In this study, the potential of kefir grains, obtained from three different towns/cities in the Southeast Region of Brazil to inhibit the growth of the five pathogenic microorganisms was evaluated. The samples showed the growth inhibition from 42.80-69.15 for Staphylococcus aureus ATCC 6538, 30.73-59.89 for Escherichia coli ATCC 11229, 44.99-73.05 for Salmonela typhi ATCC 6539, 41.45-54.18 for Listeria monocytogenes ATCC 15313 and 70.38-86.80 for Bacillus cereus RIBO 1222-173-S4. These results indicated that the kefir grains evaluated had antagonistic activity toward the different pathogens tested. The ability to inhibit, although differently depending on the regional microbiota, indicated a potential for their use as a functional food.

Species from the genus Enterococcus have been used as probiotic for humans or animals, although this genus is not considered "generally recognized as safe" (GRAS). While enterococci are considered "positive" in food technology, isolates of this genus have emerged as opportunistic pathogens for the humans. The aim of this review is to summarize the characteristics that can determine the use of this genus as probiotics. According to the guidelines used to define the genus Enterococcus strains as probiotic a case-by-case evaluation of each potential technological strain is presented and research perspectives for using enterococci as probiotic is also discussed.