Honey Varietals Differentially Impact Bifidobacterium animalis ssp. lactis Survivability in Yogurt through Simulated In Vitro Digestion

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. Objectives: 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 de Man Rogosa and Sharpe (MRS) medium followed by an overlay with a modified selective MRS medium; all underwent anaerobic incubation. B. animalis were enumerated predigestion and after oral, gastric, and intestinal digestion. There were 2 study phases: Phase 1 tested 4 honey varietals at 20% wt/wt per 170 g yogurt, and Phase 2 tested 7 dosages of clover honey (20, 14, 10, 9, 8, 6, and 4% wt/wt) per 170 g yogurt. Results: Similar B. animalis counts were observed between all treatments after oral and gastric digestion (<= 1 Log colony forming units (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 10-20% wt/wt clover honey increased B. animalis survivability after simulated in vitro digestion (<= -4.7 Log CFU/g survival; P <= 0.05). Conclusions: Yogurt with added honey improves probiotic survivability during in vitro digestion. The effective dose of clover honey in yogurt was 10-20% wt/wt per serving (1-2 tablespoons per 170 g yogurt) for increased probiotic survivability during in vitro digestion.