A human volunteer study to assess the impact of confectionery sweeteners on the gut microbiota composition

Abstract

Sweeteners are being sourced to lower the energetic value of confectionery including chocolates. Some, especially non-digestible carbohydrates, may possess other benefits for human health upon their fermentation by the colonic microbiota. The present study assessed non-digestible carbohydrate sweeteners, selected for use in low-energy chocolates, for their ability to beneficially modulate faecal bacterial profiles in human volunteers. Forty volunteers consumed a test chocolate (low-energy or experimental chocolate) containing 22·8 g of maltitol (MTL), MTL and polydextrose (PDX), or MTL and resistant starch for fourteen consecutive days. The dose of the test chocolates was doubled every 2 weeks over a 6-week period. Numbers of faecal bifidobacteria significantly increased with all the three test treatments. Chocolate containing the PDX blend also significantly increased faecal lactobacilli (P¼ 0·00 001) after the 6 weeks. The PDX blend also showed significant increases in faecal propionate and butyrate (P¼ 0·002 and 0·006, respectively). All the test chocolates were well tolerated with no significant change in bowel habit or intestinal symptoms even at a daily dose of 45·6 g of non-digestible carbohydrate sweetener. This is of importance not only for giving manufacturers a sugar replacement that can reduce energetic content, 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.

Polydextrose in Lipid Metabolism

“…Interestingly, bifidobacteria have shown a positive correlation with HDL-cholesterol [111], but the bifidobacterial counts were decreased by polydextrose when studied with pyrosequencing [114]. In other studies polydextrose administration has been shown to increase the amount of bifidobacteria and lactobacilli [17,18,49,106,107,115] while in some studies this effect has not been noted [103] or that there was no effect on the growth of lactobacilli [102]. This kind of inconsistency in the response could reflect the interindividual differences in indigenous microbiota to begin with.…”

“…Fecal SCFA concentration measurements are not the best indicators of SCFA produced as the majority of fecal SCFA is absorbed rapidly by the colonic epithelial cells [99]. Polydextrose has been observed to increase the production of butyrate, acetate and propionate in vitro [18,[100][101][102], in rats [20], pigs [11], in dogs [103] and in humans [17,49]. When compared to other fibers, polydextrose produced similar quantities of SCFAs, and the molecular ratio of acetate/propionate/butyrate produced was found to be similar to that of fructo-oligosaccharides and xylo-oligosaccharides and other carbohydrates, such as inulin, pectin, and arabinose [104,105] while in other studies polydextrose produced less total SCFAs compared to FOS, inulin and GOS [102,106,107].…”

“…Several beneficial effects have been linked to the consumption of polydextrose. Consumption of polydextrose promotes the growth of beneficial bifidobacteria and lactobacilli while preventing the growth of harmful ones, such as clostridia [17,18]. It has been suggested to possess anti-inflammatory actions and to improve the signs of osteoarthritis in canines [19], to increase IgA amount in the rat cecum [20], to reduce cyclooxygenase 2 expression in pigs distal colon, and to reduce lesions in rat colitis model [21].…”

Macronutrients and type 1 diabetes (revision number 6)

“…Four randomised controlled trials were identified that presented evidence on resistant starch supplementation in relation to faecal Bifidobacterium spp. content (Jenkins et al, 1999c;Pasman et al, 2006;Fastinger et al, 2008;Beards et al, 2010). No further trials were identified in the update search (Colo-rectal health review p85).…”

“…The data on measures of faecal bacteria content were insufficiently comparable to allow a metaanalysis. Three trials supplemented subjects with chemically modified resistant starch (RS 4 ) (Pasman et al, 2006;Fastinger et al, 2008;Beards et al, 2010), the other trials supplemented subjects with either raw resistant starch (RS 2 ) or retrograde resistant starch (RS 3 ) (Jenkins et al, 1999c …”