Abstract: The microbiome of interior space within a business facility often differs markedly from its exterior. The difference may result from attempts to reduce microbes from the outside from entering the structure housing the business, attempts to kill microbes within the structure, or the provision of an environment that promotes growth of different microbes within the structure due to differences in temperature, humidity and nutrients available. The operation of a business or its facility can be changed to influence the composition of the interior microbiome and make it more similar to an exterior microbiome without an intolerable loss of the desired proactive features of the structure housing the business. The improved microbiome can result in health benefits of workers of the business and other business efficiencies, such as reduced spoilage of product.