We all know about lactose not being digestible unless your body makes the enzyme lactase.
Lactose isn't alone, though. There are other carbohydrates that are equally problematical, some of which also create the gas that plagues those of us with lactose intolerance.
Jason Engelhart mentions some in this article from the Badger Herald.
A greater and more universal offender than lactose is inulin, a form of fiber that exists in plants such as onions, garlic and Jerusalem artichokes. In fact, the last of these is reputed to wreak such havoc on digestion that the 17th century English botanist John Gerard once remarked of them, “Which way soeuer they be drest and eaten they stirre and cause a filthie loathsome stinking winde within the bodie, thereby causing the belly to be pained and tormented and are a meat more fit for swine than men.” Delicious!
The last of our unholy trinity of indigestible carbohydrates are perhaps the most malicious of all: the oligosaccharides. These three-, four- and five-sugar carbohydrates have long been considered the reason beans are referred to as “the musical fruit,” and they are scientifically proven to produce toots. However, recent research — yes, there are people who research this kind of thing — suggests that cell-wall cements also play a role in gas production from beans. Either way, the indigestible carbohydrates in beans make them the composers of many a sad chord in the soundtracks of our lives.
[P]eople who want to eat massive quantities of Jerusalem artichokes or three-bean chili need the help of something the body does not normally produce — alpha-galactosidase. This enzyme, which is sold over the counter as Beano, breaks down the normally indigestible carbohydrates, making them cave to the digestive power of the small intestine. Because of chemistry, we need not cave to the gassy forces of evil.
A couple of things that Engelhart does not say. He doesn't really give the full story on inulin, so here's some background info from Mark Anthony at FoodProcessing.com
Consisting of relatively short chains of sugar molecules, inulin acts as a soluble fiber providing the type of bulk that aids the body’s absorption of calcium and magnesium in the small intestine. In the large intestine, inulin is broken down by beneficial bacterial through fermentation to yield short chain fatty acids. These beneficial products are believed to aid in the prevention of colorectal cancer.
Inulin has been a healthful part of our diet for thousands of years. It occurs naturally in over 36,000 plants, including many common foods such as bananas, wheat, asparagus, onions, garlic, leeks and Jerusalem artichokes. (One of the most abundant sources is chicory, the roots of which have been ground and used as coffee substitutes for decades.)
Inulin is also the fiber used in capsule form in Fiber Choice and Fiber Sure for those who need bulk fiber in their diets.
And while Engelhart is right about alpha-galactosidase being the enzyme that digests oligosaccharides, he leaves out a nifty fact.
Lactase is also known as a beta-galactosidase. Not surprisingly, the bonds that hold together the lactose molecule are very similar to those that hold together this other type of sugar. In fact, they are identical except that one is rotated up and the other is rotated down, hence known as alpha and beta bonds.
Beano was invented by the same people who made Lactaid. And why not? They already had a great deal of expertise in galactosidases.
Overall, though, a good article for a student newspaper.