Single-blind, placebo controlled randomised clinical study of chitosan for body weight reduction

Impacts of chitosan and its nanoformulations on the metabolic syndromes: a review

A significant public health issue worldwide is metabolic syndrome, a cluster of metabolic illnesses that comprises insulin resistance, obesity, dyslipidemia, hyperglycemia, and hypertension. The creation of natural treatments and preventions for metabolic syndrome is crucial. Chitosan, along with its nanoformulations, is an oligomer of chitin, the second-most prevalent polymer in nature, which is created via deacetylation. Due to its plentiful biological actions in recent years, chitosan and its nanoformulations have drawn much interest. Recently, the chitosan nanoparticle-based delivery of CRISPR-Cas9 has been applied in treating metabolic syndromes. The benefits of chitosan and its nanoformulations on insulin resistance, obesity, diabetes mellitus, dyslipidemia, hyperglycemia, and hypertension will be outlined in the present review, highlighting potential mechanisms for the avoidance and medication of the metabolic syndromes by chitosan and its nanoformulations.

Anti-Obesity Effects of Chitosan and Its Derivatives

The number of obese people in the world is rising, leading to an increase in the prevalence of type 2 diabetes and other metabolic disorders. The search for medications including natural compounds for the prevention of obesity is an urgent task. Chitosan polysaccharide obtained through the deacetylation of chitin, and its derivatives, including short-chain oligosaccharides (COS), have hypolipidemic, anti-inflammatory, anti-diabetic, and antioxidant properties. Chemical modifications of chitosan can produce derivatives with increased solubility under neutral conditions, making them potential therapeutic substances for use in the treatment of metabolic disorders. Multiple studies both in animals and clinical trials have demonstrated that chitosan improves the gut microbiota, restores intestinal barrier dysfunction, and regulates thermogenesis and lipid metabolism. However, the effect of chitosan is rather mild, especially if used for a short periods, and is mostly independent of chitosan's physical characteristics. We hypothesized that the major mechanism of chitosan's anti-obesity effect is its flocculant properties, enabling it to collect the chyme in the gastrointestinal tract and facilitating the removal of extra food. This review summarizes the results of the use of COS, chitosan, and its derivatives in obesity control in terms of pathways of action and structural activity.

Integrating omics and network pharmacology reveals the anti-constipation role of chitosan with different molecular weights in constipated mice

This study aimed to reveal the constipation-relieving role of chitosan (COS) with different molecular weights (1 kDa, 3 kDa and 244 kDa). Compared with COS3K (3 kDa) and COS240K (244 kDa), COS1K (1 kDa) more significantly accelerated gastrointestinal transit and defecation frequency. These differential effects were reflected in the regulation of specific gut microbiota (Desulfovibrio, Bacteroides, Parabacteroides and Anaerovorax) and short-chain fatty acids (propionic acid, butyric acid and valeric acid). RNA-sequencing found that the differential expressed genes (DEGs) caused by different molecular weights of COS were mainly enriched in intestinal immune-related pathways, especially cell adhesion molecules. Furthermore, network pharmacology revealed two candidate genes (Clu and Igf2), which can be regarded as the key molecules for the differential anti-constipation effects of COS with different molecular weights. These results were further verified by qPCR. In conclusion, our results provide a novel research strategy to help understand the differences in the anti-constipation effects of chitosan with different molecular weights.

The effects of chitosan supplementation on anthropometric indicators of obesity, lipid and glycemic profiles, and appetite-regulated hormones in adolescents with overweight or obesity: a randomized, double-blind clinical trial

Background

Chitosan is one of dietary fiber that has received great attention in improving obesity-related markers, but little is known on its effects on adolescents.

Objectives

To analyze the effects of chitosan supplementation on obesity-related cardiometabolic markers and appetite-related hormones in adolescents with overweight or obesity.

Methods and analysis

A randomized clinical trial was performed on 64 adolescents with overweight and obesity, who were randomly allocated to receive chitosan supplementation (n = 32) or placebo as control (n = 32) for 12 weeks. Anthropometric measures, lipid and glycemic profiles, and appetite-related hormones were examined.

