The influence of Lactobacillus casei DN 114 001 on the activity of faecal enzymes and genotoxicity of faecal water in the presence of heterocyclic aromatic amines

High activity of bacterial enzymes in human colon and genotoxicity of faecal water (FW) are biomarkers of the harmful action of microbiota. The aim of the present study was to assess the activity of β-glucuronidase and β-glucosidase and the genotoxicity of FW in vitro after incubation with 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ) or 2-amino-1-methyl-6-phenyl-1H-imidazo[4,5-b]pyridine (PhIP) and probiotic Lactobacillus casei DN 114 001 (Actimel). Our results indicate, that IQ and PhIP greatly increased the activity of faecal enzymes (it was up to four times higher, as measured by spectrophotometric methods) and the genotoxicity of FW (% DNA in the tail was up to 3.2 times higher, as evaluated by the comet assay on Caco-2 cells) in 15 individuals from three age-dependent groups (breast-fed children, adults aged 30–40 years, elderly aged 75–85 years). Lb. casei DN 114 001 decreased the activity of faecal enzymes and the genotoxicity of FW exposed to PhIP and IQ mostly to control values. The activity of faecal enzymes after incubation with IQ was reduced by 71.8% in the FW of children, 37.5% in adults and 64.2% in elderly (β-glucuronidase); as well as by 59.9% in children and 87.9% in elderly (β-glucosidase). For PhIP the reduction was by 59.0% in the FW of children, 50.0% in adults and 81.2% in elderly (β-glucuronidase) and by 20.2% in children, 20.7% in adults and 84.1% in elderly (β-glucosidase). Lb. casei DN 114 001 also decreased the genotoxicity of FW to the greatest extent in adults after incubation with IQ (by 65.4%) and PhIP (by 69.6%) and it was found to correlate positively with the decrease in faecal enzymes activity. In conclusion, Lb. casei DN 114 001 may exert the protective effects against genotoxic and possibly pro-carcinogenic effects of food processing-derived chemicals present in faecal water. •Presence of aromatic amines significantly increases activity of bacterial faecal enzymes.•Lactobacillus casei DN 114 001 inhibits activity of the enzymes in the presence of IQ or PhIP.•L. casei DN 114 001 lowers genotoxicity of faecal water after incubation with IQ or PhIP.