Understanding the role of raffinose family oligosaccharides in pea on plant fitness and gut health

Zardkoohi Burgos, Aryana (2024) Understanding the role of raffinose family oligosaccharides in pea on plant fitness and gut health. Doctoral thesis, University of East Anglia.

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Abstract

Raffinose family oligosaccharides (RFOs), including raffinose, stachyose and verbascose, are abundant in legumes, contributing to plant stress tolerance. Although once considered anti-nutritional due to their indigestibility and flatulence effects, RFOs are now being regarded as emerging prebiotics.

This study investigated the role of RFOs in pea on plant performance and their effects on human gut microbiota composition and function. Mutations in Raffinose synthase (Rfs) and Rfs-like genes resulted in pea seeds with decreased RFO content and accumulation of the RFO precursors, sucrose and galactinol. The BCFN 1551 mutant exhibited reduced tolerance to drought stress in the glasshouse and poor productivity in the field. The performance of the BCRfsTILL W521* mutant was similar to that of the commercial cultivar Cameor in the field.

Batch fermentations with human faecal samples revealed that Cameor flour led to higher Bifidobacterium longum levels compared to the BCFN 1551 mutant, along with alterations in bile acid and tryptophan metabolism. Fermentation with sucrose led to increased Bifidobacterium spp., whereas galactinol fermentation was characterised by increased Citrobacter freundii. Individual RFO fermentation assays revealed that raffinose and verbascose increased Bifidobacterium spp., with verbascose increasing butyrate production. Dynamic colon model fermentation of Cameor and BCRfsTILL W521* showed no significant differences in microbiota composition attributable to RFO reduction.

Gas production did not differ significantly among fermentations of BCFN 1551, BCRfsTILL W521*, and Cameor flours, suggesting that other fermentable carbohydrates may overshadow RFO effects. Preliminary studies with human intestinal organoids showed that fermented Cameor flour increased interleukin-8 production under healthy conditions but not following inflammatory challenge, but intestinal integrity remained unaffected.

Together, we showed that RFOs are important for pea drought tolerance and positively influence human gut microbiota. This work paves the way to the development of stress-resilient pea varieties with improved nutritional traits.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Biological Sciences
Depositing User:	Chris White
Date Deposited:	07 Jul 2025 09:53
Last Modified:	08 Jul 2025 06:09
URI:	https://ueaeprints.uea.ac.uk/id/eprint/99842
DOI:

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