GROWTH OF ENTEROBACTERIA ON FRUCTO-OLIGOSACCHARIDES

Fructo-oligosaccharides (FOS) can be fermented by most species of ente robacteria present in the human intestine. Fermentation was confirmed by increased growth rates, low final pH and degradation patterns using high performance anion exchange chromatography (HPAEC). Growth rates were increased when FOS was added to the growth medium. Growth rates o n all substrates differed widely between strains within the same speci es. HPAEC analysis showed that each strain degraded the oligosaccharid es differently, but a preference for the smaller oligosaccharides was observed. No differences were observed between the two commercial prep arations, the inulo-oligosaccharides and neosugars. Fermentation was r apid as could be determined by acidification tests using cell suspensi ons. It can be concluded that enterobacteria may play a role in overal l fermentation of FOS in the colon and, in addition. due to competitiv e exclusion, may prevent survival of ingested pathogenic enterobacteri a.