Research Communication In vitro evaluation of the fermentation properties and potential prebiotic activity of caprine cheese whey oligosaccharides in batch culture systems Diana L. Oliveira, 1,2 Adele Costabile, 1 R. Andrew Wilbey, 1 Alistair S. Grandison, 1 Luis C. Duarte, 2 and Luisa B. Roseiro 2 * 1 Department of Food and Nutritional Sciences, University of Reading, Reading RG6 6AP, UK 2 Laborat orio Nacional de Energia e Geologia (LNEG) Unidade de Bioenergia, Edifı ´cio K2. Estrada do Pac¸o do Lumiar, 22 1649-036 Lisbon Portugal Abstract. The prebiotic effect of oligosaccharides recovered and purified from caprine whey, was evaluated by in vitro fermentation under anaerobic conditions using batch cultures at 37  C with human faeces. Effects on key gut bacterial groups were monitored over 24 h by fluorescence in situ hybridization (FISH), which was used to determine a quantitative prebiotic index score. Production of short-chain fatty acids (SCFAs) as fermentation end products was analyzed by high-performance liquid chromatography (HPLC). Growth of Bifidobacterium spp was significantly higher (P  0.05) with the purified oligosaccharides compared to the negative control. Lactic and propionic acids were the main SCFAs produced. Antimicrobial activity of the oligosaccharides was also tested, revealing no inhibition though a decrease in Staphylococcus aureus and Escherichia coli growth. These findings indicate that naturally extracted oligosaccharides from caprine whey could be used as new and valuable source of prebiotics. V C 2012 International Union of Biochemistry and Molecular Biology, Inc. Volume 000, Number 000, Month 2012, Pages 000–000  E-mail: luisa.roseiro@lneg.pt Keywords: oligosaccharide, caprine whey, prebiotic, antimicrobial activity, prebiotic index 1. Introduction The significant contribution of milk components as a physio- logically functional food was first recognized in the 1980s by the Japanese. Among all the potential biological and benefi- cial functions of milk components, namely, anti-inflammatory, anti-viral, anti-cancer, and immuno-modulation, milk may also have an important role promoting the growth of bifidobacteria to confer gut-health and well-being [1–3], which is mostly attributed to minor carbohydrates. Gibson and Roberfroid [4] first described selectively metabolized dietary carbohydrates, such as oligosaccharides (OS), as prebiotics and defined them as a ‘non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improving host health’. More recently, this definition was revised and the International Scientific Association for Probiotics and Prebiotics (ISAPP) (6 th meeting in Ontario, Can- ada, November 2008), proposed that a dietary prebiotic is a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointes- tinal microbiota, thus conferring benefit(s) upon host health [5] by stimulating the growth of lactobacilli and bifidobacteria [1]. Milk OS are thought to be beneficial regarding their prebi- otic and anti-infective properties [1,3,6–8]. Human milk contains an exceptionally high level of OS, when compared to bovine and ovine milks [9]. These OS have a complex range of structures that confer prebiotic properties and are associated with growth factors and potential anti-inflammatory actions. They may also play a role in the local intestinal immune system of the breast-fed infants, as most of these oligosaccharides (95%) are not digested in the gastrointestinal tract [10–14]. However, few detailed data on OS composition are available for domesti- cated animal species, though caprine milk has a high level of sialylated and neutral OS, with a similar profile, and is *Address for correspondence: Luisa B. Roseiro, Ph.D., Laborat orio Nacional de Energia e Geologia (LNEG) Unidade de Bioenergia, Edifı ´cio K2, Estrada do Pac ¸o do Lumiar, 22 1649-036 Lisbon Portugal. Tel: þ 351 21 092 46 00 ext. 4279; Fax: þ 351 21 716 36 36; E-mail: luisa.roseiro@lneg.pt. Received 22 April 2012; accepted 10 August 2012 DOI: 10.1002/biof.1043 Published online in Wiley Online Library (wileyonlinelibrary.com) 1