Any greek yogurts are supposed to be really good for you
"Eustress" is a positive psychological response to a stressor as indicated by the presence of positive psychological states such as enthusiasm, motivation, excitement, activeness, alertness.
-Medical Student (College Level)
The best Therapeutic response would be to ensure to his coworker that every thing is okay and what they are doing is to help prevent infections.
You can by planting mint or dandelions<span> </span>which will attract lacewings and ladybug which will eat the aphids. I would know because I had the same problem and planting those plants helped.