TY  - JOUR
AB  - BACKGROUND: Obesity is a multifactorial disease reaching pandemic proportions with increasing healthcare costs, advocating the development of better prevention and treatment strategies. Previous research indicates that the gut microbiome plays an important role in metabolic, hormonal, and neuronal cross-talk underlying eating behavior. We therefore aim to examine the effects of prebiotic and neurocognitive behavioral interventions on food decision-making and to assay the underlying mechanisms in a Randomized Controlled Trial (RCT). METHOD: This study uses a parallel arm RCT design with a 26-week intervention period. We plan to enroll 90 participants (male/diverse/female) living with overweight or obesity, defined as either a Waist-to-Hip Ratio (WHR) ≥ 0.9 (male)/0.85 (diverse, female) or a Body Mass Index (BMI) ≥ 25 kg/m2. Key inclusion criteria are 18-60 years of age and exclusion criteria are type 2 diabetes, psychiatric disease, and Magnetic Resonance Imaging (MRI) contraindications. The interventions comprise either a daily supplementary intake of 30 g soluble fiber (inulin), or weekly neurocognitive behavioral group sessions, compared to placebo (equicaloric maltodextrin). At baseline and follow-up, food decision-making is assessed utilizing task-based MRI. Secondary outcome measures include structural MRI, eating habits, lifestyle factors, personality traits, and mood. Further, we obtain fecal and blood samples to investigate gut microbiome composition and related metabolites. DISCUSSION: This study relies on expanding research suggesting that dietary prebiotics could improve gut microbiome composition, leading to beneficial effects on gut-brain signaling and higher-order cognitive functions. In parallel, neurocognitive behavioral interventions have been proposed to improve unhealthy eating habits and metabolic status. However, causal evidence on how these "bottom-up" and "top-down" processes affect food decision-making and neuronal correlates in humans is still scarce. In addition, microbiome, and gut-brain-axis-related mediating mechanisms remain unclear. The present study proposes a comprehensive approach to assess the effects of these gut-brain-related processes influencing food decision-making in overweight and obesity. TRIAL REGISTRATION: ClinicalTrials.gov NCT05353504. Retrospectively registered on 29 April 2022.
AU  - Vartanian, M.*
AU  - Endres, K.J.*
AU  - Lee, Y.T.*
AU  - Friedrich, S.-O.*
AU  - Meemken, M.T.*
AU  - Schamarek, I.
AU  - Rohde-Zimmermann, K.
AU  - Schürfeld, R.*
AU  - Eisenberg, L.*
AU  - Hilbert, A.*
AU  - Beyer, F.*
AU  - Stumvoll, M.
AU  - Sacher, J.*
AU  - Villringer, A.*
AU  - Christensen, J.F.*
AU  - Witte, A.V.*
C1  - 73032
C2  - 56902
CY  - Campus, 4 Crinan St, London N1 9xw, England
SP  - 8
TI  - Investigating the impact of microbiome-changing interventions on food decision-making: MIFOOD study protocol.
JO  - BMC Nut.
VL  - 11
IS  - 1
PB  - Bmc
PY  - 2025
ER  - 

TY  - JOUR
AB  - Background The development of several disorders, such as cardiovascular diseases, diabetes and osteoporosis, has been linked to suboptimal dietary magnesium (Mg) intake. In this context, a number of studies have tried to investigate which Mg compounds are best suited for Mg supplementation. Results suggest that organic Mg compounds are superior to the inorganic Mg oxide in terms of bioavailability, but a reliable statement cannot yet be made due to systematic differences in the applied study designs. Methods This single-center, randomized, open, 2-period, 2-supplementation, 2-sequence, single-dose, cross-over study was conducted in 20 healthy male subjects of Caucasian origin to investigate and compare the bioavailability of Mg citrate, an organic Mg compound, and Mg oxide, an inorganic Mg compound. In order to reliably assess the bioavailability of both Mg compounds, subjects were supplemented with magnesium to saturate their Mg-pools before administration of each study product. The bioavailability of both Mg compounds was then assessed by measurement of the renally eliminated Mg quantity during an interval of 24 h after single-dose Mg administration (Ae 0-24h) as primary endpoint. Additionally, the Mg concentrations in a subset of leukocytes, in erythrocytes and in serum were measured on an exploratory basis. Results After administration, Ae 0-24h of magnesium was higher for Mg citrate than for Mg oxide. Ae 0-24h for both study products was compared by analysis of variance (ANOVA), revealing an adjusted mean difference of 0.565 mmol, which was statistically significant at the 5% level (95% confidence interval of 0.212 to 0.918 mmol, p = 0.0034). Besides, serum Mg concentrations were statistically significantly higher for Mg citrate than for Mg oxide at several time points after administration. No statistically significant difference was shown in intracellular Mg contents. Conclusions This study confirms former study results showing a higher bioavailability of the organic Mg compound Mg citrate compared to Mg oxide. It can be concluded that Mg citrate, similar to other organic Mg compounds, may be more suitable than Mg oxide to optimize the dietary magnesium intake.  
AU  - Kappeler, D.*
AU  - Heimbeck, I.*
AU  - Herpich, C.*
AU  - Naue, N.*
AU  - Höfler, J.*
AU  - Timmer, W.*
AU  - Michalke, B.*
C1  - 50419
C2  - 42204
TI  - Higher bioavailability of magnesium citrate as compared to magnesium oxide shown by evaluation of urinary excretion and serum levels after single-dose administration in a randomized cross-over study.
JO  - BMC Nut.
VL  - 3
PY  - 2017
ER  -