The Obese Taste Bud Study (OTB)

The sense of taste is essential for priming food preferences and is therefore important for caloric uptake and body weight regulation. Recent studies show that obesity is linked to changes in taste sensation but also to a loss of taste buds on the tongue. This study aims to evaluate underlying mechanisms within the taste buds to potentially influence the sense of taste on the level of these sensory cells and in order to develop new treatment strategies to fight obesity.

Study Overview

• Status: Recruiting
• Conditions: Obesity
• Intervention / Treatment: Procedure: taste bud biopsy; Diagnostic test: oral glucose tolerance test; Diagnostic test: Taste sensitivity; Diagnostic test: olfactory function; Diagnostic test: taste bud density; Diagnostic test: anthropometry; Other: biospecimen collection; Other: questionnaires

• Study Type: Observational
• Enrollment (Anticipated): 210

Contacts and Locations

• Study Contact: Name: Imke Schamarek, Dr.; Phone Number: +493419713803; Email: Imke.Schamarek@medizin.uni-leipzig.de
• Study Contact Backup: Name: Kerstin Rohde-Zimmermann, Dr.; Phone Number: +493419722932; Email: Kerstin.Rohde@helmholtz-muenchen.de

Study Locations

• Germany
  • Saxony
    • Leipzig, Saxony, Germany, 04103
      • Recruiting
      • Medical Clinic III, Division of Endocrinology, University Clinic of Leipzig
      • Contact: Imke Schamarek, Dr. med.; Phone Number: +493419713803; Email: imke.schamarek@medizin.uni-leipzig.de

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 69 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

the study population will mainly consits of patients who underwent a medically induced elective surgery at the head or neck area (f.e. surgery at the soft palate, plastic surgery, maintenance of congenital anomalies etc.) or healthy participants recruited elsewhere at the campus area of the Medical Faculty of the University of Leipzig, Saxony, Germany.

Description

Inclusion Criteria:

• normal weight (BMI 18.5-24.9)
• obesity (BMI >=30)
• overall healthy (no severe sickness, no cancer)
• written informed consent

Exclusion Criteria:

• current pregnancy or currently breastfeeding
• cancer or tumors
• state after radiotherapy at head-neck area
• state after or current chemotherapy
• severe psychiatric-, cardiac-, kidney- or neurological illness
• diagnosed diabetes mellitus
• known dysfunction of smelling or tasting
• drug or alcohol abuse
• permanent medication with antidepressants, anticonvulsants, steroids and/or immunosuppressants

