AB0043 The elasticity properties of probiotic bacteria wall associated with beneficial modulatory activity on innate immunity of the host
Authors: L.P. Babenko, R.V. Bubnov, L.M. Lazarenko, M.Y. Spivak
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Probiotics have tremendous potential to develop healthy diets and integrated approach for immunity-related diseases treatment and prevention;<sup>1,2</sup> are effective actors in distant sites<sup>3</sup> with strong potential for applications in rheumatology. The cell wall of probiotic bacteria plays an essential role in many aspects of modulating beneficial immune response;<sup>4</sup> its elasticity properties associated with probiotic beneficial effects and can warrant to stratify strains on their modulatory activity on innate immunity to justify individualised and personalised approach for nutrition and prevention. <h3>Objectives</h3> The aim was to study the effect of lactic acid bacteria (LAB) and bifidobacteria strains on phagocytic system cells functional activity and immunoregulatory cytokines synthesis <i>in vitro</i> in regards to the bacteria surface properties as cell walls elasticity using atomic force microscopy (AFM). <h3>Methods</h3> We conducted experimental studies on BALB/c line mice 18–20 g weight using lyophilized strains of LAB – <i>Lactobacillus acidophilus</i> IMV B-7279, <i>L. casei</i> IMV B-7280, <i>L. delbrueckii</i> subsp. <i>bulgaricus</i> IMV B-7281 and bifidobacteria – <i>Bifidobacterium animalis</i> VKL, <i>B. animalis</i> VKB. We cultivated the macrophages received from the peritoneal cavity of mice by common method individually with the strains of LAB and bifidobacteria. We estimated the impact of LAB and bifidobacteria strains on the functional activity of peritoneal cavity macrophages using the conventional methods of study oxygen-dependent bactericidal activity, nitric oxide production, their effect on the immunoregulatory cytokines. We used AFM scanning to estimate bacteria cell walls elasticity. <h3>Results</h3> All strains demonstrated a stimulating effect on the functional activity of macrophages and ability to produce NO/NO2 <i>in vitro</i>. Lactobacilli strains increased the production of IL-12 and IFN-γ <i>in vitro</i>. The AFM demonstrated different degree of the cell walls elasticity in various strains of LAB and bifidobacteria. Among lactobacilli the most elastic cell wall was found in <i>L. delbrueckii</i> subsp. <i>bulgaricus</i> IMV B-7281, and among bifidobacteria – in <i>B. animalis</i> VKL, which induced the considerable activation of the phagocytes. Probiotic strains survival in the macrophages depended on the elasticity of bacterial cell walls and on the time of their joint cultivation. <h3>Conclusions</h3> LAB and bifidobacteria strains stimulate immunomodulatory cytokines and active oxygen and nitrogen oxides compounds production in macrophages. Strains with a more elastic cell wall according to AFM data demonstrated higher resistance to intracellular digestion in macrophages and higher level of their activation. AFM might be considered as a fast and accurate method to assess parameters of probiotic strains cell wall to predict their beneficial immune-modulatory properties. Further large-scale preclinical research needed for future application in rheumatic diseases treatment and prevention. <h3>References</h3> [1] Bubnov RV, et al. EPMA J. 2015;6:14. https://doi.org/10.1186/s13167-015-0036-0 [2] Reid G, et al. Benef Microbes2017;8(4):521–533. https://doi.org/10.3920/BM2016.0222 [3] Bubnov RV, Babenko LP, Lazarenko LM, et al. EPMA Journal2017;8:357. https://doi.org/10.1007/s13167-017-0117-3 [4] Mokrozub VV, et al. EPMA Journal2015;6:13. https://doi.org/10.1186/s13167-015-0035-1 <h3>Disclosure of Interest</h3> None declared