Characterization of Lactobacillus isolates from infant faeces as dietary adjuncts

Abstract Lactobacillus paracasei subsp. paracasei (six strains), Lb. rhamnosus (six strains), Lb. acidophilus (two strains), Lb. gasseri (three strains) and Lb. reuteri (three strains) isolates from new-born infants were tested for their ability to grow and metabolize in milk and to resist specific conditions of the gastrointestinal tract. Many of the tested strains had desirable properties concerning their ability to withstand adverse conditions of the gastrointestinal tract, and produce carbonyl compounds. In general, strains of Lb. paracasei subsp.paracasei and Lb. rhamnosus were more resistant to low pH of the stomach than all the other strains. On the other hand, Lb. gasseri and Lb. reuteri strains did not acidify milk. Thus, Lb. paracasei subsp.paracasei , Lb. acidophilus and Lb. rhamnosus strains could be preferably used as starters to produce fermented milks with possibly interesting organoleptic properties, as well as dietary and possible therapeutic importance.