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Background/Objectives: There is controversy about the health risks of sugary diets. A recent study reported that chronic consumption of 11% sugar solutions improved glycemic control in lean mice. Based on this finding, we hypothesized that chronic consumption of the same 11% sugar solutions would also improve glycemic control in metabolically deranged mice. Methods: We exposed mice to a high-fat/high-sugar diet for 12 weeks. Then, we switched the mice to a control (i.e., standard chow) or one of four experimental diets for 8 weeks. The experimental diets contained standard chow plus an 11% solution of glucose or high-fructose syrup. The sugar syrups were derived from corn or cellulose. We included the cellulosic syrups because they contain polyphenols, which are thought to promote glycemic control. We measured body weight, adiposity, glucose tolerance, insulinemia, insulin sensitivity, body composition, and avidity for sweeteners. Results: Mice switched to the control diet lost weight, whereas mice switched to the experimental diets remained obese and hyperinsulinemic. Thus, the experimental diets did not cause the mice to regain normal metabolic health. Nevertheless, we observed (i) improvements in glucose tolerance in mice on both the control and experimental diets; (ii) reduced insulinemia and enhanced insulin sensitivity in mice offered the cellulosic syrups; (iii) elevations in cephalic-phase insulin responses in mice on the experimental diets; and (iv) increased avidity for sweeteners in mice on the control but not the experimental diets. Conclusions: Switching metabolically deranged mice to the experimental diets, particularly those with cellulosic sugars, improved glucose tolerance and insulin sensitivity. Full article

The entry of peptides into glycobiology has led to the development of a unique class of therapeutic tools. Although numerous and well-known peptides are active as endocrine regulatory factors that bind to specific receptors, and peptides have been used extensively as epitopes for vaccine production, the use of peptides that mimic sugars as ligands of lectin-type receptors has opened a unique approach to modulate activity of immune cells. Ground-breaking work that initiated the use of peptides as tools for therapy identified sugar mimetics by screening phage display libraries. The peptides that have been discovered show significant potential as high-avidity, therapeutic tools when synthesized as multivalent structures. Advantages of peptides over sugars as drugs for immune modulation will be illustrated in this review. Full article

The simple sugars glucose and fructose share a common “sweet” taste quality mediated by the T1R2+T1R3 taste receptor. However, when given the opportunity to consume each sugar, rats learn to affectively discriminate between glucose and fructose on the basis of cephalic chemosensory cues. It has been proposed that glucose has a unique sensory property that becomes more hedonically positive through learning about the relatively more rewarding post-ingestive effects that are associated with glucose as compared to fructose. We tested this theory using intragastric (IG) infusions to manipulate the post-ingestive consequences of glucose and fructose consumption. Food-deprived rats with IG catheters repeatedly consumed multiple concentrations of glucose and fructose in separate sessions. For rats in the “Matched” group, each sugar was accompanied by IG infusion of the same sugar. For the “Mismatched” group, glucose consumption was accompanied by IG fructose, and vice versa. This condition gave rats orosensory experience with each sugar but precluded the differential post-ingestive consequences. Following training, avidity for each sugar was assessed in brief access and licking microstructure tests. The Matched group displayed more positive evaluation of glucose relative to fructose than the Mismatched group. A second experiment used a different concentration range and compared responses of the Matched and Mismatched groups to a control group kept naïve to the orosensory properties of sugar. Consistent with results from the first experiment, the Matched group, but not the Mismatched or Control group, displayed elevated licking responses to glucose. These experiments yield additional evidence that glucose and fructose have discriminable sensory properties and directly demonstrate that their different post-ingestive effects are responsible for the experience-dependent changes in the motivation for glucose versus fructose. Full article