Traditional uses and potential health benefits of Amorphophallus konjac K. Koch ex N.E.Br

Konjac glucomannan exerts regulatory effects on macrophages and its applications in biomedical engineering

Konjac glucomannan (KGM) molecular chains contain a small amount of acetyl groups and a large number of hydroxyl groups, thereby exhibiting exceptional water retention and gel-forming properties. To meet diverse requirements, KGM undergoes modification processes such as oxidation, acetylation, grafting, and cationization, which reduce its viscosity, enhance its mechanical strength, and improve its water solubility. Researchers have found that KGM and its derivatives can regulate the polarization of macrophages, inducing their transformation into classically activated M1-type macrophages or alternatively activated M2-type macrophages, and even facilitating the interconversion between M1 and M2 phenotypes. Concurrently, the modulation of macrophage polarization states holds significant importance for chronic wound healing, inflammatory bowel disease (IBD), antitumor therapy, tissue engineering scaffolds, oral vaccines, pulmonary delivery, and probiotics. Therefore, KGM has the advantages of both immunomodulatory effects (biological activity) and gel-forming properties (physicochemical properties), giving it significant advantages in a variety of biomedical engineering applications.

The impact of dietary fibers on the construction and molecular network of extrusion-based 3D-printed chicken noodles: Unlocking the potential of specialized functional food

3D printing technology is promising in creating specialized functional foods, such as high-protein and high dietary fiber noodles. In this study, chicken breast-based noodles with varying proportions of oat bran and konjac flour were developed. The research analyzed the physicochemical, digestive properties, and 3D printability of these chicken-based doughs and noodles. The results indicated that the inclusion of fiber-rich flours notably enhanced dough viscosity and viscoelasticity. However, exceeding 4 % konjac flour negatively affected cooking quality and texture due to its strong water absorption capacity. The experimental group with fiber-rich flours exhibited prolonged starch/protein digestion time compared to the Control group. The increased ability to bind water in the fiber rich formula likely restricted water mobility, affecting mass transition in the "water channel". Notably, chicken noodles fortified with 6 % oat bran and 2 % konjac flour displayed the highest 3D printability. These results offer valuable insights for the industry in selecting appropriate dietary fiber sources for the development of nutritionally balanced 3D-printed meal options.

Taste or health: The impact of packaging cues on consumer decision-making in healthy foods

According to the theory of dietary regulation, consumers frequently encounter conflicts between healthiness and tastiness when selecting healthy foods. This study explores how packaging cue that highlight "tasty" versus "healthy" affect consumers' intentions to purchase healthy food. After an Implicit Association Test (IAT) confirmed a perceived lack of tastiness in health foods in the Preliminary study, Study 1 analyzed pricing and packaging details of the top 200 most-popular items in each of the ten healthy food categories on a major online shopping platform. Results showed that products with taste-focused cues commanded higher prices, indicating stronger consumer acceptance of healthy foods marketed as delicious. To address the causality limitations of observational studies, Study 2 used an experimental design to directly measure the impact of these cues on purchase intentions and perceptions of energy, healthiness, and tastiness. Findings revealed that taste-focused cues significantly boosted purchase intentions compared to health-focused cues, although they also diminished the perceived healthiness of the products. Moreover, in the control group exposed to unhealthy food options, health-emphasized packaging also increased purchase intentions, indicating that consumers seek a balance between healthiness and tastiness, rather than prioritizing health alone. Study 3 further explored the impact of cognitive load over these cue influences, revealing a heightened inclination among consumers to purchase healthy products with taste-focused cue under high cognitive load state. These insights have direct implications for food packaging design, suggesting that emphasizing a balance of taste and health benefits can effectively enhance consumer engagement. The study, which conducted in China, also opens avenues for future research to explore similar effects, maybe in different cultural contexts, different consumer groups, and under varied cognitive conditions.

Characterization of miRNA profiling in konjac-derived exosome-like nanoparticles and elucidation of their multifaceted roles in human health

Plant-derived exosome-like nanoparticles (ELNs) have demonstrated cross-kingdom capabilities in regulating intercellular communication, facilitating drug delivery, and providing therapeutic interventions in humans. However, the functional attributes of konjac-derived ELNs (K-ELNs) remain largely unexplored. This study investigates the isolation, characterization, and functional analysis of K-ELNs, along with the profiling and differential expression analysis of associated miRNAs in both K-ELNs and Konjac tissues. K-ELNs were successfully isolated and characterized from two konjac species using ultracentrifugation, followed by Transmission Electron Microscopy (TEM) and Nanoparticle Tracking Analysis (NTA). Small RNA sequencing identified a total of 3,259 miRNAs across all samples. Differential expression analysis revealed significant differences in miRNA profiles between K-ELNs and tissue samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis of target genes provided insights into their roles in modulating pathways associated with diseases such as cancer and neurodegenerative disorders. Additionally, six miRNAs were selected for validation of sequencing results via RT-qPCR. The 5'RLM-RACE method was employed to validate the cleavage sites between differentially expressed miRNAs (DEMs) and their predicted target genes, further substantiating the regulatory roles of miRNAs in konjac. The findings of this study enhance our understanding of the molecular mechanisms underlying the biological functions and applications of K-ELNs, laying the groundwork for future research into their potential therapeutic roles in human health.

