Metabolites from specific intestinal bacteria in vivo fermenting Lycium barbarum polysaccharide improve collagenous arthritis in rats.

Rheumatoid arthritis (RA) is an autoimmune disease affected patients' quality of life severely. Our previous study found Lycium barbarum polysaccharide (LBP) alleviated RA, but it remains unknown whether gut microbiota is necessary for the alleviation. Here, RA models were established in rats with microbiota and rats treated by antibiotic cocktail, and LBP was applied for the intervention on rats. The biochemical test, 16S rDNA sequencing and metabolome analysis were applied to analyze the effects of LBP on gut microbiota, their metabolites and hosts. Results showed the LBP intervention improved RA by inhibiting pro-inflammatory cytokines IL-1α, IL-1ß, TNF-α and IL-6 only in rats with microbiota, but not in pseudo-germ-free rats. The abundance of specific bacteria, including Romboutsia, Lactobacillus, Turicibacter, Clostridium_sensu_stricto_1, Faecalibacterium and Adlercreutzia, and several metabolites, including O-desmethylangolensin, 3-hydroxydodecanedioic acid, N-formyl-L-methionine, suberic acid, (S)-oleuropeic acid, prolyl-histidine, 13,14-dihydro PGF-1a, (R)-pelletierine and short-chain fatty acids increased only in RA rats with microbiota after the intervention. Our results suggest that intestinal bacteria are necessary for LBP alleviating RA alleviation. The fermentation metabolite acts on the host instead of LBP itself, which may be the reason for the improvement of RA.

Flaxseed oil ameliorates aging in d-galactose induced rats via altering gut microbiota and mitigating oxidative damage.

BACKGROUND: Aging causes decreased antioxidant capacity and chronic inflammation and may even elevate cancer risks. Previous studies reported that flaxseed oil (FO) can alleviate age-related diseases, including improving alcoholic liver disease, atherosclerosis and diabetes. However, whether the intestinal microbiota accountable for this alleviation is still unknown. This study aims to study the antioxidant effects of FO in an aging rat model and the underlying mechanism between the intestinal microbiota and aging. RESULTS: Our results presented that serum and liver antioxidant capacities in FO group were up-regulated, and liver inflammation in FO group was reduced. The 16S rDNA sequencing showed that FO regulated the microbial community, including up-regulation of four families of Lactobacillus and six families of Clostridium. In addition, FO had also adjusted the relative abundance of several genera such as Ruminococcaceae_UCG-005 and Prevotella_9, which may be the key bacteria associated with the aging process. Colonic transcriptome analysis showed that there were 1679 differentially expressed genes (DEGs) in the Model group and the FO group (134 up-regulated and 1545 down-regulated). Gene set enrichment analysis (GSEA) revealed FO down-regulates the expression of the upstream genes Ptprc, Lck, Zap70, Lat and Lcp2 in the T cell receptor signaling pathway. CONCLUSION: In conclusion, FO improved antioxidant capacity and reduced intestinal microbial disturbances caused by aging damage, indicating that dietary FO has the potential to fight aging damage. This study provides a more comprehensive view of dietary intervention to improve aging. © 2022 Society of Chemical Industry.

Poria cocos polysaccharides attenuate chronic nonbacterial prostatitis by targeting the gut microbiota: Comparative study of Poria cocos polysaccharides and finasteride in treating chronic prostatitis.

