Biomedical subjects

Daniela Pagnozzi

Publications and source records attributed to Daniela Pagnozzi.

3 recordsLinked to original sources

PubMed2025

Consumption of traditional Sardinian fermented milk promotes changes in the rat gut microbiota composition and functions.

BACKGROUND: Fermented milk products are part of the staple diet for many Mediterranean populations. Most of these traditional foods are enriched with lactobacilli and other lactic acid bacteria, as well as with metabolites resulting from lactose fermentation. Currently, there is very little scientific knowledge on how dietary supplementation with fermented milk affects the composition of the gut microbiota and its metabolic activities. RESULTS: We integrated 16 S rRNA gene-based taxonomic profiling with metaproteomics-based functional analysis to investigate gut microbiota changes in rats exposed to an 8-week dietary supplementation with casu axedu, a traditional fermented milk produced within rural communities in Sardinia (Italy). Several microbial taxa showed a significantly increased abundance at the end of the dietary treatment, including Phascolarctobacterium, Prevotella, Blautia glucerasea, and Lactococcus lactis, while Bacteroides dorei and Helicobacter rodentium were decreased compared to the control rats. Metaproteomic analysis highlighted a striking reshaping of the Prevotella proteome in agreement with its blooming in casu axedu-fed animals, suggesting an increase of the glycolytic activity through the Embden-Meyerhof-Parnas pathway over the Entner-Doudoroff pathway. Moreover, an increased production of enzymes involved in succinate biosynthesis was observed, which in turn significantly boosted the abundance of Phascolarctobacterium and its production of propionate. Fermented milk consumption also promoted microbial synthesis of branched chain essential amino acids L-valine and L-leucine. Finally, metaproteomic data indicated a reduction of bacterial virulence factors and host inflammatory markers, suggesting that the consumption of casu axedu can have beneficial effects on the gut mucosa health. CONCLUSIONS: Our integrated multi-omics approach reveals that dietary supplementation with the traditional Sardinian fermented milk, casu axedu, induces significant shifts in the rat gut microbiota composition and function, characterized by the enrichment of beneficial taxa and metabolic pathways associated with improved gut health and reduced inflammation.

Animals↗

PubMed2005

Functional proteomics.

BACKGROUND: With the increase in the number of genome sequencing projects, there is a concomitant exponential growth in the number of protein sequences whose function is still unknown. Functional proteomics constitutes an emerging research area in the proteomic field whose approaches are addressed towards two major targets: the elucidation of the biological function of unknown proteins and the definition of cellular mechanisms at the molecular level. METHODS: The identification of interacting proteins in stable complexes in vivo is essentially achieved by affinity-based procedures. The basic idea is to express the protein of interest with a suitable tag to be used as a bait to fish its specific partners out from a cellular extract. Individual components within the multi-protein complex can then be identified by mass spectrometric methodologies. RESULTS AND CONCLUSIONS: The association of an unknown protein with partners belonging to a specific protein complex involved in a particular mechanism is strongly suggestive of the biological function of the protein. Moreover, the identification of protein partners interacting with a given protein will lead to the description of cellular mechanisms at the molecular level. The next goal will be to generate animal models bearing a tagged form of the bait protein.

Humans↗

PubMedDate not supplied

Interaction proteomics.

The term proteome is traditionally associated with the identification of a large number of proteins within complex mixtures originating from a given organelle, cell or even organism. Current proteome investigations are basically focused on two major areas, expression proteomics and functional proteomics. Both approaches rely on the fractionation of protein mixtures essentially by two-dimensional polyacrylamide gel electrophoresis (2D-gel) and the identification of individual protein bands by mass spectrometric techniques (2D-MS). Functional proteomics approaches are basically addressing two main targets, the elucidation of the biological function of unknown proteins and the definition of cellular mechanisms at the molecular level. In the cell many processes are governed not only by the relative abundance of proteins but also by rapid and transient regulation of activity, association and localization of proteins and protein complexes. The association of an unknown protein with partners belonging to a specific protein complex involved in a particular process would then be strongly suggestive of its biological function. The identification of interacting proteins in stable complexes in a cellular system is essentially achieved by affinity-based procedures. Different strategies relying on this simple concept have been developed and a brief overview of the main approaches presently used in functional proteomics studies is described.

Chromatography, Affinity↗