Inorganic nanoparticles and the microbiome

Routine exposure to inorganic nanoparticles (NPs) that are incorporated into consumer products such as foods/drinks, packaging materials, pharmaceuticals, and personal care products (e.g. cosmetics, sunscreens, shampoos) occurs on a daily basis. The standard everyday use of these products facilitates interactions between the incorporated inorganic NPs, mammalian tissues (e.g. skin, gastrointestinal tract, oral cavity), and the community of microbes that resides on these tissues. Changes to the microbiome have been linked to the initiation/ progression of many diseases and there is a growing interest focused on understanding how inorganic NPs can initiate these changes. As these mechanisms are revealed and defined, it may be possible to rationally design microbiotamodulating therapies based on inorganic NPs. In this article, we will: (i) provide a background on inorganic NPs that are commonly found in consumer products such as those that incorporate titanium, zinc, silver, silica, or iron, (ii) discuss how NP properties, microbiota composition, and the physiological microenvironment can mediate the effects that inorganic NPs have on the microbiota, and (iii) highlight opportunities for inorganic NP therapies that are designed to interact with, and navigate, the microbiome.