Bacteriotherapy: Roseomonas on My Face

Microbiome products that support our health are on the rise. This is a quandary for regulators and manufacturers

Research into diverse and unique microbial environments over the years has demonstrated that microbial communities—known as microbiomes—play a major role in human health. The skin and its microbial community provide protection against pathogens and environmental damage; while the gut microbiota has an impact on the host’s immune system and is a necessary component of physiological homeostasis.

Dietary supplements and personal care or cosmetics products can be designed to support microbiome health using prebiotics (selective nutrient substrates that promote growth or metabolic activities of microorganisms within an environment), probiotics (viable microorganisms which confer a benefit to the consumer), and postbiotics (non-viable microorganisms or substances derived from probiotics such as certain microbial metabolites which confer a benefit to the consumer).

Products for personal use are being developed to support, enhance, or modify the skin and gut microbiome; while industrial products containing probiotics or biologically active components are being produced to address hazardous biofilms on different surfaces, including handwashing and dishwashing liquids, and multi-surface cleaners and sprays.

The regulation of microbiome products should differ

This brings future regulatory and manufacturing concerns for these microbiome products. Manufacturers of cosmetics and personal care products are well aware that, depending on the product category and claims, the regulation of these products can differ. Some cosmetics can be considered as drugs and are regulated as over-the-counter (OTC) drugs, from antiperspirants and sunscreens to antifungal products and acne medicines. Therefore, the functions of products that are to be used to modify or enhance the skin microbiome should be well defined. Products that support microbiome health with the addition of a prebiotic or postbiotic will have different, perhaps simpler designs, and fewer hurdles than products containing live probiotic organisms. There are many questions that have been raised regarding the use of probiotics in cosmetics, and many of these questions are still unanswered.

The downside of microbiome products

For example, many of the global regulatory agencies have requirements for the characterization of the microbial profile of a product, and documentation of the efficacy of preservatives. If the product itself is designed to contain a live organism, traditional microbial limits and bioburden assays will not be appropriate or sufficient. Likewise, evaluation of the use and necessity of preservatives is of importance to determine if they are needed in the case of probiotic-based products, and if they are actually detrimental to the product and claims of safety or efficacy. The extent of these safety or efficacy claims will also determine how a product is regulated – as a cosmetic or as a drug. In addition to the consideration of safety for the consumer, there are considerations such as shelf life and storage constraints for these products, the impact on the live organisms, or even the presence of spores, and the critical quality attributes of bacteriotherapy products.

One study from 2019 found a long list of contaminants in probiotic-containing products for use on or around people, including opportunistic pathogens which pose a potential risk to human health (Jeżewska-Frąckowiak, Żebrowska et al. 2019). The manufacturing procedures must result in microbiologically defined or sufficiently controlled microorganism groups. Besides potential pathogenicity, there is a possibility of antibiotic resistance propagation (Daniali, Nikfar et al. 2020). Recent studies showed the transference of antibiotic resistance genes among opportunistic pathogens, probiotics, and normal gut microbiota in the gastrointestinal tract through horizontal gene transfer. This may result in probiotics being a possible source for antimicrobial resistance genes potentially leading to clinical implications.

With the constantly increasing number of personal care and home care products containing prebiotics, probiotics, or postbiotics reaching the market, there is potential intentional and unintentional impact to microbiomes. As the trend continues towards the development of more and more microbiome products, it is increasingly important to approach this field with a certain level of due diligence.