The potential of non-starter lactic acid bacteria from Cheddar cheese to colonise the gut

Abstract

• NSLAB populations in Cheddar cheese can survive simulated gastric transit. • Many NSLAB strains capable of gastric transit exhibit probiotic traits. • Many strains bound to mucin suggesting potential for prolonged gut residence time. • No genes for antibiotic resistance, virulence or pathogenicity were identified. This study was undertaken to assess the potential of Non-Starter Lactic Acid Bacteria (NSLAB) from Cheddar cheese to survive gastric transit and display probiotic-related traits including bile salt hydrolase activity, the ability to adhere to the gut epithelium and inhibition of enteropathogen binding. Populations of NSLAB, up to 10 7 CFU/g per cheese were recovered following exposure of cheese to Simulated Stomach Duodenum Passage (SSDP) conditions. A total of 240 isolates were randomly selected from twelve Cheddar cheeses and assessed for probiotic traits. Two strains Lactobacillus paracasei DPC 7150 and Lactobacillus rhamnosus DPC 7102 showed the most probiotic potential. The Lb. paracasei and Lb. rhamnosus strains displayed adhesion rates of 64% and 79%, respectively and inhibited binding of pathogenic Escherichia coli by >20%. This research demonstrates that Cheddar cheese harbours potentially beneficial bacteria, a large portion of which can survive simulated digestion and potentially exhibit health beneficial effects once ingested.