-12 faecal IgA was higher compared with the placebo group (p = 0.021).

Taken together, the experiments support the suggestion that probiotic strains of Lactobacillus, including Lactobacillus casei CRL 431 and Bifidobacterium BB-12 exert immunostimulatory effects that may be linked to the initial response to pathogens by human macrophages and an increase in IgA levels.


- Fukushima Y, Kawata Y, Hara H, Terada A, Mitsuoka T. Effect of a probiotic formula on intestinal immunoglobulin A production in healthy children. Int J Food Microbiol 1998;42:39–44.

- Van Baarlen P, Troost F, van der Meer C, Hooiveld G, BoekschotenM, Brummer R J M and Kleerebezem M. Human mucosal in vivo transcriptome responses to three lactobacilli indicate how probiotics may modulate human cellular pathways. Proc Natl Acad Sci U S A. 2011 Mar 15; 108(Suppl 1): 4562–4569. doi: 10.1073/pnas.1000079107

- Zhang H, Yeh C , Jin Z, Ding L, Liu B Y, Zhang L, Dannelly H K. Prospective study of probiotic supplementation results in immune stimulation and improvement of upper respiratory infection rate. Synth Syst Biotechnol. 2018 Jun; 3(2): 113–120. doi: 10.1016/j.synbio.2018.03.001

- Rocha-Ramírez L M, Pérez-Solano R A, Castañón-Alonso S L, Moreno Guerrero S S, Ramírez Pacheco A, García Garibay M and Eslava C. Probiotic Lactobacillus Strains Stimulate the Inflammatory Response and Activate Human Macrophages. J Immunol Res. 2017; 2017: 4607491. doi: 10.1155/2017/4607491

- Meng H., Ba Z., Lee Y., Peng J., Lin J., Fleming J. A., et al. (2017). Consumption of Bifidobacterium animalis subsp. lactis BB-12 in yogurt reduced expression of TLR-2 on peripheral blood-derived monocytes and pro-inflammatory cytokine secretion in young adults. Eur. J. Nutr. 56 649–661. 10.1007/s00394-015-1109-5

- Mohan R, C. Koebnick, et al. (2008). Effects of Bifidobacterium lactis Bb12 supplementation on body weight, fecal pH, acetate, lactate, calprotectin, and IgA in preterm infants. Pediatr Res 64(4): 418-422.

Based on the summarised studies below, probiotic strains LC431 and BB12 may support the body’s response to vaccines.

A trial undertaken in 2012 (Rizzardini et al.), reported in the British Journal of Nutrition, found significant enhancing effects of both bifidobacterium and lactobacillus casei on the levels of antibodies (IgG, IgG1, IgG3 and vaccine specific secretory IgA) to Influenza A after vaccination.

Another human trial in 2015 reported that daily consumption of lactobacillus casei resulted in no observable effect on the components of the immune response to influenza vaccination but reduced the duration of upper respiratory symptoms.

A clinical trial (2011) using another strain of Lactobacillus (Lactobacillus GG) showed that this organism acted as an adjuvant, improving influenza vaccine immunogenicity.

A clinical study published in 2005 (deVrese et al.) utilised two different probiotics, Lactobacillus rhamnosus GG or L. acidophilus CRL431. The probiotics induced significantly higher levels of neutralising antibodies and higher levels of anti-polio serum IgG and IgA after oral polio vaccination.

A clinical trial reported in 2012 (Holscher et al.) reported that infants consuming formula with Bb12 produced faeces with detectable presence of Bb12 and augmented sIgA concentration. Moreover, Caesarean-delivered infants consuming Bb12 had heightened immune response, evidenced by increased anti-rotavirus- and anti-poliovirus-specific IgA following immunization. These results demonstrate that negative immune-related effects of not breastfeeding and Caesarean delivery can be mitigated by including Bb12 in infant formula, providing infants a safe, dietary, immune-modulating bacterial introduction.

Three of four relevant studies with BB-12 or L.casei 431 support the assertion that some specific probiotics can boost antibody responses to some oral or systemically administered vaccines, including an increase in sIgA (secretory iGA).


- Rizzardini G, Eskesen D, Calder PC, Capetti A, Jespersen L, Clerici M. Evaluation of the immune benefits of two probiotic strains Bifidobacterium animalis ssp. lactis, BB-12 and Lactobacillus paracasei ssp. paracasei, L. casei 431 in an influenza vaccination model: a randomised, double-blind, placebo-controlled study. Br J Nutr. 2012 Mar;107(6):876-84. doi: 10.1017/S000711451100420X.

- Lillian Jespersen, Inge Tarnow, Dorte Eskesen, Cathrine Melsaether Morberg, Birgit Michelsen, Susanne Bügel, Lars Ove Dragsted, Ger T Rijkers, and Philip C Calder Effect of Lactobacillus paracasei subsp. paracasei, L. casei 431 on immune response to influenza vaccination and upper respiratory tract infections in healthy adult volunteers: a randomized, double-blind, placebo-controlled, parallel-group study1–4 Am J Clin Nutr 2015;101:1188–96. doi: 10.3945/ajcn.114.103531

- Davidson LE, Fiorino AM, Snydman DR, Hibberd PL. Lactobacillus GG as an immune adjuvant for live-attenuated influenza vaccine in healthy adults: a randomized double-blind placebo controlled trial. Eur J Clin Nutr. 2011; 65:501–507.

- De Vrese, M, Rautenberg, P, Laue, C et al. (2005) Probiotic bacteria stimulate virus-specific neutralizing antibodies following a booster polio vaccination. Eur J Nutr 44, 406–413.

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