British Journal of Nutrition

Full Papers

Competitive inhibition of three novel bacteria isolated from faeces of breast milk-fed infants against selected enteropathogens

Sergio Muñoz-Quezadaa1, Miriam Bermudez-Britoa1, Empar Chenolla2, Salvador Genovésa2, Carolina Gomez-Llorentea1, Julio Plaza-Diaza1, Esther Matencioa3, María José Bernala3, Fernando Romeroa3, Daniel Ramóna2 and Angel Gila1 c1

a1 Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology “José Mataix”, Biomedical Research Centre, University of Granada, Avenida del Conocimiento s/n, 18100 Armilla, Granada, Spain

a2 Department of Food Biotechnology, Biópolis S.L., Parc Científic Universitat de València, C/Catedrático Agustín Escardino 9, Edificio 2, 46980 Paterna, Valencia, Spain

a3 Hero Global Technology Centre For Infant Nutrition, Hero Group, Avenida Murcia 1, 30820-Alcantarilla, Murcia, Spain

Abstract

Numerous in vitro and in vivo studies conducted using different probiotic micro-organisms have demonstrated their ability to interfere with the growth and virulence of a variety of enteropathogens. The reported beneficial effects of the use of probiotics to complement antibiotic therapy or prevent diarrhoea or gastrointestinal infection in infants have increased in recent years. In the present study, we demonstrated the capacity of supernatants obtained from three novel probiotics (Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036) isolated from the faeces of breastfed infants to inhibit the growth of enterotoxigenic and enteropathogenic (EPEC) bacteria, such as Escherichia coli, Salmonella and Shigella. To assess their potential antimicrobial activity, the 17 and 24 h cell-free supernatants broth concentrates (10 × ) having 1, 2 or 4 % of the three probiotics were incubated with EPEC bacteria strains. After 17 h of co-culture, the supernatants were able to inhibit the growth of E. coli, Salmonella and Shigella up to 40, 55 and 81 %, respectively. However, the inhibitory capacity of some supernatants was maintained or completely lost when the supernatants (pH 3·0) were neutralised (pH 6·5). Overall, these results demonstrated that L. paracasei CNCM I-4034, B. breve CNCM I-4035 and L. rhamnosus CNCM I-4036 produce compounds that exhibited strain-specific inhibition of enterobacteria and have the potential to be used as probiotics in functional foods.

Key Words:

  • Bacterial competition; Bifidobacterium breve; enteropathogens; Lactobacillus paracasei; Lactobacillus rhamnosus; probiotics.

Correspondence:

c1 Corresponding author: A. Gil, fax +34 958 819132, email email agil@ugr.es

Footnotes

  Abbreviations: EPEC, enteropathogenic; ETEC, enterotoxigenic