I always enjoy a good article on farting and, while this article is informative and interesting, it's rather poorly written. The author uses "comprise" when s/he should have used "compose." The parts compose the whole and the whole comprises the parts. It's basic English vocabulary and has been for several centuries. The author is no doubt the victim of sloppy schooling. Sad.
Also, the author doesn't know what the expression "beg the question" means. It certainly doesn't mean, as the author implies, that something prompts a question. It means that the author or speaker has taken something for granted, usually something important. For example, if a reporter asks the politico-du-jour, "Senator, do you still beat your wife?", that reporter has taken for granted that the Senator beats his wife. He has "begged the question" as to whether or not it's true that the Senator beats his wife. Doubly sad.