Interaction with the human intestinal microbiome

EPSs produced by starter cultures in fermented dairy products represent a complex matrix of polymers that provide a protective function to the fermenting strains against phages and toxins. After ingestion, these EPSs will ultimately come into contact with the host intestinal microbial population the question is therefore raised is there a relationship that emerges between this EPS and the microbiome  

The evolution of human food consumption happened alongside the development of a vast bacterial ecosystem resident within the human body this gut microbiome comprises a cargo of commensals and symbionts that has collectively evolved to survive in the distal part of the human intestine. This community of microorganisms is thought to harbour more than 100-fold the number of genes within the human genome (BSckhed et al., 2004). This genetic payload is carried by an excess of 10 microbial cells with over 1000 bacterial types (Wallace et al 2011) - the evolution of which probably happened in response to the particular diet available to humans at a particular time. 

Given that this complex microbial ecosystem has the means to digest complex carbohydrates in a way that endogenous human enzymes cannot, the question arises as 

Tsuda and Miyamoto (2010) compared the prebiotic activity of EPS from a mutant sttain of Lactobacillus plantarum isolated from traditional home-made cheese with the prebiotic activities of GOS and inulin against 37 LAB strains. For the seven strains that were positive for prebiotic utilisation, the EPS scored highly for prebiotic activity in comparison to the GOS and inulin prebiotics. 

Further evidence that complex carbohydrates such as EPS can be used preferentially to simpler sugars by gut microbes was provided by Semjonovs, Jasko, Auzina, and Zikmanis (2008) in this study, an enhancement was reported in the growth and acidification power of bifidobacteria and other typical dairy starter 

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