Results

Sixty-one participants completed study (chitosan = 31, placebo = 30). Chitosan supplementation significantly improved anthropometric indicators of obesity (body weight: − 3.58 ± 2.17 kg, waist circumference: − 5.00 ± 3.11 cm, and body mass index: − 1.61 ± 0.99 kg/m² and − 0.28 ± 0.19 Z-score), lipid (triglycerides: − 5.67 ± 9.24, total cholesterol: − 14.12 ± 13.34, LDL-C: − 7.18 ± 10.16, and HDL-C: 1.83 ± 4.64 mg/dL) and glycemic markers (insulin: − 5.51 ± 7.52 μIU/mL, fasting blood glucose: − 5.77 ± 6.93 mg/dL, and homeostasis model assessment of insulin resistance: − 0.24 ± 0.44), and appetite-related hormones (adiponectin: 1.69 ± 2.13 ng/dL, leptin − 19.40 ± 16.89, and neuropeptide Y: − 41.96 ± 79.34 ng/dL). When compared with the placebo group, chitosan supplementation had greater improvement in body weight, body mass index (kg/m² and Z-score), waist circumference, as well as insulin, adiponectin, and leptin levels. Differences were significant according to P-value < 0.05.

Conclusion

Chitosan supplementation can improve cardiometabolic parameters (anthropometric indicators of obesity and lipid and glycemic markers) and appetite-related hormones (adiponectin, leptin, and NPY) in adolescents with overweight or obesity.

Proximate, Mineral and Vitamin Analysis of Rebon Shrimp Diversification Products as an Indonesian Local Product: Supplementary Food for Malnourished Children

Background: Rebon shrimp (Acetes sp.) is a local food in the coastal areas of Southeast Asia that has good nutritional potential. It is a nutrient-rich food, high in protein, and beneficial to human health, but the utilization of rebon shrimp is still very low. Aims: This study aims to measure the proximate and mineral analysis of various rebon shrimp products that can be used as supplementary food, expected to be popularly used and consumed by the Indonesian people, particularly those of low economic income. Methods: The diversified products in this study are meatballs, floss, nuggets, fish sticks, and fish cakes made from Rebon Shrimp (Acetes sp.). The proximate levels were analyzed referring to the AOAC method, The mineral content Fe and Zn were analyzed using the AAS method. The Vitamins A and Vitamin C were determined by spectrophotometric methods and titrimetry methods. Results: This study revealed that rebon shrimp could be used in making children's healthy snacks. Snacks with rebon shrimp contributed to moisture (8.79 – 72.58 %), ash (5.06 – 10.29%), crude protein (20.41 – 27.93 %), crude fat (3.09 – 47.16%), and crude fiber (0.35 – 3.36 %). In addition, these foods also contained several important minerals and vitamins for the body, such as iron (9.47– 56.13 ppm), zinc (4.05– 40.02 ppm), Vitamin A (0.016 – 0.045%), and vitamin C (0.11 – 0.19%). Conclusion: Thus, rebon shrimp is potentially used as an alternative to local ingredients to improve the nutritional quality of children's food.

Chitosan as a Valuable Biomolecule from Seafood Industry Waste in the Design of Green Food Packaging

Chitosan is a versatile biomolecule with a broad range of applications in food and pharmaceutical products. It can be obtained by the alkaline deacetylation of chitin. This biomolecule can be extracted using conventional or green methods from seafood industry residues, e.g., shrimp shells. Chitin has limited applications because of its low solubility in organic solvents. Chitosan is soluble in acidified solutions allowing its application in the food industry. Furthermore, biological properties, such as antioxidant, antimicrobial, as well as its biodegradability, biocompatibility and nontoxicity have contributed to its increasing application as active food packaging. Nevertheless, some physical and mechanical features have limited a broader range of applications of chitosan-based films. Green approaches may be used to address these limitations, leading to well-designed chitosan-based food packaging, by employing principles of a circular and sustainable economy. In this review, we summarize the properties of chitosan and present a novel green technology as an alternative to conventional chitin extraction and to design environmentally friendly food packaging based on chitosan.

