Modification of Intestinal Fermentation by Propionibacterium: A Probiotic Mechanism

A. PEREZ CHAIA ; G. ZÁRATE ; M.J. LORENZO PISARELLO

Tucumán, Argentina

Conferencia; II Simposio Internacional de Bacterias Lácticas. Primer Encuentro Red BAL Argentina.; 2006

CERELA-CONICET

The microbial genera that inhabit the intestine represent an enormous biological potential for metabolic conversions that necessarily exert effects on the functions of the intestinal epithelium and the host nutrition and health. Microorganism living free at the intestinal lumen participate actively in the degradation of complex nutrients of the diet, carbohydrate fermentation and metabolism of xenobiotics. The  main products of their metabolism are short chain fatty acids: acetic, propionic and butyric acids.Its production contributes to the control of pathogens in the intestine, absorption of electrolytes and water from thelumen, nutrition of the colonocytes and influences the celular cycle and the mucus synthesis and secretion. The bacteria associated to the mucus form complex biofilms that actively participate in the formation of a barrier that protect against pathogens and influence the development of the intestinal mucosa. The diet and the composition of the bacterial populations are the only susceptible factors of external manipulation to maintain the balance between the cells of the intestinal ephitelium and the bacteria associated to the mucosa. In this sense,probiotic microorganisms and/or prebiotic carbohydrates constitute valuable tools to modulate the balance microflora-host. In this presentation, the potential of dairy propionibacteria to be used as probiotics is discussed. Changes on the fermentation products profile of inulin and related carbohydrates, due to their ability to produce acetic and propionic acids by fermentation in the intestinal enviroment, are demonstrated. It is also analized the influence of propionibacteria consumption on the synthesis and secretion of intestinal mucus. Some dairy propionibacteria, able to resist the hostile conditions of the gastrointestinal tract, may modify the intestinal fermentation, exerting a probiotic effect.