Finasteride is an antiandrogenic drug used for the clinical treatment of chronic nonbacterial prostatitis (CNP). Recently, we reported the anti-CNP activity of Poria cocos polysaccharides (PPs) in a rat model. In this study, we compared the differences between PPs and finasteride in treating CNP, especially their effects on the gut microbiota. Results showed that both PPs and finasteride significantly reduced the prostate weight and prostate index of CNP rats, and improved the histological damages in the inflamed prostate. Moreover, PPs and finasteride inhibited the production of pro-inflammatory cytokines (TNF-α, IL-2 and IL-8) and androgens (dihydrotestosterone and testosterone). By 16S rDNA sequencing, PPs and finasteride were found to reprogram the gut microbiota into distinct profiles. Further analysis presented that PPs but not finasteride recovered CNP-induced changes in the gut microbiota, including Ruminococcaceae NK4A214 group, uncultured bacterium f Ruminococcaceae, Ruminiclostridium 9, Phascolarctobacterium, Coriobacteriaceae UCG-002 and Oribacterium. LDA effect size (LEfSe) analysis revealed that PPs recovered the gut microbiota by targeting Ruminococcaceae NK4A214 group. Our results suggested that PPs alleviated CNP via different mechanisms from finasteride, especially by regulating the gut microbiota, which offers therapeutic target for the treatment of CNP.

Reprogrammed intestinal functions in Astragalus polysaccharide-alleviated osteoporosis: combined analysis of transcriptomics and DNA methylomics demonstrates the significance of the gut-bone axis in treating osteoporosis.

Researchers have noted that organ-organ communication between bone and intestine has significant effects on bone health and its related diseases. In this study, we collected colonic epithelial tissue from dexamethasone-induced osteoporotic rats and Astragalus polysaccharide (APS)-alleviated osteoporotic rats and employed transcriptome sequencing to investigate the functional changes that occurred in the intestine. Principal component analysis showed that both dexamethasone (inducer of osteoporosis) and APS reprogrammed the gene expression profile of the intestine. Further analysis identified 496 and 291 differentially expressed genes (DEGs) in osteoporotic and APS-treated osteoporotic rats, respectively. KEGG enrichment analysis of these DEGs demonstrated osteoporosis-induced intestinal dysfunctions that were further modified by APS treatment. Further analysis demonstrated that APS could restore intestinal functions by reversing the expression of 53 DEGs in osteoporotic rats. Recovery of osteoclast differentiation and the calcium signalling pathway might contribute to the improvement of osteoporosis. Moreover, utilizing methylC-capture sequencing (MCC-Seq), we studied the changes in DNA methylation and performed epigenetic analysis of dexamethasone- and APS-induced gene expression changes. In this study, osteoporosis was observed to cause intestinal dysfunction, which is a complication of this disease. More importantly, APS was determined to reprogram intestinal functions to alleviate osteoporosis via the gut-bone axis. Our results support the existence of a gut-bone axis and suggest new therapeutic opportunities for the treatment of osteoporosis via the gut-bone axis.

Reprogrammed Epigenetic Landscape-Prophesied Functions of Bioactive Polysaccharides in Alleviating Diseases: A Pilot Study of DNA Methylome Remodeling in Astragalus Polysaccharide (APS)-Improved Osteoporosis in a Rat Model.

DNA methylation is an epigenetic event that plays critical roles in the pathogenesis, progression, and treatment of human diseases. In this study, we investigated the epigenetic mechanisms for Astragalus polysaccharide (APS)-improved osteoporosis in a rat model. The results showed that APS significantly changed the DNA methylome in colonic epithelia with great efficiency. Gene set enrichment analysis (GSEA) based on differentially methylated sites (DMSs) revealed that APS caused promoter DNA methylation changes of genes associated with calcium homeostasis, osteoclast/osteoblast balance, Wnt signaling, and hormone-related processes. Further analysis showed high consistency of APS-induced gene methylomic changes in colonic epithelia and its effects on diabetes, virus infection, and wound healing, which had been reported already. Moreover, we suggested new functions and the involved mechanisms of APS in heart disease, neurological disorder, reproductive problem, and olfactory dysfunction. In this study, we offered epigenetic mechanisms for APS-improved osteoporosis. More importantly, we proposed and proved a reliable method to explore the beneficial effects of bioactive polysaccharides by studying DNA methylation changes at nonfocal sites. We firmly believed the promising prospects of this method for its great efficiency, rapidness, and economy in exploring possible beneficial or therapeutic effects of functional macromolecules with one single experiment.

