Rationale, protocol and baseline characteristics of the metabolome, microbiome, and dietary salt intervention study (MetaSalt)

Abstract

AbstractHigh sodium intake has been recognized as an important risk factor for hypertension, but the role of gut microbiota composition and metabolomic profiles in the association between dietary sodium intake and blood pressure (BP) is uncertain. The metabolome, microbiome, and dietary salt intervention study (MetaSalt) study was conducted to investigate whether low- and high-dietary sodium intake influences BP by changing the microbial and metabolomic profiles. This is a family-based, multicentre intervention study conducted in four rural field-centres across three provinces in rural Northern China. Probands with untreated prehypertension or stage-1 hypertension were identified through a community-based BP screening, and their family members included siblings, offspring, spouses and parents were subsequently included. During the dietary intervention, low-salt and high-salt diets were provided free of charge to all participants. A total of 529 participants in four field centres were included in our study, with a mean age of 48.1 years old, and about 36.7% of them were male, 76.5% had a middle school (69.5%) or higher (7.0%) diploma, 23.4% had a history of smoke, 24.4% were current drinkers. The mean systolic and diastolic BP levels in the baseline were 129.54 mm Hg and 81.02 mm Hg for all participants, and significantly decreased during the low-salt intervention and increased during the high-salt intervention. Our study is well placed to check the impacts of dietary sodium intake on microbial and metabolomic profiles, which will have important implications for discovering the mechanisms in the development of hypertension and subsequent cardiovascular disease.