Comparison of sodium content of workplace and homemade meals through chemical analysis and salinity measurements

Salt stress perception and metabolic regulation network analysis of a marine probiotic Meyerozyma guilliermondii GXDK6

Introduction

Extremely salt-tolerant microorganisms play an important role in the development of functional metabolites or drug molecules.

Methods

In this work, the salt stress perception and metabolic regulation network of a marine probiotic Meyerozyma guilliermondii GXDK6 were investigated using integrative omics technology.

Results

Results indicated that GXDK6 could accept the salt stress signals from signal transduction proteins (e.g., phosphorelay intermediate protein YPD1), thereby contributing to regulating the differential expression of its relevant genes (e.g., CTT1, SOD) and proteins (e.g., catalase, superoxide dismutase) in response to salt stress, and increasing the salt-tolerant viability of GXDK6. Omics data also suggested that the transcription (e.g., SMD2), translation (e.g., MRPL1), and protein synthesis and processing (e.g., inner membrane protein OXA1) of upregulated RNAs may contribute to increasing the salt-tolerant survivability of GXDK6 by improving protein transport activity (e.g., Small nuclear ribonucleoprotein Sm D2), anti-apoptotic ability (e.g., 54S ribosomal protein L1), and antioxidant activity (e.g., superoxide dismutase). Moreover, up to 65.9% of the differentially expressed genes/proteins could stimulate GXDK6 to biosynthesize many salt tolerant-related metabolites (e.g., β-alanine, D-mannose) and drug molecules (e.g., deoxyspergualin, calcitriol), and were involved in the metabolic regulation of GXDK6 under high NaCl stress.

Discussion

This study provided new insights into the exploration of novel functional products and/or drugs from extremely salt-tolerant microorganisms.Graphical Abstract.

Estimated dietary sodium intake in haemodialysis patients using food frequency questionnaires

BACKGROUND

In clinical practice, dietary sodium assessment requires reliable and rapid screening tools. We wished to evaluate the usefulness of food frequency questionnaires (FFQ) in estimating dietary sodium intakes in haemodialysis patients.

METHODS

We used the Derby Salt Questionnaire (DSQ), and Scored Sodium Questionnaire (SSQ) to estimate sodium intake. Body composition was determined by bioimpedance.

RESULTS

In total, 139 haemodialysis patients (95 men) completed the FFQs, with mean ± standard deviation age 67 ± 15 years. The mean FFQ scores were DSQ 3.5 ± 2.0 and SSQ 68.4 ± 24.5. Men had higher estimated dietary sodium intakes [DSQ median (range) 3.6 (0.6-10.1) versus female 2.2 (0.5-9.1), P = 0.007)]. Younger patients and those aged >75 years had the higher SSQ dietary sodium scores; 70.7 ± 27.8 and 76.8 ± 24.6 versus those aged 55-75 years, 61.8 ± 22.3, P = 0.04. Patients with greater estimated sodium intake had higher extracellular water (ECW) to intracellular water (ICW) ratios pre-dialysis [75.1 ±12.5 versus 67.7 ± 4.8, P < 0.001] and ECW excess pre-dialysis [1.8 (1.5-2.6) versus 1.3 (0.8-2.0) L, P < 0.05]. Mean arterial pressure (MAP) and inter-dialytic weight gains did not differ; however, the fall in MAP during dialysis was lower in the higher estimated dietary sodium group (0.9 ± 13.7% versus 6.5 ± 14.1%, P = 0.04).

CONCLUSIONS

Both questionnaires were acceptable to patients and identified higher estimated dietary sodium intake for men, those with greater ECW and, somewhat surprisingly, we found that older patients had a greater dietary sodium intake than expected.