Development of a potential probiotic yoghurt using selected anti-inflammatory lactic acid bacteria for the prevention of colon carcinogenesis in mice.

DEL CARMEN, S.; DE MORENO DE LEBLANC, A.; LEBLANC, JEAN GUY

San Miguel de Tucuman

Simposio; V Simposio Internacional de Bacterias Lácticas; 2016

CERELA

Yoghurt is the result of the symbiotic fermentation of milk with two microorganisms (Streptococcus thermophilus and Lactobacillus bulgaricus). In order to consider yoghurt as a probiotic food, the starter cultures (or adjunct cultures) must be able to provide beneficial effects on the consumer?s health. Therefore, the aim of this study was to evaluate the beneficial properties of a potentially probiotic yoghurt obtained by the fermentation of two previously selected anti-inflammatory bacterial strains using an in vivo mouse model of colon carcinogenesis. Yoghurt was prepared freshly on a daily basis using Streptococcus thermophilus CRL 807 and Lactobacillus bulgaricus CRL 864 as starter cultures and incubation at 37ºC until the pH reached values of 4.5. Colon carcinogenesis was induced in mice by a weekly subcutaneous injection of dimethylhydrazine (DMH, 20mg/mouse) during 10 consecutive weeks. The yoghurt was administered to the animals from the first DMH injection to the end of the experiment (6 months) as a replacement to their drinking water. As a control, mice received unfermented acidified milk in the same manner. It was shown that this novel yoghurt was able to prevent local inflammation in the intestines of mice through a regulation of the immune response. The analysis of cytokines in the intestinal fluids showed a pro-inflammatory status in mice from DMH control group with increased concentrations of the monocyte chemoattractant protein-1 (MCP-1) and the pro-inflammatory cytokine TNF. Mice that received the yoghurt showed decreased levels of MCP-1 and increases in the anti-inflammatory cytokine interleukin-10 (IL-10) compared to the DMH control group. These results correlated with the significant difference obtained for IL-10/TNF ratio that was increased in the mice that received the yoghurt compared to the control group. Mice that received yoghurt also showed decreased damage scores of their intestines throughout the experiment with significant improvements towards month 6 compared to the control DMH treated animals. This new yoghurt could thus be considered a probiotic food and be useful as a complement to current treatment protocols for inflammatory bowel diseases and colon cancer, a first since there are no current functional foods specifically oriented for these patients.