Effects of KGM and Degradation Products on Appetite Regulation and Energy Expenditure in High-Fat-Diet Mice via the Adipocyte-Hypothalamus Axis

Konjac glucomannan (KGM), high-viscosity dietary fiber, is utilized in weight management. Previous investigations on the appetite-suppressing effects of KGM have centered on intestinal responses to nutrients and gastric emptying rates, with less focus on downstream hypothalamic neurons of satiety hormones. In our studies, the molecular mechanisms through which KGM and its degradation products influence energy homeostasis via the adipocyte-hypothalamic axis have been examined. It was found that high-viscosity KGM more effectively stimulates enteroendocrine cells to release glucagon-like peptide-1 (GLP-1) and reduces ghrelin production, thereby activating hypothalamic neurons and moderating short-term satiety. Conversely, low-viscosity DKGM has been shown to exhibit stronger anti-inflammatory properties in the hypothalamus, enhancing hormone sensitivity and lowering the satiety threshold. Notably, both KGM and DKGM significantly reduced leptin signaling and fatty acid signaling in adipose tissue and activated brown adipose tissue thermogenesis to suppress pro-opiomelanocortin (POMC) expression and activate agouti-related protein (AgRP) expression, thereby reducing food intake and increasing energy expenditure. Additionally, high-viscosity KGM has been found to activate the adipocyte-hypothalamus axis more effectively than DKGM, thereby promoting greater daily energy expenditure. These findings provide novel insights into the adipocyte-hypothalamic axis for KGM to suppress appetite and reduce weight.

An Isofibrous Diet with Fiber Konjac Glucomannan Ameliorates Salmonella typhimurium-Induced Colonic Injury by Regulating TLR2-NF-κB Signaling and Intestinal Microbiota in Mice

This study aimed to investigate the hypothesis that dietary konjac glucomannan (KGM) could alleviate Salmonella typhimurium-induced colitis by modulating intestinal microbiota. Mice were fed an isocaloric and isofibrous diet supplemented with either 7% KGM or cellulose and were treated with 5 × 108 CFU of S. typhimurium. The results showed that KGM had an average molecular weight of 936 kDa and predominantly consisted of mannose and glucose at a molar ratio of 1:1.22. In vivo studies demonstrated that dietary KGM effectively mitigated colonic lesions, oxidative stress, disruption of tight junction protein 2 and occludin, and the inflammatory response induced by S. typhimurium. Moreover, KGM administration alleviated the dramatic upregulation of toll-like receptor 2 (TLR2) and phosphonuclear factor κB (NF-κB) protein abundance, induced by Salmonella treatment. Notably, dietary KGM restored the reduced Muribaculaceae and Lactobacillus abundance and increased the abundance of Blautia and Salmonella in S. typhimurium-infected mice. Spearman correlation analysis revealed that the gut microbiota improved by KGM contribute to inhibit inflammation and oxidative stress. These results demonstrated the protective effects of dietary KGM against colitis by modulating the gut microbiota and the TLR2-NF-κB signaling pathway in response to Salmonella infection.

Occurrence and characterization of viruses infecting Amorphophallus in Yunnan, China

Viral diseases are becoming an important problem in Amorphophallus production due to the propagation of seed corms and their trade across regions. In this study, combined-High-Throughput Sequencing, RT-PCR, electron microscopy, and mechanical inoculation were used to analyze virus-like infected Amorphophallus samples in Yunnan province to investigate the distribution, molecular characterization, and diversity and evolution of Amorphophallus-infecting viruses including three isolates of dasheen mosaic virus and three orthotospoviruses: mulberry vein banding associated virus (MVBaV), tomato zonate spot virus (TZSV) and impatiens necrotic spot virus (INSV). The results showed that DsMV is the dominant virus infecting Amorphophallus, mixed infections with DsMV and MVBaV to Amorphophallus were quite common in Yunnan province, China. This is the first report on infection of Amorphophallus with MVBaV, TZSV, and impatiens necrotic spot virus (INSV) in China. This work will help to develop an effective integrated management strategy to control the spread of Amorphophallus viral diseases.

Effects of different substrates on the growth and yield of Amorphophallus muelleri

Seven different substrates were prepared by mixing red soil, humus and river sand in different volume ratios and the growth and yield of Amorphophallus muelleri bulbils in different substrates was investigated. The growth of A. muelleri seedlings were tracked during the reproductive period, with measurements taken of indicators such as petiole length, petiole basal diameter and leaf size during the late period of leaf expansion. Number of surviving plants, weights and sizes of corms, and leaf bulbils were recorded after lodging. The results showed that there were differences in the physical and chemical properties of the seven substrates, but all met the growth requirements of A. muelleri. T1 (river sand), T2 (river sand: humus 1:1), T3 (humus), and T7 (river sand: humus: red soil 1:1:1) had higher emergence rates, reaching 95 %. T4 (humus: red soil 1:1) and T7 had better growth, with larger petiole and leaf sizes than other substrates. T3, T4, and T7 had higher yields, with a bulbil yield of 0.30 t hm-2 and a corm yield of 22.06 t hm-2. Compared to the use of a single substrate, whether river sand, humus, or red soil, the proportional mixture of the three test materials improved the physical structure and chemical composition of the substrate, contributing to the growth of A. muelleri. T7 (river sand: humus: red soil 1:1:1) was was found to be the best nursery substrate for A. muelleri.

