Reference Number: 206
Bread is consumed daily by billions of people, yet evidence regarding its clinical effects is contradicting. Here, we performed a randomized crossover trial of two 1-week-long dietary interventions comprising consumption of either traditionally made sourdoughleavened whole-grain bread or industrially made white bread. We found no significant differential effects of bread type on multiple clinical parameters. The gut microbiota composition remained person specific throughout this trial and was generally resilient to the intervention. We demonstrate statistically significant interpersonal variability in the glycemic response to different bread types, suggesting that the lack of phenotypic difference between the bread types stems from a person-specific effect. We further show that the type of bread that induces the lower glycemic response in each person can be predicted based solely on microbiome data prior to the intervention. Together, we present marked personalization in both bread metabolism and the gut microbiome, suggesting that understanding dietary effects requires integration of person-specific
SIGNIFICANCE OF THIS STUDY
This study found no significant change in the gut microbiome of participants after 1 week of eating either industrial white or wholegrain sourdough bread. But they did find that glycemic response to each of the breads was related to the composition of the microbiome. This suggests that the way our bodies respond to specific components of our diet might be determined by our gut microbiome, and that dietary decisions should be based on personalised information rather than general recommendations.