In vitro prebiotic evaluation of exopolysaccharides produced by marine isolated lactic acid bacteria

Lactic acid bacteria (LAB) selected based on high EPSs production yields of 14, 7.6, 4.9 and 5 g/L in sucrose containing MRS broth were identified as Weissella cibaria, Weissella confusa, Lactobacillus plantarum and Pediococcus pentosaceus, respectively based on their 16S rDNA sequences. EPSs produced by these strains did not stimulate secretion of interleukin (IL)-8, and were resistant to stomach acid and human pancreatic amylase. In pure culture system, only Bifidobacterium bifidum DSM 20456 exhibited the ability to utilize these EPSs as carbon sources but not L. plantarum TISTR 875 and Lactobacillus acidophilus TISTR 1034. EPSs from W. cibaria exhibited strong bifidogenic effect in the mixed-culture of human fecal microflora using the three-stage fermentation model. In the transverse and distal colon, bifidobacteria and lactobacilli as well as acetate and propionate increased significantly. Butyrate slightly decreased in the proximal colon region after feeding EPSs, but increased in the distal region.