Survival, metabolic status and cellular morphology of probiotics in dairy products and dietary supplement after simulated digestion

Abstract

The objective of the present study was to compare the effect of dairy matrices (fermented milk and ice cream) and a dietary supplement containing the same amounts of inulin and the same viable counts of Lactobacillus acidophilus and Bifidobacterium animalis on the survival of probiotics when submitted to simulated digestion. The survival was evaluated by plate counts in MRS agar, the metabolic status by flow cytometry and the cell morphology by scanning electronic microscopy. The percentages of live cells observed by flow cytometry and by plate counts were higher in the fermented milk when compared with the other products (p < 0.05). The cell integrity was better maintained in the dairy products as compared to the dietary supplement. The dairy matrices were more effective in maintaining the viability of probiotics during the digestion process than the dietary supplement, and the fermented milk proved to be the best way of delivering viable probiotics.

Keywords

• Probiotics
• Inulin
• Digestion
• Metabolic status
• Cell morphology