Dietary Xylitol Research Articles

Dietary Xylitol Supplement Ameliorated AD-related Neuronal Injury by Regulating Glucose Metabolism Relevant Amino Acids in Mice.

Alzheimer's disease (AD) is one of the most common irreversible degenerative diseases of the central nervous system. Recent studies have found that patients with AD generally experience abnormal glucose metabolism. Xylitol is a functional sugar alcohol, which has been reported to regulate glucose metabolism. The present study was designed to determine whether xylitol can alleviate cognitive impairment in AD mice. In the current research, 5% xylitol was supplemented in the diet to treat APP/PS1 transgenic AD mice for 2 months. Cognitive ability was measured by the Morris water maze, and anxiety-like behaviors were examined by open-field experiment. Hippocampal cellular apoptosis and mitochondria pathway related apoptotic proteins were tested by TUNEL staining and immunoblotting, respectively. By LC-MS, plasma levels of glucose metabolism intermediates and related amino acids were evaluated. Results showed that xylitol could significantly ameliorate anxiety-like activity in AD mice by partially regulating expression levels of mitochondrial pathway-related apoptotic proteins. Xylitolregulated glucose metabolism may play an important role in the process. The current study suggests that xylitol may be a potential candidate for improving neuropsychiatric behavior in AD by regulating the levels of TCA cycle intermediates and related amino acids in glucose metabolism.

Gene expression and metabolic activity of Streptococcus mutans during exposure to dietary carbohydrates glucose, sucrose, lactose, and xylitol.

Recent RNA sequencing studies have given us a deeper insight into the cariogenic impact of carbohydrate sources in the bacterium Streptococcus mutans, the principal microbial agent in dental caries etiopathogenesis. The process of dental caries development is facilitated by the ability of this bacterium to ferment some carbohydrates into organic acids contributing to a pH decrease in the oral cavity and the demineralization of the hard tissues of the tooth. Furthermore, in dental caries progression, biofilm formation, which starts and ends with free planktonic cells, plays an important role and has several unique properties called virulence factors. The most cariogenic carbohydrate is sucrose, an easily metabolizable source of energy that induces the acidification and synthesis of glucans, forming typical bacterial cell clumps. We used multifaceted methodological approaches to compare the transcriptomic and metabolomic profiles of S. mutans growing in planktonic culture on preferred and nonpreferred carbohydrates and in fasting conditions. Streptococcus mutans in a planktonic culture with lactose produced the same pH drop as glucose and sucrose. By contrast, xylitol and lactose showed high effectiveness in regulating intracellular polysaccharide metabolism, cell wall structure, and overall virulence involved in the initial phase of biofilm formation and structure but with an opposite pattern compared with sucrose and glucose. Our results confirmed the recent findings that xylitol and lactose play a vital role in biofilm structure. However, they do not reduce its formation, which is related to the creation of a cariogenic environment.

Dietary Xylitol, Sorbitol and D-Mannitol but not Erythritol Retard Bone Resorption in Rats

The aim of the present study was to compare the ability of four dietary polyols to reduce bone resorption. Urinary excretion of 3H radioactivity from [3H]tetracycline-prelabeled rats was used as a marker of bone resorption. After prelabeling, the rats were divided randomly into five groups of 10, and fed for 1 mo a nonpurified diet that was supplemented in four groups with either xylitol, sorbitol, D-mannitol or erythritol, respectively, to give a polyol concentration of 1 mol/kg. Xylitol (42%), sorbitol (44%) and to a lesser degree D-mannitol (23%) decreased the excretion of 3H relative to the basal diet. The erythritol group, however, did not differ from the controls. Sorbitol caused continuous diarrhea, whereas in the other groups, intestinal adaptation took place during the 1st wk of polyol feeding. In conclusion, dietary xylitol, sorbitol and to a lesser degree D-mannitol supplementations in rats retard bone resorption, whereas dietary erythritol has no effect.