Recovery of Ggt7 and Ace Expressions in the Colon Alleviates Collagen-Induced Arthritis in Rats by Specific Bioactive Polysaccharide Intervention.

Rheumatoid arthritis (RA) causes swollen joints and irreversible joint damage and may even elevate cancer risks. Several bioactive nonstarch polysaccharides (NSPs) were reported to alleviate RA, but the key colonic genes accountable for this alleviation were elusive. Using collagen-induced arthritis as an RA model, colonic candidate genes related to RA were selected by transcriptome and methylome. The key genes were determined by comparing the transcriptome, methylome, and quantitative reverse transcription polymerase chain reaction profiles in RA rats with and without Lycium barbarum polysaccharides' treatment and further validated using Angelica sinensis polysaccharides and Astragalus propinquus polysaccharides for comparison. Both colonic genes γ-glutamyltransferase 7 (Ggt7) and angiotensin-I-converting enzyme (Ace) were downregulated by RA, and they were upregulated after L. barbarum polysaccharides' and A. sinensis polysaccharides' intervention that reduced the RA-caused hypermethylation status in nucleotide sites in the exon/promoter region of the two genes. However, the A. propinquus polysaccharides' intervention barely reduced the hypermethylation in the corresponding sites, failing to recover the expressions of these two genes and improve RA. Therefore, the colonic Ggt7 and Ace can be considered as key genes accountable for RA alleviation by bioactive NSP intervention. This study provides a more comprehensive insight into diet intervention to improve RA.

Poria cocos Polysaccharides Alleviates Chronic Nonbacterial Prostatitis by Preventing Oxidative Stress, Regulating Hormone Production, Modifying Gut Microbiota, and Remodeling the DNA Methylome.

Chronic nonbacterial prostatitis (CNP) is a common male disease with high incidence and low cure rate. This study aims to investigate the anti-CNP potential of Poria cocos polysaccharides (PPs) in a λ-carrageenan-induced CNP rat model. Results showed that PPs exerted anti-CNP functions by reducing the prostate weight and prostate index as well as the level of C-reactive protein (CRP) and pro-inflammatory cytokines (TNF-α and IL-1ß). Further analysis on sex hormones revealed that PPs could favor CNP alleviation by regulating the production of testosterone (T), dihydrotestosterone (DTH), and estradiol (E2). PPs could also alleviate CNP by regulating the level of inducible nitric oxide synthase (iNOS), malonaldehyde (MDA), and superoxide diamutase (SOD) in inflamed prostate, thereby enhancing the anti-oxidative stress activity. As most non-digestive polysaccharides are fermented by gut microbiota rather than being digested directly by the host, we further analyzed PP-induced changes in gut microbiota. Microbiomic analysis revealed that PPs significantly change the profile of gut microbiota. Moreover, the relative abundance of five genera was recovered by PPs with a dose-effect relationship, thereby being suggested to play critical roles in the alleviation of CNP. Epigenomic (methylomic) analysis showed that PPs remodeled the DNA methylome of intestinal epithelia, by which PPs might modify hormone production. In the present study, we reported the anti-CNP activity of PPs as well as the involved mechanisms.

Pectin and inulin stimulated the mucus formation at a similar level: An omics-based comparative analysis.