Regulation of glycose and lipid metabolism and application based on the colloidal nutrition science properties of konjac glucomannan: A comprehensive review

The physicochemical properties of dietary fiber in the gastrointestinal tract, such as hydration properties, adsorption properties, rheological properties, have an important influence on the physiological process of host digestion and absorption, leading to the differences in satiety and glucose and lipid metabolisms. Based on the diversified physicochemical properties of konjac glucomannan (KGM), it is meaningful to review the relationship of structural characteristics, physicochemical properties and glycose and lipid metabolism. Firstly, this paper bypassed the category of intestinal microbes, and explained the potential of dietary fiber in regulating glucose and lipid metabolism during nutrient digestion and absorption from the perspective of colloidal nutrition. Secondly, the modification methods of KGM to regulate its physicochemical properties were discussed and the relationship between KGM's molecular structure types and glycose and lipid metabolism were summarized. Finally, based on the characteristics of KGM, the application of KGM in the main material and ingredients of fat reduction food was reviewed. We hope this work could provide theoretical basis for the study of dietary fiber colloid nutrition science.

The complete chloroplast genome sequence of Amorphophallus konjac (Araceae) from Yunnan, China and its phylogenetic analysis in the family Araceae

This work determined and analyzed the complete chloroplast genome sequence of Amorphophallus konjac K. Koch ex N.E.Br 1858 from Yunnan, China. The genome size was 167,470 bp, of which contains a large single-copy region (LSC 93,443 bp), a small single-copy region (SSC 21,575 bp), and a pair of inverted repeat regions (IR 26,226 bp). The chloroplast genome has 131 genes, including 86 protein-coding genes, 37 tRNAs, and eight rRNAs. A previous study reported deletion of accD, psbE, and trnG-GCC genes in the A. konjac chloroplast genome. Our study supports the conservative structure of A. konjac and does not support the gene deletion mentioned above. Phylogenetic analysis indicated that A. konjac shares a close relationship with another A. konjac (collected from Guizhou) and A. titanium by forming a clade in the genus Amorphophallus. Our results provide some useful information to the evolution of the family Araceae.

Characteristics of Amorphophallus konjac as indicated by its genome

Amorphophallus konjac, belonging to the genus Amorphophallus of the Araceae family, is an economically important crop widely used in health products and biomaterials. In the present work, we performed the whole-genome assembly of A. konjac based on the NovaSeq platform sequence data. The final genome assembly was 4.58 Gb with a scaffold N50 of 3212 bp. The genome includes 39,421 protein-coding genes, and 71.75% of the assemblies were repetitive sequences. Comparative genomic analysis showed 1647 gene families have expanded and 2685 contracted in the A. konjac genome. Likewise, genome evolution analysis indicated that A. konjac underwent whole-genome duplication, possibly contributing to the expansion of certain gene families. Furthermore, we identified many candidate genes involved in the tuber formation and development, cellulose and lignification synthesis. The genome of A. konjac obtained in this work provides a valuable resource for the further study of the genetics, genomics, and breeding of this economically important crop, as well as for evolutionary studies of Araceae family.

Genus Amorphophallus: A Comprehensive Overview on Phytochemistry, Ethnomedicinal Uses, and Pharmacological Activities

The genus Amorphophallus belongs to the family Araceae. Plants belonging to this genus are available worldwide and have been used in traditional medicines since ancient times, mainly in Ayurveda and Unani medical practices. Amorphophallus species are an abundant source of polyphenolic compounds; these are accountable for their pharmacological properties, such as their analgesic, neuroprotective, hepatoprotective, anti-inflammatory, anticonvulsant, antibacterial, antioxidant, anticancer, antiobesity, and immunomodulatory effects, as well as their ability to prevent gastrointestinal disturbance and reduce blood glucose. Moreover, Amorphophallus species contain numerous other classes of chemical compounds, such as alkaloids, steroids, fats and fixed oils, tannins, proteins, and carbohydrates, each of which contributes to the pharmacological effects for the treatment of acute rheumatism, tumors, lung swelling, asthma, vomiting, abdominal pain, and so on. Additionally, Amorphophallus species have been employed in numerous herbal formulations and pharmaceutical applications. There has been no extensive review conducted on the Amorphophallus genus as of yet, despite the fact that several experimental studies are being published regularly discussing these plants' pharmacological properties. So, this review discusses in detail the pharmacological properties of Amorphophallus species. We also discuss phytochemical constituents in the Amorphophallus species and their ethnomedicinal uses and toxicological profiles.

Method for Simulating the Anti-Damage Performance of Consolidation Soil Balls at the Roots of Seedlings during Transportation Using Consolidated Soil Columns

