Chitosan attenuates obesity by modifying the intestinal microbiota and increasing serum leptin levels in mice

Scutellaria baicalensis Georgi alleviates Clostridium difficile associated diarrhea and its modulatory effects on the gut microbiota

The growing incidence of Clostridium difficile associated diarrhea (CDAD) underscores the urgency for potent treatments. This research delves into the therapeutic potential of Scutellaria baicalensis Georgi (Lamiaceae) root (SR) in addressing CDAD and its influence on gut microbiota. Using a CDAD mouse model and fidaxomicin as a control, SR's impact was measured through diarrhea symptoms, colonic histopathology, and C. difficile toxin levels. Employing the PacBio platform, 16S rRNA full-length gene sequencing analyzed the gut microbial composition and the effect of SR. Results revealed SR considerably alleviated diarrhea during treatment and restoration phases, with a marked decrease in colonic inflammation. C. difficile toxin levels dropped significantly with SR treatment (P < 0.001). While SR didn't augment gut microbiota's overall abundance, it enhanced its diversity. It restored levels of Proteobacteria and Bacteroidetes, reduced Akkermansia spp. and Enterococcus spp. proportions, and modulated specific bacterial species' abundance. In essence, SR effectively mitigates CDAD symptoms, curtails inflammatory reactions, and beneficially restructures gut microbiota, suggesting its potential in advanced CDAD clinical intervention.

Green Ca-source of cockle shells converted to calcium acetate for environmental sustainability

This work aimed to synthesize and characterize the calcium acetate monohydrate (Ca(CH3COO)2·H2O) from the exothermic reaction between CaCO3 powder derived from cockle shells with three different acetic acids (8, 10, and 12 mol L-1) concentrations by the rapid and easy process without pH and temperature control to lead to cheap chemical production. The physicochemical characteristics of all synthesized Ca(CH3COO)2·H2O samples are investigated based on the chemical compositions, crystal structures, vibrational characteristics, morphologies, and thermal behavior to confirm the target compound. A suitable concentration of 10 mol L-1 CH3COOH was chosen to produce Ca(CH3COO)2·H2O with the highest yield (96.30 %), maximum calcium content (96.2 % CaO) with lower impurities, and time consumption of 17 h. The calcium acetate product obtained from cockle shells in this work shows differences in thermal stability, morphological structure purity, %yield, and metal contamination with those reported obtained from other sources and another shell type in the previous work. This research investigates the transformation of cockle shell waste into CaCO3 for the production of calcium acetate, aiming to address environmental sustainability concerns by reducing the use of calcium ore resources and greenhouse gas emissions.

Metabolites of Clostridium leptum fermenting flaxseed polysaccharide alleviate obesity in rats

Obesity is a chronic metabolic disease. Our previous research found flaxseed polysaccharide (FP) has an anti-obesity effect, and its anti-obesity effect possibly depends on Clostridium leptum (C. leptum). However, whether the strain takes the role and how it works is still being determined. Here, FP was fermented in vitro by C. leptum and its metabolites were analyzed. Subsequently, the FP fermentation broth of C. leptum (FPF) was given to the obese pseudo sterile rats. The results showed FPF was rich in various metabolites, among which the top ten in relative expression abundance were 3 beta-hydroxy-5-cholestenoate, 7,8-dihydro-3b,6a-dihydroxy-alpha-ionol 9-glucoside, Valyl-Serine, 2-amino-4-[(2-hydroxy-1-oxopropyl)amino]butanoic acid, Agavoside B, glycylproline, lycopersiconolide, armillaritin, Isoleucyl-Hydroxyproline and norethindrone acetate. After intervention with FPF, the weight, abdominal fat ratio, and total fat ratio of rats were significantly reduced and the lipid metabolism of them has been improved. This effect may be achieved by up regulating glucagon-like peptide-1 and adiponectin and further activating the AMP-activated protein kinase signaling pathway. This is the first experimental proof that FP exerts its anti-obesity effects through metabolites from C. leptum fermenting FP, not FP itself and the bacterial cells (debris) of C. leptum. It is also the first demonstration that FPF has a significant anti-obesity effect.

