Below is a map of bacterial diversity in the kitchens of East Oxford, collated from the 14 households taking part in our project. It comes with a whole bunch of scientific caveats, some of which I discuss below, but is interesting nevertheless. Kitchen floors seem to be the bacterial equivalent of rainforests, teeming with all manner of different microbial creatures. Sinks and chopping boards, by contrast, seem to be more specialised habitats, attracting a discerning set of bacterial denizens.
Map 1: Microbial diversity in all the kitchens sampled
The data comes from a ‘kitchen safari’ conducted by our participants earlier this year. Each household swabbed five common locations in their kitchens: chopping boards, work surfaces, sinks, door handles, and floors. The swabs were analysed using 16S sequencing, and the map is an early output of our analysis. But since it will take a while to analyse the data in full, the maps are based solely on the bacteria that we can recognise immediately (by comparing them to a "library" of known DNA sequences). Further analysis might change the overall patterns. And we have also had to make a series of assumptions in order to use this early data as a proxy for diversity – we will write more about this in another blogpost soon.
Despite the caveats, the broad patterns shown in the map above seem interesting – and especially when compared to what our group was expecting to find. Before we plugged the map into the dataset, we asked all of our participants to colour it in themselves, based on their own hunches about microbial life. Three things stand out. First, when combined, peoples’ hunches were pretty accurate. Second, the outlier seems to be sinks, in which the diversity appears to be relatively lower than people were expecting. This might say something about cleaning practices, constant immersion with water, or about the particularities of sinks as microbial habitats – plenty for us to explore going forward. And third, we should have asked people to swab their waste bins and their pet’s living quarters! Maybe next time that is what they will choose to swab themselves.