Water extracts prepared from SGT have significantly higher antioxidant activity and are more effective at promoting the growth of defined (pure cultures) or undefined (mixed cultures)
cultures of lactobacilli and bifidobacteria than CGT. The higher TPC and higher concentration of organic selenium in SGT or the combined effects of both may underlie this superiority of SGT over CGT. It would appear that the difference in the amount of selenium had a major effect. The chemical identity of the selenium in SGT remains unknown. Further studies are needed to identify the form of selenium found in the SGT and to determine its bioavailability and biological activities. SGT shows promise as a prebiotic material. The present work is in vitro based and it is now necessary to confirm the findings in vivo. This will be the objective of a further study by our group