In the process of landscaping or afforestation in challenging terrain, in order to improve the survival rate of transplanted seedlings, it is necessary to transplant seedlings with a mother soil ball attached. During transportation, the soil ball at the root of the seedlings is very susceptible to breakage due to compression, bumps, and collisions. In order to ensure the integrity of the soil ball of the transplanted seedlings and improve the survival rate of seedlings, a method of chemically enhancing the soil surface strength was employed. Specifically, a polymer-based soil consolidating agent was used to solidify the root balls of the seedlings. To examine the abrasion resistance performance of the soil balls formed by consolidating the surface with polymer adhesive during the transportation process, we utilized a polymer-based consolidating agent to prepare test soil columns and developed a method to simulate the damage resistance performance of seedling root balls during transportation using these soil columns. The method primarily encompasses two aspects of testing: compressive strength testing of the consolidated soil columns and resistance to transportation vibration testing. The first method for testing the resistance to transportation vibration of the consolidated soil columns is a combination test that includes three sets of tests: highway truck transportation vibration testing, combined wheel vehicle transportation vibration testing, and impact testing. Although the method is cumbersome, testing is more accurate. The second method for testing the resistance to transportation vibration of the consolidated soil columns involves simultaneously testing multiple consolidated soil columns using a simulated transportation vibration test platform. The testing method is concise and efficient, and the test results are more intuitive. The combined assessment of the resistance to transportation vibration and compressive strength testing of the consolidated soil columns allows for a comprehensive evaluation of the soil columns' resistance to damage during transportation. This study mainly provides a quick and effective method for detecting the damage resistance of consolidated soil columns/balls during transportation, providing technical support for the application of polymer-based consolidation agents in the field of seedling transplantation.

Modification of Konjac Biodegradable Material Using Deacetylation and Reinforcement Process for Its Applications in Food Packaging

Common konjac flour, especially of low grade, is a waste material produced in large quantities during purification of konjac glucomannan (KGM). It contains impurities, particularly oxalate salts, which irritate and may cause kidney stones. Konjac flour has glucomannan as a main component. Glucomannan is characterized by low crystallinity, high thermostability, and the ability to form a strong gel. Subsequently, glucomannan has good potential for the production of biodegradable material. However, its high-water affinity limits its use in packaging. The deacetylated by thermal forming process and reinforced konjac flour with 15% and 20% of microcrystalline cellulose showed improved water absorption and thermal properties of the specimen. Moreover, the thermal forming process resulted in the reduction of soluble oxalate. Therefore, due to the conditions used in this experiment, the material will be stronger, more waterproof properties, and more highly resistant to temperatures, so it is suitable to be used as a packaging that is environmentally friendly.

Selection and Evaluation of Reference Genes for RT-qPCR Analysis in Amorphophallus Konjac Based on Transcriptome Data

Combined with the Konjac transcriptome database of our laboratory and internal reference genes commonly used in plants, the eight candidate internal reference genes were screened and detected. They are the 25S ribosomal RNA gene (25S rRNA), 18S ribosomal RNA gene (18S rRNA), actin gene (ACT), glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH), ubiquitin gene (UBQ), β-tubulin gene (β-TUB), eukaryotic elongation factor 1-αgene(eEF-1α), and eukaryotic translation initiation factor 4α-1 gene (eIF-4α). The results of GeNorm, Normfinder, and BestKeeper were analyzed comprehensively. The data showed that the expression levels of 25S rRNA, 18S rRNA, and ACT at the reproductive periods, eEF-1α and eIF-4α at the nutritional periods, and eEF-1α, UBQ, and ACT at different leaf developmental periods were stable. These identified and stable internal reference genes will provide the basis for the subsequent molecular biology-related studies of Konjac.

Comparative study on the effect of inhibitory methods on the color and gelation properties of alkali induced heat-set konjac gel from Amorphophallus bulbifer

As a newly superior konjac variety, the Amorphophallus bulbifer (A. bulbifer) was easily browning during the alkali-induced process. In this study, five different inhibitory methods, such as citric-acid heat pretreatment (CAT), mixed with citric acid (CA), mixed with ascorbic acid (AA), mixed with L-cysteine (CYS), and mixed with potato starch (PS, containing TiO2), were separately used to inhibit the browning of alkali-induced heat-set A. bulbifer gel (ABG). The color and gelation properties were then investigated and compared. Results showed that the inhibitory methods had significant influences on the appearance, color, physicochemical properties, rheological properties, and microstructures of ABG. Among them, the CAT method not only significantly inhibited the browning of ABG (ΔE value dropped from 25.74 to 14.68) but also improved the water-holding capacity, moisture distribution, and thermal stability without damaging the textural properties of ABG. Moreover, SEM revealed that both CAT and adding PS methods could exhibit the more dense gel network structures of ABG than other methods. It was reasonable to conclude that ABG-CAT offered a superior method to prevent browning compared to the other methods based on the texture, microstructure, color, appearance, and thermal stability of the product.

Konjac glucomannan-dihydromyricetin complex improves viscosity and hydration capacity of konjac glucomannan as well as the thermal stability of dihydromyricetin

The nutritional benefits of soluble dietary fiber were mainly attributed to its viscosity and hydration capacity. This study was aimed to investigate the effects of the interaction between konjac glucomannan (KGM) and dihydromyricetin (DMY) on the viscosity and hydration capacity of KGM and the thermal stability of DMY. In contrary to most reports, the addition of DMY to KGM resulted in an increase of viscosity and hydration capacity determined via rheology and nuclear magnetic resonance spectroscopy characterization. Meanwhile the prototype retention of DMY in the presence of heating condition at 60 °C and 100 °C were improved. The radical scavenging capacity of DMY under heating condition was improved at 100 °C via the quantification of ABTS⁺ and DPPH. KGM-DMY complex was a non-covalent compound connected by hydrogen bonds which was characterized with particle size analyses, zeta potential analyses, transmission electron microscopy, infrared spectroscopy, X-ray diffraction, and isothermal titration calorimetry. This study was beneficial to the development of polyphenol-enriched nutrition based on KGM, especially in the aspects of satiety, appetite regulation and glucose regulation.