Recent advances in drug delivery systems based on natural and synthetic polymes for treating obesity

Obesity stands as a pervasive global public health issue, posing a formidable threat to human well-being as its prevalence continues to surge year by year. Presently, pharmacological treatment remains the favored adjunct strategy for addressing obesity. However, conventional delivery methods suffer from low bioavailability and the potential for side effects, underscoring the pressing need for more efficient and targeted delivery approaches. Recent research has delved extensively into emerging drug delivery systems employing polymers as carriers, with numerous preclinical studies contributing to the growing body of knowledge. This review concentrates on the utilization of natural polymers as drug delivery systems for the treatment of obesity, encompassing recent advancements in both natural and synthetic polymers. The comprehensive exploration includes an analysis of the advantages and disadvantages associated with these polymer carriers. The examination of these characteristics provides valuable insights into potential future developments in the field of drug delivery for obesity treatment.

Novel Lauric Acid-Butyric Structural Lipid Inhibits Inflammation: Small Intestinal Microbes May Be Important Mediators

SCOPE

Butyric acid (C4) and lauric acid (C12) are recognized as functional fatty acids, while the health benefits of the structural lipids they constitute remain unclear.

METHODS AND RESULTS

In this study, lauric acid-butyric structural lipid (SLBL ) is synthesized through ultrasound-assisted enzyme-catalyzed acidolysis and its health benefits are evaluated in a high-fat diet-induced obesity mouse model. SLBL and its physical mixture (MLBL ) do not significantly inhibit obesity in mice. However, SLBL treatment increases the ratio of n3/n6 fatty acids in the liver and improves obesity-induced hepatic lipid metabolism disorders. Furthermore, the expression of liver pro-inflammatory cytokines (interleukin [IL]-6, IL-1β, TNF-α) are significantly suppressed by SLBL , while the expression of anti-inflammatory cytokine (IL-10) is increased. Moreover, SLBL ameliorates the dysbiosis of small intestinal microbes induced by high-fat diet and regulates microbial community structure to be close to the control group. Especially, SLBL significantly alleviates the high-fat diet-induced decrease in Dubosiella and Bifidobacterium abundance. Correlation analysis reveals that SLBL treatment increases the abundance of microorganisms with potential anti-inflammatory function and decreases the abundance of potentially pathogenic bacteria.

CONCLUSION

In all, small intestinal microbes may be a significant bridge for the positive anti-inflammatory effects of SLBL , while the exact mechanism remains to be clarified.

Chitosan and its oligosaccharide accelerate colonic motility and reverse serum metabolites in rats after excessive protein consumption

Excessive protein consumption (EPC) could increase the gastrointestinal burden and impair gut motility. The present study was designed to explore the improvement of chitosan (CTS) and chitosan oligosaccharide (COS) on colonic motility and serum metabolites in rats after EPC. The results of in vivo experiments fully proved that CTS and COS could improve gut motility and reverse the serum metabolites in rats as indicated by LC-MS/MS analysis, and the COS group even showed a better effect than the CTS group. Furthermore, short-chain fatty acids (SCFAs), which could promote gut motility, were also increased to alleviate EPC-induced constipation after supplementation with CTS or COS. In addition, CTS and COS could decrease the concentration of ammonia in serum and down-regulate the levels of H2S and indole. In summary, the present study revealed that CTS and COS could produce SCFAs, improve the colonic motility in rats, reverse the levels of valine, adenosine, cysteine, 1-methyladenosine, indole, and uracil, and enhance aminoacyl-tRNA biosynthesis and valine, leucine and isoleucine degradation. The present study provides novel insights into the potential roles of CTS and COS in alleviating the adverse effects of EPC.

Polysaccharides affect the utilization of β-carotene through gut microbiota investigated by in vitro and in vivo experiments

This study aimed to evaluate the effects of six polysaccharides on the utilization of β-carotene from the perspective of gut microbiota using both in vitro simulated anaerobic fermentation systems and in vivo animal experiments. In the in vitro experiments, the addition of arabinoxylan, arabinogalactan, mannan, inulin, chitosan, and glucan led to a 31.07-79.12% decrease in β-carotene retention and a significant increase in retinol content (0.21-0.99-fold) compared to β-carotene alone. Among them, the addition of chitosan produced the highest level of retinol. In the in vivo experiments, mice treated with the six polysaccharides exhibited a significant increase (2.51-5.78-fold) in serum β-carotene content compared to the group treated with β-carotene alone. The accumulation of retinoids in the serum, liver, and small intestine increased by 13.56-21.61%, 12.64-56.27%, and 7.9%-71.69%, respectively. The expression of β-carotene cleavage enzymes was increased in the liver. Genetic analysis of small intestinal tissue revealed no significant enhancement in the expression of genes related to β-carotene metabolism. In the gut microbiota environment, the addition of polysaccharides generated more SCFAs and altered the structure and composition of the gut microbiota. The correlation analysis revealed a strong association between gut microbes (Ruminococcaceae and Odoribacteraceae) and β-carotene metabolism and absorption. Collectively, our findings suggest that the addition of polysaccharides may improve β-carotene utilization by modulating the gut microbiota.

