A large-scale study has found that the gut microbiome – the composition and function of bacteria in the intestine – changes as the day progresses, but not in people with Type 2 diabetes.
This was established by researchers based in Freising at ZIEL – Institute for Food & Health of the Technical University of Munich (TUM) with one of the most significant studies related to microbiomes and diabetes comprising more than 4,000 participants.
The microbial composition of the intestines is complex and varies widely from one individual to another. Many factors, such as environmental factors, lifestyle, genetics or illnesses, affect the intestinal ecosystem of helpful gut bacteria.
Dirk Haller, Professor for Nutrition and Immunology at TUM, and his team examined the importance of daytime-dependent fluctuations of the gut microbiome concerning Type 2 diabetes.
“When certain gut bacteria do not follow a day-night rhythm, so if their number and function does not change over the day, this can be an indicator for a potential Type 2 diabetes disease. Knowing this can improve diagnosis and outlook of Type 2 diabetes,” said Chronobiologist Dr. Silke Kiessling, another contributor to the study.
These arrhythmic bacteria – those that are not changing between day and night – are a marker for potential disease. Researchers refer to this as a risk signature. “Mathematical models also show that this microbial risk signature consisting of arrhythmic bacteria helps to diagnose diabetes,” explained Sandra Reitmeier, first author on the study.
Primarily, the scientists analysed data from an existing independent cohort by Helmholtz Zentrum München. The diabetes-related results were validated using additional groups from Germany. “By comparing our data to cohorts in England, we could confirm that there is – among other things – a strong regional factor affecting the microbial ecosystem. Therefore, there is a demand for finding locally specified arrhythmic risk signatures,” elaborated Haller.
Nutritionist Haller emphasises that “apart from bacteria and their variations over the course of the day, other parameters such as the body mass index play a role in being able to better predict a person’s future medical conditions.”
Registering the time of day when taking human faecal samples for research purposes can heavily influence disease diagnostics. “Documenting these timestamps is essential for improving risk markers,” Prof. Haller emphasises.
This research substantiates the hypothesis that changes in the microbiome have an effect of nutrition-related diseases. How gut bacteria changing (or not changing) during the day affect other microbiome-associated diseases, such as Crohn’s disease or intestinal cancer may be subject to further scientific examination.
The research is published in Cell Host & Microbe. Click HERE to read.