Post Natal Microbial and Metabolite Transmission: The Path from Mother to Infant.

The entero-mammary pathway is a specialized route that selectively translocates bacteria to the newborn's gut, playing a crucial role in neonatal development. Previous studies report shared bacterial and archaeal taxa between human milk and neonatal intestine. However, the functional implications for neonatal development are not fully understood due to limited evidence. This study aimed to identify and characterize the microbiota and metabolome of human milk, mother, and infant stool samples using high-throughput DNA sequencing and FT-ICR MS methodology at delivery and 4 months post-partum. Twenty-one mothers and twenty-five infants were included in this study. Our results on bacterial composition suggest vertical transmission of bacteria through breastfeeding, with major changes occurring during the first 4 months of life. Metabolite chemical characterization sheds light on the growing complexity of the metabolites. Further data integration and network analysis disclosed the interactions between different bacteria and metabolites in the biological system as well as possible unknown pathways. Our findings suggest a shared bacteriome in breastfed mother-neonate pairs, influenced by maternal lifestyle and delivery conditions, serving as probiotic agents in infants for their healthy development. Also, the presence of food biomarkers in infants suggests their origin from breast milk, implying selective vertical transmission of these features.

Gut Microbiota Associated with Gestational Health Conditions in a Sample of Mexican Women.

Gestational diabetes (GD), pre-gestational diabetes (PD), and pre-eclampsia (PE) are morbidities affecting gestational health which have been associated with dysbiosis of the mother's gut microbiota. This study aimed to assess the extent of change in the gut microbiota diversity, short-chain fatty acids (SCFA) production, and fecal metabolites profile in a sample of Mexican women affected by these disorders. Fecal samples were collected from women with GD, PD, or PE in the third trimester of pregnancy, along with clinical and biochemical data. Gut microbiota was characterized by high-throughput DNA sequencing of V3-16S rRNA gene libraries; SCFA and metabolites were measured by High-Pressure Liquid Chromatography (HPLC) and (Fourier Transform Ion Cyclotron Mass Spectrometry (FT-ICR MS), respectively, in extracts prepared from feces. Although the results for fecal microbiota did not show statistically significant differences in alfa diversity for GD, PD, and PE concerning controls, there was a difference in beta diversity for GD versus CO, and a high abundance of Proteobacteria, followed by Firmicutes and Bacteroidota among gestational health conditions. DESeq2 analysis revealed bacterial genera associated with each health condition; the Spearman's correlation analyses showed selected anthropometric, biochemical, dietary, and SCFA metadata associated with specific bacterial abundances, and although the HPLC did not show relevant differences in SCFA content among the studied groups, FT-ICR MS disclosed the presence of interesting metabolites of complex phenolic, valeric, arachidic, and caprylic acid nature. The major conclusion of our work is that GD, PD, and PE are associated with fecal bacterial microbiota profiles, with distinct predictive metagenomes.

Detection and Quantification of Immunoregulatory miRNAs in Human Milk and Infant Milk Formula.

Mammary gland secretory cells produce miRNA-rich milk. In humans, these miRNAs reach infant/neonate bloodstream, playing diverse roles, like neural system development, metabolism, and immune system maturation. Notwithstanding, still few works explore human milk miRNA content, and there are no reports at the population level. Our hypothesis was that miR-146b-5p, miR148a-3p, miR155-5p, mir181a-5p, and mir200a-3p immunoregulatory miRNAs are expressed in human colostrum/milk at a higher level than infant milk formulae. The aim of this work was to evaluate the expression of the five immunoregulatory miRNAs in human milk and compare it with their expression in infant milk formula. For this purpose, miRNA relative expression was measured by qPCR in cDNA prepared from total RNA extracted from sixty human colostrum/milk samples and six different formulae. The comparative Cт method 2-ΔCт using exogenous cel-miR-39 as internal control was employed, followed by statistical analysis. We found the relative expression levels of miRNAs are comparable among colostrum/milk samples, and these miRNAs are present in infant milk formulae but at very low concentrations. We conclude that the relative expression of the immunomodulatory miRNAs is comparable in all the human colostrum/milk samples and is higher than the expression in formulae.

Gut microbiota in a population highly affected by obesity and type 2 diabetes and susceptibility to COVID-19.