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.

Traversing the diverse avenues of exopolysaccharides-based nanocarriers in the management of cancer

Exopolysaccharides are unique polymers generated by living organisms such as algae, fungi and bacteria to protect them from environmental factors. After a fermentative process, these polymers are extracted from the medium culture. Exopolysaccharides have been explored for their anti-viral, anti-bacterial, anti-tumor, and immunomodulatory effects. Specifically, they have acquired massive attention in novel drug delivery strategies owing to their indispensable properties like biocompatibility, biodegradability, and lack of irritation. Exopolysaccharides such as dextran, alginate, hyaluronic acid, pullulan, xanthan gum, gellan gum, levan, curdlan, cellulose, chitosan, mauran, and schizophyllan exhibited excellent drug carrier properties. Specific exopolysaccharides, such as levan, chitosan, and curdlan, have demonstrated significant antitumor activity. Moreover, chitosan, hyaluronic acid and pullulan can be employed as targeting ligands decorated on nanoplatforms for effective active tumor targeting. This review shields light on the classification, unique characteristics, antitumor activities and nanocarrier properties of exopolysaccharides. In addition, in vitro human cell line experiments and preclinical studies associated with exopolysaccharide-based nanocarriers have also been highlighted.

Marine Chitosan-Oligosaccharide Ameliorated Plasma Cholesterol in Hypercholesterolemic Hamsters by Modifying the Gut Microflora, Bile Acids, and Short-Chain Fatty Acids

This study evaluated the cholesterol-alleviating effect and underlying mechanisms of chitosan-oligosaccharide (COS) in hypercholesterolemic hamsters. Male hamsters (n = 24) were divided into three groups in a random fashion, and each group was fed one particular diet, namely a non-cholesterol diet (NCD), a high-cholesterol diet (HCD), and an HCD diet substituting 5% of the COS diet for six weeks. Subsequently, alterations in fecal bile acids (BAs), short-chain fatty acids (SCFAs), and gut microflora (GM) were investigated. COS intervention significantly reduced and increased the plasma total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) levels in hypercholesteremic hamsters. Furthermore, Non-HDL-C and total triacylglycerols (TG) levels were also reduced by COS supplementation. Additionally, COS could reduce and increase food intake and fecal SCFAs (acetate), respectively. Moreover, COS had beneficial effects on levels of BAs and GM related to cholesterol metabolism. This study provides novel evidence for the cholesterol-lowering activity of COS.

Application of functionalized chitosan in food: A review

Environmental and sustainability issues have received increasing attention in recent years. As a natural biopolymer, chitosan has been developed as a sustainable alternative to traditional chemicals such as food preservation, food processing, food packaging, and food additives due to its abundant functional groups and excellent biological functions. This review analyzes and summarizes the unique properties of chitosan, with a particular focus on the mechanism of action for its antibacterial and antioxidant properties. This provides a lot of information for the preparation and application of chitosan-based antibacterial and antioxidant composites. In addition, chitosan is modified by physical, chemical and biological modifications to obtain a variety of functionalized chitosan-based materials. The modification not only improves the physicochemical properties of chitosan, but also enables it to have different functions and effects, showing promising applications in multifunctional fields such as food processing, food packaging, and food ingredients. In the current review, applications, challenges, and future perspectives of functionalized chitosan in food will be discussed.

