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NCT Number: NCT07776925

Effects of Maqui Supplementation on Gut Microbiota, Inflammation, and Oxidative Stress in Patients With Chronic Kidney Disease

Chronic kidney disease (CKD) is a highly prevalent condition in Chile and worldwide and is associated with a substantial burden of morbidity, particularly cardiovascular morbidity. In the early stages of CKD, treatment aims to preserve kidney function and slow the progression of associated complications. Several conditions have been reported in association with CKD, including impaired antioxidant capacity, inflammation, and alterations in the gut microbiota (GM), which contribute, among other complications, to the loss of kidney function and cardiovascular damage. In the search for therapeutic approaches to modulate CKD-related complications, there is growing interest in complementary non-pharmacological interventions, including nutritional strategies within the "Food as Medicine" concept. In this context, maqui remains largely unexplored in CKD. Maqui contains phenolic compounds with bioactive properties and strong antioxidant activity, which have also been associated with anticancer, antimicrobial, and anti-inflammatory effects, as well as inhibition of enzymes involved in metabolic syndrome, making this fruit of particular interest for human health. To date, no studies have evaluated the therapeutic potential of maqui in relation to oxidative stress, inflammation, gut microbiota, and CKD progression, or whether these biomarkers and the response to maqui supplementation differ according to biological sex.

To evaluate the effects of maqui supplementation in men and women on the modulation of gut microbiota, inflammatory parameters, and oxidative stress in patients with stage 3 and 4 chronic kidney disease.

A longitudinal, randomized, double-blind clinical trial will be conducted in patients with CKD recruited from healthcare centers in the Metropolitan Region of Santiago, Chile. Participants will receive either a dietary supplement containing dried maqui extract in powder form, equivalent to 200 mg of Delphinol, or placebo for three months. At baseline and after three months of intervention, gut microbiota composition, uremic toxins, inflammatory and oxidative stress markers (plasma antioxidant capacity, urinary polyphenols, IL-6, high-sensitivity C-reactive protein [hs-CRP], NGAL, and uremic toxins), parameters of CKD progression, and anthropometric and dietary parameters will be assessed.

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Key information

Conditions

Chronic Kidney Disease (Stage 3-4) Chronic Disease Disease Attributes Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Kidney Diseases Male Urogenital Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Renal Insufficiency Renal Insufficiency, Chronic Urogenital Diseases Urologic Diseases

Age range

45 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Santiago

Santiago, Santiago Metropolitan, 7770093, Chile

Location contact

Francisca Peña-Dardaillon

CONTACT

[email protected]

996997318

About this study

This is a three-month, randomized, double-blind, placebo-controlled pilot clinical trial designed to evaluate the effects of maqui supplementation in adults with stage 3-4 chronic kidney disease (CKD). The study focuses on biological pathways involved in CKD progression, particularly systemic inflammation, oxidative stress, gut microbiota alterations, and the generation of gut-derived uremic toxins. An exploratory component of the study will examine whether baseline characteristics and responses to the intervention differ according to biological sex.

Participants will be randomly assigned to receive either a powdered maqui supplement, providing an amount equivalent to 200 mg of Delphinol, or a maltodextrin placebo once daily for three months. Randomization will be balanced by sex and age and conducted independently from the research team. Study products will be identified using alphanumeric codes to maintain blinding of participants and the clinical and research teams throughout the intervention.

Clinical and biological assessments will be performed at baseline and after three months of supplementation. Blood and urine samples will be collected to characterize kidney function, systemic inflammation, oxidative status, and other biochemical parameters related to CKD progression. Stool samples will be collected at the same time points to evaluate gut microbiota composition and gut-derived uremic toxins. Gut microbiota will be characterized through sequencing of the V4 region of the 16S rRNA gene.

The study will also assess anthropometric and body composition parameters, blood pressure, and dietary intake. Dietary intake will be evaluated using three-day food records, which will also be used to estimate the Dietary Inflammatory Index. Participants will receive monthly follow-up by a nutritionist during the intervention to assess adherence and identify relevant changes in dietary intake or other factors that could influence the response to supplementation.

The study is intended to provide preliminary clinical and biological evidence regarding the potential effects of maqui supplementation in CKD and to generate data for the design of a larger clinical trial. Given the pilot nature of the study, analyses according to biological sex will be considered exploratory.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Men and women.
  • Age between 40 and 75 years.
  • Normal weight or overweight nutritional status.
  • Regular attendance at healthcare follow-up visits.
  • CKD stage 3-4 (eGFR 59-15)

Exclusion criteria

  • Acute kidney injury within the three months preceding the intervention.
  • Inflammatory or infectious disease within the three months preceding the intervention.
  • Current smoking.
  • Use of oral anticoagulant therapy.
  • Pregnancy.
  • Current use of dietary supplements containing maqui.
  • Cancer.
  • Current antibiotic treatment or antibiotic use within the two weeks preceding the intervention.

