In vitro effects of food extracts on selected probiotic and pathogenic bacteria

Abstract

A panel of 148 extracts from 37 food products was prepared using organic and aqueous solvents and both neutral and acidic conditions. The panel of food products tested included fruits, vegetables, grains, herbs and spices, most of which are common in a normal European-style diet. The impact of these extracts on the growth of selected probiotic bacteria (Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacteria lactis) and pathogenic bacteria (Escherichia coli 0157:H7 and Escherichia coli LF82) was assessed using a standard minimum inhibitory concentration method. The results showed that aqueous extractions of garlic and black peppercorns significantly enhanced the growth of one strain of probiotic bacteria (L. reuteri) whilst inhibiting both pathogenic strains of E. coli at a 1:50 dilution. Aqueous extracts of banana, apple and orange all enhanced the growth of the three probiotic strains significantly, and inhibited the pathogens to approximately 80% of the controls (not significant). Both aqueous and organic extractions of ginger significantly inhibited the growth of one or both E. coli strains, respectively (also at the 1:50 dilution).

Keywords::

• Lactobacillus reuteri
• Lactobacillus rhamnosus
• Bifidobacteria lactis
• Escherichia coli 0157:H7
• Escherichia coli LF82
• food components
• gut health

Acknowledgements

Nutrigenomics New Zealand is a collaboration between AgResearch Ltd, The New Zealand Institute for Crop & Food Research Ltd, HortResearch Ltd and the University of Auckland. It is funded by the New Zealand Foundation for Research, Science and Technology, through the New Economy Research Fund.