Mediterranean Diet and the Microbiota Gut Brain Axis in Major Depression

Not Applicable

Not yet recruiting

• Conditions: Depression
• Interventions: Other: Mediterranean Diet; Other: Normal hospital diet; Other: dietary coaching; Other: Psychoeducation on depression

• Registration Number: NCT04772651
• Lead Sponsor: Medical University of Graz

Brief Summary

The purpose of this study is to assess the efficacy of a Mediterranean diet on the function of the vagal nerve in patients with depression.

Detailed Description

After being informed about the study and potential risks, all patients giving written informed consent will be screened for eligibility. Subjects meeting the inclusion criteria will be randomized in a group recieiving a Mediterranean diet (3 mediterranean meals a day) and dietary coaching (1 session per week for 4 weeks) or a group with conventional hospital food and psychoeducation on depression (1 session per week for 4 weeks).

Study Timeline

• Study First Submitted: 2021-02-23
• Study First Submitted QC: 2021-02-25
• Study First Posted: 2021-02-26
• Status Verified: 2023-03
• Last Update Submitted: 2023-03-13
• Last Update Posted: 2023-03-14
• Study Start: 2025-11-01
• Primary Completion: 2028-09-01
• Study Completion: 2029-09-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 108

Inclusion Criteria

• legally competent persons aged 18-80 years
• diagnosis of depression according to ICD-10 or DSM.

Exclusion Criteria

• other neurologic or psychiatric disorders (epilepsy, brain tumor, head injury, head surgery, trauma)
• drug or alcohol dependency
• acute suicidality
• heart disorders, disorders of the circulatory system
• pregnancy and period of breastfeeding
• severe mental disability, dementia (MMST<20)
• autoimmune disorder, severe immunosuppression (Lupus, HIV, multiple sclerosis)
• therapy with antibiotics in the last month
• chronic laxative abuse
• acute infectious diarrhea
• GI surgeries (except appendectomy)
• regular intake of probiotics, antibiotics and food supplements (1 month before and during the study)
• food allergies or other food intolerances which are incompatible with a mediterranean diet
• vegetarians, vegans

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Mediterranean Diet and dietary coaching	Mediterranean Diet	Patients receive 3 Mediterranean meals a day for 4 weeks and dietary coaching sessions (á 50 minutes once a week for 4 weeks)
Mediterranean Diet and dietary coaching	dietary coaching	Patients receive 3 Mediterranean meals a day for 4 weeks and dietary coaching sessions (á 50 minutes once a week for 4 weeks)
Diet as usual and psychoeducation for depression	Normal hospital diet	Patients receive normal hospital diet with 3 meals a day for 4 weeks and psychoeducation sessions (á 50 minutes once a week for 4 weeks)
Diet as usual and psychoeducation for depression	Psychoeducation on depression	Patients receive normal hospital diet with 3 meals a day for 4 weeks and psychoeducation sessions (á 50 minutes once a week for 4 weeks)

Primary Outcome Measures

Name	Time	Method
Change in Vagal function	at study entry, after 7 days, after 4 weeks and after 3 months	Vagal function measured by 24-hr ECG (logRSA, SDNN)

Secondary Outcome Measures

Name	Time	Method
Change of C-reactive protein (CRP)	at study entry, after 7 days, after 4 weeks and after 3 months	CRP will be measured from serum samples at the Institute of laboratory diagnostics (Cobas analyzer)
Change in Interleukine-6	at study entry, after 7 days, after 4 weeks and after 3 months	Interleukine-6 will be measured from serum samples at the Institute of laboratory diagnostics
Change in International Physical Acitivity Questionnaire	at study entry, after 7 days, after 4 weeks and after 3 months	Questionnaire to rate physical activity; Physical activity is given in MET-minutes (METs are multiples of the resting metabolic rate)
Change in Oxytocin	at study entry, after 7 days, after 4 weeks and after 3 months	measured from serum samples with ELISA
Change of Gut microbiome	at study entry, after 7 days, after 4 weeks and after 3 months	16S sequencing of a stool sample, gut microbiome data will be analyzed with QIIME2 with regard to diversity metrices (alpha-diversity, beta-diversity) and differential bacterial abundance.
Change of Body mass Index	at study entry, after 7 days, after 4 weeks and after 3 months	Weight will be measured with a calibrated scale, height will be measured with a non-expandable measuring tape. BMI will be calculated according to the formula \[kg/m2\].
Change in Hamilton Scale for Depression (HAMD)	at study entry, after 7 days, after 4 weeks and after 3 months	Scale to rate severity of depressive symptoms; Scoring is based on the 17-item scale and scores of 0-7 are considered as being normal, 8-16 suggest mild depression, 17-23 moderate depression and scores over 24 are indicative of severe depression
Change in Beck Depression Inventory (BDI)	at study entry, after 7 days, after 4 weeks and after 3 months	Self-rated scale to rate severity of depressive symptoms; Total score of 0-13 is considered minimal range, 14-19 is mild, 20-28 is moderate, and 29-63 is severe depression.
Change in Pittsburgh Sleep Quality Inventory (PSQI)	at study entry, after 7 days, after 4 weeks and after 3 months	Questionnaire to assess sleep quality; global PSQI score is calculated by totaling the seven component scores, providing an overall score ranging from 0 to 21, where lower scores denote a healthier sleep quality.
Change in Adult Attachment Scale	at study entry, after 7 days, after 4 weeks and after 3 months	Questionnaire to assess attachment style in adults; The scale consists of 18 items scored on a 5 point likert-type scale. It measures adult attachment styles named "Secure", "Anxious" and "Avoidant", defined as: * Secure = high scores on Close and Depend subscales, low score on Anxiety subscale; * Anxious = high score on Anxiety subscale, moderate scores on Close and Depend subscales; * Avoidant = low scores on Close, Depend, and Anxiety subscales
Change in Wiener Ernährungsprotokoll	at study entry, after 7 days, after 4 weeks and after 3 months	24-hr food recall
Change in Mediterranean Diet Score	at study entry, after 7 days, after 4 weeks and after 3 months	Questionnaire rating the diet according to Mediterranean dietary style; three categories of adherence to the Mediterranean diet can be calculated (≤5, 6-9 and ≥10 points of the 14-item questionnaire)