Functional and morphological investigation on Lactobacillus plantarum subs plantarum grown in the presence of prebiotics.

Since many decades, food and health companies showed an increasing interest in using probiotics ad dietary adjusts. To produce the desired benefits, probiotics should persist in the product as viable cells during its shelf life. Probiotics are food components capable to resist host digestion and absorption, and are fermented by microbiota, which can stimulate the growth and/or activity of specific positive bacteria, generating also the production of specific useful short chain fatty acids. The growth and viability of a probiotic strain of Lactobacillus plantarum subs. plantarum during a simulated gastrointestinal transit were evaluated, when strains were grown using inulin or pectin as carbon source, compared to glucose used as control. The in vitro coaggregation of the strain with E.coli as well as the potential morphological changes (by SEM) were also investigated. Pectin and inulin, in contrast induced a greeter cell stress resistance against gastrointestinal juices (Delta log 10=1.5 and 2.4 colony forming units/ml. respectively) conversely to glucose /delta log 10=4.0). The presence of the two prebiotics positively affected the capability of the strain to co-aggregate E.coli: inulin and pectin at the same way increased such property, with an increase of about 20% respect to the initial value of co-aggregation observed using glucose as energy source. SEM analysis did non show any morphological difference.