NEW ARTICLE SUMMARY:

Contribution of Lactobacillus iners to Vaginal Health and Diseases: A Systematic Review

Published: 2021

What was studied?

This study investigated the species Lactobacillus iners and its role in the vaginal microbiome.

This was done by reviewing a multitude of studies on this species and commenting on their findings as a whole.

Lactobacillus iners as a transitional species

The review found that L. iners has unique characteristics compared to other Lactobacillus species in the vaginal microbiome.

While most Lactobacillus species play a protective role, Lactobacillus iners has a more complicated impact on vaginal health and the microbiome.

L. iners has a strong ability to coexist with both benefical and pathogenic bacteria species. This means it has been deemed as a transitional species.

Lactic acid producing ability of Lactobacillus iners

L. iners is only able to produce L-lactic acid due to lacking a specific gene in its genome.

Whereas, other Lactobacillus species [such as:

L. gasseri, L. crisptaus & L. jensenii] can produce

both L-lactic acid and D-lactic acid .

As D-lactic acid has been shown to have more of an impact on inhibiting the growth of pathogenic bacteria, it is therefore thought this makes L. iners less effective in protecting against pathogens and STIs.

Lactobacillus iners & infertility

Multiple studies have linked an abundance of L. iners to being unfavourable for positive pregnancy outcomes.

For example, its role as a transitional species may facilitate movements between balanced and imbalanced vaginal microbiomes, particularly while under treatments such as IVF.

However, there is still much more work to be done in this field to fully determine this relationship.

Jessica Hobbis