Shellfish industrial waste reuse

The global production of aquatic organisms has grown steadily in recent decades. This increase in production results in high volumes of by-products and waste, generally considered to be of low commercial value and part of them are consequently discarded in landfills or in the sea, causing serious environmental problems when not used. Currently, a large part of the reused aquaculture waste is destined for the feed industry. This generally undervalued waste presents an important source of bioactive compounds in its composition, such as: amino acids, carotenoids, chitin and its derivatives, fatty acids and minerals. These compounds are capable of offering numerous benefits due to their bioactive properties. However, the applicability of these compounds may be opportune in several other sectors. This review describes studies that seek to obtain and apply bioactive compounds from different sources of aquaculture waste, thus adding commercial value to these underutilized biomasses.HIGHLIGHTSVolume of aquaculture industrial waste from crustaceans and mollusks.Quantity and quality of bioactive components in aquaculture waste.Applications of recovered proteins, lipids, chitin, carotenoids and minerals.Future prospects for the destination of aquaculture waste.

Effects of arabinoxylan and chlorogenic acid on the intestinal microbiota in dextran sulfate sodium–treated mice

Dietary non-starch polysaccharides and phenolics are usually ingested at the same time. They are both regarded as prebiotics, and they regulate the intestinal microbiota through various mechanisms. Notably, however, reports of their combined or synergistic effects are rare. Arabinoxylan (AX), a polysaccharide, and chlorogenic acid (CA), a polyphenol, are widely consumed, and their effects on the microbiota have previously been discussed. In the present study, they were given to dextran sulfate sodium (DSS)–treated mice, separately and together, and the intestinal microbiota were investigated by high-throughput sequencing. The data showed that CA attenuated body weight loss, colon shortening, and histological damage in DSS-treated mice, while neither AX nor the AX+CA combination exhibited any ameliorating potential. AX+CA had less of a modulating effect on intestinal microbiota profiles than did CA. AX+CA administration increased the relative abundance of Flavonifractor, Coprobacillus, and Clostridium_XlVa, and decreased the abundance of Robinsoniella and Lactobacillus. Compared to AX and CA, AX+CA contributed to a more complicated shift in the biological functions of the intestinal microbiotaAX seemed to weaken the beneficial effects of CA, at least in the present experimental model of DSS-induced colitis. The combined effects and mechanisms of dietary polysaccharides and phenolic compounds on the intestinal microbiota and on overall health still need to be further investigated.

Crabs Marine Waste-A Valuable Source of Chitosan: Tuning Chitosan Properties by Chitin Extraction Optimization

Chitin extraction from crab shells was studied experimentally and optimized aiming to obtain chitosan with predefined deacetylation degree and molecular mass. To find out the optimum operating conditions that ensure the obtaining of a chitosan with highest deacetylation degree and specific molecular mass four parameters were varied: the concentration of NaOH and the temperature for deproteinization step, respectively HCl concentration and the number of acidic treatments for the demineralization stage. The experiment was carried on following Taguchi orthogonal array L9, and the best combination of factors was found using the desirability function approach. The optimization results showed that 5% NaOH concentration and low temperatures lead to a chitosan with high deacetylation degree. High molecular mass chitosan is obtained when a single step acidic treatment is used, while a chitosan with low molar mass is obtained for multiple acid contacts and higher HCl concentration.

Beneficial Effects of Anti-Inflammatory Diet in Modulating Gut Microbiota and Controlling Obesity

Obesity has consistently been associated with an increased risk of metabolic abnormalities such as diabetes, hyperlipidemia, and cardiovascular diseases, as well as the development of several types of cancer. In recent decades, unfortunately, the rate of overweight/obesity has increased significantly among adults and children. A growing body of evidence shows that there is a relationship between metabolic disorders such as obesity and the composition of the gut microbiota. Additionally, inflammation is considered to be a driving force in the obesity–gut microbiota connection. Therefore, it seems that anti-inflammatory nutrients, foods, and/or diets can play an essential role in the management of obesity by affecting the intestinal flora and controlling inflammatory responses. In this review, we describe the links between the gut microbiota, obesity, and inflammation, and summarize the benefits of anti-inflammatory diets in preventing obesity.

Polysaccharide from Salviae miltiorrhizae Radix et Rhizoma Attenuates the Progress of Obesity-Induced Non-Alcoholic Fatty Liver Disease through Modulating Intestinal Microbiota-Related Gut–Liver Axis

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide, thus treatments for it have attracted lots of interest. In this study, the Salviae miltiorrhizae Radix et Rhizoma (SMRR) polysaccharide was isolated by hot water extraction and ethanol precipitation, and then purified by DEAE anion exchange chromatography and gel filtration. With a high-fat-diet-induced obesity/NAFLD mouse model, we found that consumption of the SMRR polysaccharide could remarkably reverse obesity and its related progress of NAFLD, including attenuated hepatocellular steatosis, hepatic fibrosis and inflammation. In addition, we also reveal the potential mechanism behind these is that the SMRR polysaccharide could regulate the gut–liver axis by modulating the homeostasis of gut microbiota and thereby improving intestinal function.

