Temperature and moisture condition changes have been linked to changes in microbial community composition (Lipson [2007]).
Future research should examine whether these changes have cascading effects on nutrient cycling, microbial communities, or plant growth.
These changes have been reflected in studies measuring variations in microbial activity, biomass, and community structure.
Importantly, these genome changes have the potential to fuel rapid adaptation in microbial populations (Selmecki et al. 2006; Rancati et al. 2008; Yona et al. 2012).
MetaHIT's Ehrlich points to other research suggesting that a baby's microbe population changes continuously, until around two years of age, so it is not clear whether this early difference – or any microbial change in early childhood – has any long-term health implications.
The resilience of microbial community compositions after environmental changes has been observed ubiquitously in various other environments, and the return to original compositions sometimes requires much longer periods (e.g. more than several years).
In the last 30 years, through the use of environmental DNA studies and the more recently developed metagenomic techniques, microbial ecologists have changed our perspective regarding microbial biogeography, metabolic interactions, and community dynamics.
Their genomes contain a vast array of biochemical transformations, and the microbial cells have accumulated DNA changes over a period of billion years of environmental change and evolution [ 3].
While exciting findings have been coming thick and fast, including Finlay and Arrieta's own work showing there is a short window of time in which microbial changes in a baby's gut can have long-term consequences in the lungs – we still don't know if microbes are a cause or effect of diseases.
The proposition that reduced infection and/or changed microbial exposure may have driven the rapid rise in atopic disease requires evaluation on several levels.