Glucomannan as a polysaccharide adjuvant improved immune responses against Staphylococcus aureus: Potency and efficacy studies

Staphylococcus aureus is a gram-positive bacterium, representing one of the most important nosocomial pathogens. The treatment of infections, caused by S. aureus, has become increasingly intricate due to the emergence of highly resistant strains. Therefore, it is obvious that an effective prevention strategy against this bacterium could significantly decrease such infections. In the present study, the protective efficacy and immunological properties of recombinant autolysin, formulated in Montanide ISA266 and Alum adjuvants with Glucomannan as a polysaccharide, were assessed in the systemic mouse model of infection. Mice were immunized with the purified recombinant protein in various formulations in different groups and, subsequently, mice were challenged with 5 × 10⁸ CFU of bacteria for the evaluation of their survival and bacterial clearances in the internal organs. ELISA was performed to determine the type of induced immunity, cytokine secretion (IFN-γ, IL-4, IL-2, and IL-17), and isotyping (IgG1 and IgG2a). In addition, we measured the opsonophagocytic activities of the antibodies. Results showed that immunization with r-autolysin + Alum + Glucomannan and r-autolysin + MontanideISA266+Glucomannan formulations significantly increased total IgG and isotypes (IgG1 and IgG2a), as compared with other vaccinated and control groups. Furthermore, the formulation of r-autolysin in Alum and MontanideISA266 adjuvants with Glucomannan enhanced IFN-γ, IL-4, and IL-17 cytokine secretion as well as protectivity, following experimental challenge. We concluded that Glucomannan has the potential to induce immune responses and would be used as an adjuvant factor in vaccine formulation.

Evaluation of the composition of konjac glucomannan on the color changes during the deacetylation reaction

As a newly superior konjac variety, the Amorphophallus bulbifer (A. bulbifer) has several unique advantages of high reproductive coefficient, short growth cycle, high disease resistance, high konjac glucomannan (KGM) content and climate adaption to hot or humid conditions. However, the gel formed by KGM from the A. bulbifer flour is easily browning during the alkali-induced process and the mechanism underlying them is still unclear. In order to explore the browning mechanisms, the changes of composition and color parameters of KGM were investigated during deacetylation in this research. The L*, h*, total phenols, total flavonoids, reducing sugars, and amino acids decreased along with the increase of deacetylation degree of KGM while a*, ΔЕ, and browning index increased. The results indicated that the oxidation or polymerization of polyphenols and flavones in alkaline circumstances, and the carbonyl ammonia reaction between reducing sugars and amino acids may be the main reasons for color changes of KGM flour during deacetylation. Hence, this study was expected to provide the theoretical basis for the inhibition of KGM gel browning and further broaden the application range of KGM in food and other industries.

Active Consumption of Konjac and Konjac Products Improves Blood Glucose Control in Patients with Type 2 Diabetes Mellitus

OBJECTIVE

Konjac is a food mainly consumed in Asian countries with high fiber and low energy. Although glucomannan, a component of konjac, have been used for several clinical studies, there is few reports using konjac itself. This study examined the effects of the active consumption of konjac in patients with type 2 diabetes mellitus (T2DM).

METHODS

The study included 26 Japanese patients with T2DM. Participants were recommended to take konjac at least once a day using free konjac products (various noodles, rice, and desserts) and plate konjac for 12 weeks.

RESULTS

HbA1c and fasting plasma glucose levels significantly decreased from 8.3 ± 0.9% to 8.0 ± 0.8% and from 173.2 ± 44.4 to 152.8 ± 36.7 mg/dL, respectively. No significant changes were observed in body weight and insulin resistance indices, but the index for insulin secretion significantly increased. Serum high molecular weight adiponectin levels significantly increased. Plasma ghrelin, leptin and glucagon-like peptide-1 levels tended to decrease (p = 0.084), decrease (p = 0.057) and increase (p = 0.071), respectively. Actual konjac intake positively correlated with age (r = 0.61, p = 0.001). Body weight and HbA1c significantly decreased in patients aged ≥50 years than in those aged <50 years, and the changes significantly inversely correlated with age.

CONCLUSION

Active consumption of konjac and konjac products seems to be a useful dietary therapy with multifaceted action for T2DM. Further studies with greater sample size and long-term are needed to confirm these findings.

Physicochemical and Structural Properties of Gluten-Konjac glucomannan Conjugates Prepared by Maillard Reaction

Gluten (Glu) is important to wheat products by forming a three-dimensional matrix. This study aimed to investigate the physicochemical and structural properties of gluten after conjugation with konjac glucomannan (KGM) through the Maillard reaction. The study revealed that the degree of graft increased with the prolonged reaction time. The Glu-KGM conjugates were possessed of increased β-sheet but decreased α-helix and β-turn, as well as unfolding and loose tertiary structures as the reaction proceeded. Among three different proportions, the Glu-KGM 1:1 conjugate was proved to have the most excellent foaming and emulsifying properties, and could form more rigid and firm gelation structures, which could be related to the decreased particle size and increased zeta potential of the conjugate. Overall, the physicochemical and structural properties of gluten were significantly related to the KGM ratios as well as the reaction period.

