Following are a number of back-translations as well as a sample translation for translators of Proverbs 15:30:

• Kupsabiny: “A happy person makes people happy,
  and good news strengthens/encourages people.” (Source: Kupsabiny Back Translation)
• Newari: “A face full of joy makes the heart happy.
  Good news gives strength to the body.” (Source: Newari Back Translation)
• Hiligaynon: “A cheerful face can-give joy, and a good news can-strengthen.” (Source: Hiligaynon Back Translation)
• Kankanaey: “A person who smiles causes-happiness and good news causes-encouragement.” (Source: Kankanaey Back Translation)
• English: “If people have a smile on their faces, it makes them/others happy,
  and when people hear good news, it refreshes their spirits.” (Source: Translation for Translators)