Abstract: A water-soluble dietary fiber comprising as a main component a partially hydrolyzed product of a hemicellulose extracted from a vegetable fiber material by an alkali treatment and subjected to enzymolysis. Various kinds of food and drink can be prepared by mixture of this dietary fiber. Also disclosed is a method of preparing a water-soluble dietary fiber, comprising the steps of subjecting a vegetable fiber material to extraction by an alkali treatment, and treating an extract therefrom with a xylanase to give a partially hydrolyzed product of hemicellulose.

Abstract: This invention relates to a method for production on an industrial scale of the branched fructooligosaccharide indicated by the general structural formula below using microorganisms or an enzyme produced by microorganisms which belong to the genus Aspergillus, ##STR1## wherein in the formula above, m=0-10, n=0-8 and m+n=3-10.

Abstract: A .beta.-glucooligosaccharide-containing composition comprising at least one material selected from food, drink and medicine, and at least one selected from a glucooligosaccharide comprising at least one .beta.-1,6 bond and a reduced product thereof. A method of improving intestinal floras, comprising administering to a human or animal for ingestion a physiologically effective amount of at least one selected from a glucooligosaccharide comprising at least one .beta.-1,6 bond and a reduced product thereof. The ingestion of the .beta.-glucooligosaccharide and/or the reduced product thereof can bring about promotion of the selective growth of useful bacteria such as Bifidobacteria and lactic acid bacteria, inhibition of the growth of harmful bacteria or putrefactive bacteria, and hence improvement in the intestinal floras.