Changing one’s dietary regimen can cause dramatic changes in the balance of bacteria in the gut, a new insight that could help doctors better monitor the digestive system and detect chronic diseases such as ulcerative colitis and Crohn’s disease, according to a new study conducted at the Massachusetts Institute of Technology (MIT). While researchers studied bacteria in the digestive tract and made new discoveries about the gut microbiome, they noted that since there are trillions of bacteria, their role in human health is still yet to be fully understood.
MIT scientists analyzed mutations in the bacteria of two people over the course of one year in order to understand the effects of bacteria in the body. The researchers collected daily samples from the two subjects to monitor both the amount and types of bacteria present. The participants were asked to use an iPhone app that tracked lifestyle factors, such as diet, sleep, mood, and exercise, all factors which the scientists believe may influence gut bacteria, according to the study published in this month’s issue of the journal Genome Biology.
The researchers verified that both of the participants experienced an event during the study period that significantly influenced the number and types of bacteria in the digestive tract. While one of the participants suffered from diarrhea during a two-week trip to a developing country, the scientists identified significant changes in the balance of gut bacteria. When he returned home to the United States, the gut bacteria returned to normal.
The other patient involved in the study suffered food poisoning from salmonella, during which the scientists verified that gut salmonella jumped from 10 percent to nearly 30 percent, while populations of helpful bacteria nearly disappeared. After the recovery of the patient, the beneficial bacteria rebounded to about 40 percent of the total microbiome. However, the scientists noted that most of the strains were different from the original ones.
“On any given day, the amount of one species could change manyfold, but after a year, that species would still be at the same median level. To a large extent, the main factor we found that explained a lot of that variance was the diet,” explained the study’s senior author, Eric Alm, an associate professor of biological and environmental engineering, as quoted in an article on Philly.com.
The next step for the research team is to start a new phase of the investigation to study the way in which gut bacteria returns to normal levels after fluctuating widely after adverse events.