Treatment and study plan

maqui supplementation

Dietary Supplement

Participants will receive either a powdered maqui supplement (equivalent to 200 mg of Delphinol) or placebo (maltodextrin), administered orally once daily, dissolved in water or incorporated into breakfast.

PLA

Dietary Supplement

Participants will receive either a powdered maqui supplement (equivalent to 200 mg of Delphinol) or placebo (maltodextrin), administered orally once daily, dissolved in water or incorporated into breakfast.

Primary outcomes

  1. inflamation

    Time frame: basal and final (3 months)

    High-sensitivity C-reactive protein (hs-CRP) , Serum concentration of hs-CRP, measured by ELISA and reported in mg/L

  2. Inflamation

    Time frame: Baseline and 3 months

    Interleukin-6 (IL-6), Relative expression of IL-6, assessed by Western blot and reported as relative protein expression.

  3. Renal function

    Time frame: basal and final (3 months)

    Estimated glomerular filtration rate (eGFR), calculated using the CKD-EPI equation based on serum creatinine and reported in mL/min/1.73 m²

  4. Renal function

    Time frame: baseline and 3 months

    Urinary albumin-to-creatinine ratio (UACR), calculated from urinary albumin and urinary creatinine concentrations and reported in mg/g.

Secondary outcomes

  1. Gut microbiota alpha diversity

    Time frame: basal and final (3 months)

    Gut microbiota alpha diversity assessed by 16S rRNA gene sequencing of stool samples and reported using Shannon index.

  2. Gut microbiota beta diversity

    Time frame: beseline and 3 months

    Gut microbiota beta diversity assessed by 16S rRNA gene sequencing of stool samples and evaluated using a prespecified distance metric.

  3. Relative abundance of gut microbial taxa

    Time frame: baseline and 3 months

    Relative abundance of gut microbial taxa will be assessed in stool samples by sequencing the V4 region of the 16S rRNA gene and reported as relative abundance (%).

  4. Plasma antioxidant capacity

    Time frame: basal and final (3 months)

    Plasma antioxidant capacity will be assessed using a colorimetric assay.

  5. Protein carbonylation

    Time frame: baseline and 3 month

    Plasma protein carbonylation assessed using the 2,4-dinitrophenylhydrazine (DNPH) method and reported as carbonyl group concentration relative to total protein

  6. Plasma indoxyl sulfate (IS) concentration

    Time frame: baseline and 3 months

    Plasma concentration of indoxyl sulfate, measured by reverse-phase high-performance liquid chromatography with fluorescence detection and reported in mg/L

  7. Plasma p-cresyl sulfate (p-CS) concentration

    Time frame: baseline and 3 months

    Plasma concentration of p-cresyl sulfate, measured by reverse-phase high-performance liquid chromatography with fluorescence detection and reported in mg/L.

  8. Plasma indole-3-acetic acid (IAA) concentration

    Time frame: baseline and 3 monts

    Plasma concentration of IAA, measured by reverse-phase high-performance liquid chromatography with fluorescence detection and reported in µg/L.

Other outcomes

  1. Waist circumference

    Time frame: basal and final (3 months)

    Waist circumference measured using a non-stretchable measuring tape and reported in centimeters (cm).

  2. Body fat percentage

    Time frame: baseline and 3 months

    Body fat percentage assessed by bioelectrical impedance analysis using the InBody 270 and reported as percentage (%)

  3. Dietary Inflammatory Index

    Time frame: baseline and 3 monts

    Dietary Inflammatory Index score calculated from dietary intake assessed using food records and reported as DII score.

Study contacts

Contact information is provided by the study sponsor or research team.

Francisca FP Peña, PI

CONTACT

[email protected]

+569 96997318

Marcell ML Leonario, CoI

CONTACT

[email protected]

+569 37681326

Sponsors and collaborators

Lead sponsor

Universidad Mayor

Other

Registry information

Official study title

Effects of Maqui Supplementation on Gut Microbiota, Inflammation, and Oxidative Stress in Patients With Chronic Kidney Disease: A Gender-Based Approach

Acronym: maquibiota

Important dates

Study start
2026
Primary completion
2026
Study completion
2027
First posted
Aug 20, 2026
Registry last updated
Aug 20, 2026

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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