Improved oral nutraceutical-based intervention for the management of obesity: pterostilbene-loaded chitosan nanoparticles

Aim: To formulate and assess the oral anti-obesity effect of polymeric-based pterostilbene (PS)-loaded nanoparticles. Methods: Pterostilbene-hydroxypropyl β-cyclodextrin inclusion complex loaded in chitosan nanoparticles (PS/HPβCD-NPs) were prepared and characterized in vitro. Cytotoxicity, pharmacokinetics and anti-obesity effects were assessed on Caco-2 cell line and high-fat-diet-induced obesity rat model, respectively. In vivo assessment included histological examination, protein and gene expression of obesity biomarkers in adipose tissues. Results: Safe PS/HPβCD-NPs were successfully prepared with improved bioavailability compared with free PS. PS/HPβCD-NPs showed an improved anti-obesity effect, as supported by histological examination, lipid profile, UCP1 gene expression and protein expression of SIRT1, COX2, IL-6 and leptin. Conclusion: Orally administered PS nanoparticles represent a new and promising anti-obesity strategy owing to the sustainable weight loss and minimal side effects; this may be of great socio-economic impact.

The Role of Gut Microbiota Modulation Strategies in Obesity: The Applications and Mechanisms

Nowadays, obesity is a leading public health problem worldwide. The growing prevalence of obesity significantly accounts for other cardio-metabolic diseases, including hypertension and diabetes. Several studies have shown that obesity is strongly associated with genetic, environmental, lifestyle, and dietary factors, especially the disordered profiles of gut microbiota (GM). The present review concluded mechanistic studies and potential correspondent treatments for obesity. Specifically, the anti-obesity effects of food-derived compounds manipulating GM were highlighted. The potential limitations of bioactive compounds on absorption in the intestinal tract were also discussed. Thus, the future direction of fecal microbiota transplantation (FMT) as an approach to support modulating host GM (considered to be a potential therapeutic target for obesity) was discussed. This review shed light on the role of GM modulation strategies for the prevention/treatment of obesity.

Chitosan and Chitooligosaccharide: The Promising Non-Plant-Derived Prebiotics with Multiple Biological Activities

Biodegradable chitin is the second-most abundant natural polysaccharide, widely existing in the exoskeletons of crabs, shrimps, insects, and the cell walls of fungi. Chitosan and chitooligosaccharide (COS, also named chitosan oligosaccharide) are the two most important deacetylated derivatives of chitin. Compared with chitin, chitosan and COS not only have more satisfactory physicochemical properties but also exhibit additional biological activities, which cause them to be widely applied in the fields of food, medicine, and agriculture. Additionally, due to their significant ability to improve gut microbiota, chitosan and COS are deemed prospective prebiotics. Here, we introduced the production, physicochemical properties, applications, and pharmacokinetic characteristics of chitosan and COS. Furthermore, we summarized the latest research on their antioxidant, anti-inflammatory, and antimicrobial activities. Research progress on the prebiotic functions of chitosan and COS is particularly reviewed. We creatively analyzed and discussed the mechanisms and correlations underlying these activities of chitosan and COS and their physicochemical properties. Our work enriched people's understanding of these non-plant-derived prebiotics. Based on this review, the future directions of research on chitosan and COS are explored. Collectively, optimizing the production technology of chitin derivatives and enriching understanding of their biological functions will shed more light on their capability to improve human health.

Advances in the treatment of inflammatory bowel disease: Focus on polysaccharide nanoparticulate drug delivery systems

The complex pathogenesis of inflammatory bowel disease (IBD) explains the several hurdles for finding an efficient approach to cure it. Nowadays, therapeutic protocols aim to reduce inflammation during the hot phase or maintain remission during the cold phase. Nonetheless, these drugs suffer from severe side effects or poor efficacy due to low bioavailability in the inflamed region of the intestinal tract. New protocols based on antibodies that target proinflammatory cytokines are clinically relevant. However, besides being expensive, their use is associated with a primary nonresponse or a loss of response following a long administration period. Accordingly, many researchers exploited the physiological changes of the mucosal barrier for designing nanoparticulate drug delivery systems to target inflamed tissues. Others exploited biocompatibility and relative affordability of polysaccharides to test their intrinsic anti-inflammatory and healing properties in IBD models. This critical review updates state of the art on advances in IBD treatment. Data on using polysaccharide nanoparticulate drug delivery systems for IBD treatment are reviewed and discussed.

