In vitro fermentation of sugar beet arabinan and arabino-oligosaccharides by the human gut microflora

Al-Tamimi, M.A.H.M., Palframan, R.J., Cooper, J.M., Gibson, G.R. ORCID: https://orcid.org/0000-0002-0566-0476 and Rastall, R.A. (2006) In vitro fermentation of sugar beet arabinan and arabino-oligosaccharides by the human gut microflora. Journal of Applied Microbiology, 100 (2). pp. 407-414. ISSN 1364-5072 doi: 10.1111/j.1365-2672.2005.02780.x

Abstract/Summary

Aims: To determine the fermentation profiles by human gut bacteria of arabino-oligosaccharides of varying degree of polymerization. Materials and Methods: Sugar beet arabinan was hydrolyzed with a commercial pectinase and eight fractions, of varying molecular weight, were isolated by gel-filtration chromatography. Hydrolysis fractions, arabinose, arabinan and fructo-oligosaccharides were fermented anaerobically by gut bacteria. Total bacteria, bifidobacteria, bacteroides, lactobacilli and the Clostridium perfringens/histolyticum sub. grp. were enumerated using fluorescent in situ hybridization. Results: Bifidobacteria were stimulated to different extents depending on molecular weight, i.e. maximum increase in bifidobacteria after 48 h was seen on the lower molecular weight fractions. Lactobacilli fluctuated depending on the initial inoculum levels. Bacteroides numbers varied according to fraction; arabinan, arabinose and higher oligosaccharides (degree of polymerization, dp > 8) resulted in significant increases at 24 h. Only carbohydrate mixtures with dp of 1-2 resulted in significant increases at 48 h (log 8.77 +/- 0.23). Clostridia decreased on all substrates. Conclusions: Arabino-oligosaccharides can be considered as potential prebiotics. Significance and Impact of the Study: Arabinan is widely available as it is a component of sugar beet pulp, a co-product from the sugar beet industry. Generation of prebiotic functionality from arabinan would represent significant added value to a renewable resource.