It’s an exciting time to be a phage researcher! Progress has been made at the basic science, clinical and policy levels; highlighting the need for phage therapy. We still have a long road ahead, particularly in generating data from clinical trials, but phage therapy is on its way.

Pregnancy is often ruled out

The level of phage diversity opens up a range of potential applications in terms of which infections to target. There are several factors to consider when determining a suitable clinical scenario, and pregnancy is often ruled out. This vulnerable population really consists of two patients rather than one: the fetus and mother. Protection of these patients is clearly warranted, however, it shouldn’t suggest we simply give up on treatment options for this group.

Bacterial infections can be devastating during pregnancy

Bacterial infections can be devastating when occurring in utero and can lead to babies being born too early (preterm birth); this is associated with significant morbidity and mortality. Immune naivety can allow bacteria to thrive, and this paired with increasing incidence of antimicrobial resistance is cause for concern. Additionally, the ranges of antibiotics that are safe for use in pregnancy are limited even further. Eventually, additional strategies to treat mothers and neonates will need to be explored.

Don’t mess with the microbiome

The expanding interest in microbiome research has also raised questions about the impact that disruption of the commensal microbiota could have on the establishment of newborn babies’ gut microbiota. Although controversy exists in this field in relation to the use of appropriate contamination controls and software for data analysis, it is hard to imagine that our microbial colleagues would not have a significant influence on our health during early life.

Phetal phage?

The estimation that ~31 billion phages are absorbed by the human gut each day emphasises the ubiquity of phages and our constant exposure. With phages isolated from body sites such as the brain, could phages play a role in utero? Lim and colleagues identified phage DNA in amniotic fluid and this may suggest that phages can gain entry to the uterine cavity. This is an area I am particularly interested in, and the data generated from this could help to determine the feasibility of phage therapy in this vulnerable population.

Perinatal phage research

There is a huge scope for perinatal (the time just before and after birth) phage research. This extends beyond use of whole phages, such as the use of lysins to remove the prominent neonatal pathogen Group B Streptococcus from the vagina and/or gut to prevent vertical transmission. This area includes our most vulnerable population, and has the potential to provide exciting future therapeutic strategies. By understanding our exposure to phages in this period, we can begin to assess their influence in shaping our health.