D-Methionine and 2-hydroxy-4-methylthiobutanoic acid i alter beta-casein, proteins and metabolites linked in milk protein synthesis in bovine mammary epithelial cells

Dietary L-Methionine modulates the gut microbiota and improves the expression of tight junctions in an in vitro model of the chicken gastrointestinal tract

BACKGROUND

The poultry industry encounters a number of factors that affect growth performance and productivity; nutrition is essential for sustaining physiological status and protecting against stressors such as heat, density, and disease. The addition of vitamins, minerals, and amino acids to the diet can help restore productivity and support the body's defense mechanisms against stress. Methionine (Met) is indispensable for poultry's energy metabolism, physiology, performance, and feed utilization capacity. Through this study, we aimed to examine the physiological effects of methionine supplementation on poultry as well as alterations of intestinal microbiome.

METHODS

We utilized the DL- and L- form of methionine on Caenorhabditis elegans and the FIMM (Fermentor for intestine microbiota model) in-vitro digesting system. A genomic-analysis of the transcriptome confirmed that methionine supplementation can modulate growth-related physiological metabolic pathways and immune responses in the host poultry. The C. elegans model was used to assess the general health benefits of a methionine supplement for the host.

RESULTS

Regardless of the type or concentration of methionine, supplementation with methionine significantly increased the lifespan of C. elegans. Feed grade L-Methionine 95%, exhibited the highest lifespan performance in C. elegans. Methionine supplementation increased the expression of tight junction genes in the primary intestinal cells of both broiler and laying hens, which is directly related to immunity. Feed grade L-Methionine 95% performed similarly or even better than DL-Methionine or L-Methionine treatments with upper doses in terms of enhancing intestinal integrity. In vitro microbial cultures of healthy broilers and laying hens fed methionine revealed changes in intestinal microflora, including increased Clostridium, Bacteroides, and Oscillospira compositions. When laying hens were given feed grade L-Methionine 95% and 100%, pathogenic Campylobacter at the genus level was decreased, while commensal bacteria were increased.

CONCLUSIONS

Supplementation of feed grade L-Methionine, particularly L-Methionine 95%, was more beneficial to the host poultry than supplementing other source of methionine for maintaining intestinal integrity and healthy microbiome.

Molecular complexity of mammary glands development: a review of lactogenic differentiation in epithelial cells

The mammary gland is a dynamic organ with various physiological processes like cellular proliferation, differentiation, and apoptosis during the pregnancy-lactation-involution cycle. It is essential to understand the molecular changes during the lactogenic differentiation of mammary epithelial cells (MECs, the milk-synthesizing cells). The MECs are organized as luminal milk-secreting cells and basal myoepithelial cells (responsible for milk ejection by contraction) that form the alveoli. The branching morphogenesis and lactogenic differentiation of the MECs prepare the gland for lactation. This process is governed by many molecular mediators including hormones, growth factors, cytokines, miRNAs, regulatory proteins, etc. Interestingly, various signalling pathways guide lactation and understanding these molecular transitions from pregnancy to lactation will help researchers design further research. Manipulation of genes responsible for milk synthesis and secretion will promote augmentation of milk yield in dairy animals. Identifying protein signatures of lactation will help develop strategies for persistent lactation and shortening the dry period in farm animals. The present review article discusses in details the physiological and molecular changes occurring during lactogenic differentiation of MECs and the associated hormones, regulatory proteins, miRNAs, and signalling pathways. An in-depth knowledge of the molecular events will aid in developing engineered cellular models for studies related to mammary gland diseases of humans and animals.

Multi-Omics Approaches to Improve Meat Quality and Taste Characteristics

With rapid advances in meat science in recent decades, changes in meat quality during the pre-slaughter phase of muscle growth and the post-slaughter process from muscle to meat have been investigated. Commonly used techniques have evolved from early physicochemical indicators such as meat color, tenderness, water holding capacity, flavor, and pH to various omic tools such as genomics, transcriptomics, proteomics, and metabolomics to explore fundamental molecular mechanisms and screen biomarkers related to meat quality and taste characteristics. This review highlights the application of omics and integrated multi-omics in meat quality and taste characteristics studies. It also discusses challenges and future perspectives of multi-omics technology to improve meat quality and taste. Consequently, multi-omics techniques can elucidate the molecular mechanisms responsible for changes of meat quality at transcriptome, proteome, and metabolome levels. In addition, the application of multi-omics technology has great potential for exploring and identifying biomarkers for meat quality and quality control that can make it easier to optimize production processes in the meat industry.