Low molecular weight chitosan oligosaccharides (LMW-COSs) prevent obesity-related metabolic abnormalities in association with the modification of gut microbiota in high-fat diet (HFD)-fed mice

In this study, the two enzymatic low molecular weight chitosan oligosaccharides (LMW-COSs), LMW-COS-H and LMW-COS-L, were prepared with average MWs of 879.6 Da and 360.9 Da, respectively. Compared to LMW-COS-L, the LMW-COS-H was more effective in improving high-fat diet (HFD)-induced metabolic abnormalities, such as obesity, hyperlipidemia, low-grade inflammation and insulin resistance. The subsequent analysis of gut microbiota showed that the supplement of LMW-COSs caused overall structural and genus/species-specific changes in the gut microbiota, which were significantly correlated with the metabolic parameters. Specifically, both of the LMW-COSs significantly decreased the relative abundance of inflammatory bacteria such as Erysipelatoclostridium and Alistipes, whereas that of the beneficial intestinal bacteria (such as Akkermansia and Gammaproteobacteria) increased significantly. This study suggested that there were potential prebiotic functions of LMW-COSs in HFD fed mice, which regulated the dysfunctional gut microbiota, alleviated low-grade inflammation and maintained the intestinal epithelial barrier.

Chitosan modifies glycemic levels in people with metabolic syndrome and related disorders: meta-analysis with trial sequential analysis

BACKGROUND

Chitosan supplementation has been shown to modulate glycemic levels; however, studies have reported conflicting results. The present meta-analysis with trial sequential analysis was conducted to verify the overall influence of chitosan on glycemic levels in patients with metabolic syndrome.

METHODS

The PubMed, Cochrane library, and EMBASE databases were systematically searched for randomized controlled studies of chitosan intake and glycemic levels.

RESULTS

A total of ten clinical trials including 1473 subjects were included in this meta-analysis. Pooled effect sizes were determined by random-effects meta-analysis. Subgroup analysis was performed to analyze the sources of heterogeneity and their influence on the overall results. The results revealed a significant reduction in fasting glucose levels (SMD: - 0.39 mmol/L, 95% CI: - 0.62 to - 0.16) and hemoglobin A1c (HbA1c) levels (SMD: -1.10; 95% CI: - 2.15 to - 0.06) following chitosan supplementation but no effect on insulin levels (SMD: - 0.20 pmol/L, 95% CI: - 0.64 to 0.24). Subgroup analyses further demonstrated significant reductions in fasting glucose levels in subjects administered 1.6-3 g of chitosan per day and in studies longer than 13 weeks. Trial sequential analysis of the pooled results of the hypoglycemic effect demonstrated that the cumulative Z-curve crossed both the conventional boundary and trial sequential monitoring boundary for glucose and HbA1c.

CONCLUSIONS

The glucose level of patients who are diabetic and obese/overweight can be improved by supplementation with chitosan for at least 13 weeks at 1.6-3 g per day. Additional clinical research data are needed to confirm the role of chitosan, particularly in regulating glycosylated hemoglobin and insulin.

Chitosan alleviated menopausal symptoms and modulated the gut microbiota in estrogen-deficient rats

PURPOSE

Menopause disturbs energy, glucose, and lipid metabolisms and changes the composition of the gut microbiota, but dietary fibers without phytoestrogens may ameliorate menopausal metabolic disorders. The objective of the present study was to assess whether consuming the prebiotics chitosan and citrus pectin can improve postmenopausal symptoms, possibly by modulating the gut microbiota in ovariectomized (OVX) rats, and the mechanism of action was examined.

METHODS

The OVX rats were given 4.5% cellulose (OVX-Control), chitosan (OVX-Chitosan), or citrus pectin (OVX-Pectin) in a 43% fat diet and the sham rats were given the same diet as the OVX-Control for 12 weeks. Sham-operated rats had the same diet as OVX-Control (Normal-Control). Body-weight, visceral fat mass, tail skin temperature, serum 17β-estradiol, glucose intolerance, and insulin tolerance were determined. Gut microbiota in the fecal samples was measured by NGS and analyzed with PICRUSt2. Short-chain fatty acids (SCFA) and metabolomic characteristics of serum were also measured with UPLC-mass spectrometry.

