Correlation Between Zinc Nutritional Status with Serum Zonulin and Gastrointestinal Symptoms in Diarrhea-Predominant Irritable Bowel Syndrome: A Case-Control Study

Zonulin as a Potential Therapeutic Target in Microbiota-Gut-Brain Axis Disorders: Encouraging Results and Emerging Questions

The relationship between dysbiosis and central nervous diseases has been proved in the last 10 years. Microbial alterations cause increased intestinal permeability, and the penetration of bacterial fragment and toxins induces local and systemic inflammatory processes, affecting distant organs, including the brain. Therefore, the integrity of the intestinal epithelial barrier plays a central role in the microbiota-gut-brain axis. In this review, we discuss recent findings on zonulin, an important tight junction regulator of intestinal epithelial cells, which is assumed to play a key role in maintaining of the blood-brain barrier function. In addition to focusing on the effect of microbiome on intestinal zonulin release, we also summarize potential pharmaceutical approaches to modulate zonulin-associated pathways with larazotide acetate and other zonulin receptor agonists or antagonists. The present review also addresses the emerging issues, including the use of misleading nomenclature or the unsolved questions about the exact protein sequence of zonulin.

Association of Zinc Status with Matrix Metalloproteinases, Advanced Glycation End-Products, and Blood Pressure in Patients with Chronic Kidney Disease

Inflammation, oxidative stress, and hypertension trigger the development of chronic kidney disease (CKD). Zinc is known to have antioxidant and anti-inflammatory properties and a possible role in regulating blood pressure. The aim of this study was to investigate the correlation of serum zinc with matrix metalloproteinase-2 and-9 (MMP-2, MMP-9), advanced glycation end products (AGEs), and blood pressure in patients with CKD. This cross-sectional study included 90 patients with CKD. Serum zinc and the levels of MMP-2, MMP-9, AGEs, and creatinine were measured using validated biochemical methods. Three 24-h food recalls were completed to evaluate dietary zinc intake. Systolic and diastolic blood pressure (SBP, DBP) were measured using a digital sphygmomanometer. Participants' mean age was 60.68 ± 8.81 years. The prevalence of zinc deficiency in our participants was 10%. Serum zinc was negatively correlated with MMP-9 (r =  - 0.231, p = 0.032) and creatinine (r =  - 0.304, p = 0.004). However, after adjusting for confounding variables, the association between serum zinc and MMP-9 was near the significance level (β =  - 0.174, p = 0.09) and zinc remained in the model as one of the predictors. Serum zinc was positively correlated with the dietary intake of zinc (r = 0.241, p = 0.025) and estimated glomerular filtration rate (eGFR) (r = 0.259, p = 0.015). In conclusion, our results showed that serum zinc might be one of the predictors of serum MMP-9 in patients with CKD. In addition, serum zinc was positively associated with its dietary intake and eGFR. Future longitudinal studies or clinical trials are required to reveal any causal association between zinc status and profibrotic or inflammatory biomarkers among patients with CKD.

The Relationship between Gastrointestinal Health, Micronutrient Concentrations, and Autoimmunity: A Focus on the Thyroid

Currently, there is a lack of understanding of why many patients with thyroid dysfunction remain symptomatic despite being biochemically euthyroid. Gastrointestinal (GI) health is imperative for absorption of thyroid-specific nutrients as well as thyroid function directly. This comprehensive narrative review describes the impact of what the authors have conceptualized as the “nutrient–GI–thyroid axis”. Compelling evidence reveals how gastrointestinal health could be seen as the epicenter of thyroid-related care given that: (1) GI conditions can lower thyroid-specific nutrients; (2) GI care can improve status of thyroid-specific nutrients; (3) GI conditions are at least 45 times more common than hypothyroidism; (4) GI care can resolve symptoms thought to be from thyroid dysfunction; and (5) GI health can affect thyroid autoimmunity. A new appreciation for GI health could be the missing link to better nutrient status, thyroid status, and clinical care for those with thyroid dysfunction.

The Impact of Zinc and Zinc Homeostasis on the Intestinal Mucosal Barrier and Intestinal Diseases

Zinc is an essential trace element for living organisms, and zinc homeostasis is essential for the maintenance of the normal physiological functions of cells and organisms. The intestine is the main location for zinc absorption and excretion, while zinc and zinc homeostasis is also of great significance to the structure and function of the intestinal mucosal barrier. Zinc excess or deficiency and zinc homeostatic imbalance are all associated with many intestinal diseases, such as IBD (inflammatory bowel disease), IBS (irritable bowel syndrome), and CRC (colorectal cancer). In this review, we describe the role of zinc and zinc homeostasis in the intestinal mucosal barrier and the relevance of zinc homeostasis to gastrointestinal diseases.

Sodium and potassium intakes and adiposity among Iranian pre-adolescents and adolescents: a cross-sectional study

Background

High sodium and low potassium intakes are associated with the early development of chronic diseases (e.g., hypertension, obesity). Taking into account the limited data on sodium and potassium intakes by 24-h excretion in urine in pre-adolescents and adolescents, we wished to determine baseline salt intake in Iranian subjects aged 11–18 years.

Methods

This was an observational study involving 374 pre-adolescents and adolescents (154 boys and 220 girls). Sodium and potassium intakes were ascertained by measuring sodium and potassium excretion in urine over 24 h. Creatinine level was used to validate the completeness of the urine collections. The association between sodium and potassium intake and adiposity was determined based on body fat percentage.

Results

The mean 24-h urine sodium concentration was 3130 ± 2200 mg/day, equal to 7.961 ± 5.596 g/day salt intake. Approximately half of the study participants exceeded the upper limit of Na intake. The mean potassium intake was estimated 1480 ± 1050 mg/day. There was a positive association between urinary sodium excretion and adiposity in crude (OR 1.79; 95% CI: 1.08—2.74) and full adjusted model (OR: 3.15; 95% CI: 2.28–4.63). Also, in subsample analysis, there was a positive correlation between urinary sodium and adiposity in both pre-adolescents (OR: 2.71; 95% CI: 2.29—3.93) and adolescents (OR: 3.55; 95% CI: 2.17—4.74). However, no significant association was found between 24-h urinary potassium and adiposity.

Conclusion

Sodium intake, as estimated by 24-h urinary excretion, was higher than recommended and it was positively associated with adiposity. Also, this study reported low compliance of potassium intake recommendations in 11–18 years’ Iranian pre-adolescents and adolescents. Health promotion interventions are needed in order to broaden public awareness of high sodium intake and potassium inadequacy to reduce chronic diseases.