A new study in the open access journal Genome Biology has found that significant life events like visiting another country or contracting a disease has changes in the shifting make-up of our gut microbiota. Microbiota are the community of bacteria living in perfect harmony with us within the digestive system. Everyone has an individual microbiota that is different from another person. It is thought to have a close relationship to our health.

Researchers from MIT and Harvard appointed two participants, after various screening processes, to collect information on their daily activity such as diet, exercise, bowel movements and moods via their smartphones apps. They would also instructed to send regular stool and saliva samples. They did this for a year. After the year ended all data was analyzed in detail to determine what had the greatest effect on the composition of the microbiota.

The results found that the participants had a ‘default’ microbiota. This was the microbiota that was not affected by sleep levels, exercise or moods. The greatest effects with most significance found that two different yet extreme events like when one participant moved abroad and the other having a serious bout of food poisoning caused most of the pre-existing gut bacterial species to decline. Even diets had a significant relationship on specific groups of bacteria that manifested within a single day.

“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.” Says Professor Lawrence David from Duke University.