The Effect of Drinking Yoghurt Containing Free and Microencapsulated Probiotic Bacteria on Changes of the Population of These Bacteria in the Digestive System

Abstract Background & Aims: Probiotic bacteria have beneficial effects on host's health. However, one of the most important reasons which affect the probiotic activity of a microorganism is its survival during the gut transit. Microencapsulation techniques could be applied to bacteria to improve this parameter. Methods: In this study, feces of 60 healthy volunteers were analyzed during 28-day test period to assess changes of probiotic bacteria. Participants were divided into equal 4 groups; group 1 did not receive probiotic drinking yoghurt (control); group 2 received probiotic drinking yoghurt containing free Lactobacillus acidophilus and Bifidobacterium animalis, subspecies lactis; group 3 recieved the same strains microencapsulated with sodium alginate/resistant starch; and group 4 received probiotic drinking yoghurt containing microencapsulated probiotic bacteria with sodium alginate/chitosan. Results: A significant increase was recorded in the population of lactobacilli and bifidobacteria in the feces of participant in three groups at the end of the treatment compared with control group (P < 0.05 for all), confirming the ability of the 2 strains to colonize the human gut, either in a gastroprotected form or not. Participants treated with the microencapsulated bacteria reported more viability than those received not encapsulated strains. Feces of group 3 that received drinking yoghurt containing encapsulated probiotic bacteria with alginate/resistant starch had higher amount of probiotic bacterial populations, 1.3 ± 0.26 × 107 and 2.4 ± 0.37 × 109 cfu/g Lactobacillus acidophilus and Bifidobacterium animalis subs lactis, respectively. Conclusion: Consumption of the drinking yoghurts containing probiotic bacteria increased the Lactobacillus acidophilus and Bifidobacterium animalis, subspecies lactis, contents of the feces and encapsulation process improved stability of probiotic bacteria. Keywords: Fecal analysis, Probiotic bacteria, Drinking yoghurt, Encapsulatio