Dietary Inorganic Nitrate and the Enteral Microbiome (DINE)

Influence of Exogenous Dietary Inorganic Nitrate on Downstream Metabolites of the Enteral Microbiome

A growing body of data shows that the enteral microbiome has an effect on cardiovascular diseases. Exogenous inorganic dietary nitrate mediates cardioprotective effects and has been shown to have an influence on the oral microbiome. The nutritional aspects of these cardioprotective effects are particularly intriguing since nitrate is abundant in our everyday diet.

Whether dietary nitrate influences the enteral microbiome and downstream metabolites like short-chain fatty acids (SCFA) and TMAO will be investigated in the present study.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Health
• Intervention / Treatment: Dietary supplement: Nitrate; Dietary supplement: Control

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • NRW
    • Essen, NRW, Germany, 45147
      • University Hospital Essen

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Patients aged 40-80 years
• no regular medication intake
• no chronic diseases

Exclusion Criteria:

• Regular systemic drug intake
• Active smoking
• Chronic diseases
• Acute diarrhea or vomiting
• Short gut syndrome
• Pregnancy or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Nitrate; Dietary inorganic nitrate (0,12 mmol sodium-nitrate/kg BW/day) dissolved in 200 ml tap water. Supplementation for 30 days.	Dietary supplement: Nitrate; Dietary inorganic nitrate (0,12 mmol sodium-nitrate/kg BW/day) dissolved in 200 ml tap water. Supplementation for 30 days.
Placebo Comparator: Control; Dietary sodium-chloride (0,12 mmol sodium-chloride/kg BW/day) dissolved in 200 ml tap water. Supplementation for 30 days.	Dietary supplement: Control; Dietary sodium-chloride (0,12 mmol sodium-chloride/kg BW/day) dissolved in 200 ml tap water. Supplementation for 30 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of the enteral microbiome composition	Changes in enteral microbiome composition in stool samples at baseline and after 30 days of placebo/verum supplementation. The 16S rRNA amplicon reads obtained from an Illumina MiSeq System will be analyzed using pipeline QIIME2 (v. 2019.1).	30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of the oral microbiome composition	Changes in oral microbiome composition in oral swabs samples at baseline and after 30 days of placebo/verum supplementation. The 16S rRNA amplicon reads obtained from an Illumina MiSeq System will be analyzed using pipeline QIIME2 (v. 2019.1).	30 days
Change of circulating SCFA levels	Changes in circulating SCFA blood levels at baseline and after 30 days of placebo/verum supplementation will be measured by high-performance liquid chromatography.	30 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in the oral-enteral microbiome axis	Changes in oral-enteral microbiome axis composition in oral swabs and stool samples at baseline and after 30 days of placebo/verum supplementation. The 16S rRNA amplicon reads obtained from an Illumina MiSeq System will be analyzed using pipeline QIIME2 (v. 2019.1).	30 days
Changes in arterial stiffness parameters	Changes in cardiovascular function measured by arterial stiffness parameters as pulse wave velocity measured in m/s at baseline and after 30 days of placebo/verum supplementation.	30 days
Changes in blood pressure	Changes in cardiovascular function measured by systolic and diastolic blood pressure in mmHg at baseline and after 30 days of placebo/verum supplementation.	30 days
Change of the nitrate-nitrite-NO metabolism	Changes of nitrate and nitrite content in plasma measured by ENO-20 analysis at baseline and after 30 days of placebo/verum supplementation.	30 days
Genetic variants (single nucleotide polymorphism)	The effect of the genes NOS3 and GUCY1A3 variation on dietary nitrate response. Genetic polymorphism will be measured by qPCR and analyzed by allelic discrimination.	30 days
Epigenetic changes	Changes of DNA methylation analysis by pyrosequencing at baseline and after 30 days of placebo/verum supplementation.	30 days
Changes in TMAO levels	Changes in TMAO blood levels at baseline and after 30 days of placebo/verum supplementation will be measured by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).	30 days

Collaborators and Investigators

• Sponsor: University Hospital, Essen
• Investigators: Study Director: Tienush Rassaf, Professor, Clinic of cardiology and angiology, University Hospital Essen

Study record dates

Study Major Dates

• Study Start (Actual): November 22, 2021
• Primary Completion (Actual): June 1, 2024
• Study Completion (Actual): June 1, 2024

Study Registration Dates

• First Submitted: September 10, 2021
• First Submitted That Met QC Criteria: November 14, 2021
• First Posted (Actual): November 17, 2021

Study Record Updates

• Last Update Posted (Actual): September 25, 2024
• Last Update Submitted That Met QC Criteria: September 23, 2024
• Last Verified: July 1, 2024

More Information

Terms related to this study

• Keywords: diet; microbiome; cardiovascular; nitrate; dietary nitrate
• Other Study ID Numbers: Dietary nitrate and microbiome

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No