Objective: To assess whether b-glucan (which is fermented in the colon) lowers postprandial glucose concentrations through mechanisms distinct from a delayed carbohydrate absorption and inhibits de novo lipogenesis. Design: Administration of frequent small meals each hour over 9 h allows a rate of intestinal absorption to be reached which is independent of a delayed absorption. A group of 10 healthy men received either an isoenergetic diet containing 8.9 gaday b-glucan or without b-glucan for 3 days. On the third day, the diet was administered as fractioned meals ingested every hour for 9 h. Setting: Laboratory for human metabolic investigations. Subjects: Ten healthy male volunteers. Main outcome measures: Plasma glucose and insulin concentrations, glucose kinetics, glucose oxidation, de novo lipogenesis. Results: On the third day, plasma glucose and free fatty acid concentrations, carbohydrate and lipid oxidation, and energy expenditure were identical with b-glucan and cellulose. Plasma insulin concentrations were, however, 26% lower with b-glucan during the last 2 h of the 9 h meal ingestion. Glucose rate of appearance at steady state was 12% lower with b-glucan. This corresponded to a 21% reduction in the systemic appearance rate of exogenous carbohydrate with b-glucan, while endogenous glucose production was similar with both diets. De novo lipogenesis was similar with and without b-glucan. Conclusion: Administration of frequent meals with or without b-glucan results in similar carbohydrate and lipid metabolism. This suggests that the lowered postprandial glucose concentrations which are observed after ingestion of a single meal containing b-glucan are essentially due to a delayed and somewhat reduced carbohydrate absorption from the gut and do not result from the effects of fermentation products in the colon. Descriptors: glucose production; de novo lipogenesis; substrate oxidation

Our results suggest that an adapted diet containing specific long-chain polyunsaturated fatty acids, prebiotics and probiotics can revert the negative imprinting of neonatal stress on both intestinal barrier function and growth.

ABSTRACT. An abnormality in galactosylation of complex carbohydrates may be important in the pathogenesis of the long-term complications of classic (galactose-lphosphate uridyltransferase-deficient) galactosemia. The ability of nine galactosemic fibroblast preparations to be galactosylated with a purified galactosyltransferase was measured as an indicator of vacant sites where galactose would normally reside. The amount of galactose transferred to cell protein from galactosemic patients was significantly higher than that transferred to a group of seven controls (p < 0.005). Galactosyltransferase activity of the galactosemic cell preparation toward N-acetylglucosamine was also significantly higher than normal (p < 0.01), and there was a linear relationship between these two parameters in galactosemic but not normal cells. These findings suggest that there is defective galactosylation of galactosemic cell complex carbohydrates and that such cells increase their galactosyltransferase levels in an attempt to compensate for the defect. Defective galactosylation may be implicated as an etiologic factor in complications observed in galactosemic patients even when treated with galactose-restricted diets. (Pediatr Res 31: 508-511, 1992) Abbreviations UDPgalactose, uridine diphosphogalactose UDPglucose, uridine diphosphoglucose OPCA, olivopontocerebellar atrophy Although dietary restriction of galactose has been the basis for treatment of classical galactosemia for over 50 years (I), the longterm efficacy of this approach has been seriously questioned. A survey of over 300 patients indicates that even well-treated patients whose galactose restriction was initiated at birth have developmental delay, speech abnormalities, and ovarian failure in females (2). Older galactose-restricted patients have developed an ataxia syndrome (3).Two theories have been proposed, both involving the sugar nucleotide UDPgalactose, to explain the presence of the complications seen despite the absence of dietary galactose. Gitzelmann et al. (4) (7) recently found that the galactose to mannose ratio is abnormally low in a hydrolysate of the cultured fibroblasts of galactosemic patients, supporting the idea of defective galactosylation in these cells. To test the latter hypothesis, we studied the galactosylation state of glycoproteins in cultured fibroblasts by determining the extent to which cellular glycoproteins would serve as galactose acceptors when extracts were incubated with a purified galactosyltransferase. The rationale for this approach was that an impairment of galactosylation would result in a greater number of glycoprotein oligosaccharides being terminated in N-acetylglucosamine. Normally, galactose is linked to N-acetylglucosamine in the biosynthesis of the carbohydrate moieties of glycoproteins by a galactosyltransferase (Fig. 1). We reasoned that if we incubated cell extracts with radiolabeled UDPgalactose and purified galactosyltransferase, radioactive galactose would be transferred to terminal N-acetylglucosamine sites (Fig. 1)....

No abstract