RESULTS

Chitosan and citrus pectin were selected because the incubation of rat feces with these two prebiotics in vitro had shown increased butyrate production. OVX-Chitosan reduced the weight, visceral fat content, and tail skin temperature, and OVX-Chitosan and OVX-Pectin improved glucose tolerance, compared to the OVX-Control. Both alleviated dyslipidemia, compared to the OVX-Control. OVX-Chitosan and OVX-Pectin elevated serum propionate and butyrate concentrations but only OVX-Chitosan lowered serum acetate concentrations. In PICRUSt2, chitosan upregulated the functional genes of gut microbiota involved in valine, leucine, and isoleucine biosynthesis, whereas the OVX-Control exhibited significantly upregulated lipopolysaccharide biosynthesis. OVX-Pectin exhibited increased α-diversity in the fecal bacteria. Metabolomic analysis revealed higher serum urate concentrations in the OVX-Control group than the other groups, and serum arginine and leucine concentrations were higher in the OVX-Chitosan group (P < 0.05).

CONCLUSION

Chitosan and citrus pectin consumptions improved menopausal symptoms by improving the diversity and composition of the gut microbiota, and serum metabolites and SCFA originating from fecal bacteria. Chitosan was more effective for improving menopausal symptoms than citrus pectin.

Borassus aethiopum-Fortified Bread Reduces Metabolic Risk Factors among Cardiovascular Disease Outpatients at 37 Military Hospital, Accra: A Pilot Study

Background

Dyslipidemia and hypertension are the leading causes of morbidity and mortality in patients with cardiovascular diseases (CVDs).

Objective

The study sought to evaluate the effects of Borassus aethiopum-fortified bread on metabolic risk factors among CVD outpatients.

Method

From August 2016 to April 2017, a pilot study using a single-blinded randomized placebo-controlled trial was conducted by administering Borassus-fortified bread (150 g) and indistinguishable placebo (150 g white flour bread) daily to 122 CVD outpatients at 37 Military Hospital, Accra, Ghana, for 90 days. Body composition, blood pressure, and biochemical parameters were evaluated before and after the intervention.

Results

Following the intervention, the mean waist circumference (before: 98.3 ± 14.6 cm, after: 95.9 ± 15.8 cm, P = 0.030), BMI (before: 31.4 ± 6.9 kg/m², after: 28.0 ± 5.8 kg/m², P = 0.027), and visceral fat (before: 10.4 ± 3.2, after: 9.9 ± 3.0, P = 0.013), as well as systolic (from 161.2 ± 25.5 to 137.6 ± 22.9and diastolic (from 99.2 ± 13.6 to 85.1 ± 10.8) blood pressure, were significantly reduced among the experimental group. Likewise, serum total cholesterol (TC), LDL, and HDL were significantly reduced within the experimental group before (TC: 5.9 ± 1.1, LDL: 3.4 ± 1.1, and HDL: 2.2 ± 0.5) and after the intervention (TC: 4.9 ± 1.1, LDL: 2.8 ± 0.9, and HDL: 1.5 ± 0.4) (TC: P = 0.001, LDL: P = 0.016, and HDL: P < 0.001, in mmol/L). These reductions were not observed in the controls.

Conclusion

The Borassus-fortified bread significantly reduced blood pressure and improved lipid profile and other metabolic risk factors among the CVD outpatients studied. Therefore, its potential in the management of CVDs and other metabolic-related diseases should be looked at.

Regular Consumption of Lipigo® Promotes the Reduction of Body Weight and Improves the Rebound Effect of Obese People Undergo a Comprehensive Weight Loss Program

