Anthocyanin Addition to Kefir: Metagenomic Analysis of Microbial Community Structure

The addition of anthocyanin to kefir for the production of more functional and bio-diversified kefir beverages has the potential to increase kefir's healthful activities. In the present study, anthocyanin extracts, obtained from black carrots, were added into kefir mixture during the fermentation process in different concentrations (1% and 5%, w/v). These kefir samples were then analyzed in terms of their microbiological qualities by metagenomic analysis. The results of the analyses show that the addition of anthocyanin has significant impacts on the community structure of kefir microbiome which in turn directly affects the expected health impacts of the beverage. Kefir with no anthocyanin included predominantly probiotic bacteria such as Lactococcus lactis (34%) and Lactobacillus kefiri (34%). On the other hand, kefir with 1% anthocyanin demonstrated a more balanced distribution of probiotic species like Lb. kefiri (17%), Leuconostoc mesenteroides (9%), and Lc. lactis (5%) at similar abundance rates. 5% anthocyanin kefir demonstrated the highest polarity in the community with a strong dominance of probiotic Lb. kefiri (72%), and distinctly less abundant bacteria such as Streptococcus salivarius subsp. thermophilus (3%). These findings provide that fortification with anthocyanins can be utilized to enhance the quality, composition, and beneficial functions of kefir.