Does sucrase deficiency in black South Africans protect against colonic disease?

Health potential of polyols as sugar replacers, with emphasis on low glycaemic properties

Abstract Polyols are hydrogenated carbohydrates used as sugar replacers. Interest now arises because of their multiple potential health benefits. They are non-cariogenic (sugar-free tooth-friendly), low-glycaemic (potentially helpful in diabetes and cardiovascular disease), low-energy and low-insulinaemic (potentially helpful in obesity), low-digestible (potentially helpful in the colon), osmotic (colon-hydrating, laxative and purifying) carbohydrates. Such potential health benefits are reviewed. A major focus here is the glycaemic index (GI) of polyols as regards the health implications of low-GI foods. The literature on glycaemia and insulinaemia after polyol ingestion was analysed and expressed in the GI and insulinaemic index (II) modes, which yielded the values: erythritol 0, 2; xylitol 13, 11; sorbitol 9, 11; mannitol 0, 0; maltitol 35, 27; isomalt 9, 6; lactitol 6, 4; polyglycitol 39, 23. These values are all much lower than sucrose 65, 43 or glucose 100, 100. GI values on replacing sucrose were independent of both intake (up to 50 g) and the state of carbohydrate metabolism (normal, type 1 with artificial pancreas and type 2 diabetes mellitus). The assignment of foods and polyols to GI bands is considered, these being: high (> 70), intermediate (> 55–70), low (> 40–55), and very low (< 40) including non-glycaemic; the last aims to target particularly low-GI-carbohydrate-based foods. Polyols ranged from low to very low GI. An examination was made of the dietary factors affecting the GI of polyols and foods. Polyol and other food GI values could be used to estimate the GI of food mixtures containing polyols without underestimation. Among foods and polyols a departure of II from GI was observed due to fat elevating II and reducing GI. Fat exerted an additional negative influence on GI, presumed due to reduced rates of gastric emptying. Among the foods examined, the interaction was prominent with snack foods; this potentially damaging insulinaemia could be reduced using polyols. Improved glycated haemoglobin as a marker of glycaemic control was found in a 12-week study of type 2 diabetes mellitus patients consuming polyol, adding to other studies showing improved glucose control on ingestion of low-GI carbohydrate. In general some improvement in long-term glycaemic control was discernible on reducing the glycaemic load via GI by as little as 15–20 g daily. Similar amounts of polyols are normally acceptable. Although polyols are not essential nutrients, they contribute to clinically recognised maintenance of a healthy colonic environment and function. A role for polyols and polyol foods to hydrate the colonic contents and aid laxation is now recognised by physicians. Polyols favour saccharolytic anaerobes and aciduric organisms in the colon, purifying the colon of endotoxic, putrefying and pathological organisms, which has clinical relevance. Polyols also contribute towards short-chain organic acid formation for a healthy colonic epithelium. Polyol tooth-friendliness and reduced energy values are affirmed and add to the potential benefits. In regard to gastrointestinal tolerance, food scientists and nutritionists, physicians, and dentists have in their independent professional capacities each now described sensible approaches to the use and consumption of polyols.

Review article: lactose--a potential prebiotic

Lactose maldigestion, which affects a large majority of the world's population, has been mostly linked with uncomfortable symptoms. In addition, dairy consumption is variably blamed or recommended for a number of ill effects. There is, however, emerging evidence that certain lactic acid-producing bacteria, which selectively consume prebiotics, may be beneficial against some lower intestinal diseases. Lactose maldigestion and lactose should perhaps be re-evaluated as a potential provider of such a prebiotic. This historical and observational review discusses lactose and argues the opinion that it has prebiotic potential. Moreover, in maldigesters, natural ingestion or lack thereof may be relevant in the pathogenesis of diseases such as colorectal cancer and inflammatory bowel diseases.

Ethnic differences in intestinal disaccharidase values in children in Finland

BACKGROUND

Intestinal disaccharidase activities tend to be low in villous atrophy, but there are only a few reports of enzyme activities in children with normal villous architecture.

METHODS

In the current study the data were reviewed on disaccharidase activities in duodenal biopsy specimens of normal villous structure in 223 children undergoing upper gastrointestinal endoscopy in 1997 and 1998. The ancestry was Finnish in 188 children (median age 8.0 years; range, 0.2-18 years), African in 27 children (median age 5.0 years; range, 1-13 years), and other in eight children.

RESULTS

The mean activities of lactase, sucrase, and maltase were significantly higher in Finnish children than in children of African origin (P < 0.0001, P < 0.002, and P < 0.02, respectively). Lactase activity decreased with increasing age (P < 0.001), but age had no significant effect on maltase and sucrase activities. Among Finnish children, 31% (59/188) had lactase activity below the established reference range of 20 units (units are micromoles of substrate hydrolyzed per minute at 37 degrees C per gram of protein) and one child had a probable sucrase-isomaltase deficiency. When these 60 children with low enzyme activities were excluded, the geometric means were lactase, 35.7 units (95% confidence interval [CI], 32.8-38.6 units); maltase, 241 units (95% CI, 225-258 units); and sucrase, 57.5 units (95% CI, 53.5-61.6 units). Among the children of African origin, lactase activity was decreased in 67% (18/27). All three enzyme activities were decreased in parallel more often among the African children (8/27) than among the Finnish children (9/188; P < 0.002).

CONCLUSIONS

Ethnicity has a strong effect on disaccharidase values in children with normal villous structure. African children have lower activities of lactase, sucrase, and maltase in duodenal specimens than do children of Finnish origin.