I was reading a book recently, Chasm City. One of the plot points was that on particular planet the native animal life had a sufficiently different set of proteins that ingestion in either direction resulted in rapid and painful death. I’m not enough of a biologist to know if that’s possible but it seems plausible due to allergic reactions.
The problem, though, is that there was a viable human colony on the planet which was relatively low tech (not much beyond present day Earth for various reasons). This colony lived “outdoors”, i.e. not in hermetically sealed habitats. So the problem arises, how would you keep those native proteins out of the food supply? You would probably be quite surprised at how much food contamination is allowed. It’s permitted because it’s considered impossible to completely eliminate. This includes both animal and plant contaminants. It would seem likely to be even more difficult on a struggling colony world. It’s difficult to see how waves of food poisonings wouldn’t be the norm.
Just a minor nit but these things really bug me. Otherwise (i.e., for normal people), it was a good book.