Oral Presentation Joint Annual Scientific Meeting of the Nutrition Society of NZ and the Nutrition Society of Australia

Large intestinal bacterial community and the effect of mango, purified pectin, and low fibre diets (262)

Lucas J Grant 1 2 , Deirdre Mikkelsen 1 2 , Di Ouwerkerk 3 , Athol V Klieve 1 3 , Michael J Gidley 1 2 , Barbara A Williams 1 2
  1. Queensland Alliance for Agriculture and Food Innovation, St Lucia, QLD, Australia
  2. ARC CoE in Plant Cell Walls, CNAFS, UQ, St Lucia
  3. REU Dept. Ag. and Fisheries, Dutton Park, QLD

Background/Aims: Plant cell walls (PCW) of ingested fruit, while resistant to digestive enzymes, are available for bacterial fermentation in the large intestine (LI). Bioactive nutrients are often metabolic end-products of fermented substrates. Thus, LI bacterial composition and function is key. Furthermore, understanding the influence of these dietary components, will aid in future recommendations for functional foods, which will beneficially change the LI microbiota. Our aim was to investigate shifts in the LI bacterial community after consumption of fruit pulp (mango) or a soluble fruit fibre(pectin).
Methods: Eighteen male pigs were fed one of three diets: low-fibre(S), 15% mango-pulp(M), or 10% pectin(P). The diets were fed for ~3 weeks, the pigs euthanised, and LI digesta collected from four sites. The bacterial 16S rRNA gene amplicon was sequenced from digesta, thus enabling us to investigate LI microbial community dynamics.
Results: Principal coordinates analysis showed separation between diets, though M & P were clustered more closely to each other, than the S diet (P<0.05). Clustering of samples from all LI sites was tighter at the distal colon than at the caecal level.
Conclusions: Mango and pectin diets changed the LI bacterial population, both in terms of species and abundance. Such changes are relevant as they indicate that fruit consumption (with intact PCWs), can shift the population, though a detailed species characterization will provide more information. This study is novel in its characterisation of the in vivo response of the LI-associated bacterial community to a fruit pulp.
Funding source: ARC CoE Plant Cell Walls