Colonization of the Rectum byLactobacillusSpecies and Decreased Risk of Bacterial Vaginosis

Abstract

Lactobacilli colonizing the rectum may be a reservoir for vaginal lactobacilli. In a cross-sectional study of 531 females, vaginal and rectal colonization by lactobacilli were assessed by culture methods. A subset of isolates was identified to the species level by use of whole-chromosomal DNA probes. Lactobacillus crispatus (16%), L. jensenii (10%), and L. gasseri (10%) were the prevalent lactobacilli colonizing the rectums of 290 females. Only 13 (9%) of 147 females colonized by L. crispatus or L. jensenii vaginally and/or rectally had bacterial vaginosis (BV), compared with 12 (44%) of 27 females colonized by other H(2)O(2)-producing lactobacilli (P < .001). Cocolonization of the vagina and rectum by H(2)O(2)-producing lactobacilli was associated with the lowest prevalence of BV (5%), whereas females colonized only vaginally, only rectally, or at neither site had a successively increased risk of BV (P < .001). Lactobacillus species in the rectum may contribute to the maintenance of vaginal microflora.

Identification and in vitro production of Lactobacillus antagonists from women with or without bacterial vaginosis

“…Our results are in general agreement with other studies (17,19,20) showing that only one or a few Lactobacillus species colonize the healthy human vagina (1.94 species/individual) and that species within the L. acidophilus complex predominate (L. crispatus). Antonio et al (21) (20) found that L. crispatus was the only Lactobacillus species linked to a single grade (as determined by Gram stain-based grading of vaginal smears), namely grade Ia, while the other lactobacilli were more evenly distributed over all specimens.…”

Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics

“…Owing to the anatomical proximity of rectum to vulva, some microorganisms capable of utilizing pre biotics in the gut are also present in the vagina, including Bifidobacterium and Lactobacillus spp. [58][59][60] .…”

Reducing Urogenital Infections Including HIV in Sub-Saharan Africa - Can Probiotics Be a Viable Paradigm?

“…The use of orally administered lactobacilli was more recently tested, on the basis that if pathogens infect the host from the anal skin, why couldn't lactobacilli also ascend from the anus to the vagina and repopulate the area? This concept was verified in several labs Antonio et al 2005), and Lactobacillus strains GR-1 and RC-14 were shown to reduce UTI, BV and yeast pathogens as well as infections Reid et al 2003]. The mechanism of action is likely multifactorial and could include the ingested lactobacilli ascending from the rectal skin to the vagina, or causing a reduced pathogen ascension, or influencing the immune or host system in a way that reduces infectivity.…”