Impact of Microbiome-changing Interventions on Food Decision-making (MIFOOD)

"SFB 1052/3 - Mechanismen Der Adipositas, Projekt A1: Veränderung Der Neurobiologischen Grundlagen Von Ess-Entscheidungen Bei Adipositas" Engl. "CRC 1052/3 - Obesity Mechanisms, Project A1: Targeting Neurobehavioral Determinants of Obesity"

Universitätsklinikum Leipzig, DFG - Deutsche Forschungs Gemeinschaft (German Research Foundation), Helmholtz-Zentrum für Umweltforschung - UFZ

The investigators aim to test the hypothesis that a microbiome-changing dietary intervention improves food decision-making and to determine the underlying microbiotal and metabolic mechanisms. To this end, 90 overweight/obese adults will be enrolled in a randomized controlled trial to test the effects of a pre-biotic dietary intervention (supplementary intake of soluble fibre) or a behavioural lifestyle intervention (weekly educational program) vs. control condititon (supplementary intake of isocaloric starch) over a period of 26 weeks. Before and after the intervention/control period, participants will undergo task-based functional and structural MRI and cognitive testing. The gut microbiota will be assessed using 16S rDNA next-generation sequencing (V3/V4 region) in stool samples. Diet, anthropometry and lifestyle will be monitored with questionnaires and metabolomics will be assayed in peripheral blood and stool (e.g. SCFA). Using a modulation of gut-brain communication through a prebiotic diet and lifestyle intervention, respectively, the investigators will be able to discover microbiota communities that play a key role for eating behaviour. Related mechanistic insights could help to develop novel preventive and therapeutic options to combat unhealthy weight gain in our obesogenic society.

People will be randomly assigned to the three arms and blinded towards receipt of dietary fibre supplement or placebo supplement. However, behavioural lifestyle intervention arm cannot be blinded to participants.

BOLD-acitvity will be measured using event-related echo-planar T2*-weighted magnetic resonance imaging (MRI) during food wanting task according to previously described procedures (details of preprocessing at: https://osf.io/ynkxw). Onsets of food and art stimuli presentation will be modelled as separate regressors convolving delta functions with a canonical hemodynamic response function. Wanting rating scores (on an 8-point likert scale) per stimulus will be added as covariates. In a parallel model, kcal of food stimuli will be added multiplied with wanting scores to model high caloric food wanting interaction. At the group level, we will assess the contrasts food > art and wanting modulation.

BOLD-acitvity will be measured using event-related echo-planar T2*-weighted magnetic resonance imaging (MRI) during food wanting and food memory recognition tasks according to previously described procedures (details of preprocessing at: https://osf.io/ynkxw). Onsets of food and art stimuli presentation in encoding and recognition will be modelled as separate regressors convolving delta functions with a canonical hemodynamic response function. Correctly remembered and correctly rejected, as well as misses and false alarms will be modeled separately. In parallel models, similar and new items als well as wanting rating scores (on an 8-point likert scale) per stimulus and kcal of food stimuli multiplied with wanting scores will be added as covariates. At the group level, we will assess the contrasts correct > false and wanting modulation.

self-reported hunger feeling on a 8-point score from minimum 0 (not at all) to maximum 8 (very much).

high sensitive C-reactive protein mg/l (and optionally tumor necrosis factor alpha and interleukin 6 in blood, pg/ml)

Inclusion Criteria: BMI >= 25 kg/m2 or WHR >= 0.9/0.85 (m/d, f) no MRI contra-indication written informed consent Exclusion Criteria: athletes occurrence of a clinically relevant psychiatric disease in the last 12 months, e.g. depression, substance abuse, eating disorders, schizophrenia any chronic inflammatory or malignant disease type 1 diabetes previous bariatric/gastric surgery pregnancy or breastfeeding woman

We plan to share all data openly but anonymized on secured German servers of the institute after registration with ID.