Integrated multi-omics uncovers reliable potential biomarkers and adverse effects of zinc deficiency.

BACKGROUND: Zinc deficiency is a worldwide public health problem. Currently, there are no established biomarkers available for the accurate diagnosis of zinc-deficiency in individuals. Additionally, a comprehensive view of the adverse effects of zinc deficiency is lacking. Our aim was to identify superior biomarkers of zinc deficiency and uncover the adverse effects of zinc deficiency. METHODS: We performed multi-omics analysis using serum proteomics-metabolomics and liver proteomics on zinc-deficient rats to identify candidate biomarkers and reveal the associated adverse effects of zinc deficiency. Secondly, the candidate biomarkers were validated in two zinc-deficient populations and an RCT zinc supplementation trial on a zinc-deficient population. RESULTS: Our integrated multi-omics approach revealed numerous biomarkers (>2000) and glutathione metabolism as the most important changed pathway in zinc deficiency. Three candidate biomarkers from glutathione metabolism were validated in repeated zinc-deficient rats by quantitative analysis. Only glutathione sulfotransferase omega-1 (GSTO1) (among 3 candidate biomarkers) was validated in the two zinc-deficient populations and zinc-supplemented population. Compared with serum zinc, serum GSTO1 yielded a better response to zinc supplementation and a higher correlation coefficient with zinc intake and the AUC value and has the potential for diagnosing zinc deficiency. By integrated multi-omics, we identified both established and novel adverse effects of zinc deficiency. CONCLUSIONS: Our integrated multi-omics analysis revealed more complete information about zinc deficiency; GSTO1 was found to be a reliable potential biomarker for diagnosis of zinc deficiency. This trial is registered at http://www.chictr.org.cn/registry.aspx as ChiCTR1900028162.

Discrimination of heating and frying vegetable oils based on UPLC/Q-TOF MSMS and chemometrics.

Fried foods have potential adverse effects on health. However, the compounds produced during the process of frying in different vegetable oils are unknown. In this work, ultra performance liquid chromatography (UPLC), quadrupole time-of-flight mass spectrometry (Q-TOF MSMS) and chemical pattern recognition analysis was first conducted to analyze the changes in compounds in 8 different vegetable oils before and after thin-layer heating (without food) and to reveal the potential markers of oil used for deep-frying food. Then, these markers were validated in used frying oil. Our results of principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA) indicated that both thin-layer heating and deep-frying significantly change the compounds of vegetable oils. Thirty-six of the markers associated with thin-layer heating from the 8 different oils were identified in used frying oils and can be used as common markers of oil used for deep-frying. Additionally, 22 markers detected in individual vegetable oils provided unique markers of used frying oils. These markers can be used to distinguish used frying oil and have the potential to reveal the associated physiological harm.

The effects of zinc deficiency on homeostasis of twelve minerals and trace elements in the serum, feces, urine and liver of rats.

BACKGROUND: Zinc deficiency can change the concentrations of minerals and trace elements in the body. However, previous studies still had many limitations. OBJECTIVE: To reveal the effects of zinc deficiency on homeostasis of 16 minerals and trace elements. METHODS: Forty-five rats were divided randomly into three groups: normal zinc diet (30 mg/kg), low zinc diet (10 mg/kg), and pair-fed diet(30 mg/kg). The concentrations of 16 minerals and trace elements in serum, feces, urine, and liver were measured by inductively coupled plasma mass spectrometry. The excretion of 16 elements in urine and feces were calculated and compared. RESULTS: Zinc-deficient rats exhibited significant changes in up to 12 minerals and trace elements. The low zinc diet induced decreased excretion of zinc and concentrations of zinc in serum, feces, urine, and liver. Zinc deficiency increased feces concentrations of Mg, Cu, Se, K, Ag, Fe and Mn; decreased the concentrations of Mg, Cu, Se, K in liver and urine, and a diminished amount of Ag was observed in serum. Decreased urinary concentrations of Zn Ca, Mg, Cu, Se, K, Na, As and Cr, suggested that zinc-deficient rats increased the 9 elements' renal reabsorption. Decreased concentrations of Ca in liver, urine, and feces, decreased excretion in urine and feces and increased serum total Ca suggested that zinc deficiency increased the redistribution of Ca in serum or other tissues. Zinc deficiency increased excretion of Cu, Se, Fe; and decreased the excretion of other 8 elements except for Ag. CONCLUSIONS: Zinc deficiency changed the excretion, reabsorption and redistribution of 12 minerals and trace elements in rats. Our findings are the first to show that zinc deficiency alters the concentrations of Ag, Cr, and As. SUPPLEMENTARY INFORMATION: Supplementary information accompanies this paper at 10.1186/s12986-019-0395-y.