Mucin 2 (MUC2) is the skeleton of colonic mucus that comprises the physical intestinal barrier. Different dietary polysaccharides may affect colonic mucus at different extents. The effect of pectin on MUC2 production is contradictory. To investigate whether and how pectin affected hosts' colonic mucus, the amount of MUC2 in colon, the cecal, mucosal microbiota, and metabolites profiles were analyzed and compared with inulin. The results showed pectin stimulated the production of MUC2 at a similar level to inulin. Both interventions increased the abundance of cecal Lachnospira and Christensenellaceae_R-7_group, and enhanced the production of specific metabolites including soyasapogenol B 24-O-b-d-glucoside, lucyoside Q, trans-EKODE-(E)-Ib, and 1,26-dicaffeoylhexacosanediol. Additionally, pectin increased the relative abundance (RA) of cecal Lactobacillus, and induced less RA of potentially harmful bacteria such as Helicobacter in mucosal microbiota than inulin. In conclusion, we first reported that pectin and inulin stimulated the mucus formation at a similar level. Two genera of cecal bacteria and four metabolites may play an important role in enhancing the production of MUC2. Moreover, the MUC2 production may be unrelated to several traditional health-beneficial bacteria; pectin possibly performed as good as or better than the inulin in rats' gut.

Dietary Supplementation of n-3 LCPUFAs Prevents Salmonellosis in a Murine Model.

Salmonellosis is a world-wide epidemic, and n-3 long chain polyunsaturated fatty acids (LCPUFAs) possess various health benefits. This study is aimed to investigate the preventive effects of n-3 LCPUFAs against Salmonella infection. By pretreatment with n-3 LCPUFAs, but not n-6 LCPUFAs, the survival rate of the infected mice was increased. Further studies showed that n-3 LCPUFAs significantly increased the fecal contents of short-chain fatty acids (SCFAs). The cytokine expression in the liver and production in serum were both modulated by n-3 LCPUFAs into an anti-inflammatory profile against infection. Moreover, the changes in gut microbiota by n-3 LCPUFAs favored the host against pathogens, closely related to the modified SCFA production and immune responses. In conclusion, n-3 LCPUFAs prevented Salmonella infection through multiple mechanisms, especially by the interaction with gut microbiota and host immunology. Our results suggested great perspectives for n-3 LCPUFAs and their related products to control the prevalence of Salmonella, a most predominant food-borne pathogen.

Alliin alters gut microbiota and gene expression of colonic epithelial tissues.

Alliin is a natural organosulfur-containing phytochemical in garlic. It is possible that alliin can regulate the gut microbiota for its strong antimicrobial activity against many pathogens. Here, we assessed whether alliin impacts the distal small intestinal bacteria, hence the cecal microbiota, thus altering the gene expression of colonic epithelial tissues (CETs). Eighty mg/kg alliin was orally administered to rats for 14 days, and the 16S rDNA from small intestinal and cecal microbiota as well as mRNA from CETs were sequenced and analyzed. The results showed that alliin consumption affected microbiota composition in both the small intestine and cecum, although there was only one specific genus, Allobaculum that was significantly altered in the rat cecum. The altered composition of microbiota indirectly impacted 174 genes in the CETs. Specifically, five genes, including RT1-Ba, RT1-Bb, Cd80, Madcam1, and Aicda, indicated this consumption related to the intestinal immune network for IgA production. PRACTICAL APPLICATIONS: We firstly reported alliin consumption in vivo potentially affected the intestinal immunity of healthy rats by slightly alteration of microbiota composition in small intestine and cecum. The alteration subsequently amplified, resulting in the change of the colonic epithelial expression of several genes related to the intestinal immune network for IgA production. Hence, we suggested the alliin consumption may potentially affect the immune system of healthy individuals by alteration of gut microbiota and epithelial gene expression.

Antiobesity Effect of Flaxseed Polysaccharide via Inducing Satiety due to Leptin Resistance Removal and Promoting Lipid Metabolism through the AMP-Activated Protein Kinase (AMPK) Signaling Pathway.