Effects of Glucomannan Supplementation on Type II Diabetes Mellitus in Humans: A Meta-Analysis

The hypoglycemic and lipid-lowering effects of glucomannan are widely known, and it is a potential effective treatment for type II diabetes. In this study, we evaluated the effects of glucomannan supplementation on blood-lipid-related indicators, blood-glucose-related indicators, blood pressure (BP), and body weight (BW) in patients suffering from type II diabetes. We searched databases including PubMed, Cochrane, the comprehensive biomedical research database (Embase), Web of Science, and China National Knowledge Infrastructure (CNKI) for literature on glucomannan and type II diabetes. Six randomized controlled trials (RCTs) were eligible (n = 440 participants) to be included in our analysis. Glucomannan not only reduced the total cholesterol (TC) (MD -0.38 [95% CI: -0.61, -0.15], p = 0.001) and low-density lipoprotein (LDL) levels (MD -0.35 [95% CI: -0.52, -0.17], p < 0.0001) compared with the control group, but also reduced the fasting blood glucose (FBG) (MD -1.08 [95% CI: -1.65, -0.50], p = 0.0002), 2 h postprandial blood glucose (P2hBG) (MD -1.92 [95% CI: -3.19, -0.65], p = 0.003), fasting insulin (FINS) (MD -1.59 [95% CI: -2.69, -0.50], p = 0.004), and serum fructosamine (SFRA) levels (SMD -1.19 [95% CI: -1.74, -0.64], p < 0.0001). Our analysis indicates that glucomannan is an effective nutritional intervention for type II diabetes.

Konjac Glucomannan: An Emerging Specialty Medical Food to Aid in the Treatment of Type 2 Diabetes Mellitus

There are many factors causing T2DM; thus, it is difficult to prevent and cure it with conventional treatment. In order to realize the continuous intervention of T2DM, the treatment strategy of combining diet therapy and traditional medication came into being. As a natural product with the concept of being healthy, konjac flour and its derivatives are popular with the public. Its main component, Konjac glucomannan (KGM), can not only be applied as a food additive, which greatly improves the taste and flavor of food and extends the shelf life of food but also occupies an important role in T2DM. KGM can extend gastric emptying time, increase satiety, and promote liver glycogen synthesis, and also has the potential to improve intestinal flora and the metabolic system through a variety of molecular pathways in order to positively regulate oxidative stress and immune inflammation, and protect the liver and kidneys. In order to establish the theoretical justification for the adjunctive treatment of T2DM, we have outlined the physicochemical features of KGM in this article, emphasizing the advantages of KGM as a meal for special medical purposes of T2DM.

The Effects of Soluble Dietary Fibers on Glycemic Response: An Overview and Futures Perspectives

The properties of each food, composition, and structure affect the digestion and absorption of nutrients. Dietary fiber (DF), especially viscous DF, can contribute to a reduction in the glycemic response resulting from the consumption of carbohydrate-rich foods. Target and control of postprandial glycemic values are critical for diabetes prevention and management. Some mechanisms have been described for soluble DF action, from the increase in chyme viscosity to the production of short-chain fatty acids resulting from fermentation, which stimulates gastrointestinal motility and the release of GLP-1 and PYY hormones. The postprandial glycemic response due to inulin and resistant starch ingestion is well established. However, other soluble dietary fibers (SDF) can also contribute to glycemic control, such as gums, β-glucan, psyllium, arabinoxylan, soluble corn fiber, resistant maltodextrin, glucomannan, and edible fungi, which can be added alone or together in different products, such as bread, beverages, soups, biscuits, and others. However, there are technological challenges to be overcome, despite the benefits provided by the SDF, as it is necessary to consider the palatability and maintenance of their proprieties during production processes. Studies that evaluate the effect of full meals with enriched SDF on postprandial glycemic responses should be encouraged, as this would contribute to the recommendation of viable dietary options and sustainable health goals.

Effect of konjac glucomannan with different viscosities on the quality of surimi-wheat dough and noodles

It was investigated that the rheology, starch-gluten-surimi network, thermal properties, and water distribution of surimi-wheat dough, and texture characteristics, cooking properties, and microscopic characteristics of the surimi-wheat noodles with konjac glucomannan (KGM) of different viscosities in different concentrations. The results showed that the storage (G'), loss (G″), and complex (G⁎) moduli of dough increased with adding KGM. With the increase of KGM viscosity, the reduction in the free sulfhydryl (SH) content to 0.84 μmol/g and the increase in the free water content to 8.25 % led to significantly improved enthalpy and the microstructure density. The hardness and tensile length of noodles were substantially increased by adding 3 % KGM. In addition, the KGM enhanced the starch-gluten-surimi network and improved the cooking qualities and textural properties of noodles. More importantly, the application of KGM in the wheat flour composite system also showed better performance. Thus, the introduction of KGM into the surimi-wheat dough had a significant effect on the optimization of the macro- and micro-characteristics of dough and noodles.