Obesity is a global public health problem. Objective: To evaluate the effect of the regular consumption of the product Lipigo^® on body weight and rebound effect on overweight/obese subjects undergoing a comprehensive weight loss program. Methods: A randomized, parallel, double-blind, placebo-controlled clinical trial was conducted with male and female subjects presenting a BMI 25–39.9 kg/m². All subjects underwent a comprehensive weight loss program (WLP) for 12 weeks, which included an individualized hypocaloric diet, physical activity recommendations, nutritional education seminars, and three times a day consumption of the product Lipigo^® or Placebo. After-WLP, subjects continued the treatment for 9 months to assess rebound effect. Body weight (BW), BMI, and body composition were measured at the beginning and the end of the WLP, and in the follow-up. Results: A total of 120 subjects (85% women) 49.0 ± 9.5 years old and with a BW of 81.57 ± 13.26 kg (BMI 31.19 ± 3.44 kg/m²) were randomized and 73 subjects finished the study. At the end of the WLP, there was a tendency toward reduced BW (p = 0.093), BMI (p = 0.063), and WC (p = 0.059) in the treated group. However, subjects with obesity type 1 (OB1) from the treated group significantly reduced body weight (−5.27 ± 2.75 vs. −3.08 ± 1.73 kg; p = 0.017) and BMI (−1.99 ± 1.08 vs. −1.09 ± 0.55 kg/m²; p = 0.01) compared with placebo. They also presented a minor rebound effect after 9 months with product consumption (−4.19 ± 3.61 vs. −1.44 ± 2.51 kg; p = 0.026), minor BMI (−1.61 ± 1.43 vs. −0.52 ± 0.96 kg/m²; p = 0.025) and tended to have less fat-mass (−3.44 ± 2.46 vs. −1.44 ± 3.29 kg; p = 0.080) compared with placebo. Conclusions: The regular consumption of the product Lipigo^® promotes the reduction of body weight and reduces the rebound effect of obese people after 52 weeks (12 months), mainly in obesity type 1, who undergo a comprehensive weight loss program.

The effects of chitosan supplementation on body weight and body composition: a systematic review and meta-analysis of randomized controlled trials

Although several clinical trials studied the efficacy of chitosan on weight loss, controversial results have been found. Herein, we evaluated randomized controlled trials (RCTs) of chitosan consumption in adult participants on body weight and body composition through a meta-analysis with trial sequential analysis (TSA). We searched EMBASE, MEDLINE, Web of Science, and CENTRAL databases. The primary body composition indices including body weight, body mass index (BMI), waist circumference, body fat, and hip circumference were extracted. The quality of included articles was assessed according to the Cochrane risk of bias tool. Data were pooled using the random-effects models and calculated as weighted mean difference (WMD) with 95% confidence intervals (CI). Heterogeneity investigated using I² statistics. TSA, subgroup analyses, sensitivity analysis, meta-regression and publication bias were also evaluated. Overall, 15 eligible trials (18 treatment arms) with 1130 subjects were included. The pooled analyses revealed a significant reduction in body weight (WMD, -0.89 kg; 95% CI, -1.41 to -0.38; P = 0.0006), BMI (WMD, -0.39 kg/m²; 95% CI, -0.64 to -0.14; P = 0.002) and body fat (WMD, -0.69%; 95% CI, -1.02 to -0.35; P = 0.0001) receiving chitosan supplementation. Subgroup analyses also showed that consuming chitosan in dose (>2.4 g/d), shorter-term (<12 weeks), studies with parallel design and studies including participants with obese or overweight had positive effects on body composition. TSA provided conclusive evidence for the benefit of chitosan supplementation. Our findings provided evidence that chitosan consumption might be a useful adjunctive pharmacological therapeutic tool for body weight management particularly in overweight/obese participants. Further well-constructed clinical trials that target body weight and body composition as their primary outcomes are needed.

A Meta-Analysis on Randomised Controlled Clinical Trials Evaluating the Effect of the Dietary Supplement Chitosan on Weight Loss, Lipid Parameters and Blood Pressure

Background and objectives: Erratic results have been published concerning the influence of the dietary supplement chitosan used as a complementary remedy to decrease the body weight of overweight and obese people. The published articles mention as secondary possible benefits of usage of chitosan the improvement of blood pressure and serum lipids status. We performed a meta-analysis evaluating body weight, body mass index, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressure among overweight and obese patients. Materials and Methods: Searching MEDLINE, Cochrane up to December 2017 on clinical trials that have assessed the influence of chitosan used as a dietary supplement on overweight and obese patients. An additional study was identified in the References section of another meta-analysis. A total of 14 randomised control trials (RCT) were used to assess the effect on body weight, serum lipids and blood pressure. Results: The usage of chitosan as a dietary supplement up to 52 weeks seems to slightly reduce the body weight (-1.01 kg, 95% CI: -1.67 to -0.34). Considering the other parameters studied, the most significant improvement was observed in systolic and diastolic blood pressure: -2.68 mm Hg (95% CI: -4.19 to -1.18) and -2.14 mm Hg (95% CI: -4.14 to -0.14) in favour of chitosan versus a placebo. Conclusions: Based on the meta-analysis realized with 14 RCT we concluded that the usage of chitosan as a dietary supplement can lead to a slight short- and medium-term effect on weight loss and to the improvement of serum lipid profile and cardiovascular factors.