Obesity is a metabolic syndrome worldwide that causes many chronic diseases. Recently, we found an antiobesity effect of flaxseed polysaccharide (FP), but the mechanism remains to be elucidated. In this study, rats were first induced to develop obesity by being fed a high-fat diet. The obese rats were then fed a control diet, AIN-93M (group HFD), or a 10% FP diet (group FPD). The body weight, body fat, adipose tissue and liver sections, serous total triglycerides, levels of fasting blood glucose in serum, serous insulin, inflammatory cytokines in serum, and serous proteins within the leptin-neuropeptide Y (NPY) and AMP-activated protein kinase (AMPK) signaling pathway were determined and analyzed. FP intervention significantly reduced body weight and abdominal fat from 530 ± 16 g and 2.15% ± 0.30% in group HFD to 478 ± 10 g and 1.38% ± 0.48% in group FPD, respectively. This effect was achieved by removing leptin resistance possibly by inhibiting inflammation and recovering satiety through the significant downregulation of NPY and the upregulation of glucagon-like peptide 1. Adiponectin was then significantly upregulated probably via the gut-brain axis and further activated the AMPK signaling pathway to improve lipid metabolism including the improvement of lipolysis and fatty acid oxidation and the suppression of lipogenesis. This is the first report of the proposed antiobesity mechanism of FP, thereby providing a comprehensive understanding of nonstarch polysaccharides and obesity.

Encapsulation of Vitamin E and Soy Isoflavone Using Spiral Dextrin: Comparative Structural Characterization, Release Kinetics, and Antioxidant Capacity during Simulated Gastrointestinal Tract.

Spiral dextrin subfraction (SD-40) obtained through enzyme debranching and gradient ethanol precipitation could interact with vitamin E (VE) or soy isoflavone (SIO) to form V-type inclusion complexes. The formation of two inclusion complexes was confirmed by Fourier transform-infrared spectroscopy, atomic force microscopy, and differential scanning calorimetry. In this study, an in vitro gastrointestinal model was used to investigate the breakdown of inclusion complexes and release behavior of bioactive compounds. The results indicated that the two inclusion complexes exhibited a controlled and sustained release behavior during digestion. In addition, the SD-40/VE inclusion complex presented higher stability and stronger antioxidant capacity than the SD-40/SIO inclusion complex. Furthermore, the first and zero order models were applied to understand the release kinetics of VE and SIO from inclusion complexes in the stomach, whereas the first order model was chosen to describe the release of VE and SIO from inclusion complexes in the intestine.

Catechin supplemented in a FOS diet induces weight loss by altering cecal microbiota and gene expression of colonic epithelial cells.

Our previous study showed that catechin controlled rats' body weights and changed gut microbiota composition when supplemented into a high-fructo-oligosaccharide (FOS) diet. This experiment is devised to further confirm the relationship between specific bacteria in the colon and body weight gain, and to investigate how specific bacteria impact body weight by changing the expression of colonic epithelial cells. Forty obese rats were divided into four groups: three catechin-supplemented groups with a high-FOS diet (100, 400, and 700 mg kg-1 d-1 catechin, orally administered) and one group with a high-FOS diet only. Food consumption and body weights were recorded each week. After one month of treatment, rats' cecal content and colonic epithelial cells were individually collected and analyzed with MiSeq and gene expression profiling techniques, respectively. Results identified some specific bacteria at the genus level-including the increased Parabacteroides sp., Prevotella sp., Robinsoniella sp., [Ruminococcus], Phascolarctobacterium sp. and an unknown genus of YS2, and the decreased Lachnospira sp., Oscillospira sp., Ruminococcus sp., an unknown genus of Peptococcaceae and an unknown genus of Clostridiales in rats' cecum-and eight genes-including one downregulated Pla2g2a and seven upregulated genes: Apoa1, Apoa4, Aabr07073400.1, Fabp4, Pik3r5, Dgat2 and Ptgs2 of colonic epithelial cells-that were due to the consumption of catechin. Consequently, various biological functions in connection with energy metabolism in colonic epithelial cells were altered, including fat digestion and absorption and the regulation of lipolysis in adipocytes. In conclusion, catechin induces host weight loss by altering gut microbiota and gene expression and function in colonic epithelial cells.

