The Salty Gut: Effects of High Dietary Salt Intake on the Gut Microbiota

Gut microbiota has a role in cardiovascular disease and recent findings in rodents show dietary salt can negatively alter gut microbiota composition. High salt intake is a risk factor for cardiovascular disease. Americans consume dietary salt in excess of Dietary Guidelines and American Heart Association recommendations. The objective of this project is to investigate the influence of high dietary salt consumption on the gut microbiota composition in men and women.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Risk Factor
• Intervention / Treatment: Other: High Salt; Other: Recommended Salt

Detailed Description

Gut microbiota composition and function has an important role in host physiology. In general, gut microbial diversity is positively correlated with health status. Recent evidence confirms the role of gut dysbiosis in cardiovascular disease. Americans consume 50% more salt than the amount recommended by the Dietary Guidelines and 130% more than recommended by the American Heart Association. Excess salt intake is considered a modifiable risk factor for cardiovascular disease. Changes in the gut microbiota composition followed by immune system activation is reported with high salt intake in animals. In particular, abundance of proinflammatory T helper 17 (Th17) cells increases with excess salt consumption. In contrast, T regulatory (Treg) cells oppose Th17 cell action and may aid in reducing inflammation associated with high salt intake, a hypothesis that has not yet been tested in humans. Only one preliminary study assessed changes in gut bacterial composition with high salt intake in humans, when only men were recruited. The study also found an increase in Th17 cell abundance. Thus, the objective of this study is to investigate the influence of high salt intake on the gut microbiota diversity and Th17 and Treg cell abundance in men and women.

• Study Type: Interventional
• Enrollment (Actual): 31
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Delaware
    • Newark, Delaware, United States, 19716
      • University of Delaware

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• healthy
• normal blood pressure

Exclusion Criteria:

• hypertension
• cardiovascular disease
• renal disease
• diabetes
• cancer
• current use of anti-inflammatory agents, glucocorticoids or other immune regulating medications, or certain anti-depressants
• history of intestinal surgery
• inflammatory bowel disease, celiac disease, lactose intolerance, chronic pancreatitis or other malabsorption disorder
• antibiotic use in the past 3 months
• prebiotic, probiotic, or antioxidant supplementation in the past 3 months
• ≥10 lbs weight gain or loss in the past 6 months
• use of tobacco products
• highly trained endurance athletes
• current pregnancy or lactation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High Salt; 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 6,900 mg/d sodium.	Other: High Salt; Consumption of pills containing table salt for 10 days.
Placebo Comparator: Recommended Salt; Subjects will be counseled to consume a diet with 2,300 mg/d sodium which they will supplement with placebo pills.	Other: Recommended Salt; Consumption of pills containing dextrose for 10 days.; Other Names: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gut microbiota diversity	The difference in gut microbiota diversity between the two arms.	On day 10
T cell profile	The difference in T regulatory and T helper 17 cells between each arm.	On day 10

Collaborators and Investigators

• Sponsor: University of Delaware
• Investigators: Principal Investigator: Shannon L Lennon, PhD, RD, University of Delaware

Study record dates

Study Major Dates

• Study Start (Actual): April 16, 2019
• Primary Completion (Actual): February 24, 2021
• Study Completion (Actual): February 24, 2021

Study Registration Dates

• First Submitted: January 13, 2020
• First Submitted That Met QC Criteria: January 13, 2020
• First Posted (Actual): January 18, 2020

Study Record Updates

• Last Update Posted (Actual): October 2, 2023
• Last Update Submitted That Met QC Criteria: September 28, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Keywords: Gut microbiota; Dietary sodium
• Other Study ID Numbers: 1423170

Drug and device information, study documents

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