Open AccessPhysical properties of lactic acid bacteria influence the level of protection against influenza infection in mice
Author(s) -
Taiji Watanabe,
Kyoko Hayashi,
Isao Takahashi,
Makoto Ohwaki,
Tatsuhiko Kan,
Toshio Kawahara
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0251784
Subject(s) - lactic acid , bacteria , microbiology and biotechnology , enterococcus faecalis , virus , immune system , streptococcaceae , biology , chemistry , virology , staphylococcus aureus , immunology , antibiotics , genetics
We evaluated whether the water dispersibility of lactic acid bacteria ( Enterococcus faecalis KH2) affects their efficacy. When cultured lactic acid bacteria are washed, heat-killed, and powdered, adhesion occurs between results in aggregation (non-treated lactic acid bacteria, n-LAB). However, dispersed lactic acid bacteria (d-LAB) with a lower number of aggregates can be prepared by treating them with a high-pressure homogenizer and adding an excipient during powdering. Mice were administered n-LAB or d-LAB Peyer’s patches in the small intestine were observed. Following n-LAB administration, a high amount of aggregated bacteria drifting in the intestinal mucosa was observed; meanwhile, d-LAB reached the Peyer’s patches and was absorbed into them. Evaluation in a mouse influenza virus infection model showed that d-LAB was more effective than n-LAB in the influenza yield of bronchoalveolar lavage fluids on day 3 post-infection and neutralizing antibody titers of sera and influenza virus-specific immunoglobulin A in the feces on day 14 post-infection. Therefore, the physical properties of lactic acid bacteria affect their efficacy; controlling their water dispersibility can improve their effectiveness.