DOI: 10.5593/sgem2017H/63/S25.051


B.A. Karetkin, E.V. Guseva, A.S. Mishchenko, S.A. Evdokimova, V.D. Grosheva
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-29-4 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 63, 397-404 pp; DOI: 10.5593/sgem2017H/63/S25.051


Commonly, “prebiotics” are defined as “nondigestible food ingredients that beneficially affects host health by selectively stimulating the growth and/or activity of one or the limited number of bacteria in the colon” and they are associated with so-called bifidogenic effect. In addition, there are the alternative definitions of prebiotics to expand the number of compounds attributed as prebiotics. Nevertheless, the most of such substances improve gut microbiota modulation by means of especially metabolism of prebiotics.
To estimate the prebiotic activity in vitro the fermentation of carbohydrate candidate by fecal cultures or pure cultures of probiotic and non-probiotic (enteric) bacteria have been carried out. The limitation of this approach is that the specific interactions of different types of intestinal microbes are not quantitatively described. One can suggest that the influence of prebiotics to gut microbiota composition causes by the advantages to probiotics growth. These advantages are presumably related to the higher specific growth rate, substrate consumption utilization rate and inhibitiors formation rate of non-probiotic bacteria growth (including lactic and acetic acids). The parameters of Monod equation, equation of inhibition growth and exponential growth can be applied to describe quantitatively this interaction. It is very difficult to use the fecal cultures to create the model and to use the pure cultures are not authentically. So the mixed culture of the limited number of gut microbiota members can be applied. The binary interaction model has a lot of limitations and it can be imperfect but it is able to help to understand the basic principles of prebiotic activity.
The growth of Bifidobacterium adolescentis (as probiotics) and Bacillus cereus (as enterics) in pure and mixed cultures in medium with fructooligosaccharides (as prebiotics) has been studied to create a model of inhibition growth. The bacilli strains are not able to consume the fructooligosaccharides. If bifidobacteria specific growth rate will be maximal then according to the model the count and growth rate of enterics are to be determined by initial content of probiotics. When the growth rate of enteric strains influenced by production of lactic and acetic acids by bifidobacteria will be less than growth rate of probiotics the prebiotic effect can be quantitatively confirmed.

Keywords: prebiotics, model, concurrence, inhibition, gut microbiota