Strong vaginal coloniser, considered a protective bacteria^​1​ (for the most part), helps protect against sexually transmitted infections and other pathogens, while helping restore healthy flora after infection/imbalance^​2​.

Positive indicator of vaginal health.

L. crispatus is used by the food industry to produce lactase, the enzyme that breaks down lactose.

Causes positive effect on vaginal cells to support vaginal cell immunity^​3​.

Can cause cytolytic vaginosis in certain circumstances, which is an overgrowth, resulting in symptoms like a yeast infection, but yeast treatments don’t work.

L. crispatus has a larger genome that contains a broader array of metabolic machinery, likely allowing it to function under a more diverse subset of environmental conditions^​4​.

L. crispatus has also been identified in other habitats, like the vertebrate gastrointestinal tract (28)

Lactobacillus helveticus and Lactobacillus acidophilus are sisters to L. crispatus^​4​.

L. crispatus relies heavily on fermentation to generate energy. In total, L. crispatus has 85 enzymes related to carbohydrate metabolism and can metabolize glucose, mannose, maltose, trehalose, lactose, galactose, sucrose, and fructose^​4​.

L. crispatus can produce L- and D-lactic acid^​4​.

The core genome of L. crispatus also contains the gene pyruvate oxidase which converts pyruvate into acetate, generating hydrogen peroxide in the process^​4​.

L. crispatus also has the capability to breakdown putrescine, a malodorous amino acid commonly found in vaginal secretions during episodes of bacterial vaginosis (71). We found the core genome of L. crispatus to contain an iron transport system that is absent in the core genome of L. iners. This transport system may allow L. crispatus to sequester the iron released by the host during menses (72), thereby preventing other species, including vaginal pathogens, from acquiring this vital resource. We also found that the core genome of L. crispatus contains a gene encoding lactocepin, a serine protease that has been shown to degrade the proinflammatory chemokine interferon-gamma-inducible protein 10 (IP-10) (45). Our analysis of this gene indicated that it may be experiencing positive selection in L. crispatus, which could reflect adaptation via changes in this function. In vitro tests have demonstrated that colonization of vaginal epithelial cells with L. iners resulted in a more-proinflammatory signaling response from the host tissue than colonization by L. crispatus (22). 

ABLE 2

Functional category and metabolic pathways encoded in the core genome

^aEntries in bold font represent functional categories while indented entries are specific metabolic pathways within each category. Enzymes can appear in multiple pathways but are only counted once in the functional category total. CoA, coenzyme A.

References