IELTS Reading: gap-fill

 A student asked me for help with this exercise from Cambridge IELTS 14.

Here's the relevant part of the passage:

There are even more insects that are masters of exploiting filthy habitats, such as faeces and carcasses, where they are regularly challenged by thousands of microorganisms. These insects have many antimicrobial compounds for dealing with pathogenic bacteria and fungi, suggesting that there is certainly potential to find many compounds that can serve as or inspire new antibiotics.

Choose ONE WORD from the passage to fill each gap below.

They are also interested in compounds which insects use to protect themselves from pathogenic bacteria and fungi found in their _____. Piper hopes that these substances will be useful in the development of drugs such as _____.