The sugar composition of the fibre in selected plant foods modulates weaning infants\u2019 gut microbiome composition and fermentation metabolites in vitro

Shanthi G Parkar,Halina M Stoklosinski,Jovyn K T Frost,Carel M H Jobsis,Doug Rosendale,Pramod Gopal,Duncan I Hedderley

doi:10.1038/s41598-021-88445-8

Shanthi G Parkar, Halina M Stoklosinski + Show 5 more

Open Access

https://doi.org/10.1038/s41598-021-88445-8

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Abstract

Eight plant-based foods: oat flour and pureed apple, blackcurrant, carrot, gold- and green-fleshed kiwifruit, pumpkin, sweetcorn, were pre-digested and fermented with pooled inocula of weaning infants’ faecal bacteria in an in vitro hindgut model. Inulin and water were included as controls. The pre-digested foods were analysed for digestion-resistant fibre-derived sugar composition and standardised to the same total fibre concentration prior to fermentation. The food-microbiome interactions were then characterised by measuring microbial acid and gas metabolites, microbial glycosidase activity and determining microbiome structure. At the physiologically relevant time of 10 h of fermentation, the xyloglucan-rich apple and blackcurrant favoured a propiogenic metabolic and microbiome profile with no measurable gas production. Glucose-rich, xyloglucan-poor pumpkin caused the greatest increases in lactate and acetate (indicative of high fermentability) commensurate with increased bifidobacteria. Glucose-rich, xyloglucan-poor oats and sweetcorn, and arabinogalactan-rich carrot also increased lactate and acetate, and were more stimulatory of clostridial families, which are indicative of increased microbial diversity and gut and immune health. Inulin favoured a probiotic-driven consortium, while water supported a proteolytic microbiome. This study shows that the fibre-derived sugar composition of complementary foods may shape infant gut microbiome structure and metabolic activity, at least in vitro.

Highlights

Eight plant-based foods: oat flour and pureed apple, blackcurrant, carrot, gold- and green-fleshed kiwifruit, pumpkin, sweetcorn, were pre-digested and fermented with pooled inocula of weaning infants’ faecal bacteria in an in vitro hindgut model
Whereas cellulose (1→4-β-linked glucose) and xyloglucan (1→4-β-linked glucose substituted with short xylose sidechains) have relatively simple structures, pectins are highly variable in their chemical composition and in their degree of b ranching[12,13]
Eight foods, inulin as a positive control, and water were digested in vitro and the non-cellulosic neutral sugar and uronic acid composition of the foods were analysed after digestion (Table 2)

Summary

Introduction

Eight plant-based foods: oat flour and pureed apple, blackcurrant, carrot, gold- and green-fleshed kiwifruit, pumpkin, sweetcorn, were pre-digested and fermented with pooled inocula of weaning infants’ faecal bacteria in an in vitro hindgut model. This study shows that the fibre-derived sugar composition of complementary foods may shape infant gut microbiome structure and metabolic activity, at least in vitro. Plant foods are commonly introduced (along with cheese and meat) to the infants at about 6 months of age, supporting the growth and development needs of the infants[5] They are rich sources of plant cell wall polysaccharides, known as dietary fibres, that provide the major source of energy for the bacteria in the growing. Pectin’s “hairy” sidechains are called rhamnogalacturonans-I, and they consist of repeating units of (1,4)-galacturonosyl and α-(1,2)-rhamnosyl chains to which are attached glycans made up of neutral sugars, rhamnose and galactose[12] This compositional and structural complexity of pectin has been suggested to stimulate the growth of different members of the gut bacterial community[12]

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