That is part of it, but not the complete story. I talked about the same things in a comment elsewhere here, but in a nutshell it’s the combination of fiber and the oligosaccharides in beans. The latter is what leeches out into the bean juice, which is why rinsing beans can go a long way toward reducing gas.

But for the fiber there is no getting around the need to just eat it everyday to get the microbiome adjusted to it. Where people go wrong is eating a ton of high fiber foods all at once and getting miserable with a ton of gas. It’s better to add those foods more gradually to get used to them.