RECOVERY OF INULIN FROM JERUSALEM-ARTICHOKE (HELIANTHUS-TUBEROSUS L) IN THE SMALL-INTESTINE OF MAN

The recovery of inulin, a naturally occurring beta(2-->1)-fructan isol ated from Jerusalem artichoke (Helianthus tuberosus L.), in the small intestine of man was studied in ileostomy subjects, The ileostomists w ere given a low-dietary-fibre diet based on white wheat bread and virt ually free of inulin, and the same diet with the addition of 10 g and 30 g inulin product respectively, and the recovery and mean transit ti me (MTT) of inulin were estimated by tracking inulin in ileal effluent . The recovery of inulin was approximately 87% at both ingestion level s, MTT was 4.9 (SE 0.6) h at an intake of 10 g inulin product decreasi ng to 3.4 (SE 0.3) h at an intake of 30 g inulin product. A significan t change in the fructose:glucose ratio of inulin from ingestion (4.1) to recovery in ileal effluent (4.5-4.7) and a lower recovery of the gl ucose residue than of the fructose residue of inulin indicate that the low-molecular-weight inulins are more sensitive to hydrolysis than th e high-molecular-weight fragments. The loss of inulin during passage t hrough the small intestine is presumably due to hydrolysis by either a cids or enzymes and to microbial degradation by the microflora permane ntly colonizing the distal small intestine. The concentrations of lact ic acid (LA) and short-chain fatty acids (SCFA) in frequently collecte d ileal effluents on the control day were approximately 6 mmol/l and a pproximately 55 mmol/l respectively. During periods with inulin ingest ion the concentration of LA increased to 18-26 mmol/l (P < 0.052), whi le the concentration of SCFA ran converse and decreased to 18-32 mmol/ l (P < 0.023), The osmotic loads (68 and 204 mosmol/l) associated with the ingestion of inulin product caused minor malabsorption of low-mol ecular-weight sugars.