Topical Probiotics Do Not Satisfy New Criteria for Effective Use Due to Insufficient Skin Microbiome Knowledge

Abstract

We propose a set of criteria for topical probiotics to adhere to for safe and effective use for the skin microbiome. To form the basis of the criteria, we redefine the term “probiotics” and discuss successful and unsuccessful high-profile examples of the artificial addition of organisms to ecosystems in nature to understand what worked and what did not. Probiotics are often immediately assumed to have health benefits. However, as ecologists are aware, interfering with ecosystems is potentially catastrophic. The addition or removal of just one organism can significantly upset the delicate ecosystem balance. If our criteria are not met, we argue that topical probiotics could also cause damage and will not be beneficial. Due to the large intra- and inter-personal variation of the skin microbiome, our current knowledge of a healthy skin microbiome composition is not complete enough to fully satisfy the criteria. In follow-up work, we will investigate whether current topical probiotics research and commercial products meet our new criteria. We will also discuss problems with how to measure their effectiveness and suggest alternative solutions to replacing the lost biodiversity of the skin microbiome that was stripped away by environmental factors in the Western world.

Commercial Topical Probiotics for the Skin Microbiome: The Majority Do Not Contain Live Microbes and May Not Satisfy Criteria for Safe and Effective Use

“…To sum up, a successful probiotic solution for one person will not necessarily be a success for another. Therefore, it will be crucial to tailor probiotic solutions to the individual in the future [1]. Table 1.…”

“…In this paper, we analyse the current commercial topical probiotics on the market to determine whether they pass the criteria for the safe and effective use as defined in previous work [1]. We also discuss whether they contain live microbes, can therefore be called probiotics in accordance with the WHO's definition, and the implications of this.…”

“…In comparison, the same research focus the skin is virtually unheard of [15][16][17][18]. Topical probiotics, or the application of live microbes to the skin, is a method that has incredible potential for restoring our skin to levels of health and biodiversity seen on our ancestors and as a treatment for skin diseases linked to a dysbiotic microbiome [1,14]. Recently, their use has been linked to improving skin conditions such as acne, atopic dermatitis, wound and burn healing, psoriasis, and rosacea [15,19,20].…”

“…However, it is important to note that probiotics could also potentially disrupt the delicate microbiome balance and reduce biodiversity. The artificial addition of organisms to an ecosystem without understanding the exact numbers and which type to introduce, has produced catastrophic effects across nature throughout human history [1]. For humans, this is made even more complicated by the fact that everyone possesses a 'virtually unique' microbiome that also varies between body sites [21][22][23].…”

“…Previous work has warned against the use of probiotics without proper implementation [1,24], that universal health benefits are a falsehood [2], that side effects remain a concern [16,25], and a growing problem is unsubstantiated therapeutic claims [16,26].…”