Structural changes of waxy and normal maize starches modified by heat moisture treatment and their relationship with starch digestibility.

In the present study, the variations in structure of waxy and normal maize starches modified by heat-moisture treatment (HMT) for different treating time (3h and 9h) were investigated. HMT caused the destruction of starch granules. The 1H NMR confirmed that glycosidic bonds were broken during HMT. The 13C NMR result suggested that HMT caused the transformation of starch granules from double and single helical components into amorphous components. Heat-moisture treated starches exhibited higher gelatinization temperature (To, Tp and Tc), narrower gelatinization temperature range (Tc-To) and lower gelatinization enthalpy (ΔH). HMT caused the rearrangement of starch molecules, degeneration of double helices and formation of new single helix. In addition, in vitro digestibility assessment indicated that the contents of rapidly digestible starch (RDS) and slowly digestible starch (SDS) were improved and resistant starch (RS) was reduced after HMT, which was related to the decrease of single and double helical components.

Phenolic Fractions from Muscadine Grape "Noble" Pomace can Inhibit Breast Cancer Cell MDA-MB-231 Better than those from European Grape "Cabernet Sauvignon" and Induce S-Phase Arrest and Apoptosis.

Tons of grape pomace which still contained a rich amount of plant polyphenols, is discarded after winemaking. Plant polyphenols have multi-functional activities for human body. In this study, polyphenols of pomaces from Muscadinia rotundifolia "Noble" and Vitis vinifera "Cabernet Sauvignon" were extracted and fractionated, and then they were analyzed with LC-MS and the inhibitory effects on breast cancer cells were compared. The inhibition on MDA-MB-231 cells of fractions from "Noble" was further evaluated. The results showed that polyphenols from 2 grape pomaces could be separated into 3 fractions, and ellagic acid and/or ellagitannins were only detected in fractions from "Noble" pomace. All 3 fractions from "Noble" pomace inhibited MDA-MB-231 better than MCF-7. But fraction 2 from "Cabernet Sauvignon" inhibited MCF-7 better while fraction 1 and fraction 3 inhibited both 2 cells similarly. Moreover, the fractions from "Noble" pomace rather than "Cabernet Sauvignon" can inhibit MDA-MB-231 better. Finally, fractions from "Noble" pomace can induce S-phase arrest and apoptosis on MDA-MB-231. These findings suggested the extracts from grape pomace especially those from "Noble," are potential to be utilized as health beneficial products or even anti-breast cancer agents.

Different Flavonoids Can Shape Unique Gut Microbiota Profile In Vitro.

The impact of flavonoids has been discussed on the relative viability of bacterial groups in human microbiota. This study was aimed to compare the modulation of various flavonoids, including quercetin, catechin and puerarin, on gut microbiota culture in vitro, and analyze the interactions between bacterial species using fructo-oligosaccharide (FOS) as carbon source under the stress of flavonoids. Three plant flavonoids, quercetin, catechin, and puerarin, were added into multispecies culture to ferment for 24 h, respectively. The bacterial 16S rDNA amplicons were sequenced, and the composition of microbiota community was analyzed. The results revealed that the tested flavonoids, quercetin, catechin, and puerarin, presented different activities of regulating gut microbiota; flavonoid aglycones, but not glycosides, may inhibit growth of certain species. Quercetin and catechin shaped unique biological webs. Bifidobacterium spp. was the center of the biological web constructed in this study.

Plant polyphenols alter a pathway of energy metabolism by inhibiting fecal Bacteroidetes and Firmicutes in vitro.