Lipid-Modifying Effects of Chitosan Supplementation in Humans: A Pooled Analysis with Trial Sequential Analysis

SCOPE

We performed a pooled analysis with trial sequential analysis (TSA) to evaluate the efficacy and safety of chitosan supplementation on serum lipids in humans.

METHODS AND RESULTS

Medline, EMBASE, and CENTRAL databases were queried. Impact was expressed as a weighted mean difference (WMD) and 95% confidence interval (CI). Sensitivity analysis was conducted using the leave-one-out method. Statistical heterogeneity, publication bias, TSA, and subgroup analyses were also assessed. Fourteen trials (21 treatment arms) encompassing 1108 participants were suitable for statistical pooling. Chitosan supplementation significantly improved the total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations in all patients. The WMDs were -0.20 mmol L^-1 (95% CI, -0.35 to -0.05; p = 0.009) for TC, and -0.20 mol L^-1 (95% CI, -0.26 to -0.15; p = 0.0001) for LDL-C, respectively. TSA demonstrated that the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit providing conclusive evidence for the benefit of chitosan. However, no significant changes were seen with high-density lipoprotein cholesterol (HDL-C) and triglycerides. Our findings were robust after sensitivity analyses, and no serious adverse events were reported with chitosan intake.

CONCLUSION

Supplementation with chitosan effectively reduces plasma concentrations of TC and LDL-C. Current evidence indicates daily chitosan supplementation as a candidate for therapeutic lipid management strategies.

Protective Effect of Chitosan Oligosaccharides Against Cyclophosphamide-Induced Immunosuppression and Irradiation Injury in Mice

Chitosan oligosaccharides (COS), hydrolyzed products of chitosan, was found to display various biological activities. Herein, we assessed the immunostimulatory activity of COS both in in vitro and in vivo studies. In vitro cytotoxicity studies to murine macrophage RAW264.7 revealed that COS is safe even at the maximum tested concentration of 1000 μg/mL. It also stimulates the production of nitric oxide (NO) and tumor necrosis factor (TNF-α) and enhances the phagocytosis in COS-stimulated RAW264.7. We have shown that the COS could significantly (P < 0.05) restore the reduced immune organs indices, phagocytic index, lymphocyte proliferation, natural killer cell activity, and antioxidant enzyme activities in a cyclophosphamide-induced immunosuppressed mice model. COS can also improve the survival rate in irradiation injury mice and significantly (P < 0.05) increased the spleen indices and up-regulates the CD4+/CD8+ ratio in splenocytes. In sum, the aforementioned results suggest that COS might has the potential to be used as an immunostimulatory agent in patients with immune dysfunctions or be a model for functional food development.

PRACTICAL APPLICATION

COS might has the potential to be used as an immunostimulatory agent in patients with immune dysfunctions or be a model for functional food development.

Effects of isolated soluble fiber supplementation on body weight, glycemia, and insulinemia in adults with overweight and obesity: a systematic review and meta-analysis of randomized controlled trials

Background: There is strong epidemiologic evidence that dietary fiber intake is protective against overweight and obesity; however, results of intervention studies have been mixed. Soluble fiber beneficially affects metabolism, and fiber supplementation may be a feasible approach to improve body composition and glycemia in adults with overweight and obesity.Objective: We evaluated randomized controlled trials (RCTs) of isolated soluble fiber supplementation in overweight and obese adults on outcomes related to weight management [body mass index (BMI; in kg/m²), body weight, percentage of body fat, and waist circumference] and glucose and insulin metabolism (homeostasis model assessment of insulin resistance and fasting insulin) through a systematic review and meta-analysis.Design: We searched PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature and Cochrane Library databases. Eligible studies were RCTs that compared isolated soluble fiber with placebo treatments without energy-restriction protocols. Random-effects models were used to estimate pooled effect sizes and 95% CIs. Meta-regressions were performed to assess outcomes in relation to the intervention duration, fiber dose, and fiber type. Publication bias was assessed via Begg's and Egger's tests and funnel plot inspection.Results: Findings from 12 RCTs (n = 609 participants) from 2 to 17 wk of duration are summarized in this review. Soluble fiber supplementation reduced BMI by 0.84 (95% CI: -1.35, -0.32; P = 0.001), body weight by 2.52 kg (95% CI: -4.25, -0.79 kg; P = 0.004), body fat by 0.41% (95% CI: -0.58%, -0.24%; P < 0.001), fasting glucose by 0.17 mmol/L (95% CI: -0.28, -0.06 mmol/L; P = 0.002), and fasting insulin by 15.88 pmol/L (95% CI: -29.05, -2.71 pmol/L; P = 0.02) compared with the effects of placebo treatments. No publication bias was identified. Considerable between-study heterogeneity was observed for most outcomes.Conclusions: Isolated soluble fiber supplementation improves anthropometric and metabolic outcomes in overweight and obese adults, thereby indicating that supplementation may improve fiber intake and health in these individuals. However, the interpretation of these findings warrants caution because of the considerable between-study heterogeneity. This trial was registered at clinicaltrials.gov as NCT03003897.

