The recent papers by Nishijima et al 1 and Morelli et al.2 not only confirmed our previous studies that orally administered lactobacilli can confer benefits on vaginal health, but began to uncover new concepts of disease prevention. Each day, over 7,000 women acquire HIV, a disease whose prevalence is significantly raised by absence of lactobacilli from the vagina3. In addition, over 23,000 babies (conservative 7% estimate) are born premature each day, and although it’s difficult to know how many are associated with bacterial vaginosis (BV), it could represent over 2,000 babies per day. Nishijima’s use of culture and failure to perform Gram stain Nugent studies, likely underestimated the presence of pathogens. Nevertheless, the ability to displace pathogens from the vagina confirms our human studies with Lactobacillus rhamnosus GR-1 and L. reuteri (formerly L. fermentum) RC-144. The mechanisms of action could in part be due to killing effects of bacteriocins, hydrogen peroxide and acids produced by GR-1, RC-14 and L. johnsonii La1, but BV organisms mostly exist in dense biofilms not easily eradicated by antimicrobials. Using in vitro studies, we have now shown that Lactobacillus GR-1 can penetrate urogenital pathogen biofilms within one hour5, and a biosurfactant mixture produced by Lactobacillus RC14 can inhibit growth and adhesion of a range of urogenital pathogens. Futhermore, parallel flow cell studies, set at 2ml per minute urine for 1 hr, have shown that a lactobacilli by-product,0.19 mM lactic acid, can detach 30% fimbriated E. coli 67 biofilms at pH3 and 15% at pH 4. Such probiotic effects not only appear to be safe for mothers and help to prevent preterm delivery, as suggested by Nishijima, but they may also enhance the mother’s appetite and heath of the newborn as shown when 75 200- 250g Sprague-Dawley albino rats were fed 2mls of placebo or 1 x 109 CFU/ml Lactobacillus GR-1 and RC-14 in drinking water for 30 days. The net effect was increased birth weight (6.5+0.7g versus 4.58+0.6g)(p<.01). In summary, we would support Nishijima’s call for more support for the application of probiotics for women, including during pregnancy. There is a good rationale for their efficacy and large numbers of women and newborns who could potentially benefit from this approach. While use of live bacterial therapies are not without risk, pregnant women are often treated with antibiotics, anti-retrovirals and other chemicals, some possessing potentially serious side effects. As mechanisms of action of probiotics become more understood, the arguments against supporting studies using well characterized strains in pregnancy become less easy to justify.