First Report of Achromobacter Xylosoxidans Causing Stem Soft Rot on Amorphophallus Konjac in China

Amorphophallus konjac is one of the important commercial crops cultivated in south China and has long been used as a food source and a traditional medicine, because it is the only species with glucomannan and other trace elements (Ban et al. 2009; Melinda et al. 2010). In June of 2021, an outbreak of stem soft rot disease was observed on A. konjac plants in more than 2,000 square meters of agricultural planting fields in the Fuyuan country (25°34'50″N, 104°04'21″E), Qujing City, Yunnan Province, China. The disease incidence ranged from 30 to 35% in severely infested fields. The diseased plants displayed the first symptoms were damp brown spots. As the brown spots expanded, dark brown water stains appeared at the basal part of the stem and the bulbs were rotting with a foul smell, gradually extending to the underground parts. Progressively, the whole plants wilted and collapsed, and even the plants ultimately died. To identify the pathogen, symptomatic stems were cut into pieces, surface sterilized with 75% (v/v) ethanol, and placed on LB (tryptone/yeast extract/NaCl) medium for 24 to 48 hours at 28 ± 2°C. Six single-colony isolates were obtained from the diseased stems. The colonies on LB present a raised milky white opaque colonies moisture on the surface, round and convex in shape, with neat edges. Scanning electron microscopy showed that the cells were short rods (0.3∼0.5) × (1.9∼2.1)μm in size without any flagellum and were often arranged in pairs or clusters at certain angles. The 16S rDNA sequence of the randomly selected strain MY-G1 with primers 27F/1492R (Ying et al. 2012) and the housekeeping genes nusA, eno, lepA and nuoL (Spilker et al. 2012) were amplified and sequenced. The 16S rDNA sequence of the 1326 bp product was deposited in GenBank (accession no. ON786717) and showed a 99.77% similarity to A. xylosoxidans strain E2 (accession no. MK849863.1). The nusA (OP680477), eno (OP680479), lepA (OP680481) and nuoL (OP680482) sequences showed 94.71%, 97.24%, 94.64% and 95.95% similarity to A. xylosoxidans strain DN002 (accession no. CP045222.1), respectively. The phylogenetic trees built based on 16S rRNA and the nusA-eno-lepA-nuoL multilocus analysis showed the isolate MY-G1 to cluster with A. xylosoxidans. Based on morphological and molecular analysis, the isolated MY-G1 was identified as A. xylosoxidans, which indicates that MY-G1 is a new strain of A. xylosoxidans. Pathogenicity tests were confirmed on the stem and petiole of one-year-old A. konjac. The wounds were made by puncturing with a MY-G1 bacteria suspension containing 108 CFU/ml (15ul/inoculation site). As a negative control, control seedlings were injected with the same amount of sterilized distilled water. Control and inoculated seedlings (each six) were kept in greenhouses and watered as needed in controlled conditions: 28°C, 75% relative humidity. Inoculated seedlings presented similar symptoms of stem soft rot, inner medulla disintegration, and wilt of leaves on developed within 3 to 9 days. The bacterial pathogen was re-isolated from inoculated seedlings and identified by morphological and molecular methods to fulfill Koch's postulates test. According to previous research, A. xylosoxidans can cross-kingdom infect animals and plants (Aisenberg et al.,2004; Ye et al.,2018). To the best of our knowledge, this is the first report of A. xylosoxidans causing stem soft rot of A. konjac in China, expanding the known pathogen for the soft rot of A. konjac, and also the host range of A. xylosoxidans.

Glucomannan as a Dietary Supplement for Treatment of Breast Cancer in a Mouse Model

Konjac glucomannan (KGM) is a water-soluble polysaccharide derived from the Amorphophallus’s tuber and, as herbal medicine has shown, can suppress tumor growth or improve health. However, there has been no investigation into the effects of KGM on breast tumor-bearing mice. Therefore, in two cohort experiments, we assessed the effect of glucomannan at daily doses of 2 and 4 mg for 28 days as a dietary supplement and also glucomannan in combination with tumor lysate vaccine as an adjuvant. Tumor volume was monitored twice weekly. In addition, TNF-α cytokines and granzyme B (Gr–B) release were measured with ELISA kits, and IL-2, IL-4, IL-17, and IFN-γ were used as an index for cytotoxic T lymphocyte activity. Moreover, TGF-β and Foxp3 gene expression were assessed in a real-time PCR test. The results show that glucomannan as a dietary supplement increased the IFN-γ cytokine and Th1 responses to suppress tumor growth. Glucomannan as a dietary supplement at the 4 mg dose increased the IL-4 cytokine response compared to control groups. In addition, cell lysate immunization with 2 or 4 mg of glucomannan suppressed tumor growth. As an adjuvant, glucomannan at both doses showed 41.53% and 52.10% tumor suppression compared with the PBS group. Furthermore, the administration of glucomannan as a dietary supplement or adjuvant reduced regulatory T cell response through decreasing TGF-β and Foxp3 gene expression in the tumor microenvironment. In conclusion, glucomannan as a dietary supplement or adjuvant enhanced the immune responses of tumor-bearing mice and decreased immune response suppression in the tumor milieu, making it a potentially excellent therapeutic agent for lowering breast tumor growth.

Effect of Ethanol on Preparation of Konjac Emulgel-Based Fat Analogue by Freeze-Thaw Treatment

In the current study, a method using ethanol to modulate the texture properties of konjac gel during freeze-thaw process was used to prepare konjac emulgel-based fat analogue. A certain amount of ethanol was added to konjac emulsion, heated to form a konjac emulgel, then frozen at −18 °C for 24 h, and finally thawed to obtain konjac emulgel-based fat analogue. The effects of different ethanol contents on the properties of frozen konjac emulgel were explored, and data was analyzed by one-way analysis of variance (ANOVA). The emulgels were compared with pork backfat in terms of hardness, chewiness, tenderness, gel strength, pH, and color. The results showed that the konjac emulgel with 6% ethanol had similar mechanical and physicochemical properties to pork backfat after freeze-thaw treatment. The results of syneresis rate and SEM showed that adding 6% ethanol could not only reduce the syneresis rate, but also effectively weaken the damage to the network structure caused by freeze-thaw treatment. The pH value of konjac emulgel-based fat analogue was between 8.35–8.76, and the L* value was similar to that of pork backfat. The addition of ethanol provided a new idea for the preparation of fat analogues.