Functional Comparison for Lipid Metabolism and Intestinal and Fecal Microflora Enzyme Activities between Low Molecular Weight Chitosan and Chitosan Oligosaccharide in High-Fat-Diet-Fed Rats

The present study investigated and compared the regulatory effects on the lipid-related metabolism and intestinal disaccharidase/fecal bacterial enzyme activities between low molecular weight chitosan and chitosan oligosaccharide in high-fat-diet-fed rats. Diet supplementation of low molecular weight chitosan showed greater efficiency than chitosan oligosaccharide in suppressing the increased weights in body and in liver and adipose tissues of high-fat-diet-fed rats. Supplementation of low molecular weight chitosan also showed a greater improvement than chitosan oligosaccharide in imbalance of plasma, hepatic, and fecal lipid profiles, and intestinal disaccharidase activities in high-fat-diet-fed rats. Moreover, both low molecular weight chitosan and chitosan oligosaccharide significantly decreased the fecal microflora mucinase and β-glucuronidase activities in high-fat-diet-fed rats. These results suggest that low molecular weight chitosan exerts a greater positive improvement than chitosan oligosaccharide in lipid metabolism and intestinal disaccharidase activity in high-fat-diet-induced obese rats.

Chitosan dosage regimen to trap fecal oil excretion after peroral lipase inhibitor administration in mice

This study was designed to investigate the oil entrapment and systemic oil absorption-reducing activities of chitosan. High-molecular-weight chitosan formed gel aggregates with oil and bile salts in vitro. The oil/chitosan ratio and the molecular weight of chitosan were optimized for the in vivo study, and a molecular weight >100,000 was effective in reducing the oil contamination of mouse fur. The oil/chitosan weight ratio required for effective oil entrapment was less than 13 and 5 in the in vitro and in vivo experiments, respectively. Chitosan administration was most effective during meals, and high-molecular-weight chitosan could trap and facilitate the reduction of systemic absorption of oil droplets separated by orlistat. The activity of the lipase inhibitor was not altered by chitosan as evidenced by thin layer chromatography, and orlistat was not absorbed systemically by the co-administration of chitosan.

Chitosan oligosaccharide: Biological activities and potential therapeutic applications

Chitosan oligosaccharide (COS) is an oligomer of β-(1➔4)-linked d-glucosamine. COS can be prepared from the deacetylation and hydrolysis of chitin, which is commonly found in the exoskeletons of arthropods and insects and the cell walls of fungi. COS is water soluble, non-cytotoxic, readily absorbed through the intestine and mainly excreted in the urine. Of particular importance, COS and its derivatives have been demonstrated to possess several biological activities including anti-inflammation, immunostimulation, anti-tumor, anti-obesity, anti-hypertension, anti-Alzheimer's disease, tissue regeneration promotion, drug and DNA delivery enhancement, anti-microbial, anti-oxidation and calcium-absorption enhancement. The mechanisms of actions of COS have been found to involve the modulation of several important pathways including the suppression of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPK) and the activation of AMP-activated protein kinase (AMPK). This review summarizes the current knowledge of the preparation methods, pharmacokinetic profiles, biological activities, potential therapeutic applications and safety profiles of COS and its derivatives. In addition, future research directions are discussed.