Iodine deficiency disturbs the metabolic profile and elemental composition of human breast milk

Long-term iodine deficiency and excess inhibit β-casein and α-lactalbumin secretion of milk in lactating rats

Iodine is critical for thyroid hormone synthesis and developmental programming in the first 1,000 days of life. The effect of maternal iodine on milk protein secretion remains unknown. We aimed to explore the effect of long-term maternal iodine deficiency and excess on milk protein secretion in lactating rats and its mechanisms preliminarily. Animal models of iodine deficiency and excess were generated by treating Wistar rats a low-iodine diet and deionized water with different potassium iodide concentrations from reproductive age to lactation. Under iodine deficiency, CSN2 and α-LA secretion of milk was inhibited in early and mid-lactation, respectively, and the inhibition of milk CSN2 and α-LA secretion weakened in late lactation. Under iodine excess, milk CSN2 secretion was inhibited in early lactation, and the inhibition of milk CSN2 and α-LA secretion was more pronounced in late lactation. Under iodine deficiency and excess, the concentrations of CSN2 and α-LA and protein expression levels of THRα1, THRβ1, and PRLR in the mammary gland decreased. These results demonstrate the negative impact of long-term maternal iodine malnutrition on milk protein secretion.

Research progress on factors affecting the human milk metabolome

Human milk is the gold standard for infant nutrition and contains macronutrients, micronutrients, and various bioactive substances. The human milk composition and metabolite profiles are complex and dynamic, complicating its specific analysis. Metabolomics, a recently emerging technology, has been used to identify human milk metabolites classes. Applying metabolomics to study the factors affecting human milk metabolites can provide significant insights into the relationship between infant nutrition, health, and development and better meet the nutritional needs of infants during growth. Here, we systematically review the current status of human milk metabolomic research, and related methods, offering an in-depth analysis of the influencing factors and results of human milk metabolomics from a metabolic perspective to provide novel ideas to further advance human milk metabolomics.

Critical Factors in Sample Collection and Preparation for Clinical Metabolomics of Underexplored Biological Specimens

This review article compiles critical pre-analytical factors for sample collection and extraction of eight uncommon or underexplored biological specimens (human breast milk, ocular fluids, sebum, seminal plasma, sweat, hair, saliva, and cerebrospinal fluid) under the perspective of clinical metabolomics. These samples are interesting for metabolomics studies as they reflect the status of living organisms and can be applied for diagnostic purposes and biomarker discovery. Pre-collection and collection procedures are critical, requiring protocols to be standardized to avoid contamination and bias. Such procedures must consider cleaning the collection area, sample stimulation, diet, and food and drug intake, among other factors that impact the lack of homogeneity of the sample group. Precipitation of proteins and removal of salts and cell debris are the most used sample preparation procedures. This review intends to provide a global view of the practical aspects that most impact results, serving as a starting point for the designing of metabolomic experiments.

Omics insights into the responses to dietary selenium

Selenium is a well-known health-relevant element related with cancer chemoprevention, neuroprotective roles, beneficial in diabetes, and in several infectious diseases, among others. It is naturally present in some foods, but deficiency in people led to the production of nutraceuticals, supplements, and functional food enriched in this element. There is a U-shaped link between selenium levels and health and a narrow range between toxic and essential levels, and thus, supplementation should be performed carefully. Omics methodologies have become valuable approaches to delve into the responses of dietary selenium in mammals that allowed a deeper knowledge about the metabolism of this element as well as its biological role. In this review, we discuss omics approaches from the workflows to their applications that has been previously used to deep insight into the metabolism of dietary selenium. There is a special focus on selenoproteins, metabolomics responses in blood and tissues (e.g., brain, reproductive organs, etc.) as well as the impact on gut microbiota and its metabolites profile. Thus, we mainly reviewed heteroatom-tagged proteomics, metallomics, metabolomics, and metataxonomics, usually combined with transcriptomics, genomics, and other molecular methods.

The Human Milk Metabolome: A Scoping Literature Review

BACKGROUND

Human milk is a complex source of nutrition and other bioactives that protects infants from disease, holding a lifetime of beneficial effects. The field of metabolomics provides a robust platform through which we can better understand human milk at a level rarely examined.

RESEARCH AIM

To Identify, describe, synthesize, and critically analyze the literature within the past 5 years related to the human milk metabolome.

METHODS

We conducted a scoping literature review and quality analysis of the recent science reflecting untargeted metabolomic approaches to examining human milk. We searched six databases using the terms "breast milk," "metabolome," "metabolite," and "human milk," Out of more than 1,069 abstracts, we screened and identified 22 articles that met our inclusion criteria.

