Investigation Into the Variations in the Interactions Between Different Selenium Sources and Gut Microbiota

Area of Science:

• Biochemistry
• Microbiology
• Materials Science

Background:

• Selenium (Se) exists in diverse chemical forms, impacting biological systems.
• The interaction mechanisms between selenium and gut microbiota are not fully understood.
• Selenium nanoparticles (SeNPs) offer a novel form for studying Se-gut interactions.

Purpose of the Study:

• To investigate the effects of different polysaccharide-stabilized Se nanoparticles (PS-SeNPs) on gut microbiota.
• To determine how polysaccharide molecular properties influence SeNP bioavailability and microbial metabolism.
• To elucidate the specific microbial communities modulated by various PS-SeNPs.

Main Methods:

• Utilized an in vitro colonic fermentation model.
• Systematically evaluated various PS-SeNPs, including chitosan-based variants.
• Employed metabolomics analysis to assess metabolic pathway activation.

Main Results:

• Polysaccharide properties (molecular weight, charge) critically affect PS-SeNP gut microbiota modulation.
• Chitosan-based SeNPs (CS-Se, HACC-Se) enriched beneficial bacteria (Lactobacillus, Bacteroidales), boosting short-chain fatty acids and selenocompound production (selenocystine, Se-Methylselenocysteine).
• Other PS-SeNPs showed limited bioavailability, while inorganic selenium (H2SeO3) promoted opportunistic pathogens.

Conclusions:

• Molecular characteristics of polysaccharides are crucial for designing effective SeNPs for gut microbiota modulation.
• Chitosan-based SeNPs show promise for enhancing beneficial gut bacteria and Se metabolism.
• Findings advance understanding of Se-microbiota interactions and inform the development of Se-based functional foods or therapeutics.