For anyone who’s ever wondered whether microbes living within the digestive system live parallel lives to their human hosts, the answer is yes — and we know this because of smartphones.
Two study participants used smartphone apps every day for a year to meticulously record diet, exercise, bowel movements, and mood. They also submitted saliva and stool samples on a regular basis to allow analysis of how a person’s microbiota, the assortment of bacteria living within the body, adjusts to events here in middle space.
The participants were screened before the experiment for their willingness to track such a broad range of daily actions. The two participants then logged their activity for a year, and the data from the diaries and genetic analysis of the bacteria in the samples were analysed in detail, to see what had the greatest effect on the composition of the microbiota.
The results showed that the participants had a ‘default’ microbiota, which were unaffected by sleep levels, exercise and mood. What did have a significant effect on the microbiota were two life events – one subject moved abroad, while the other had a significant bout of food poisoning which caused most pre-existing gut bacterial species to decline. The effects of relationships between diet and specific groups of bacteria manifested in a single day.
Professor Lawrence David from Duke University said: “I was surprised by our results in several ways. First, I wasn’t sure we would find correlations between fiber intake and gut bacterial dynamics on such short time scales.
And I was amazed to see how profoundly a single food poisoning event impacted the gut bacteria. This has given us a lot of new ideas for follow up studies and analyses of gut microbial ecology, as well as enteric infectious diseases in humans.”