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NCT Number: NCT06985381

ESAN III - Energy Sensing in Depression

The purpose of this study is to assess the effects of carotenoids from natural carrot juice on the immune system. Therefore, the study aims to distinguish the effects of natural juices that are rich in phytonutrients such as carotenoids in healthy and depressive individuals, to explore their potential use in therapeutic settings. The consumption of natural fruit juices rich in polyphenols and carotenoids serves as a model for a vegetarian diet, due to the increased micronutrient density derived from plant-based foods. The results obtained may provide preliminary explanatory models for the beneficial effects of a vegetarian diet.

It is hypothesized that the consumption of a natural carotenoid-rich juice alters the expression of regulatory T cells-specific immune cells that contribute to immunomodulation. Furthermore, beneficial changes in the gut microbiome, metabolome, and nutritional status are expected.

This study was registered retrospectively (after recruitment had started) on ClinicalTrials.gov.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Obesity Body Weight Gut Microbiota Modulation Immunomodulation Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–65 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Medical Universtiy of Graz

Graz, Styria, 8010, Austria

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Socio-demographic criteria:

  • Gender: female
  • Age: 18-65 years

Confirmation of study participation:

  • Received information on the aims, methods, anticipated benefits, potential risks, and entailed discomforts of the study
  • Signed declaration of consent

Subgroup of depressive patients:

  • Diagnosis of depression according to the ICD-10 criteria
  • Diagnosis confirmed by an experienced psychiatrist

Subgroup of normal weight participants:

  • WHO criteria for normal weight (Body Mass Index [BMI] 18.5-24.99 kg/m²)

Subgroup of obese participants:

  • WHO criteria for obesity (BMI > 30.0 kg/m²)

Exclusion criteria

Formal criteria:

  • Lack of informed consent

Health criteria:

  • Alcohol or drug abuse
  • Acute or chronic diseases or infections (including cancer, fever, pneumological or renal disorders, cardiovascular disease, hematopoietic disorders)
  • Digestive disorders (including fructose intolerance, inflammatory bowel disease, irritable bowel syndrome)
  • Treatment that may have influenced the microbiome (including antibiotic or antifungal treatment within the previous two months, and daily or irregular intake of prebiotics or probiotics within the previous two months; the intake of yogurt and dairy products is permitted)
  • History of gastrointestinal surgery (other than appendectomy)
  • Psychiatric disorders (schizophrenia, dementia, bipolar disorder)
  • Pregnancy or breastfeeding

Treatment and study plan

Carotenoid-rich juice

Other

The intervention is based on the additional consumption of 200 ml natural carotneoid-rich juice a day for a period of six weeks. The participants are asked to drink the natural and commercially available juice in addition to their regular diet. Further, they are asked not to change their diets and lifestyle behaviour during the intervention.

Control

Other

Participants assigned to the control group are asked to drink additional 200ml of water a day to control liquid intake.

Primary outcomes

  1. Change of baseline regulatory T cells (Tregs) at week 6 (after the intervention) and after a wash-out period at week 12.

    Time frame: From enrollment (baseline) to the end of intervention at week 6 and after a wash-out period at week 12.

    Tregs are involved in modulating the immune system and maintaining tolerance to self-antigens and preventing autoimmune diseases. Regulatory T cells (Treg) will be quantified using multiparameter flow cytometry. Monoclonal antibodies specific for surface markers such as CD3, CD4, CD45RA, CD39 and CD25 will be combined with intracellular anti-Foxp3 for the identification of human Treg.

    Tregs are involved in modulating the immune system and maintaining tolerance to self-antigens and preventing autoimmune diseases. The assessment of Tregs after 12 weeks aims to identify any persisting effects of the intervention.

Secondary outcomes

  1. Effect of carotenoid-rich juice consumption on gut microbiota composition, assessed by changes in alpha diversity (Shannon Index) between intervention and control groups.

    Time frame: From enrollment (baseline) to the end of intervention at week 6 and after a wash-out period at week 12.

  2. Change in plasma carotenoid concentration following carotenoid-rich juice consumption, compared between intervention and control groups.

    Time frame: From enrollment (baseline) to the end of intervention at week 6 and after a wash-out period at week 12.

    Carotenoid plasma concentration is quantified by High-Performance Liquid Chromatography (HPLC).

  3. Change in skin carotenoid levels (measured non-invasively), following carotenoid-rich juice consumption, compared between intervention and control groups.

    Time frame: From enrollment (baseline) to the end of intervention at week 6 and after a wash-out period at week 12.

    Skin carotenoid score is determined on an arbitrary scale non-invasively by spectroscopic devices (Veggimeter and Biozoom). A higher score indicates higher carotenoid content stored in the skin (Score Ranges: Biozoom 0-12M; Veggimeter 0-800).

Other outcomes

  1. Change in depressive symptom severity, as measured by the Beck Depression Inventory-II (BDI-II), from baseline to week 6.

    Time frame: From enrollment (baseline) to the end of intervention at 6 weeks.

    [Range: 0-63; higher scores indicate more severe depressive symptoms.]

Sponsors and collaborators

Lead sponsor

Medical University of Graz

Other

Registry information

Official study title

ESAN III - Energy Sensing in Depression Effects of Daucus Carota Subsp. Sativus on Immunomodulation in Patients With Obesity, Depression, and Normal Weight Controls

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
May 22, 2025
Registry last updated
Jun 27, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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