Received: 13-12-2013 / Accepted: 19-02-2014
In this study, microbial compositions and probiotic properties of 24 commercial probiotic products for human available in 2012 in Hanoi were evaluated. According to the labeled information, all probiotic bacteria in those products belonged to Bacillus, Lactobacillus, Streptococcus and Bifidobacteriumgenera, wherebyL. acidophiluswasmost frequently found with an approximatevalue of 80%. Plate counting method revealed that 13 out of 24 investigated products had lower live cell numbers than those claimedon the labels or in the statustory regulations. In addition, no Bifidobacteriumstrains could beisolated from any products labeled with their names. All 54 isolated strains showedgood adherence to chicken mucus, strong gastric acidic fluid tolerance and high resistance to bile salts. Their antibiotic resistance towards six antibiotics and their antagonistic effect against three common pathogenic bacterial species differed largely with 59.3% of the strains resistant to at least one antibiotic; 5 strains could inhibited at least one pathogenic bacterial species and 9 strains can inhibited all three pathogens.