Effects of Consuming Xylitol on Gut Microbiota and Lipid Metabolism in Mice

The sugar alcohol xylitol inhibits the growth of some bacterial species including Streptococcus mutans. It is used as a food additive to prevent caries. We previously showed that 1.5–4.0 g/kg body weight/day xylitol as part of a high-fat diet (HFD) improved lipid metabolism in rats. However, the effects of lower daily doses of dietary xylitol on gut microbiota and lipid metabolism are unclear. We examined the effect of 40 and 200 mg/kg body weight/day xylitol intake on gut microbiota and lipid metabolism in mice. Bacterial compositions were characterized by denaturing gradient gel electrophoresis and targeted real-time PCR. Luminal metabolites were determined by capillary electrophoresis electrospray ionization time-of-flight mass spectrometry. Plasma lipid parameters and glucose tolerance were examined. Dietary supplementation with low- or medium-dose xylitol (40 or 194 mg/kg body weight/day, respectively) significantly altered the fecal microbiota composition in mice. Relative to mice not fed xylitol, the addition of medium-dose xylitol to a regular and HFD in experimental mice reduced the abundance of fecal Bacteroidetes phylum and the genus Barnesiella, whereas the abundance of Firmicutes phylum and the genus Prevotella was increased in mice fed an HFD with medium-dose dietary xylitol. Body composition, hepatic and serum lipid parameters, oral glucose tolerance, and luminal metabolites were unaffected by xylitol consumption. In mice, 40 and 194 mg/kg body weight/day xylitol in the diet induced gradual changes in gut microbiota but not in lipid metabolism.

Ameliorating Effect of Dietary Xylitol on Human Respiratory Syncytial Virus (hRSV) Infection.

Human respiratory syncytial virus (hRSV) is the most common cause of bronchiolitis and pneumonia in infants. The lack of proper prophylactics and therapeutics for controlling hRSV infection has been of great concern worldwide. Xylitol is a well-known sugar substitute and its effect against bacteria in the oral cavity is well known. However, little is known of its effect on viral infections. In this study, the effect of dietary xylitol on hRSV infection was investigated in a mouse model for the first time. Mice received xylitol for 14 d prior to virus challenge and for a further 3 d post challenge. Significantly larger reductions in lung virus titers were observed in the mice receiving xylitol than in the controls receiving phosphate-buffered saline (PBS). In addition, fewer CD3(+) and CD3(+)CD8(+) lymphocytes, whose numbers reflect inflammatory status, were recruited in the mice receiving xylitol. These results indicate that dietary xylitol can ameliorate hRSV infections and reduce inflammation-associated immune responses to hRSV infection.

Protective effect of dietary xylitol on influenza A virus infection.

Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases.

Xylitol Affects the Intestinal Microbiota and Metabolism of Daidzein in Adult Male Mice

This study examined the effects of xylitol on mouse intestinal microbiota and urinary isoflavonoids. Xylitol is classified as a sugar alcohol and used as a food additive. The intestinal microbiota seems to play an important role in isoflavone metabolism. Xylitol feeding appears to affect the gut microbiota. We hypothesized that dietary xylitol changes intestinal microbiota and, therefore, the metabolism of isoflavonoids in mice. Male mice were randomly divided into two groups: those fed a 0.05% daidzein with 5% xylitol diet (XD group) and those fed a 0.05% daidzein-containing control diet (CD group) for 28 days. Plasma total cholesterol concentrations were significantly lower in the XD group than in the CD group (p < 0.05). Urinary amounts of equol were significantly higher in the XD group than in the CD group (p < 0.05). The fecal lipid contents (% dry weight) were significantly greater in the XD group than in the CD group (p < 0.01). The cecal microbiota differed between the two dietary groups. The occupation ratios of Bacteroides were significantly greater in the CD than in the XD group (p < 0.05). This study suggests that xylitol has the potential to affect the metabolism of daidzein by altering the metabolic activity of the intestinal microbiota and/or gut environment. Given that equol affects bone health, dietary xylitol plus isoflavonoids may exert a favorable effect on bone health.

The effects of oral xylitol administration on bone density in rat femur

To examine the effects of oral xylitol administration on rat femur bone density, 36 four-week-old male Wistar rats divided into three groups were fed CE-2 diet (control, n = 12) alone or supplemented with 10% (n = 12) or 20% (n = 12) dietary xylitol for 40 days. Biochemical, morphological, and histological analyses were performed. The 10% and 20% xylitol groups showed higher levels of both serum Ca and alkaline phosphatase activity and lower levels of serum tartrate-resistant acid phosphatase than the control group. Although no significant differences in the three-dimensional bone structure or trabecular bone structure of the femur were observed, both xylitol groups showed significantly higher bone density than the control group. Compared to the control group, the 10% and 20% xylitol groups showed an increase in trabeculae. Thus, oral administration of xylitol appears to affect bone metabolism, leading to increased bone density in rat femur.

