Alvarado, D. A.; Ibarra-Sanchez, L. A.; Mysonhimer, A. R.; Khan, T. A.; Cao, R.; Miller, M. J.; Holscher, H.

Background: Bifidobacterium animalis ssp. lactis DN-173 010/CNCM I-2494 (B. animalis) is a probiotic strain commonly added to yogurt. Yogurt and honey are a popular culinary pairing. Honey improves bifidobacteria survival in vitro. However, probiotic survival in yogurt with honey during in vitro digestion has not been investigated. Objective: The study aimed to evaluate the effects of different honey varietals and concentrations on B. animalis survivability in yogurt through in vitro digestion. Methods: Yogurt with honey or control-treated samples underwent in vitro simulated oral, gastric, and intestinal digestion. B. animalis cells were enumerated on MRS medium followed by an overlay with a modified selective MRS medium; all underwent anaerobic incubation. B. animalis were enumerated pre-digestion and after oral, gastric, and intestinal digestion. There were two study phases: phase 1 tested four honey varietals at 20% w/w per 170g yogurt, and phase 2 tested seven dosages of clover honey (20, 14, 10, 9, 8, 6, and 4% w/w) per 170g yogurt. Results: Similar B. animalis counts were observed between all treatments after oral and gastric digestion (<1 Log CFU/g probiotic reduction). Higher B. animalis survivability was observed in yogurt with clover honey after exposure to simulated intestinal fluids (~3.5 Log CFU/g reduction; P < 0.05) compared to all control treatments (~5.5 Log CFU/g reduction; P < 0.05). Yogurt with 10 to 20% w/w clover honey increased B. animalis survivability after simulated in vitro digestion (up to ~4.7 Log CFU/g survival; P < 0.05). Conclusion: Yogurt with added honey improves probiotic survivability during in vitro digestion. The effective dose of clover honey in yogurt was 10 to 20% w/w per serving (1 - 2 tablespoons per 170g yogurt) for increased probiotic survivability during in vitro digestion.