By definition, prebiotics should stimulate the growth of a limited number of bacteria, leading to changes in the balance of microbiota in the large intestine. A stationary batch culture of human bacteria showed that fructooligosaccharides (FOS), galacto-oligosaccharides (GOS), xylo-oligosaccharides (XOS), isomalt-oligosaccharides (IMO), and lactulose could alter the microbiota , increase bifidobacteria and / or lactic acid bacteria, while Clostridium and Bacteroidetes decreased. Three oligosaccharides, which are abundantly available in Europe, are effective: FOS (including inulin), trans-GOS, and lactulose. The prebiotic effects of FOS and lactulose were demonstrated in human experiments using molecular-level methods. Adding FOS to biscuits and other foods, calculated at 8g per day, also showed great efficacy.
According to the test methods of the existing literature, most of the indicators used to evaluate the effect of prebiotics are: proliferation effect on beneficial bacteria (such as bifidobacteria, lactobacillus); inhibition and potential pathogenic bacteria (such as Clostridium) on harmful bacteria. Non-proliferative effect of bacteria (such as Escherichia coli, Enterococcus, Bacteroides, etc.); acid production and gas production after being metabolized by intestinal flora. Prebiotics with different functional oligosaccharides (isomalt oligosaccharides (IMO), fructooligosaccharides (FOS), galactooligosaccharides (GOS) commonly found in the market)
1. Bifidobacterium proliferation effect
Generally speaking, there are 8 types of bifidobacteria in the intestine, among which Bifidobacterium bifidum, Bifidobacterium infantis, Bifidobacterium adolescentis, Bifidobacterium longum and Bifidobacterium breve are the most abundant. The composition and proportion of Bifidobacterium in the intestine of people of different ages are different to a certain extent. For example, in children, Bifidobacterium infantis, Bifidobacterium bifidum, and Bifidobacterium longum are mainly in the intestinal tract of young adults and the elderly. Bifidobacterium adolescentis and Bifidobacterium longum. With the increase of age, or the influence of bad eating habits and diseases, the number and proportion of bifidobacteria in the intestine are likely to drop significantly, which is not conducive to the maintenance of human health.
Numerous studies have respectively confirmed that isomaltooligosaccharides, fructooligosaccharides, galacto-oligosaccharides, xylo-oligosaccharides, etc. have obvious effects on the proliferation of bifidobacteria. The in vitro fermentation study by Ryerofi et al. showed that the seven oligosaccharides can significantly proliferate bifidobacteria, but the degree of proliferation is slightly different (see Figure 1). Specifically, the availability and utilization of different oligosaccharides by the five Bifidobacterium species in the intestine also varied (see Table 1).
The study by Claire et al. showed that galactooligosaccharides and isomaltooligosaccharides are prebiotics that can be well utilized by various bifidobacteria and have a high proliferation rate, but the latter are affected by Bifidobacterium longum and Bifidobacterium adolescentis. Higher utilization. In addition to the availability of xylo-oligosaccharides by Bifidobacterium adolescentis and Bifidobacterium longum, the availability of other bifidobacteria is poor. Therefore, galactooligosaccharides and isomaltooligosaccharides are prebiotics suitable for people of all ages.