Effects of xylitol on metabolic parameters and visceral fat accumulation

Xylitol is widely used as a sweetener in foods and medications. Xylitol ingestion causes a small blood glucose rise, and it is commonly used as an alternative to high-energy supplements in diabetics. In previous studies, a xylitol metabolite, xylulose-5-phosphate, was shown to activate carbohydrate response element binding protein, and to promote lipogenic enzyme gene transcription in vitro; however, the effects of xylitol in vivo are not understood. Here we investigated the effects of dietary xylitol on lipid metabolism and visceral fat accumulation in rats fed a high-fat diet. Sprague-Dawley rats were fed a high-fat diet containing 0 g (control), 1.0 g/100 kcal (X1) or 2.0 g/100 kcal (X2) of xylitol. After the 8-week feeding period, visceral fat mass and plasma insulin and lipid concentrations were significantly lower in xylitol-fed rats than those in high-fat diet rats. Gene expression levels of ChREBP and lipogenic enzymes were higher, whereas the expression of sterol regulatory-element binding protein 1c was lower and fatty acid oxidation-related genes were significantly higher in the liver of xylitol-fed rats as compared with high-fat diet rats. In conclusion, intake of xylitol may be beneficial in preventing the development of obesity and metabolic abnormalities in rats with diet-induced obesity.

Dietary xylitol protects against the imbalance in bone metabolism during the early phase of collagen type II–induced arthritis in dark agouti rats

The aim of the present study was to evaluate the changes in bone metabolism during the early phase of type II collagen–induced arthritis in rats and to evaluate whether a 10% dietary xylitol supplementation is able to protect against these changes. Arthritis was induced in female dark agouti rats by injections of type II homologous rat collagen emulsified with an equal volume of incomplete Freund adjuvant. In one group, the diet was supplemented with 10% xylitol. After 17 days, the rats were killed. Serum osteocalcin, as a marker of bone formation, and serum tartrate-resistant acid phosphatase, as a marker of bone resorption, were measured. Histologic measurements were made from Masson-Goldner trichrome–stained sections of distal tibiae. All the collagen-injected rats had arthritic symptoms at the end of the experiment. Serum osteocalcin was significantly higher in the collagen-injected rats fed a xylitol-supplemented diet (CI-X) than in the collagen-injected rats not fed xylitol (CI) and in the controls. Serum tartrate-resistant acid phosphatase was significantly higher in the CI and CI-X groups than in the controls. Trabecular bone volume was significantly lower in the CI group as compared with the CI-X and control groups. These results suggest that, at the time of the appearance of arthritic symptoms, bone resorption activity is high, but bone formation is not severely affected. Furthermore, dietary xylitol seems to protect against the imbalance of bone metabolism during the early phase of collagen type II–induced arthritis.

Effects of a Long-Term Dietary Xylitol Supplementation on Collagen Content and Fluorescence of the Skin in Aged Rats

Background: Dietary xylitol has been shown to increase the amounts of newly synthesized collagen, and to decrease fluorescence of the collagenase-soluble fraction in the skin of both healthy and diabetic rats. As in diabetic rats, a decreased rate of collagen synthesis and increased collagen fluorescence has also been detected in the skin of aged rats. We hypothesize that dietary xylitol supplementation may protect against these changes during aging. Objective: The purpose of the present study was to investigate whether a long-term dietary supplementation can protect against the decrease in the amounts of newly synthesized collagen, and against the increase in fluorescence in the collagenase-soluble fraction in the skin of aged rats. Methods:Twenty-four male Sprague-Dawley rats were used in the study. After weaning, the rats were divided into 2 groups of 12 animals. The rats in the control group were fed a basal RM1 diet, while the rats in the experimental group were fed the same diet supplemented with 10% xylitol. After 20 months, the rats were killed and pieces of skin from their dorsal areas were excised. The thickness of the samples was measured with a micrometer screw gauge. The collagen contents of rat skin were measured as hydroxyproline, and glycosylation as fluorescent intensity of collagen. Statistical significances of the differences between the groups were determined using the unpaired t test. Results: No general side effects were detected in the rats during the experimental period. The skin of the xylitol-fed rats was a little thicker than that of the control rats. The hydroxyproline content of the acid-soluble fraction was significantly greater in the xylitol group as compared to the controls. However, there were no significant differences in the hydroxyproline content of the collagenase-soluble fraction between the groups. The fluorescence of the collagenase-soluble fraction was significantly smaller in the xylitol-fed aged rats than in the aged rats fed the basal diet. Conclusions: The results of this study indicate that xylitol caused an increase in the amount of newly synthesized collagen and a decrease in collagen fluorescence in the skin of aged rats.

