Gut Microbiota Modulation, Immunomodulation, Obesity
Conditions
Keywords
Carotenoids, Antioxidant effects, Micronutrient absorption, In-vitro digestion, Intervention study, Nutrition, Natural juice
Brief summary
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.
Interventions
OTHERCarotenoid-rich juice
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.
OTHERControl
Participants assigned to the control group are asked to drink additional 200ml of water a day to control liquid intake.
Sponsors
Medical University of Graz
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
The present placebo-controlled, randomized, open, prospective, monocentric study can be classified as a food product study (comparison between in trade available carotenoid-rich juice and a placebo). Six study groups are designated: Group VN = normal weight participants receiving carotenoid-rich juice (verum) (n=20) Group VA = adipose participants receiving carotenoid-rich juice (verum) (n=20) Group VD = depressive patients receiving carotenoid-rich juice (verum) (n=20) Group CN = normal weight participants receiving water (control) (n=20) Group CA = adipose participants receiving water (control) (n=20) Group CD = depressive patients receiving water (control) (n=20)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 65 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change of baseline regulatory T cells (Tregs) at week 6 (after the intervention) and after a wash-out period at week 12. | 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
| Measure | Time frame | Description |
|---|---|---|
| Effect of carotenoid-rich juice consumption on gut microbiota composition, assessed by changes in alpha diversity (Shannon Index) between intervention and control groups. | From enrollment (baseline) to the end of intervention at week 6 and after a wash-out period at week 12. | — |
| Change in plasma carotenoid concentration following carotenoid-rich juice consumption, compared between intervention and control groups. | 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). |
| Change in skin carotenoid levels (measured non-invasively), following carotenoid-rich juice consumption, compared between intervention and control groups. | 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
| Measure | Time frame | Description |
|---|---|---|
| Change in depressive symptom severity, as measured by the Beck Depression Inventory-II (BDI-II), from baseline to week 6. | From enrollment (baseline) to the end of intervention at 6 weeks. | \[Range: 0-63; higher scores indicate more severe depressive symptoms.\] |
Countries
Austria
Outcome results
None listed