Development and characterization of fermented soy beverages containing encapsulated or non-encapsulated vaginal probiotics

Human microbial niches such as the healthy vagina, are recently emerging as “unconventional” sources of candidate probiotics capable of preventing from different vaginal diseases. These microorganisms could be provided as oral preparations since they can reach the vaginal niche passing through the gastrointestinal tract. However, their use in food would be challenging. The aim of this work was to develop and characterize fermented soy beverages with encapsulated and non-encapsulated vaginal lactobacilli, namely Lactobacillus crispatus BC4 and Lactobacillus gasseri BC9, as future dietary strategies for vaginal dysbiosis. The viability of vaginal strains remained stable at 7 log CFU/mL of product during the entire 28 days of storage, despite the use of encapsulated or non-encapsulated bacteria. Samples containing encapsulated bacteria, especially E-BC4+BC9, showed higher Water Holding Capacity (62.29%), lactic acid content (1.43%), and a remarkable antagonistic activity against enteropathogens. Moreover, encapsulation protected the strains from simulated GIT conditions (>1 Log) but reduced the acceptability of the final products. Overall, strain BC4 and BC9, alone or in mix, demonstrated to be promising co-starter cultures providing a characteristic flavor (pleasant smell and taste) and aroma (lower hexanal, benzaldehyde and higher diacetyl, and 2,3-pentanedione, compared to control) to the fermented soy beverages.