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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Cardiovascular Risk Factor

Intervention / Treatment
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* Other: High Salt
* Other: Recommended Salt


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: All participants will complete each arm.
Masking: Single


Arms and Interventions

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

What is the study measuring?
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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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dietary sodium, Gut microbiota