Probiotics are suggested to prevent colorectal cancer (CRC). This study aimed to investigate the anticancer properties of some potential probiotics in vitro and in vivo. Anticancer effects of potential probiotic groups were investigated following of in LS174T cancer cells compared to IEC-18 normal cells. 1. a single strain of Bifidobacterium. breve, 2. a single strain of Lactobacillus. reuteri, 3. a cocktail of 5 strains of Lactobacilli (LC), 4. a cocktail of 5 strains of Bifidobacteria (BC), 5. a cocktail of 10 strains from Lactobacillus and Bifidobacterium (L+B). Apoptosis rate, EGFR, HER-2 and PTGS-2 (COX-2 protein) expression levels were assessed as metrics of evaluating anticancer properties. Effect of BC, as the most effective group in vitro, was further assessed in mice models. BC induced ~21% and only ~3% apoptosis among LS174T and IEC-18 cells respectively. BC decreased the expression of EGFR by 4.4 folds, HER-2 by 6.7 folds, and PTGS-2 by 20 folds among the LS174T cells. In all these cases, BC did not interfere significantly with the expression of the genes in IEC-18 cells. This cocktail has caused only 1.1 folds decrease, 1.8 folds increase and 1.7 folds decrease in EGFR, HER-2 and PTGS-2 expression, respectively. Western blot analysis confirmed these results in the protein level. BC significantly ameliorated the disease activity index, restored colon length, inhibited the increase in incidence and progress of tumors to higher stages and grades. BC was the most efficient treatment in this study. It had considerable “protective” anti-cancer properties and concomitantly down regulated EGFR, HER-2 and PTGS-2 (COX-2), while having significant anti-CRC effects on CRC mice models. In general, this potential probiotic could be considered as a suitable nutritional supplement to treat and prevent CRC.

Considering the importance of the poultry industry and the increasing interest in alternative growth promoters, probiotics are considered as a potential candidate for use in the poultry industry. In this study, Lactobacillus species were isolated from 21 rectal swabs of 11 healthy 6-day-old and 10 healthy 21-day-old chickens and their fecal and feed samples. The isolates were characterized and their probiotic characteristics, including resistance to gastric acid and bile salts, biofilm formation and adherence to epithelium or mucus, amylase and protease activity and production of inhibitory compounds, were assessed. From 31 acid and bile resistant lactobacilli, only 2 Lactobacillus brevis and 1 Lactobacillus reuteri strains showed significant probiotic properties. These isolates indicated detectable attachment to Caco-2 cells and significant antibacterial activities against Gram-positive and Gram-negative pathogens. Additionally, phenotypic and genotypic diversity of lactobacilli isolates were studied by Phene Plate (PhP) system (PhP-LB) and random amplified polymorphic DNA (RAPD)-PCR, respectively. PhP-LB results of 24 L. brevis isolates showed a high phenotypic variation among the isolates. In comparison, results of RAPD-PCR highlighted a low diversity. Therefore, it seems that combination of the 2 techniques (PhP and RAPD-PCR) could result in a significant discriminatory power than each of them used alone.