This is correct and does not contradict anything I said. It is quite easy to try it for yourself and see if it does anything. Of course you will want to avoid consuming large amounts of other dairy sources while you are trying it.

In order to build confidence in the results of a personal experiment like this one, it's best to (double-)blind it as much as possible and log lots of concrete data every day (e.g. keep track of your bowel movements, sleep quality, alertness levels, blood pressure, etc). This should help limit the impact of any (conscious or subconscious) preconceptions or other psychosomatic effects.

Also, change as little else in your life as possible while you're performing the experiment to control for confounding variables.

While anecdotal evidence is useful it doesn't prove anything. Research is stronger, but more limited in scope.

My experience is that they eat a lot of potato chips and biscuits. Where do you get your vitamin b12 from?

Regardless, the rest of my comment points out why the person I was replying to is wrong. Even your comment points it out. All you need to do to be a vegan is not eat animal products. This means you can avoid all of the foods that are good for your biome. That was the entire point of the quote from the article that was completely missed by the op.

In addition, not all vegetables are equal with regards to bacteria.