Alginate oligosaccharide structures differentially affect DSS-induced colitis in mice by modulating gut microbiota

Area of Science:

• Marine biotechnology
• Carbohydrate chemistry
• Microbiology

Background:

• Alginate oligosaccharides (AOS) comprise three types: oligomannuronate (MAOS), oligoguluronate (GAOS), and heterogeneous AOS (HAOS).
• The differential health effects and gut microbiota modulation by AOS structures remain largely unknown.

Purpose of the Study:

• To investigate the structure-function relationship of different AOS types.
• To explore their efficacy in an in vivo colitis model and an in vitro enterotoxigenic Escherichia coli (ETEC)-challenged cell model.

Main Methods:

• In vivo mouse model of experimental colitis.
• In vitro ETEC-challenged cell model.
• Fecal microbiota transplantation (FMT) from AOS-treated mice.

Main Results:

• MAOS administration significantly alleviated colitis symptoms and enhanced gut barrier function.
• HAOS and GAOS showed less efficacy compared to MAOS.
• MAOS increased gut microbiota abundance and diversity, unlike HAOS or GAOS.
• Microbiota from MAOS-treated mice improved colitis parameters and gut barrier function via FMT.

Conclusions:

• MAOS demonstrates superior therapeutic potential in experimental colitis compared to GAOS and HAOS.
• MAOS-mediated gut microbiota modulation is key to its beneficial effects.
• Targeted production of MAOS could enable precise pharmaceutical applications for colitis treatment.