Fermented foods-improved nutritive value and easily digestible too

First off, fermentation is a process where the foods are allowed to be acted upon by friendly bacteria that then digest previously undigestible components of foods and then make them more available in a form which is easily absorbed in the gut.
How does it increase nutritive value?
Well the microbes covert certain foods structures into simpler forms that can then be absorbed with ease in the gut and such.
Examples of fermented foods you might ask
Even simply soaking and sprouting your beans prior to cooking will prevent flatulence or farting later.
farting primarily with bean consumption is due to the fact that bean shells have a sugar called raffinose which has no corresponding enzyme in our body to digest it.
Microbes on the other hand are able to digest this sugar and make it simpler .
If we consume raffinose as such, it never gets absorbed and therefore reaches our large intestine where there the bacteria in the gut convert it into gas .
other examples of fermented foods will be
Fermented rice and black lentil cake very famous in southern india called as Idli
Fermented lentil flour pancakes very famouns in ethiopia and locally called as injera.
Tempeh , fermented soybean cake , very nutritive and used commonly in java.
Fermented soy bean cake , especially in china.

Some fermented food may be highly sour too and some of them might qualify as an acquired taste too..But, hey, anything vegetarian or vegan is worth trying.