Fermentations of Inulin and Related Carbohydrates are Modified by a Dairy Propionibacteria Cultured in Mice Cecal Homogenates

LORENZO PISARELLO MARÍA JOSÉ; GULTEMIRIAN MARÍA DE LOURDES; NIETO PEÑALVER CARLOS; PEREZ CHAIA, ADRIANA

Egmond aan Zee, Holanda

Simposio; 9th Symposium on Lactic Acid Bacteria; 2008

Federación Europea de Microbiología y Sociedad Holandesa de Microbiología

FERMENTATIONS OF INULIN AND RELATED CARBOHYDRATES ARE MODIFIED BY A DAIRY PROPIONIBACTERIA CULTURED IN MICE CECAL HOMOGENATES María José LORENZO-PISARELLO1,2, Lourdes GULTEMIRIAN1, Carlos NIETO-PEÑALVER2 and Adriana PEREZ CHAIA1,2 *. 1 Centro de Referencias para Lactobacilos (CERELA)-CONICET. Chacabuco 145, (4000). San Miguel de Tucumán, Argentina. 2 Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Argentina.                       Diet is the main nutrient sources for colonic bacteria and determines the composition of gut flora. In this sense three microflora modulation tools have emerged: the addition of exogenous living microorganisms to foods (i.e., probiotics), the selective stimulation of the growth and activity of beneficial microorganisms indigenous to the gut (i.e., prebiotics), and a combination of both approaches (i.e., synbiotics).Therefore, the aim of this study was to investigate whether the effect  of Inulin (INU) or its component sugars may influence in the composition of the intestinal microbiota in a simultaneous supplementation with a dairy propionibacteria in vitro. Sterile saline solution, Propionibacterium acidipropionici CRL 1198 (109 per gram of wet weight), 10 g. L-1 inulin or a combination of both were added to mice cecal homogenates. They were incubated for 0, 2, 6 and 10 hours and bacterial population groups were investigated by in situ hybridization employing 16S rRNA- targeted probes. Total cell numbers increased in all treatments after 2 hours suggesting that bacteria used endogenous substrates like mucus to obtain the energy for growth and cellular maintenance. A remarkable growth of bacteroides since the first 2 hours, and of clostridia after 6 hours, was observed in homogenates supplemented with INU. Both homogenates containing propionibacteria showed a significant reduction on clostridia, and in lesser extent bacteroides populations. A slightly but not significant decrease of Lactobacillus was also observed. These results suggested that INU was used by bacteroides as the energy source, and the short oligofructose fraction produced during the fermentation process was used for other bacteria genera. Dairy products with INU would be supplemented with propionibacteria to control clostridia development, especially in aged humans.