An antimicrobial peptide variant having an amino acid sequence selected from SEQ ID NOs: 2-30 is provided. The antimicrobial peptide variant can have antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Staphylococcus aureus MRSA, Staphylococcus epidermidis, Cutibacterium acnes, or Clostridium perfringens. A composition, pharmaceutical composition, food additive, cosmetic composition, or hygiene product having an antimicrobial peptide variant including an amino acid sequence selected from SEQ ID NOs: 2-30 is also provided. The antimicrobial peptide can be an active ingredient in such compositions, additives, and products. A method of treating an infectious disease caused by bacteria is also provided. The method can include administering a pharmaceutical composition having the antimicrobial peptide as an active ingredient.