The effect of a simultaneous dietary administration of xylitol and ethanol on bone resorption

Our previous studies have shown that dietary xylitol supplementation diminishes bone resorption in rats, as well as protects against ovariectomy-induced increase of bone resorption during experimental osteoporosis. Interestingly, ethanol, when given simultaneously with xylitol, is known to increase blood concentration of xylitol. On the other hand, ethanol, when given alone, has been shown to increase bone resorption. The aim of the present study was to evaluate the effects of a simultaneous dietary administration of 10% xylitol and 10% ethanol on bone resorption. Bone resorption was determined using measurement of urinary excretion of hydrogen 3 ( 3H) radioactivity in 3H-tetracycline prelabeled rats. Already 4 days after the beginning of dietary supplementations, excretion of 3H was about 15% lower in the xylitol group (diet supplemented with 10% xylitol) and about 25% lower in the xylitol-ethanol group (diet supplemented with 10% xylitol and 10% ethanol) as compared to the controls. The excretion of 3H in these groups remained smaller than that of the controls throughout the entire study period of 40 days. The excretion of 3H in the xylitol-ethanol group remained also smaller than that of the xylitol group. Bone mineral density and bone mineral content were determined with a peripheral quantitative computed tomography (pQCT) system from the rat tibiae at the end of the experiment. Trabecular bone mineral density and trabecular bone mineral content were significantly greater in the xylitol group and in the xylitol-ethanol group compared to the controls. They were also greater in the xylitol-ethanol group as compared to the xylitol group. Cortical bone mineral density and cortical bone mineral content did not differ significantly between the groups. In conclusion, a simultaneous dietary supplementation with 10% xylitol and 10% ethanol seems to diminish bone resorption and to increase trabecular bone mineral density and trabecular bone mineral content in rats. These effects seem to be stronger than the effects induced by 10% xylitol supplementation alone.

Effect of Xylitol Feeding on Antibody Production and Inflammatory Responses in Broiler Chicks

Effect of dietary xylitol on antibody titers to sheep blood red cells (SRBC) and immunoglobulin (Ig) G concentration in plasma and concanvalin A stimulated-blood T cell proliferation was studied in broiler chicks. In addition, changes in feed intake, and plasma acute phase proteins concentration such as alpha-1 acid glycoprotein and ceruloplasmin following single injection of lipopolysaccharide (LPS, Salmonella enteritidis, 1.5mg/kg body weight) were also determined. Male broiler chicks (8 days of age, Ross strain) were fed either diet containing glucose or xylitol for 22 days. A SRBC suspension (5 : 100, v/v) in a phosphate buffer was intravenously injected at 15 and 25 days of age and a blood sample was obtained at 21 and 29 days of age from wing vein. Thereafter, chicks were intraperitoneally injected with LPS and blood was obtained 0, 9 and 24 hours after the injection. Growth performance for 22 days before the LPS injection did not differ between dietary groups. The antibody titers against SRBC and plasma IgG concentration were greater in chicks fed the xylitol diet than those in chicks fed the glucose diet at 21 days of age, but not at 29 days of age. Proliferation of T cell induced by Con A before the injection of LPS did not differ in dietary treatments. Significantly greater feed intake during 24 hours following LPS injections was observed in chicks fed the xylitol diet relative in chicks fed the glucose diet. Acute phase proteins concentration in plasma at 9 and 24 hours following single injection of LPS did not differ in chicks fed the xylitol and glucose diets, except ceruloplasmin concentration at 9 hours after LPS injection. The results suggested that dietary xylitol enhanced antibody production without impairing growth performance, and alleviated reduction of feed intake without impairing early inflammatory responses even when they were received relatively high level of immune stimulation.