RESULTS

We extracted data related to the study author, geographic location, research design, analyses, platform used, and results. We also extracted data related to human milk research activities, including collection protocol, infant/maternal considerations, and time. Selected studies focused on a variety of phenotypes, including maternal and infant disease. Investigators used varying approaches to evaluate the metabolome, and differing milk collection protocols were observed.

CONCLUSION

The human milk metabolome is informed by many factors-which may contribute to infant health outcomes-that have resulted in disparate milk metabolomic profiles. Standardized milk collection and storage procedures should be implemented to minimize degradation. Investigators may use our findings to develop research questions that test a targeted metabolomic approach.

Functional instant beverages

Brown algae are a source of hydrothermal extracts that can serve as an effective raw material for instant beverages. This article offers new formulations of functional instant beverages made of concentrated fruit juices and algal extracts of Saccharina japonica and Sargassum miyabei Yendo. The research objective was to define their bioactive and antioxidant profiles. The research featured S. miyabei Yendo and S. japonica brown algae from the Far East of Russia, their dry hydrothermal extracts, and instant drinks based on these extracts combined with concentrated juices of cranberry, sea buckthorn, and chokeberry. The list of methods included spectrophotometry, high-performance liquid chromatography, and gas chromatography. The hydrothermal algal extracts of S. miyabei and S. japonica were rich in fucoidan, phenolic compounds, and iodine. The new instant beverages underwent a sensory evaluation. They contained iodine, phenolic compounds, vitamins (ascorbic acid), fucoidan, pectin, flavonoids, anthocyanins, catechins, carotenoids, and tocopherols. All the samples could be classified as functional, but the best antiradical properties belonged to the sample with black chokeberry juice and S. miyabei. The new functional instant beverages had a high radical-binding activity, which reached 96.3%. One portion (200 mL) covered 27–30 % of the recommended daily intake of iodine and 22–50% of vitamin C. The obtained results prove that instant beverages made of S. japonica and S. miyabei Yendo can be used as functional products.

Impact of "chemical cocktails" exposure in shaping mice gut microbiota and the role of selenium supplementation combining metallomics, metabolomics, and metataxonomics

Biological systems are exposed to a complex environment in which pollutants can interact through synergistic or antagonistic mechanisms, but limited information is available on the combined effects. To this end, conventional and antibiotic-treated (Abx) mice models were fed regular rodent or selenium (Se) supplemented diets and exposed to a "chemical cocktail" (CC) including metals and pharmaceuticals. Metallomics, metabolomics, and metataxomics were combined to delve into the impact on gut microbiota, plasma selenoproteome, metabolome, and arsenic metabolization. At the molecular level, Se decreased the concentration of the antioxidant glutathione peroxidase in plasma and increased the arsenic methylation rate, possibly favoring its excretion, but not in the Abx and also plasma metabolomes of Abx, and Abx-Se were not differentiated. Moreover, numerous associations were obtained between plasma selenoproteins and gut microbes. Se-supplementation partially antagonizes the gut microbiota alteration caused by Abx, and slightly by CC, but strongly altered profiles were observed in CC-Abx-Se, suggesting synergistic deleterious effects between pollutants, Abx and Se. Moreover, although CC and Abx changed gut microbiota, several common taxa were enriched in CC-Abx and control mice, indicating possible synergistic effects. Our results suggest a potential beneficial impact of supplementation, but mediated by gut microbes being reversed in their absence.

Metallomic and Untargeted Metabolomic Signatures of Human Milk from SARS-CoV-2 Positive Mothers

Scope

Lack of information about the impact of maternal severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection on the elemental and metabolomic profile of human milk (HM).

Methods and results

An observational study on HM from mothers with COVID‐19 is conducted including a prepandemic control group. Maternal–infant clinical records and symptomatology are recorded. The absolute quantification of elements and untargeted relative metabolomic profiles are determined by inductively coupled plasma mass spectrometry and gas chromatography coupled to mass spectrometry, respectively. Associations of HM SARS‐CoV‐2 antibodies with elemental and metabolomic profiles are studied. COVID‐19 has a significant impact on HM composition. COVID‐19 reduces the concentrations of Fe, Cu, Se, Ni, V, and Aluminium (Al) and increases Zn compared to prepandemic control samples. A total of 18 individual metabolites including amino acids, peptides, fatty acids and conjugates, purines and derivatives, alcohols, and polyols are significantly different in HM from SARS‐CoV‐2 positive mothers. Aminoacyl‐tRNA biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine, and linoleic acid pathways are significantly altered. Differences are obtained depending on COVID‐19 symptomatic and asymptomatic status.

Conclusions

This study provides unique insights about the impact of maternal SARS‐CoV‐2 infection on the elemental and metabolomic profiles of HM that warrants further research due the potential implications for infant health.