Prebiotics effect

Inulin has no sweetness and possesses a bland taste. Physiologically, inulin behaves as a dietary fibre. At relatively high dose levels (15-40 g/day) it can have a prebiotic effect (i.e. it can selectively promote the growth of beneficial bacteria in the colon) and at high dose levels it may also have a laxative effect (Kolida el al., 2002). This is dependent on the specific composition of the product and the degree of polymerisation, which can vary. The caloric value for inulin is 1 kcal/g. Its use in soft drinks is as a fibre source, prebiotic and partial sugar replacer. 

It has been reported to be synergistic with intense sweeteners such as aspartame and acesulfame K and, when used at low levels (0.2%), improves certain flavour profiles (Eriknauer, 2003 LFRA, 2001). The relative sweetness of tagatose is 0.92. On ingestion, 20% of tagatose is absorbed in the small intestine and the rest is metabolised by the microflora of the colon. Dose-response studies indicate a prebiotic effect at 10 g/day (Eriknauer, 2003). 

Tuohy, K.M., Finlay, R.K., Wynne, A.G., and Gibson, G.R., A human volunteer study on the prebiotic effects of HP-inulin-faecal bacteria enumerated using fluorescent in situ hybridization (FISH), Ecol. Environ. Microbiol., 7, 113-118, 2001. 

Tuohy KM, Ziemer CJ, Klinder A, Knobel Y, Pool-Zobel BL, Gibson GR. A human volunteer study to determine the prebiotic effects of lactulose powder on human colonic microbiota. Microb Ecol Health Dis 2002 14 165-73. 

As HMOS are resistant to digestion, they reach the colon unchanged, where they can develop their prebiotic effect. Finally, they can be detected in the feces as well as in the urine of breastfed infants (21). 

Apart from their prebiotic effects, there is also evidence that HMOS act as receptor analogues to inhibit the adhesion of pathogens on the epithelial surface (22) and interact directly with human immune cells (23) as well as with animal immune cells in preclinical experiments (24,25). 

In summary, the studies performed in term infants during infancy indicate that a prebiotic effect achieved during breastfeeding is comparable with the effect that can be seen with ingredients with molecular structures different from HMOS. 

Due to the very complex composition of the intestinal microbiota and considering the great variety of structures found in HMOS, it is now plausible that mixtures of different oligosaccharide types and chain lengths, which are composed to meet the different metabolic requirements of the different bacteria, will have a better chance of mimicking the prebiotic effect of breastfeeding than individual compounds. 

Laminarin, a less viscous phycolloid amply foimd in Laminaria and Saccharina, has shown its capability to promote higher production of butyric acid through bacterial fermentation (Deville et al., 2004). Butyrates are important energy-yielding metabolites for the colonial epithelial cells and account for about 70% of the energy requirement of the colon (Reilly et al., 2008). Prebiotic effects of laminarin studied in animal models reported that 1% dietary supplementation resulted in an increase in... 

The influence of seaweed intake on glucose metabolism has been shown in a pig animal model (Amano et ah, 2005 Hoebler et ah, 2000 Vaugelade et ah, 2000). Other studies deal with the effect of edible seaweeds (Kombu (Laminaria spp.) and Nori) and fucoidan from Laminaria japonica on lipid metabolism in a h)q5ercholesterolemic rat model (Amano et ah, 2005 Bocanegra et ah, 2006 Hoebler et ah, 2000) and prebiotic effect (Deville et ah, 2007). Prebiotic effect of Laminaria polysaccharide has been shown in the gut metabolism through its effects on mucosal composition, intestinal pH, and short chain fatty acids production (Deville et ah, 2007). 

Falony G, Calmeyn T, Leroy F, De Vuyst L. Coculture fermentations of Bifidobacterium species and Bacteroides thetaiotaomicron reveal a mechanistic insight into the prebiotic effect of inulin-type fructans. Appl Environ Microbiol. 2009 75 2312-2319. 

Tuohy KM, Kolida S, Lustenberger A, Gibson GR. The prebiotic effects of biscuits containing partially hydrolyzed guar gum and fructooligosaccharides - a human volunteer study. Br Nutr. 2001 86 341-348. 

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