Bread Affects Clinical Parameters and Induces Gut Microbiome-Associated Personal Glycemic Responses

• Published in: Cell metabolism 2017-06, Vol.25 (6), p.1243-1253.e5
• Main Authors: Korem, Tal, Zeevi, David, Zmora, Niv, Weissbrod, Omer, Bar, Noam, Lotan-Pompan, Maya, Avnit-Sagi, Tali, Kosower, Noa, Malka, Gal, Rein, Michal, Suez, Jotham, Goldberg, Ben Z., Weinberger, Adina, Levy, Avraham A., Elinav, Eran, Segal, Eran
• Format: Article
• Language: English
• Subjects: Adult; Blood Glucose - metabolism; Bread; Cross-Over Studies; Female; Gastrointestinal Microbiome - physiology; glycemic responses; gut microbiome; Humans; Male; Middle Aged; nutrition; personalization; prediction
• ISSN: 1550-4131; 1932-7420
• DOI: 10.1016/j.cmet.2017.05.002

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 sourdough-leavened 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 factors. [Display omitted] •Crossover trial shows no differential clinical effect of white versus sourdough bread•The microbiome composition was generally resilient to dietary intervention of bread•The glycemic response to the two types of bread varies greatly across people•Microbiome-based classifier accurately predicts glycemic-response-inducing bread type Korem et al. performed a crossover trial of industrial white or artisanal sourdough bread consumption and found no significant difference in clinical effects, with the gut microbiome composition remaining generally stable. They showed the glycemic response to bread type to be person specific and microbiome associated, highlighting the importance of nutrition personalization.