Personalized Obesity Management - Matching Dietary Fibers and Microbial Enterotype

First, we hypothesize that participants who have a predominantly Prevotella enterotype (inferred by a high Prevotella/Bacteroides-ratio) will lose more body weight after AX supplementation compared to participants with a predominantly Bacteroides enterotype (inferred by a low Prevotella/Bacteroides-ratio). Specifically, we hypothesize that weight loss and P/B-ratio will be positively correlated in the AX supplementation-group whereas there will be no such correlation in the control-group. Consequently, we hypothesize that participants with the Bacteroides enterotype - and the lowest P/B-ratio - will have no benefit after AX supplementation while the weight loss effect of the AX supplementation will increase with increasing P/B-ratio.

Second, we hypothesize that the ability to digest starch in the upper gastrointestinal tract - evaluated by salivary alpha amylase gene (AMY1) copy number - will influence the interactions among AX intake, P/B ratio, and body weight change. Specifically, we hypothesize that there will be an association between body weight change and P/B ratio among subjects with a low AMY1 copy number, but not among the ones with a high AMY1 copy number, when consuming AX.

Inclusion criteria

• Apparently healthy men or women (self-reported nonpregnant, nonlactating, and not planning a pregnancy in the next 4 months)
• BMI: 25 to 40 kg/m2
• Non-smoker
• Want to maintain or lose weight
• Willing to consume wheat buns on a daily basis

Exclusion criteria

• Consumption of whole grain products with every meal
• Use of antibiotics 60 days prior to the start of the study. If a participant uses antibiotics prior to randomization, they will be invited to be re-screened 3 months after the last use of antibiotics, provided that it is realistic to complete the study no later than the scheduled LPLV
• Dietary supplements with pro- and/or prebiotics 6 weeks prior to study
• Self-reported eating disorders
• Being a bodybuilder (>4 strength training sessions per week)
• Alcohol intake above the recommendation from the Danish Health and Medicines Authority (>21 units of alcohol per week)
• Night- or shift work
• Chronic diseases e.g. cancer within the past 5 years (except adequately-treated localized basal cell skin cancer), asthma, thyroid disease, cardiovascular disease, type 1 or 2 diabetes, inflammatory diseases, and celiac disease
• Disorders: neurological, sleep, diagnosed psychiatric disorder and gastrointestinal and liver disorders
• Surgical treatment of obesity and abdominal surgery
• Inability, physically or mental, to comply with the procedures required by the study protocol as evaluated by the daily study manager, principal investigator or clinical responsible
• Subject's general condition contraindicates continuing the study as evaluated by the daily study manager, principal investigator or clinical responsible
• Simultaneous blood donation for another purpose than this study
• Simultaneous participation in other clinical intervention studies