Effects of maltitol and xylitol chewing-gums on parameters involved in dental caries development.

AIM: The effects on plaque parameters of sugar free chewing-gums (CG) sweetened with either maltitol or xylitol were assessed to better understand the role polyols can play in dental caries prevention. MATERIALS AND METHODS: A double-blind, parallel, randomised, controlled study was conducted in China. Subjects (N = 258, age = 13 to 15 years-old) were divided into 4 groups: 2 receiving polyols CG, containing respectively maltitol or xylitol, a group receiving gum base (placebo) and a negative control group not receiving any gum. CG were chewed for 30 days. This corresponds to a 10 g consumption of polyol per day. Plaque parameters (growth, pH, bacteria and insoluble glucans) were evaluated throughout the experimental period. RESULTS: All parameters studied were significantly modified with gum base compared to no-gum: plaque pH increased; plaque growth, bacteria (S. mutans, S. sobrinus, A. viscosus and Lactobacillus) and insoluble glucans decreased. Maltitol and xylitol CG led similarly to a higher plaque pH (AUC, p⋜0.05) on short (at baseline after the first CG consumption) and long term (after 4 weeks of daily CG consumption), with or without saliva stimulation compared to both control and placebo groups. They led to a decrease in plaque growth (p=0.02) over the experimental period compared to controls. Moreover, they significantly reduced the concentration of 4 cariogenic bacteria species (p⋜0.05) in dental plaque compared to gum base. CONCLUSION: Sugar free CG sweetened with either maltitol or xylitol can similarly reduce plaque acidogenicity compared to gum base through a decrease in oral bacteria presence. The use of a gum base placebo allowed to isolate effects on parameters involved in dental caries development specific to maltitol and xylitol, and to show these effects were similar.

In vivo efficacy of microbiota-sensitive coatings for colon targeting: a promising tool for IBD therapy.

The first proof of concept in vivo for a new type of microbiota-sensitive film coatings allowing for colon targeting is presented. The efficacy of these polysaccharide barriers to optimize drug release for the treatment of inflammation is demonstrated in an experimental colitis model with Wister rats. 5-Aminosalicylic acid (5-ASA) pellets were prepared by extrusion-spheronization and coated with Nutriose:ethylcellulose (EC) 1:4 or peas starch:ethylcellulose 1:2 blends. The pellets were mixed with standard chow, and the daily drug dose was 150mg/kg. For reasons of comparison, also commercially available Pentasa pellets and placebo pellets were studied. At day 3 after the beginning of the treatment, colitis was induced by intrarectal administration of trinitrobenzene sulfonic acid (TNBS). Animals were sacrificed on day 6. Macroscopic and histological evaluations of colitis were performed blindly. In addition, inflammatory markers were evaluated using ELISA and real-time PCR. Rats receiving TNBS and placebo pellets developed a severe colitis in the distal half of the colon. 5-ASA administered in the form of Pentasa pellets reduced macroscopic inflammation by only 5%. In contrast, the colon lesions were much less severe upon treatment with Nutriose:EC- and peas starch:EC-coated pellets: The macroscopic score was reduced by 25 and 24%, respectively. Decreases of 37 and 38% of the histological lesions confirmed the efficacy of these new colon targeting systems. Also, inflammatory markers (MPO, IL-1ß mRNA, TNF mRNA) were significantly decreased in rats receiving Nutriose:EC- and peas starch:EC-coated pellets compared to Pentasa pellets. Furthermore, real-time PCR analysis indicated increased activation of the target receptor PPAR-γ and the HMGCS2 gene in rats upon administration of 5-ASA loaded Nutriose:EC- and peas starch:EC pellets compared to the commercial product. Also, HPLC-MS/MS analysis of plasma samples demonstrated that the level of the main metabolite of the drug (N-acetyl-5-ASA) was much lower upon administration of Nutriose:EC or peas starch:EC coated pellets compared to Pentasa pellets, indicating that undesired premature drug release in the upper gastrointestinal tract was more effectively hindered. In addition to the rat study, in vivo imaging of transgenic mice expressing the luciferase gene evidenced much more pronounced PPAR-γ activation upon 5-ASA administration in the form of Nutriose:EC-coated pellets versus Pentasa pellets. All these results clearly demonstrate the superiority of these microbiota-sensitive polysaccharide-based film coatings for colon targeting in vivo.

Evaluation of soluble corn fiber on chemical composition and nitrogen-corrected true metabolizable energy and its effects on in vitro fermentation and in vivo responses in dogs.

Dietary fermentable fiber is known to benefit intestinal health of companion animals. Soluble corn fiber (SCF) was evaluated for its chemical composition, nitrogen-corrected true ME (TMEn) content, in vitro digestion and fermentation characteristics, and in vivo effects on nutrient digestibility, fecal fermentation end products, and modulation of the fecal microbiome of dogs. Soluble corn fiber contained 78% total dietary fiber, all present as soluble dietary fiber; 56% was low molecular weight soluble fiber (did not precipitate in 95% ethanol). The SCF also contained 26% starch and 8% resistant starch and had a TMEn value of 2.6 kcal/g. Soluble corn fiber was first subjected to in vitro hydrolytic-enzymatic digestion to determine extent of digestibility and then fermented using dog fecal inoculum, with fermentative outcomes measured at 0, 3, 6, 9, and 12 h. Hydrolytic-enzymatic digestion of SCF was only 7%. In vitro fermentation showed increased (P < 0.05) concentrations of short-chain fatty acids through 12 h, with acetate, propionate, and butyrate reaching peak concentrations of 1,803, 926, and 112 µmol/g DM, respectively. Fermentability of SCF was higher (P < 0.05) than for cellulose but lower (P < 0.05) than for pectin. In the in vivo experiment, 10 female dogs (6.4 ± 0.2 yr and 22 ± 2.1 kg) received 5 diets with graded concentrations of SCF (0, 0.5, 0.75, 1.0, or 1.25% [as-is basis]) replacing cellulose in a replicated 5 × 5 Latin square design. Dogs were first acclimated to the experimental diets for 10 d followed by 4 d of total fecal collection. Fresh fecal samples were collected to measure fecal pH and fermentation end products and permit a microbiome analysis. For microbiome analysis, extraction of DNA was followed by amplification of the V4 to V6 variable region of the 16S rRNA gene using barcoded primers. Sequences were classified into taxonomic levels using a nucleotide basic local alignment search tool (BLASTn) against a curated GreenGenes database. Few changes in nutrient digestibility or fecal fermentation end products or stool consistency were observed, and no appreciable modulation of the fecal microbiome occurred. In conclusion, SCF was fermentable in vitro, but higher dietary concentrations may be necessary to elicit potential in vivo responses.