Anti-influenza Activity of a Bacillus subtilis Probiotic Strain

Antimicrob Agents Chemother. 2017 Jun 27;61(7):e00539-17. doi: 10.1128/AAC.00539-17. Print 2017 Jul.


Among Bacillus bacteria, B. subtilis is the species that produces the most antimicrobial compounds. In this study, we analyzed the activity of probiotic strain B. subtilis 3 against the influenza virus. The antiviral effect of this strain has been demonstrated in vitro and in vivo A new peptide, P18, produced by the probiotic strain was isolated, purified, chemically synthesized, and characterized. Cytotoxicity studies demonstrated no toxic effect of P18 on Madin-Darby canine kidney (MDCK) cells, even at the highest concentration tested (100 μg/ml). Complete inhibition of the influenza virus in vitro was observed at concentrations of 12.5 to 100 μg/ml. The protective effect of P18 in mice was comparable to that of oseltamivir phosphate (Tamiflu). Further study will assess the potential of peptide P18 as an antiviral compound and as a promising candidate for the development of new antiviral vaccines.

Keywords: Bacillus subtilis; antiviral peptide; influenza virus; probiotics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiviral Agents / pharmacology
  • Bacillus subtilis / physiology*
  • Cell Line
  • Dogs
  • Humans
  • Influenza Vaccines / pharmacology
  • Influenza, Human / drug therapy
  • Influenza, Human / immunology*
  • Influenza, Human / prevention & control*
  • Madin Darby Canine Kidney Cells
  • Orthomyxoviridae / drug effects*
  • Orthomyxoviridae Infections / drug therapy
  • Orthomyxoviridae Infections / immunology
  • Orthomyxoviridae Infections / prevention & control
  • Oseltamivir / pharmacology
  • Probiotics / pharmacology*


  • Antiviral Agents
  • Influenza Vaccines
  • Oseltamivir