I think specifically the oligosaccharides in beans that, if your digestive system has not been accustomed to, will be unpleasant if you all of a sudden ingest a lot of. Also poorly prepared beans that have not been sufficiently soaked, etc. to draw these out.
95% of Americans don’t get their recommended daily amount of fiber. So when they finally do have beans, it’s an experience.
I think specifically the oligosaccharides in beans that, if your digestive system has not been accustomed to, will be unpleasant if you all of a sudden ingest a lot of. Also poorly prepared beans that have not been sufficiently soaked, etc. to draw these out.