PREBIOTIC ACTIVITY OF COMMERCIAL FIBERS FOR USE IN NEWBORNS

Bifidobacteria are well known for their health promoting properties and are widely used as probiotics for therapeutic purposes (Sanders et al., 2010). A wide literature documentation reports clinical benefits with treatment of infant gastrointestinal disease with probiotics. In addition, the supplementation of infant formula with oligosaccharides stimulates the growth of bifidobacteria in the intestine resembling the effect of breast-feeding (Boehm and Moro, 2008). A recent study in our laboratory has allowed the selection of four Bifidobacterium strains (B. breve B632, B2274 and B7840 and B. longum subsp. longum B1975) as potential probiotics for the treatment of enteric disorders in newborns such as infant colics (Aloisio et al., 2012). This work was therefore aimed at the formulation of a synbiotic product with an appropriate prebiotic fibre capable of supporting the growth of the previously selected Bifidobacterium strains. The bifidogenic potential of eleven commercial fibres was determined. The polysaccharides used included galactooligosaccharides (GOS), fructooligosaccharides (FOS), inulins, glucooligosaccharide, an arabinogalactan and a partially hydrolised guar gum. The growth of the previously selected em>Bifidobacterium strains was evaluated by using the fibres (1% w/v) as the sole carbon source. The assay was performed incubating the bifidobacteria cultures at 37 °C under anaerobic conditions and the bacterial growth was determined by measuring A620 nm at regular intervals. Significant differences were obtained in the growth profiles of the four Bifidobacterium strains on the different fibres, which is not surprising considering that early studies on prebiotics reported that carbohydrate utilization pattern differs greatly among Bifidobacterium species and strains. A common feature was that the 4 strains could grow well on two GOS (Vivinal®GOS and Cup-Oligo®), on the FOS Actilight® and the low molecular weight inulin Orafti®HSI. In addition, B632 could also grow well on the glucooligosaccharide BioEcolians®. The efficacy of a prebiotic fibre has to be evaluated not only by studying its capability of sustaining the growth of a probiotic strain but also taking into consideration the growth stimulation of potentially harmful bacteria (Huebner et al., 2007). A prebiotic activity score was therefore calculated for the four strains on each fibre by comparing the growth of bifidobacteria with that of a mixture of coliform strains isolated from colicky infants and potentially involved in enteric diseases in newborns (E.coli, K.pneumonia, E. cloacae). The results obtained evidenced a significant prebiotic*strain interaction. The highest prebiotic scores were obtained with Orafti®HSI*B632, Orafti®HSI*B2274, Orafti®HSI*B7840 and Actilight®*B7840. These results provide a basis for the formulation of a synbiotic product for the treatment of enteric disorders in newborns. In addition, considering the high prebiotic scores obtained with Vivinal, a mixture of GOS and FOS can be assayed in further studies.