Investigation of the effects of dietary fibres on gut microbiota, metabolism and glycaemic control across generations
File(s)
Author(s)
Hill, Monica-Maria
Type
Thesis
Abstract
Dietary fibres represent a cornerstone of a healthy diet, nonetheless, their intake has decreased recently being below the recommended 30g/day. This trend has been accompanied by a rise in non-communicable diseases. A mice study showed that rearing them on a low fibre diet over generations led to a significant loss in gut bacteria species. Individuals from a non-westernised society moving to a westernised one experienced a loss in gut microbiota diversity accompanied by weight gain, effects which exacerbated across generations. It is unknown whether the current low fibre intake had any impact on the gut microbiota composition, short-chain fatty acids production and metabolism in individuals from different generations. This thesis’ aims were to explore these unknowns through an in vitro batch fermentation study and a dietary intervention clinical trial. The in vitro study showed a significant increase in propionate production in mothers compared to offspring when stool samples were incubated with beta-glucan for 6h and inulin for 19h. There were significant generational differences at phylum and family levels in response to inulin, pectin, beta-glucan, cellulose, and the mix of these fibres. The randomised cross-over trial compared the effects of a two-weeks dietary fibre mix (DFM) supplementation, containing inulin, pectin, and beta-glucan, to a cellulose control on the gut microbiota and glycaemia in mothers and their daughters. The daughters’ microbiota produced significantly more propionate, butyrate and isobutyrate following the DFM while the mothers produced more propionate following the control. There were generational differences at family and genus levels following each supplement intake. The mothers experienced an improvement in postprandial insulin following the DFM while the daughters had a significantly higher postprandial glucose peak following the control. Altogether, these pilot studies suggest that intergenerational differences in response to fibres may exist and further investigations are warranted to confirm our preliminary observations.
Version
Open Access
Date Issued
2024-05-10
Date Awarded
2024-12-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Frost, Gary
Blanchard, Carine
Sponsor
Medical Research Council (Great Britain)
Nestle (Firm)
Publisher Department
Department of Metabolism, Digestion and Reproduction
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)