Starch Microspheres Entrapped with Chitosan Delay In Vitro Fecal Fermentation and Regulate Human Gut Microbiota Composition

A slow dietary fiber fermentation rate is desirable to obtain a steady metabolite release and even distribution throughout the entire colon, ensuring to meet the energy needs in the distal colon. In this study, we prepared starch-entrapped microspheres with a variable chitosan-to-starch ratio by means of electrospraying and investigated the fermentability by human fecal microbiota in an in vitro batch system. Starch encapsulation reduced microbial gas production and the concentration of short-chain fatty acids. Butyrate production, in particular, gradually decreased with increasing chitosan proportions. Moreover, the starch and chitosan composites induced a synergistic effect on the gut microbiota composition. Roseburia, Lachnospiraceae, and Clostridiales were promoted by all of the microspheres, and the abundance of the aforementioned health-promoting taxa reached a maximum in chitosan/starch microspheres with a 1:6 (w/w) ratio. Our findings highlight the possible benefits of rationally designing functional foods targeting functional and taxonomic gut microbiota modulation.

The phytonutrient cinnamaldehyde limits intestinal inflammation and enteric parasite infection

Phytonutrients such as cinnamaldehyde (CA) have been studied for their effects on metabolic diseases, but their influence on mucosal inflammation and immunity to enteric infection are not well documented. Here, we show that consumption of CA in mice significantly down-regulates transcriptional pathways connected to inflammation in the small intestine, and alters T-cell populations in mesenteric lymph nodes. During infection with the enteric helminth Heligomosomoides polygyrus, CA treatment attenuated infection-induced changes in biological pathways connected to cell cycle and mitotic activity, and tended to reduce worm burdens. Mechanistically, CA did not appear to exert activity through a prebiotic effect, as CA treatment did not significantly change the composition of the gut microbiota. Instead, in vitro experiments showed that CA directly induced xenobiotic metabolizing pathways in intestinal epithelial cells and suppressed endotoxin-induced inflammatory responses in macrophages. Collectively, our results show that CA down-regulates inflammatory pathways in the intestinal mucosa and can limit the pathological response to enteric infection. These properties appear to be largely independent of the gut microbiota, and instead connected to the ability of CA to induce antioxidant pathways in intestinal cells. Our results encourage further investigation into the use of CA and related phytonutrients as functional food components to promote intestinal health in humans and animals.

Anti-Hyperlipidemia and Gut Microbiota Community Regulation Effects of Selenium-Rich Cordyceps militaris Polysaccharides on the High-Fat Diet-Fed Mice Model

Supplementation of polysaccharides is a promising gut microbiota-targeted therapeutic method for obesity and metabolic diseases. Biological activities of Cordyceps militaris polysaccharides have been well reported, but the effect of selenium (Se)-rich C. militaris polysaccharides (SeCMP) on obesity and associated metabolic disorder and gut microbiota composition has been rarely studied. This study aimed to investigate the anti-obesity and gut microbiota modulatory effect of crude polysaccharides separated from Se-rich C. militaris on a high-fat diet (HFD)-fed C57BL/6J mice model. Mice were treated with a normal diet (CHOW), HFD alone, HFD plus C. militaris polysaccharides (CMP), or low/medium/high dosage of SeCMP for 8 weeks. Body weight, fat content, serum lipid, appetite hormone, lipid gene expression, inflammation cytokines, thermogenic protein, short-chain fatty acids (SCFAs), and gut microbiota structure of the mice were determined. Compared with HFD-fed mice, the serum triglyceride and low-density lipoprotein cholesterol (LDL-C) in the SeCMP-200 group were decreased by 51.5% and 44.1%, respectively. Furthermore, serum lipopolysaccharide-binding proteins (LBP), adiponectin level, and pro-inflammation gene expression in the colon and subcutaneous fat were inhibited, whereas anti-inflammation gene expression was improved, reflecting SeCMP-200 might mitigate obese-induced inflammation. Meanwhile, SeCMP-200 promoted satiety and thermogenesis of obese mice. It also significantly decreased gut bacteria, such as Dorea, Lactobacillus, Clostridium, Ruminococcus, that negatively correlated with obesity traits and increased mucosal beneficial bacteria Akkermansia. There was no significant difference between CMP and SeCMP-100 groups. Our results revealed a high dose of SeCMP could prevent HFD-induced dyslipidemia and gut microbiota dysbiosis and was potential to be used as functional foods.