The function of plant polyphenols in controlling body weight has been in focus for a long time. The aim of this study was to investigate the effect of plant polyphenols on fecal microbiota utilizing oligosaccharides. Three plant polyphenols, quercetin, catechin and puerarin, were added into liquid media for fermenting for 24 h. The pH values, OD600 of the cultures and the content of carbohydrates at 0, 6, 10, 14, 18 and 24 h were determined. The abundance of Bacteroidetes and Firmicutes in each culture was quantified with qPCR after 10 h of fermentation, and the bacterial composition was analyzed using the software Quantitative Insights Into Microbial Ecology. The results revealed that all three plant polyphenols could significantly inhibit the growth of Bacteroidetes (P < 0.01) and Firmicutes (P < 0.01) while at the same time down-regulate the ratio of Bacteroidetes to Firmicutes (P < 0.01). But the fecal bacteria could maintain the ability to hydrolyze fructo-oligosaccharide (FOS) in vitro. Among the tested polyphenols, catechin presented the most intense inhibitory activity towards the growth of Bacteroidetes and Firmicutes, and quercetin was the second. Only the samples with catechin had a significantly lower energy metabolism (P < 0.05). In conclusion, plant polyphenols can change the pathway of degrading FOS or even energy metabolism in vivo by altering gut microbiota composition. It may be one of the mechanisms in which plant polyphenols can lead to body weight loss. It's the first report to study in vitro gastrointestinal microbiota fermenting dietary fibers under the intervention of plant polyphenols.

Effects of dietary fibers and their mixtures on short chain fatty acids and microbiota in mice guts.

Dietary fiber (DF) can be broken down into short-chain fatty acids (SCFAs) such as acetic, propionic and n-butyric acid by gut microbiota to obtain energy. Therefore, dietary fibers have effects on the balance of gut microbiota and the production of SCFAs. In the four-week feeding, mice were fed with four dietary fibers, including pectin, resistant starch (RS), fructo-oligosaccharide (FOS) and cellulose. The results showed that the mice body-weight gain was the smallest (7.0 ± 2.3 g) when the mixture of RS-FOS-cellulose was ingested, followed by the mixture of RS-cellulose (7.2 ± 3.5 g) and FOS-cellulose (8.3 ± 2.5 g). Ingestion of the mixture of pectin-FOS-cellulose, RS-FOS and RS-FOS-cellulose can respectively increase the diversity of the gut microbiota with 12, 11 and 11 terminal restriction fragments (TRFs) detected (digested by Hha I). The maximum amount of total SCFAs were produced by the mixture of FOS-cellulose (5.504 ± 0.029 µmol mL(-1)), followed by pectin-FOS-cellulose (3.893 ± 0.024 µmol mL(-1)) and pectin-RS-FOS-cellulose (3.309 ± 0.047 µmol mL(-1)). In conclusion, the addition of DFs (pectin, RS, FOS and cellulose), in single or mixture pattern, can exert different effects. An amount of 10.7% of single DF in the diet cannot be conducive to the balance of gut microbiota after ingestion for a long time, however, it can help with body weight loss like the mixtures of DFs in this study; FOS is a very important component in the mixture of DFs for both the balance of the gut microbiota and the production of SCFAs.

Preparation and properties of enzyme-modified cassava starch-zinc complexes.

Starch-zinc complexes were synthesized by reaction of enzyme-modified starch with zinc acetate. The effect of reaction parameters such as hydrolysis rate, reaction temperature, reaction time, pH value, and concentration of zinc acetate on the zinc content and zinc conversion rate was studied. The zinc content and conversion rate of the product prepared under optimal conditions were 100.24 mg/g and 87.06%, respectively. The results of scanning electron microscopy (SEM) demonstrated that the obtained starch-zinc complexes displayed a porous appearance. The results of Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and (13)C cross-polarization/magic-angle spinning nuclear magnetic resonance ((13)C CP/MAS NMR) showed that zinc was mainly coordinated to the oxygen atoms of the glucose unit 6-CH2OH. The formation of starch-zinc complexes was also indirectly confirmed by the results of conductivity measurements. Thermal properties of the complexes were influenced by the zincatation process. This study revealed that nonallergenic starch might be used effectively as a carrier of zinc for zinc supplementation purpose.