Beano (dietary supplement)
Beano is an enzyme-based dietary supplement that is alleged by its manufacturer to reduce gas in the digestive tract, thereby preventing flatulence. It contains the enzyme alpha galactosidase that breaks down oligosaccharides such as raffinose, which is claimed that the human digestive tract does not contain.

# How Beano works
Beano is a product containing the enzyme alpha galactosidase, which is derived from the fungus Aspergillus niger. The enzyme works in the digestive tract to break down the complex or branching sugars (polysaccharides and oligosaccharides) in foods such as legumes (beans and peanuts) and cruciferous vegetables (cauliflower, broccoli and brussels sprouts). The enzyme breaks those complex sugars into simple sugars, making these foods somewhat more digestible, and the negative feelings that arise as a consequences of eating those foods are said to be less pronounced as a result.
The polysaccharides and oligosaccharides found in these foods might otherwise pass through the small intestine unaffected. Once in the large intestine, those sugars may be worked on by intestinal flora, fermenting to produce the gases that cause discomfort.
Two randomized controlled trials show reduction in gas by subjects taking oral alpha galactosidase (PMID 17151807 and PMID 7964541). Another study indicates alpha galactosidase may interfere with the diabetic medication acarbose (PMID 9663365).

# Use in the brewing of beer
Simple sugars are also produced as a consequence of the malting process that eventually produces beer.  The complex sugars are not broken down by the yeast, and are eventually consumed by the beer drinker, possibly causing flatulence. Homebrewers have found that it is possible to add Beano to their brew to produce a beer that causes less flatulence. The Beano breaks the complex sugars into simple sugars, and these simple sugars are consumed by the yeast, producing alcohol (or some acetic acid in the aerobic reactions in early fermentation).
The addition of Beano to the brew reduces the complex sugar content of the final product, thereby reducing the carbohydrate content of the beer, and also slightly increasing the alcohol content of the beer.  A disadvantage of the addition of Beano to homebrew is that the lower carbohydrates lead to less head retention of the beer, the loss of the sugars results in a less sweet flavour of the final product, and fewer of the malty flavours are conveyed since some of those flavours are from the complex sugars that are affected.
The addition of Beano to homebrew beer (at a rate of about four tablets per 5 gallon brew) gives a low flatulence, low carbohydrate beer (about half the carbohydrates that it would otherwise have), but also alters some of the flavours of the beer. The loss of flavour is less apparent the darker the beer is, and the higher the alcohol content of the beer (since the alcohol numbs the tastebuds somewhat). Consequently it is suggested that a dark ale or a stout would be the best candidates for the use of Beano with minimal effect on the final taste of the beer.

## Caution
Homebrewers who add Beano to their beer fermentation should expect to see slightly lower final gravity readings than they are used to for a given recipe, so should wait until they get two identical hydrometer readings at 24 hours apart before deciding that the fermentation has finished. Not doing so may increase the risk of exploding beer bottles.

# History
Beano was developed in 1990 by Alan Kligerman of AkPharma Inc. after research into gas-causing vegetables that had begun in 1981.