Salt and Gut Study

High Sodium Intake, Gut Microbiome and Blood Pressure Control

High sodium intake is a significant risk factor for hypertension. Recently, animal studies connect high sodium intake to the gut-immune axis and highlight the gut microbiome as a potential therapeutic target to counteract salt-sensitive conditions and hypertension. The objective of this project is to determine the effects of high salt intake on gut microbiota composition and gut intestine barrier integrity, leading to increased BP in humans. The investigators also hypothesize that high salt intake affects the gut microbiome in a sex-specific manner. In this pilot study, The investigators also test whether telehealth or in-person nutritional coaching help to decrease dietary sodium intake and improve diet quality

Study Overview

• Status: Recruiting
• Conditions: High Blood Pressure
• Intervention / Treatment: Dietary supplement: Salt pills; Dietary supplement: Placebo pills

Detailed Description

The investigators will conduct a randomized, double-blind, placebo-controlled trial in normotensive and stage 1 hypertensive drug naïve participants (age 18-50 years, equal distribution of blacks and whites, and males and females, BP <140/90 mmHg). The average intake of sodium in the American diet is 3,400 mg per day. The average recommended dose is 2,300 mg per day. Eligible participants will be enrolled and provided with one-hour in-person/telehealth nutritional counseling at the GPI to reduce their sodium intake by 1,100 mg per day to achieve the sodium intake of 2,300 mg/day. Participants will then be randomized to receive either placebo or salt pills of 2,000 mg per day for four weeks while continuously receiving weekly telehealth nutritional counseling. The salt group's sodium intake will be 4,300 mg per day, while the sodium intake in the placebo group will be 2,300 mg per day. Participants will have a follow-up visit at six months after the 4-week sodium intervention. Participants will be tested four times (Figure 1). Participants will receive the first 1-hour in-person/telehealth nutrition counseling at GPI (baseline) and three weekly telehealth nutrition counseling during the 4-week intervention period.

• Study Type: Interventional
• Enrollment (Anticipated): 40
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Haidong Zhu, MD, PhD; Phone Number: 706-721-4534; Email: hzhu@augusta.edu
• Study Contact Backup: Name: Yanbin Dong, MD, PhD; Phone Number: 706-721-4534; Email: ydong@augusta.edu

Study Locations

• United States
  • Georgia
    • Augusta, Georgia, United States, 30912
      • Recruiting
      • Georgia Prevention Institute/ Augusta University
      • Contact: Yanbin Dong, MD, PhD; Phone Number: 706-721-4534; Email: ydong@augusta.edu
      • Contact: Haidong Zhu, MD, PhD; Phone Number: 706-712-4534; Email: hzhu@augusta.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion criteria:

• Aged between 18-50 years
• African Americans (AAs) or European Americans (EAs)
• BP <140/90 mmHg
• Not on any prescription medications
• Normal kidney function (eGFR ≥ 90 ml/min/1.73 m2)

Exclusion criteria:

• Pregnant or nursing
• Previous diagnosis of major cardiovascular diseases including myocardial infarction, congestive heart failure or stroke, diabetes, autoimmune, chronic liver and kidney disease
• Previous diagnosis of Crohn's disease or any other intestinal conditions
• Previous diagnosis of major lung diseases such as chronic obstructive pulmonary disease (COPD)
• Previous diagnosis of cancer
• Alcohol and drug abuse.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High sodium; Subjects will be counseled to consume a diet with 2,300 mg/d sodium which they will supplement with pills containing salt to achieve an intake of 4,300 mg/d sodium for 4 weeks.	Dietary supplement: Salt pills; Subjects will supplement salt pills with meals.
Placebo Comparator: Placebo; Subjects will be counseled to consume a diet with 2,300 mg/d sodium and will supplement with taking placebo pills for 4 weeks.	Dietary supplement: Placebo pills; Subjects will supplement placebo pills with meals.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gut microbiota diversity using 16s rRNA Sequencing	Subjects will be provided instructions and kits on how to collect feces and saliva samples. Saliva samples will be collected on the testing day. Feces sample will be collected on the testing day if possible; if not, it will be brought back the following day. DNA will be extracted from collected feces and saliva samples using the MoBioPowerSoil kit. The V3-V5 region of the 16S rRNA will be amplified and sequenced using the Illumina MiSeq platform. The outcome variables for microbiome data will be alpha diversity, beta diversity, and overall composition.	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gut intestine barrier integrity measured by non-invasive biomarkers	Gut intestine barrier function will be determined by non-invasive biomarkers. Plasma LPS, I-FABP, DAO, zonulin, IL-6, TLR4 will be measured.	4 weeks

Collaborators and Investigators

• Sponsor: Augusta University

Study record dates

Study Major Dates

• Study Start (Actual): December 18, 2020
• Primary Completion (Anticipated): December 31, 2022
• Study Completion (Anticipated): December 31, 2022

Study Registration Dates

• First Submitted: May 21, 2021
• First Submitted That Met QC Criteria: June 29, 2021
• First Posted (Actual): July 12, 2021

Study Record Updates

• Last Update Posted (Actual): July 12, 2021
• Last Update Submitted That Met QC Criteria: June 29, 2021
• Last Verified: June 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypertension
• Other Study ID Numbers: 1612471

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided
• IPD Plan Description: If we can share data without risking the identity of our participants, we will plan to share.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No