This study is a double-blind, randomized, controlled trial (RCT) aimed at evaluating the effects of Lactobacillus sp. probiotic administration on the vaginal microbiota changes in postmenopausal women with bacterial vaginosis and how its affect to immunology profile. Postmenopausal women diagnosed with bacterial vaginosis will be recruited as subjects as long as collected period in this study. All patients will receive Metronidazole antibiotic treatment then blind-randomly be divided into two groups: the treatment group, receiving Floragyn® probiotic tablets (Lapi, Indonesia), and the placebo group, receiving Cal 95® (Lapi, Indonesia). As a control, postmenopausal women without bacterial vaginosis will also be included and receive Floragyn® probiotic tablets only.