In vitro evaluation of gastrointestinal survival of Lactobacillus amylovorus DSM 16698 alone and combined with galactooligosaccharides, milk and/or Bifidobacterium animalis subsp. lactis Bb-12 Rafael C.R. Martinez a, b , Azz-Eddine Aynaou c , Simone Albrecht d , Henk A. Schols d , Elaine C.P. De Martinis e , Erwin G. Zoetendal b , Koen Venema c , Susana M.I. Saad f, ⁎, Hauke Smidt b a Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes 580, 05508-000, São Paulo, SP, Brazil b Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands c TNO Healthy Living, Utrechtseweg 48, 3700 AJ, Zeist, The Netherlands d Laboratory of Food Chemistry, Wageningen University, Bomenweg 2, 6703 HD, Wageningen, The Netherlands e Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n, 14040-903, Ribeirão Preto, SP, Brazil f Departamento de Tecnologia Bioquímico-Farmacêutica, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes 580, 05508-000, São Paulo, SP, Brazil abstract article info Article history: Received 14 January 2011 Received in revised form 19 April 2011 Accepted 18 June 2011 Available online 25 June 2011 Keywords: Lactobacillus Probiotic Galactooligosaccharides In vitro survival Bifidobacterium Milk Probiotic properties of Lactobacillus amylovorus DSM 16698 were previously demonstrated in piglets. Here, its potential as a human probiotic was studied in vitro, using the TIM-1 system, which is fully validated to simulate the human upper gastrointestinal tract. To evaluate the effect of the food matrix composition on the survival of L. amylovorus DSM 16698 in TIM-1, the microorganism was inoculated alone or with prebiotic galactooligosaccharides (GOS), partially skimmed milk (PSM) and/or commercial probiotic Bifidobacterium animalis subsp. lactis Bb-12 (Bb-12). Samples were collected from TIM-1 for six hours, at one-hour intervals and L. amylovorus populations were enumerated on MRS agar plates with confirmation of identity of selected isolates by randomly amplified polymorphic DNA (RAPD) fingerprinting. The cumulative survival for L. amylovorus alone (control) was 30% at the end of the experiment (t = 6 h). Co-administration of L. amylovorus with GOS, PSM and/or Bb-12 increased its survival in comparison with the control significantly from the 4th hour after ingestion onwards (P b 0.05). Furthermore, by the use of High Performance Anion Exchange Chromatography, both L. amylovorus and Bb-12 were observed to promptly degrade GOS compounds in samples collected from TIM-1, as assessed at t = 2 h. Hence, food matrix composition interfered with survival and growth of L. amylovorus during passage through TIM-1, providing leads towards optimization of probiotic properties in vivo. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Probiotics are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host (FAO/WHO, 2001). Among the most well-known probiotic microorganisms are strains belonging to the Lactobacillus and Bifidobacterium genera (Saxelin et al., 2005). The search for potential probiotic strains and validation of their positive effects are of great interest for the functional foods industry. There is growing evidence of health benefits derived from consumption of probiotic lactobacilli and bifidobacteria, including inhibition of pathogenic microorganisms, improvement of lactose digestion, reduction of serum cholesterol levels, lowering of risk of cancer and enhancement of the host's immune system (Ehrmann et al., 2002; Guarner and Malagelada, 2003; Gobbetti et al., 2010; Vitali et al., 2010). L. amylovorus DSM 16698 is a probiotic candidate, the potential of which was already demonstrated in weaned piglets (Konstantinov et al., 2008). It was isolated from the feces of an unweaned piglet and is an abundant species in the intestine of healthy animals (Konstantinov et al., 2006a, 2006b). Besides probiotic consumption, it has been suggested that the modulation of gastrointestinal tract (GIT) microbiota may be achieved by the use of prebiotics, defined as selective fermentable ingredients that allow specific modifications in the composition and/or activity of the GIT microbiota (Gibson et al., 2004; Roberfroid, 2007; Wells et al., 2008). In fact, indigenous populations of L. amylovorus were shown to be stimulated in vivo in the ileum and colon of weaned piglets after administration of a mix of prebiotic carbohydrates, including wheat International Journal of Food Microbiology 149 (2011) 152–158 ⁎ Corresponding author. Tel.: + 55 11 30912378; fax: + 55 11 38156386. E-mail address: susaad@usp.br (S.M.I. Saad). 0168-1605/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.ijfoodmicro.2011.06.010 Contents lists available at ScienceDirect International Journal of Food Microbiology journal homepage: www.elsevier.com/locate/ijfoodmicro