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
normal weight; Normal weight adults with BMI ranging from 18.5-24.9; men and women; age range 18-69years; written informed consent	Procedure: taste bud biopsy; Taste buds will be surgically removed a) during a planned and medically induced elective surgery under full anesthesia; b) by local anesthesia in subjects without a medically induced surgery; Diagnostic test: oral glucose tolerance test; 75g glucose will be applied in drinking water following blood sample collection to evaluate glucose, insulin and C-peptide level.; Diagnostic test: Taste sensitivity; Subjects are given taste strips with 4 concentrations per each taste quality of sweet, sour, salty, bitter and umami in a pseudo-randomized manner. Subjects are asked to identify the taste quality, state the intensity, preference and certainty.; Diagnostic test: olfactory function; Subjects will be presented 16 different sniffing sticks in a randomized order, each for about 4seconds. People are then asked to identify the smell by choosing one out of 4 options (forced choice).; Diagnostic test: taste bud density; The number of taste buds on the anterior tongue will be determined by colouring the tongue surface with food colour. Taste buds will apply more reddish as compared to non-taste tissue. Based on a digital photography the number of taste buds per subjects is counted manually.; Diagnostic test: anthropometry; Anthropometric data collection will include measures of body height, body weight, arm-, upper- and lower leg circumferences, waist- and hip circumferences and a bioimpedance analysis to obtain data about body composition.; Other: biospecimen collection; Blood and saliva samples will be taken as well as a tongue swab.; Other: questionnaires; Through the use of several questionnaires, data about eating behavior, food preferences, life style factors and other will be obtained.
obese; Subjects with obesity as defined by BMI >= 30; men and women; age range 18-69 years; written informed consent	Procedure: taste bud biopsy; Taste buds will be surgically removed a) during a planned and medically induced elective surgery under full anesthesia; b) by local anesthesia in subjects without a medically induced surgery; Diagnostic test: oral glucose tolerance test; 75g glucose will be applied in drinking water following blood sample collection to evaluate glucose, insulin and C-peptide level.; Diagnostic test: Taste sensitivity; Subjects are given taste strips with 4 concentrations per each taste quality of sweet, sour, salty, bitter and umami in a pseudo-randomized manner. Subjects are asked to identify the taste quality, state the intensity, preference and certainty.; Diagnostic test: olfactory function; Subjects will be presented 16 different sniffing sticks in a randomized order, each for about 4seconds. People are then asked to identify the smell by choosing one out of 4 options (forced choice).; Diagnostic test: taste bud density; The number of taste buds on the anterior tongue will be determined by colouring the tongue surface with food colour. Taste buds will apply more reddish as compared to non-taste tissue. Based on a digital photography the number of taste buds per subjects is counted manually.; Diagnostic test: anthropometry; Anthropometric data collection will include measures of body height, body weight, arm-, upper- and lower leg circumferences, waist- and hip circumferences and a bioimpedance analysis to obtain data about body composition.; Other: biospecimen collection; Blood and saliva samples will be taken as well as a tongue swab.; Other: questionnaires; Through the use of several questionnaires, data about eating behavior, food preferences, life style factors and other will be obtained.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Identification of differential gene and protein regulation in isolated human taste cells between lean and obese subjects	Transcriptomics (RNAsequencing (seq), single cell seq) and epigenomics (open chromatin mapping (ATACseq), Infinium MethylationEPIC Array) will be performed in isolated papillae fungiformes. Validation analyses by in vitro primary cell cultures of taste cell biopsy	through study completion, an average of 2 years
Identification of correlations between taste cell biology with parameters of intervention	corrleation analyses will include factors of eating behavior, food preferences, life style factors, data from taste and smell screenings, anthropometric data, blood and saliva parameters	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Differences of salivary and tongue microbiome on taste cells in obesity in contrast to lean	whole mouth saliva as well as local tongue microbiome diversity will be analysed by 16S ribosomal RNA seq and related to further parameters of this study.	2 years
extracellular vesicle analyses of saliva in lean and obese subjects	The content of extracellular vesicles from saliva samples will be analysed and compared between the study groups as well as related to other parameters of this study.	2 years

Collaborators and Investigators

• Sponsor: University of Leipzig
• Collaborators: Helmholtz Institut für Metabolismus-, Adipositas- und Gefäßforschung; Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde; Klinik und Poliklinik für Mund-, Kiefer- und Plastische Gesichtschirurgie; Poliklinik für Zahnärztliche Prothetik und Werkstoffkunde
• Investigators: Study Director: Michael Stumvoll, Prof. Dr., Medical Faculty of the University of Leipzig, Leipzig, Germany; Principal Investigator: Imke Schamarek, Dr., Medical Faculty of the University of Leipzig, Leipzig, Germany

Study record dates

Study Major Dates

• Study Start (Actual): November 9, 2020
• Primary Completion (Anticipated): July 15, 2022
• Study Completion (Anticipated): July 30, 2022

Study Registration Dates

• First Submitted: November 6, 2020
• First Submitted That Met QC Criteria: November 16, 2020
• First Posted (Actual): November 18, 2020

Study Record Updates

• Last Update Posted (Actual): January 14, 2021
• Last Update Submitted That Met QC Criteria: January 13, 2021
• Last Verified: January 1, 2021

More Information

Terms related to this study

• Keywords: Obesity; food preferences; taste disorder; taste bud; metabolic disease; feeding behavior
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity
• Other Study ID Numbers: OTB-2020; DRKS00022950 (Registry Identifier: DRKS)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: one aim of this study is to obtain large-scale sequencing data. with this several not yet defined research questions will be generated which shall be explored through later analyses and projects. in order to exploit the potential of the data and to avoid misinterpretation, the data should only be accessible to the scientists and collaborators involved.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No