We all know what it’s like to suffer from a pimple on the most visible spot on our face just when we’re having a social event, and we’ve often resorted to reliable or home remedies to get rid of acne. A recent study takes a somewhat more sophisticated approach: using a virus to kill acne-causing bacteria.
Why do we get acne?
Acne is a chronic inflammation of the pilosebaceous complexes , which are structures in the skin that contain a hair follicle and a sebaceous gland. It can affect more than 85% of adolescents and young adults.
The causes of the appearance of acne are varied. Among them we find hormonal changes , irritation caused by cosmetic products, stress , having a genetic predisposition or a dysbiosis of the microbiota .
These factors may have greater or lesser importance throughout our lives. For example, during adolescence, the great hormonal changes can be the most important element in the appearance of acne. However, in the adult stage , microbial dysbiosis may be the most relevant factor.
The problem of microbial dysbiosis
The skin microbiota is the set of microorganisms that inhabit our epidermis and that carry out vital functions . Each person’s microbiota is similar to a fingerprint, where the types and amounts of each microorganism create an almost unique signature.
However, the microbiota differs from the fingerprint in that it is changeable . We do not have the same microbiota in childhood as in adulthood, whether we live in contact with animals or not, whether we play sports, whether we eat a varied diet… Therefore, the study of the microbiota becomes complex.
Despite the limitations, numerous studies have shown that the composition of the microbiota is decisive in the appearance or maintenance of certain diseases. In the case of the skin microbiota , it has been linked to diseases such as atopic dermatitis , alopecia , psoriasis, and acne .
When a person presents an imbalance in the composition of their microbiota , favoring the presence of harmful bacteria and hindering the colonization of beneficial bacteria, we speak of dysbiosis .
Does “acne bacteria” exist?
Studies of the composition of the skin microbiota associated with the appearance of acne have presented contradictory evidence . Some blamed the bacterium Cutibacterium acnes as the culprit, while other studies found no difference between chronic acne patients and healthy volunteers.
More detailed investigations have proposed that not only the presence or absence of this bacterium is important, but also the proportion that it presents to other populations of bacteria and its interaction with them.
Acne treatment: antibiotics
Since the bacterial overgrowth of some species is a determining factor in the appearance of acne, one of the standard treatments is the use of antibiotics . However, eliminating the entire bacterial population can be detrimental if we kill off the bacteria that help maintain the integrity of the skin .
The main problem with the use of antibiotics is the increasing presence of antibiotic- resistant bacteria . Chronic acne is a particularly worrying example because people who apply antibiotics need to do so repeatedly for a long time.
This type of treatment favors the maintenance and increase of the strains of bacteria that present these resistance genes . The consequence is that the treatment stops having an effect in controlling acne and patients need to look for another strategy.
Alternative Treatment: Photodynamic Therapy
In these cases, a pulsed light treatment may be more effective because it has been shown to regulate the balance between various species of bacteria, promoting a beneficial ratio rather than killing them all equally.
This photodynamic therapy was effective in five patients with moderate or severe acne , and a change in microbial composition towards an increase in diversity was observed. This was attributed, in part, to a downregulation of the bacteria Cutibacterium acnes.
However, this treatment can be quite expensive for patients since the sessions must be carried out in an aesthetic or dermatological clinic that has the device that emits light pulses with the appropriate characteristics.
Treatment in development: bacteriophage viruses
A recent study pending peer review proposes a new strategy to modify the composition of skin bacteria involved in acne. In this article, they have designed eight types of bacteriophage viruses , which infect bacteria, specifically the bacteria Cutibacterium acnes .
Application of these eight viruses along with standard antibiotic treatment was sufficient to eliminate Cutibacterium acnes bacteria in a mouse model of acne . Although it is necessary to confirm these results in humans, it could be an alternative for people with antibiotic-resistant bacteria.
References:
Carmona-Cruz. 2022. The Human Skin Microbiome in Selected Cutaneous Diseases. Front Cell Infect Microbiol. Doi: 10.3389/fcimb.2022.834135
Rimon et al. 2022. Towards phage therapy for acne vulgaris: Topical application in a mouse model. Pre-print bioRxiv.
Yang et al. 2021. Modulation of Skin Microbiome in Acne Patients by Aminolevulinic Acid–Photodynamic Therapy. Photodiagn. Photodyn. Ther. 36, 102556. doi: 10.1016/j.pdpdt.2021.102556
