Microbiota and urban grey space

Appropriate song to play while reading this post: “Fade to Grey” by Visage

A new paper in the Journal of Physiological Anthropology touches upon some interesting viewpoints. The paper is called Dysbiotic drift: mental health, environmental grey space, and microbiota, and was written by Alan C Logan. And it’s Open Access, which we all appreciate!

The article, which is rather philosophical and theoretical in nature, starts off with the WHO statement ‘No Health without Mental Health’. But, unfortunately, mental health is not distributed equally across populations or neighborhoods. The authors argue that this might be caused because humans live in environments with unequal distributions of green space and “grey space”. Although it is not clearly defined in the paper, I assume that “grey space” are those areas that have little or no vegetation, so urban areas consisting only of houses, streets, concrete, and asphalt surfaces.

Not everybody can afford housing within, or regular access to natural environments. Parks and diverse vegetation are more often found nearby wealthier urban areas, while socioeconomically disadvantaged neighborhoods have more grey space with no plants or soil. People living in those grey zones might have less exposure to the microbes associated with “green space”. In addition, healthy foods such as fruits and vegetables are often more expensive than fast food, and the stores that sell healthy food items are often lacking from areas with a low average income.

The authors suggest that we should take these socioeconomic differences into account when considering the – already complicated! – relationship between the human microbiome and mental health. From the abstract:

“It is argued here that a ‘disparity of microbiota’ might be expected among the socioeconomically disadvantaged, those whom face more profound environmental forces.”

“Matching the developing microbiome research with existing environmental justice research suggests that grey space may promote dysbiosis by default. ”

“If microbiota are indeed at the intersection of nutrition, environmental health, and lifestyle medicine (as these avenues pertain to mental health), then perhaps the rapidly evolving gut-brain-microbiota conversation needs to operate through a wider lens. In contrast to the more narrowly defined psychobiotic, the term eco-psychotropic is introduced.”

Although the article is very theoretical, it highlights some important issues to consider when we talk about the built environment and its microbes.

Dysbiotic drift: mental health, environmental grey space, and microbiota
Alan C Logan – Journal of Physiological Anthropology

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Elisabeth Bik

After receiving my PhD at Utrecht University in The Netherlands, I worked at the Dutch National Institute for Health and the St. Antonius Hospital in Nieuwegein. In 2001, I joined the Department of Microbiology and Immunology at Stanford, where I have worked on the characterization of the human microbiome in thousands of oral, gastric, and intestinal samples. I currently study the microbiome of marine mammals. When I am not in the lab, I can be found working on my blog Microbiome Digest , an almost daily compilation of scientific papers in the rapidly growing microbiome field, or on Twitter at @MicrobiomDigest.