Coronavirus disease 2019 (COVID-19) is a disease produced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is currently causing a catastrophic pandemic affecting humans worldwide. This disease has been lethal for approximately 3.12 million people around the world since January 2020. Globally, among the most affected countries, Mexico ranks third in deaths after the United States of America and Brazil. Although the high number of deceased people might also be explained by social aspects and lifestyle customs in Mexico, there is a relationship between this high proportion of deaths and comorbidities such as high blood pressure (HBP), type 2 diabetes, obesity, and metabolic syndrome. The official epidemiological figures reported by the Mexican government have indicated that 18.4% of the population suffers from HBP, close to 10.3% of adults suffer from type 2 diabetes, and approximately 36.1% of the population suffers from obesity. Disbalances in the gut microbiota (GM) have been associated with these diseases and with COVID-19 severity, presumably due to inflammatory dysfunction. Recent data about the association between GM dysbiosis and metabolic diseases could suggest that the high levels of susceptibility to SARS-CoV-2 infection and COVID-19 morbidity in the Mexican population are primarily due to the prevalence of type 2 diabetes, obesity, and metabolic syndrome.

Study of perinatal transmission of SARS-CoV-2 in a Mexican public hospital.

OBJECTIVES: COVID-19 is a viral transmissible disease and there is limited evidence on vertical transmission and prevalence of SARS-CoV-2 during pregnancy, birth, and the postnatal period. This descriptive cross-sectional study aimed to evaluate the possible perinatal transmission of SARS-CoV-2 in mothers and neonates in a Mexican population. METHODS: A total of 133 nasopharyngeal swab samples from mothers, 131 swab samples from neonates, and 140 colostrum samples were obtained, and the presence of SARS-CoV-2 was determined by qPCR. RESULTS: One in eight asymptomatic 38-39 weeks' pregnant women were positive for the presence of SARS-CoV-2 in nasopharyngeal swabs taken just before delivery; and one in 12 nasopharyngeal swabs collected from neonates immediately after delivery without breast feeding were also positive. It was also determined that one in 47 colostrum/milk samples were positive for the test. In addition, there was no association between positive results and any collected metadata of mothers or newborns. CONCLUSIONS: Asymptomatic women carried the SARS-CoV-2 virus during delivery, with perinatal transmission of SARS-CoV-2 to newborns. Since neonates were sampled immediately after birth, the detection of positive cases might be due to infection by the virus in utero.

A role for dystroglycan in the pathophysiology of acute leukemic cells.

AIMS: Previous reports have demonstrated that alterations or reduced expression of Dystroglycan (Dg) complex (αDg and ßDg subunits) are related to progression and severity of neoplastic solid tissues. Therefore we determined the expression pattern and subcellular distribution of Dg complex in Acute Myeloid Leukemia (AML) primary blasts (M1, M2, and M3 phenotypes), as well as HL-60 and Kasumi-1 leukemia cell lines. Additionally, we evaluated the relative expression of the main enzymes controlling α-Dg glycosylation to ascertain the post-translational modifications in the leukemia cell phenotype. MAIN METHODS: Primary leukemia blasts and leukemia cell lines were processed by confocal analysis to determine the subcellular distribution of α-Dg, ß-Dg, and phosphorylated ß-Dg (Y892), to evaluate the expression pattern of the different Dg species we performed Western Blot (WB) assays, while the messenger RNA (mRNA) expression of enzymes involved in α-Dg glycosylation, such as POMGnT1, POMT1, POMT2, LARGE, FKTN, and FKRP, were evaluated by qualitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Finally, in an attempt to ameliorate the leukemia cell phenotype, we transfected leukemia cells with a plasmid expressing the Dg complex. KEY FINDINGS: The Dg complex was altered in leukemia cells, including decreased mRNA, protein, and α-Dg glycosylated levels, mislocalization of ß-Dg, and a diminution of mRNA expression of LARGE in patients leukemia blasts and in cell lines. Interestingly, the exogenous expression of Dg complex promoted filopodial formation, differentiation, and diminished proliferation, attenuating some HL-60 and Kasumi cells characteristics. SIGNIFICANCE: Dg complex integrity and balance are required for a proper hematopoietic cell function, in that its disruption might contribute to leukemia pathophysiology.