Viability and therapeutic properties of probiotic bacteria

Enumeration of viable probiotic bacteria {Lactobacillus acidophilus and bifidobacteria) in yogurt products obtained from 5 major manufacturers was carriedout at 3-day interval over a 5-week period. The results showed that most products contained low numbers of L. acidophilus and bifidobacteria. Based on this screening, 3 strains of bifidobacteria and 1 strain of L. acidophilus were selected as suitable strains for incorporation into yogurt asprobiotic dietary adjuncts. The performance of the selected strains of probiotic bacteria (L acidophilus 2409, B. itifantis 1912, B. longum 1941 and B. pseudolongum 20099) was assessed in terms of their viability and sensory attributes of the products manufactured incorporating these strains as compared with commercially available probiotic starter cultures. The selected strains performed better than the commercial strains in terms of their survival in yogurt and the sensory properties of the products were similar to those manufactured using commercial strains of L. acidophilus and bifidobacteria. Effect of probiotic bacteria on the growth rate of Ht-29 carcinoma cells was also studied. The results have shown that the growth rate of the carcinoma cells reduced in the presence of probiotic bacteria, especially bifidobacteria. The results have also shown that the inhibitory effect on the growth of cancer cells was higher with the probiotic bacterial strains that produced butyric acid.