Fermented Meats / Fishes
Most dried salted meats (and fishes?) could not be preserved without the help of the (lactic) bacteria living on it.
A possible research program would be the comparisons of the different traditions throughout the world and to identifiy the bacteria involved.
Another program would be to study the process of garum making.
(Idem with the nước mắm and the Worcestershire sauce).