Biochemical and immunological changes in obesity

Obesity is a syndemia that promotes high expenditures for public health, and is defined by the excess of adipose tissue that is classified according to its function and anatomical distribution. In obese people, this tissue generates oxidative stress associated with a chronic inflammatory response, in which there is an imbalance in relation to the release of hormones and adipokines that cause loss of body homeostasis and predisposition to the development of some comorbidities. The purpose of this review is to summarize the main events that occur during the onset and progression of obesity with a special focus on biochemical and immunological changes. Hypertrophied and hyperplasia adipocytes have biomarkers and release adipokines capable of regulating pathways and expressing genes that culminate in the development of metabolic changes, such as changes in energy balance and intestinal microbiota, and the development of some comorbidities, diabetes mellitus, dyslipidemias, arterial hypertension, liver disease, cancer, allergies, osteoporosis, sarcopenia and obstructive sleep apnea. Thus, it is necessary to treat and/or prevent pathology, using traditional methods based on healthy eating, and regular physical and leisure activities.

Adipose Tissue Immunomodulation and Treg/Th17 Imbalance in the Impaired Glucose Metabolism of Children with Obesity

In the last few decades, obesity has increased dramatically in pediatric patients. Obesity is a chronic disease correlated with systemic inflammation, characterized by the presence of CD4 and CD8 T cell infiltration and modified immune response, which contributes to the development of obesity related diseases and metabolic disorders, including impaired glucose metabolism. In particular, Treg and Th17 cells are dynamically balanced under healthy conditions, but imbalance occurs in inflammatory and pathological states, such as obesity. Some studies demonstrated that peripheral Treg and Th17 cells exhibit increased imbalance with worsening of glucose metabolic dysfunction, already in children with obesity. In this review, we considered the role of adipose tissue immunomodulation and the potential role played by Treg/T17 imbalance on the impaired glucose metabolism in pediatric obesity. In the patient care, immune monitoring could play an important role to define preventive strategies of pediatric metabolic disease treatments.

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.

Highly Branched RG-I Domain Enrichment Is Indispensable for Pectin Mitigating against High-Fat Diet-Induced Obesity

Obesity is associated with gut microbiome dysbiosis. Our previous research has shown that highly branched rhamnogalacturonan type I (RG-I)-enriched pectin (WRP, 531.5 kDa, 70.44% RG-I, Rha/(Gal + Ara) = 20) and its oligosaccharide with less branched RG-I [DWRP, 12.1 kDa, 50.29% RG-I, Rha/(Gal + Ara) = 6] are potential prebiotics. The present study is conducted to uncover the impact of the content, molecular size, and branch degrees of RG-I on the inhibiting effect of high-fat diet (HFD)-induced obesity. The commercial pectin (CP, 496.2 kDa, 35.77% RG-I, Rha/(Gal + Ara) = 6), WRP, and DWRP were orally administered to HFD-fed C57BL/6J mice (100 mg kg^-1 d^-1) to determine their individual effects on obesity. WRP significantly prevented bodyweight gain, insulin resistance, and inflammatory responses in HFD-fed mice. No obvious anti-obesity effect was observed in either CP or DWRP supplementation. A mechanistic study revealed that CP and DWRP could not enhance the diversity of gut microbiota, while WRP treatment positively modulated the gut microbiota of obese mice by increasing the abundance of Butyrivibrio, Roseburia, Barnesiella, Flavonifractor, Acetivibrio, and Clostridium cluster IV. Furthermore, WRP significantly promoted browning of white adipose tissues in HFD-fed mice, while CP and DWRP did not. WRP can attenuate the HFD-induced obesity by modulation of gut microbiota and lipid metabolism. Highly branched RG-I domain enrichment is essential for pectin mitigating against the HFD-induced obesity.