[podcast] Microbiome Interactions, Part II: External Forces

Part I in this podcast series, sponsored by Givaudan Active Beauty, explored new research implicating the gut microbiome in our skin microbiome's health. It also examined changes in our skin microbiome that appear to relate to age. Now, in part II, we consider: Is there a way to alter (and optimize) the microbiome forces at play, for improved skin health and appearance?

Here, Greg Hillebrand (GH), Ph.D., of Amway and Malcolm Kendall (MK), of Microbiome Insights, share what's known and what's missing. Following is an excerpt. Click on the full podcast below to hear more.

Cosmetics & Toiletries: If the microbiome were treated topically to improve compromised skin, would it not eventually revert back to the original state? 

GH: In the gut, we know the diet has a huge influence on the composition and diversity of the microbiome. There have been studies of individuals placed on a diet showing that once the new diet ends and [the individual reverts back to the original diet], the gut microbiome reverts back. In the case of skin, however, less has been done, especially in topical products, to track the microbiome before and after the use of a lotion, for example.

C&T: Do we know if everything we put on the skin affects the microbiome?

GH: There’s been some work done in this area but there’s a lot of work left to do. Some really good, quality experiments tracked in a thorough way are needed. One of the concerns I have in this area, though, is: Let’s not jump to conclusions too quickly. We’ve been using topical products for a long time without any evidence that we’ve harmed the microbiome. And in the case of preservatives, for example, there's a trade-off with [the need to ensure bacteria do not proliferate and make products unsafe].

C&T: Do we know if pollution or UV can affect the microbiome?

GH: For UV, most likely yes, through mechanisms that involve UV-induced immune suppression. UV could also have direct effects, affecting the DNA of the microbes like the DNA of your keratinocytes. 

Pollution is whole new area. We’ve been studying the effects of UV on the skin for 40-50 years; it will be interesting as scientists begin to tackle pollution.

C&T: Do we know if our microbiome interacts with our epigenome?

GH: The epigenetics of the human body are inheritable changes that occur in DNA other than the sequence—changes like methylation patterns and histone modifiications, and are highly related to the environment with which we come into contact, for example, smoking or dietary influences. So you can image the whole of our microbiome organism could affect the epigenetics of human cells.

MK: There’s a lot of work going on in this area and it’s pretty clear that your genome is static while the surrounding environment affects you, and thereby your epigenome.