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PLoS One
. 2021 May 18;16(5):e0251784.
doi: 10.1371/journal.pone.0251784. eCollection 2021.
Physical properties of lactic acid bacteria influence the level of protection against influenza infection in mice
Takumi Watanabe 1 2 , Kyoko Hayashi 2 , Isao Takahashi 3 , Makoto Ohwaki 4 , Tatsuhiko Kan 1 , Toshio Kawahara 5
Affiliations
- PMID: 34003877
- DOI: 10.1371/journal.pone.0251784
Abstract
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.