The probiotic potential of dairy propionibacteria evidenced in vivo and in vitro

JAN, G.; PEREZ CHAIA, A.; ZÁRATE, G.; HERVÉ, C.; ROLAND, N.; LAN, A.

Papendal, the Netherlands

Conferencia; 4th NIZO DAIRY CONFERENCE: Prospects for Health, Well-being and Safety; 2005

NIZO Food Research y Editorial Elsevier

Dairy propionibacteria (DPAB), GRAS microorganisms used as cheese ripening starters, receive growing interest as probiotics. Immunomodulation was evidenced in mice where DPAB (or their cell wall) exert a positive effect on lymphocytes proliferation. In mice, they also reverse hyperlipidemia caused by diet, enhance activity of ƒÒ-galactosidase and beneficially modulate intestinal flora (lowering of bacterial ƒÒ-glucuronidase and of coliforms). In humans, consumption of DPAB leads to an increase in intestinal bifidobacteria. Propionibacteria possess a peculiar fermentative metabolism which leads to the production of carbon dioxide and short chain fatty acids (SCFA), mainly propionate and acetate. This peculiarity may constitute a key probiotic potential. Indeed, SCFA are known to play a regulatory role in the intestine. In particular, they promote growth and differentiation of normal colon epithelial cells and inhibit proliferation of transformed ones. They also favour electrolytes absorption and may prevent local inflammation. We have shown in vitro that DPAB metabolites kill human colon cancer cell lines by arresting cell cycle, depolarising mitochondria and activating pro-apoptotic caspases. In order to order to exert beneficial effects related to the release of SCFA, DPAB must survive and metabolise substrates in the intestine. We have evidenced in vitro efficient adaptative response leading to digestive stresses tolerance in DPAB. Human studies confirmed survival of significant amounts of viable DPAB after transit in the digestive tract. We have evidenced an elevated concentration of propionate in the ceacum of mice as a result of DPAB consumption. Furthermore, after transit in the human digestive tract, transcription of genes encoding a key enzyme of the propionic fermentation was detected. Hence, the possibility to reach alive the human intestine and produce locally pro-apoptotic SCFA constitute a promising probiotic potential, particularly in the context of cancer prevention or as a diet complement to chemotherapy.  Keywords: Propionibacterium, probiotic, stress, survival, short chain fatty acids, apoptosis