Abstract
Objectives
Consumption of yogurt containing the probiotic Bifidobacterium animalis lactis DN-173 010/CNCM I-2494 (B. animalis) improves digestive health and quality of life in adults. To optimize the benefits of this probiotic, we aimed to test our hypothesis that yogurt with honey would increase the survivability of B. animalis under simulated gastrointestinal tract digestion conditions.
Methods
Phase 1 tested four honey varietals (alfalfa, buckwheat, clover, and orange) at a final concentration of 20% w/w in yogurt containing B. animalis. Undiluted yogurt and yogurt with added sucrose or water (20% w/w) were included as control treatments. Phase 2 assessed clover honey at final concentrations of 20, 14, 10, 9, 8, 6, 4% w/w. Yogurt samples were subjected to in vitro simulated oral, gastric, and intestinal digestion using simulated salivary, gastric, and intestinal fluids, respectively. At four time points—pre-digestion, and after each phase of digestion (oral, gastric, intestinal)—probiotic cells were enumerated first by spread plating on MRS agar and incubated for 5 h at 37°C under anaerobic conditions. Then, plates were overlaid with MRS supplemented with lithium chloride and sodium propionate and incubated an additional 67 h prior to quantification of the probiotic colony forming units (CFU).
Results
Phase 1 demonstrated similar probiotic counts between honey varietals and controls after exposure to oral and gastric simulated fluids (< 1 Log CFU/g of probiotic reduction after gastric phase). There was comparable probiotic survival after the simulated intestinal phase for yogurt with the alfalfa, buckwheat, and orange honey varietals relative to control yogurt treatments. However, higher B. animalis survivability was observed in yogurt with clover honey after exposure to simulated intestinal fluids (∼3.5 Log CFU/g reduction) compared to all control treatments (∼5.5 Log CFU/g reduction, P ˂ 0.05). Phase 2 revealed that 20%, 14% and 10% w/w clover honey similarly supported B. animalis survivability after exposure to simulated intestinal fluids.
Conclusions
These results demonstrated that clover honey increased B. animalis survivability in yogurt during in vitro digestion when provided at doses equivalent to 1 to 2 tablespoons per serving (170g) of yogurt.
Funding Sources
The National Honey Board.