Effect of Dietary Xylitol on Growth Performance and Nitrogen Retention in Male Broiler Chicks during Immunological Stimulation

The effect of dietary xylitol on growth performance and nitrogen retention was studied in male broiler chicks during immunological stimulation. In experiment 1, chicks (10 day of age) were fed a corn-soybean diet containing 10% glucose or 10% xylitol with identical metabolizable energy and crude protein for 14 days. In experiment 2, ten-day-old chicks were fed 10% glucose or 6% xylitol diet for 8 days. During the final 6 days of the experimental periods, a half of birds fed each diet were injected intraperitoneally with 0.5 mg/kg body weight of Escherichia coli lipopolysaccharide (LPS, 0127:B8) on days 1, 3 and 5, and with 250 mg/kg body weight of Sephadex-G50 superfine on days 2 and 4 to stimulate immune system in both experiments. Feeding of the xylitol diets partially prevented the reduction in body weight gain or feed efficiency due to LPS and Sephadex injections, but the glucose diet did not in both the experiments. LPS and Sephadex injections decreased nitrogen retention, whereas the diet containing xylitol partly in experiment 1 and almost completely in experiment 2, prevented the reduction due to immunological stimulation. These results indicate that dietary xylitol probably prevents the reduction in nitrogen retention with growth retardation due to LPS and Sephadex injection. The beneficial effect on nitrogen retention is obtained when chicks are given xylitol 2 days before stimulating the immune system. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 1 : 84-88)

Increased Bone Volume and Bone Mineral Content in Xylitol-Fed Aged Rats

Background: Our previous studies have shown that dietary xylitol supplementation protects against the loss of bone mineral after ovariectomy. The ovariectomy-induced decrease in trabecular bone volume is significantly retarded by dietary xylitol. Objective: To study whether dietary xylitol can protect against bone loss also during aging, a long-term experimental study was performed with rats. Methods: Twenty-four male Sprague-Dawley rats were divided into two groups. The rats in the control group were fed a basal RM1 diet, while the rats in the experimental group were continuously fed the same diet supplemented with 10% (w/w) xylitol. The rats were killed after 20 months. Their tibiae were used for the analyses of bone density and trabecular bone volume, and their femurs were used for the scanning analyses with peripheral quantitative computed tomography (pQCT). Results: The tibial density of the xylitol-fed aged group (1.73 ± 0.14 g/mm³) was significantly greater than that of the aged group without xylitol (1.56 ± 0.14 g/ mm³). The trabecular bone volume of the xylitol-fed rats was 21.2 ± 4.0%. It was significantly greater than that of the rats not receiving xylitol (9.3 ± 4.3%). The pQCT-measured cortical bone mineral density and the pQTC-measured cortical bone mineral content of the femoral diaphysis were significantly greater in the xylitol-fed group than in the control group. The trabecular bone mineral density and the trabecular bone mineral content of the femoral distal metaphysis were also significantly greater in the xylitol-fed group than in the non-xylitol group. The total bone mineral density and the total bone mineral content of the femoral neck in the xylitol-fed aged group significantly exceeded those in the aged group without xylitol supplementation. Conclusions: A continuous moderate dietary xylitol supplementation leads to increased bone volume and increased bone mineral content in the long bones of aged rats. This indicates a xylitol-induced protection against aging-related osteoporotic changes.

Effects of dietary xylitol on collagen content and glycosylation in healthy and diabetic rats

The effects of three-month dietary xylitol supplementation on the amounts and hexose contents of acid-soluble collagen as well as on the amounts and fluorescence of collagenase-soluble collagen were studied in healthy and streptozotocin-diabetic male rats. Collagen was extracted from skin samples. In the healthy rats, supplementation with xylitol (10%) increased the hydroxyproline content of the acid-soluble fraction and skin thickness. In diabetic rats receiving and not receiving xylitol, the acid-soluble collagen fraction was markedly lower than in healthy rats. However, its amount was significantly elevated when xylitol had been added to the diet. Supplementation with xylitol caused no changes in the amounts of collagenase-soluble fraction in either healthy or diabetic rats. Supplementation with xylitol (10%) significantly decreased the hexose content of acid-soluble collagen and the fluorescence of the collagenase-soluble fraction in both healthy and diabetic rats. The results indicate that dietary xylitol affects collagen synthesis and collagen glycosylation.

Can the pentitol-hexitol theory explain the clinical observations made with xylitol?

