People fed chocolate containing blends of polydextrose and maltitol experienced increases in levels of bifidobacteria and lactobacilli, as well as the production of short-chain fatty acids (SCFA), all of which are prominent markers of prebiotic activity, according to findings published in the British Journal of Nutrition.
The study’s findings are important to both consumers and manufacturers, report Emma Beards, Dr Kieran Tuohy, and Prof Glenn Gibson from the Department of Food Biosciences.
“Manufacturers need to keep up with the demand through sourcing alternative ingredients that combine a range of benefits for the consumers,” they wrote. “In the present study, it can be seen that at the optimal dose, the polydextrose blend could not only lower the energetic value of chocolate, but also provide prebiotic effects for the consumers.”
The study was supported financially by confectionery giant Cadbury.
Tolerated and effective
Corresponding author Dr Tuohy told NutraIngredients.com that the effect of the individual sweeteners on gut microbiota has been tried previously, but this is the first study to try them as blends.
“The biggest result for us was that the dose – up to 50 grams a day was tolerated without any adverse effects,” said Dr Tuohy.
The authors note that many sugar replacers are not digested in the upper gut, and therefore have could be considered potential prebiotics. “What may become problematic for consumers is that overconsumption of certain prebiotics has been reported to result in unwanted intestinal side effects such as increased flatulence or intestinal bloating or pain,” they explained.
Not so for the sweetener blends used in this study, according to the data. This result is important “not only for giving manufacturers a sugar replacement that can reduce energetic content”, wrote the researchers, “but also for providing a well-tolerated means of delivering high levels of non-digestible carbohydrates into the colon, bringing about improvements in the biomarkers of gut health”.
The researchers tested the effects of the bulk sweetener maltitol (Maltisorb, Roquette) and the bulking agents, polydextrose (Litesse, Danisco) and resistant starch (Nutriose, Roquette), as substitutes for sucrose in chocolate.
Forty volunteers participated in the study, and were randomly assigned to receive normal milk chocolate made with sucrose, or chocolate formulated with 22.8 g of maltitol alone, maltitol plus polydextrose, or maltitol plus resistant starch for 14 days. The dose of chocolate was doubled every two weeks over a six week period.
At the end of the study, Beards and her co-workers observed all three test chocolates were associated with increases in levels of bifidobacteria in the faeces. Furthermore, the polydextrose-maltitol blend was associated with significant increases in lactobacilli levels after six weeks.
This group also experienced increases in levels of beneficial SCFA, including propionate and butyrate, said the researchers.
The optimal dose of 34.2 grams was found to beneficially impact gut microflora without producing any abdominal discomfort, while simultaneously lowering the caloric intake from confectionery products.
Source: British Journal of Nutrition
Published online ahead of print, doi: 10.1017/S0007114510001078
“A human volunteer study to assess the impact of confectionery sweeteners on the gut microbiota composition”
Authors: E. Beards, K. Tuohy, G. Gibson