50 years ago, there were a wide array of animal and vegetable based gums, gelatins and adhesives deployed and in use. Generally they were water soluble. Gum Arabic is one you've probably heard of. Acacia gum is another. Horse hooves used to be another source, in addition to various other ones derived from animal offal, skeletons, connective tissues, etc. There was even one (isinglass) derived from the swim bladders of some fish.
They mostly fell from favor as plastic alternatives and options exploded. Pressure from animal rights groups also ended production of others - I'm uncertain if hoove derived glues are even a thing any more. It may be that the technology became arcane and it was abandoned, or maybe it was regulated out of existence. But the point is natural alternatives were once used - and perhaps could be again. Not everything requires a high tech solution.