Biodegradability of food-associated extracellular polysaccharides

Exopolysaccharides (EPSs) produced by lactic acid bacteria, which are commo n in fermented foods, are claimed to have various beneficial physiological effects on humans. Although the biodegradability of EPSs is important in re lation to the bioactive properties, knowledge on this topic is limited. The refore, the biodegradability of eight EPSs, six of which were produced by l actic acid bacteria, was compared with microorganisms from human feces or s oil. EPS-degradation was determined from the decrease in polysaccharide-sug ar concentration and by high-performance size exclusion chromatography (HPS EC). Xanthan, clavan, and the EPSs produced by Streptococcus thermophilus S R 39 and SFi 12 were readily degraded, in contrast to the EPSs produced by Lactococcus lactis ssp. cremoris B40, Lactobacillus sakei 0-1, S. thermophi lus SFi20, and Lactobacillus helveticus Lh59. Clearly, the susceptibility o f exopolysaccharides to biological breakdown can differ greatly, implying t hat the physiological effects of these compounds may also vary a lot.