The natural dietary carbohydrate xylitol has been used as a source of energy in infusion therapy and found to act curatively in certain clinical situations. Xylitol has also been used as a sweetener in the diabetic diet and as a non- or anticariogenic agent. Xylitol is a sugar alcohol (polyhydric alcohol) of the pentitol type. The various advantageous clinical effects associated with enteral and parenteral administration of xylitol can be considered to result from the five-carbon (pentitol) nature of the molecule and from the molecule’s special configuration even when compared with other pentitols. Such effects may be regarded as simple consequences of evolutionary expediency in a situation where human nutrition and man’s significant energy-yielding metabolic pathways are associated with the six-carbon nature of D-glucose and the close derivatives and polymers of D-glucose and related sugars, and the physiologic involvement of the five-carbon xylitol in several ancillary pathways. Consequently, most clinical effects occasioned by xylitol cannot be expected to be caused by six-carbon hexitols such as D-mannitol and D-glucitol. A simple pentitol-hexitol theory seems to explain most of the clinical effects associated with the administration of xylitol. This theory is in congruence with the general evolutionary development in which the metabolism of C6-based carbohydrates is often inhibited by C5-based ones (as manifested in certain bacterial infections in man), or where the presence of the C5-based xylitol forwards therapeutically significant metabolic pathways (as observed in parenteral nutrition and treatment of certain enzyme deficiencies). The validity of the theory can be verified in controlled clinical trials.

Biomarkers used to assess the effect of dietary xylitol or sorbitol in the rat

Because sugar alcohols can be used as bulk sweeteners and their possible lower energy values, interest has increased. Sorbitol and xylitol are hydrogenated monosaccharides that have widespread application. Male Fisher-344 rats were fed semipurified diets containing glucose without or with either 10% or 20% sorbitol or xylitol for 8 weeks following a 4-week adaptation period. The addition of sugar alcohols decreased food efficiency and total body weight gain regardless of the type fed. The addition of sugar alcohols to the diets decreased liver glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme (ME). However, rats fed either 10% xylitol or sorbitol or 20% sorbitol had higher levels of epididymal fat tissue G6PD and ME. Plasma glucagon levels were decreased with the addition of sugar alcohols; whereas, in plasma insulin and glucose there was little effect. Diets containing sugar alcohols decreased levels of plasma triglyceride and cholesterol. The addition of sugar alcohols to the diets increased plasma alkaline phosphatase levels. Dietary treatments had no effect on urine or adrenal norephinephrine and epinephrine, and urine dihydroxyphenylacetic acid and dopamine. The addition of sugar alcohols to the diets had more of a metabolic effect than the type of sugar alcohol fed.

Effect of dietary xylitol on growth and inflammatory responses in immune stimulated chickens

1. It has been argued that stimulation of the immune system depresses performance. Accordingly , an experiment was conducted to determine the effect of dietary xylitol (150 g/kg diet) on growth and selected inflammatory responses in male broiler chickens. 2. During the final 6 d of the experimental periods, chicks were injected with antigens: Escherichia coli lipopolysaccharide (LPS) on days 1, 3 and 5 and with Sephadex-G50 superfine on days 2 and 4 to stimulate macrophage functions. 3. The immune stimulation reduced body weight gain and food intake, but enhanced alpha 1 acid glycoprotein (AGP) concentration and interleukin (IL-1) like activity in plasma. 4. Feeding the xylitol diet partially, but significantly, prevented the reductions in body weight gain and food intake, without affecting the early stage of inflammatory responses triggered by LPS and Sephadex injections.

Dietary Xylitol Protects Against Weakening of Bone Biomechanical Properties in Ovariectomized Rats

The effects of dietary xylitol (xyl) on bone biomechanical properties in ovariectomized rats (ovx) were studied. Forty-two 3-mo-old female Wistar rats were divided into three groups of 14. Rats in two groups were ovariectomized, while those in the control group underwent a sham operation. All rats received a basal diet, and half of the ovx were given an additional 10 g/100 g dietary xyl supplementation. Three months later the rats were killed and their tibias, femurs and humeri were prepared. The tibias were used for analyses of bone density and trabecular bone volume (BV/TV) and for the three-point bending test. The femurs were used for the torsion test and for the loading test of the femoral neck. The humeri were used for analyses of bone ash weight and bone concentrations of calcium and phosphorus. Dietary xyl gave a significant protection against ovariectomy-caused decline of tibial stress in the three-point bending test, of femoral shear stress in the torsion test, and of stress of the femoral neck, without affecting bone elasticity values. Xyl restricted the ovariectomy-caused reduction in bone density, in bone ash weight and in concentrations of bone calcium and phosphorus. Furthermore, trabecular bone loss in ovx was significantly suppressed by dietary xyl. These results indicate that a 10% dietary supplementation of xyl in ovx has a protective effect against the weakening of bone biomechanical properties. This is related to greater BV/TV and maintained bone mineral content.