Food resilience in a dark catastrophe: A new way of looking at tropical wild edible plants

A global sun-blocking catastrophe is more plausible than anyone would like to think. Models have consistently shown the devastating effects these events could have to the world's agricultural systems for upwards of 15 years. New shade-, drought-, and cool-tolerant crops and more food stockpile sources must be found if there would be any hope of feeding the global population in such a scenario. Wild edible plants (WEPs) are important buffers of food security to indigenous peoples, impoverished peoples, and those in areas with erratic growing seasons across the globe. Here, we suggest WEP species that have the potential to be scaled up through cultivation in post-catastrophe conditions, and the use of foraged food stockpiles to function as stop-gap foods until conventional agriculture returns. We also propose policy initiatives for habitat protection, education programs, and general preparedness.

Improvement of Storage Stability of Zein-Based Pickering Emulsions by the Combination of Konjac Glucomannan and L-Lysine

In this work, L-lysine (Lys) was employed together with konjac glucomannan (KGM) to fabricate zein colloidal particles (ZCPs) aimed at enhancing the storage stability of Pickering emulsions. With the addition of Lys, zein-Lys colloidal particles (ZLCPs) and zein-Lys-KGM (ZLKCPs) exhibited smaller particle size (133.64 ± 1.43, 162.54 ± 3.51 nm), polydispersity index (PDI) (0.10 ± 0.029, 0.13 ± 0.022), π value, and more adsorbed protein. Meanwhile, KGM underwent deamidation in an alkaline solution, so the emulsions stabilized by ZLKCPs exhibited a solid gel-like structure with higher storage modulus (G′) and loss modulus (G′′), leading to lower fluidity and better stability. The synergistic effects of Lys and KGM improved the stability of the emulsion. Hydrophobic interactions and hydrogen bonds were the main driving forces forming colloidal particles, which were determined by driving force analysis.

Effect of Preparation Conditions on Application Properties of Environment Friendly Polymer Soil Consolidation Agent

In order to improve the survival rate of transplanted seedlings and improve the efficiency of seedling transplantation, we developed an environmental friendly polymer konjac glucomannan (KGM)/chitosan (CA)/polyvinyl alcohol (PVA) ternary blend soil consolidation agent to consolidate the soil ball at the root of transplanted seedlings. In the previous research, we found that although the prepared KGM/CA/PVA ternary blend soil consolidation agent can consolidate the soil ball at the root of the seedling, the medium solid content of the adhesive was high, which affects its spraying at the root of the seedling. At the same time, the preparation temperature of the KGM/CA/PVA ternary blend was also high. Therefore, to reduce the energy consumption and the cost of the KGM/CA/PVA ternary blend soil consolidation agent in the preparation process, this paper studied the influence of preparation conditions on the application performance of the environmental friendly polymer soil consolidation agent. We aimed to reduce the highest value CA content and preparation temperature of the KGM/CA/PVA ternary blend adhesive on the premise of ensuring the consolidation performance of the KGM/CA/PVA ternary blend adhesive on soil balls. It was prepared for the popularization and application of the environmental friendly polymer KGM/CA/PVA ternary blend soil consolidation agent in seedling transplanting. Through this study, it was found that the film-forming performance of the adhesive was better when the KGM content was 4.5%, the CA content was in the range of 2-3%, the PVA content was in the range of 3-4%, and the preparation temperature was higher than 50 °C. The polymer soil consolidation agent prepared under this condition has a good application prospect in seedling transplanting.

Comparative analysis of buds transcriptome and identification of two florigen gene AkFTs in Amorphophallus konjac

Leaves and flowers of Amorphophallus konjac do not develop simultaneously thus unique features can be elucidated through study of flowering transformation in A. konjac. In this study, transcriptome libraries of A. konjac leaf buds (LB) and flower buds (FB) were constructed followed by high-throughput sequencing. A total of 68,906 unigenes with an average length of 920 bp were obtained after library assembly. Out of these genes, 24,622 unigenes had annotation information. A total of 6859 differentially expressed genes (DEGs) were identified through differential expression analysis using LB as control. Notably, 2415 DEGs were upregulated whereas 4444 DEGs were downregulated in the two transcriptomes. Go and KEGG analysis showed that the DEGs belonged to 44 functional categories and were implicated in 98 metabolic pathways and 38 DEGs involved in plant hormone signal transduction. Several genes were mined that may be involved in A. konjac flower bud differentiation and flower organ development. Eight DEGs were selected for verification of RNA-seq results using qRT-PCR analysis. Two FLOWERING LOCUS T (FT) genes named AkFT1 and AkFT2 were identified though homologous analysis may be the florigen gene implicated in modulation of A. konjac flowering. These genes were significantly upregulated in flower buds compared with the expression levels on leaf buds. Overexpression of AkFT genes though heterologous expression in Arabidopsis showed that the transgenics flowered at a very early stage relative to wild type plants. These findings indicate that AkFT1 and AkFT2 function as regulation genes in A. konjac flowering development and the two genes may present similar functions during flowering transition.

Amorphophalli Rhizoma inhibits breast cancer growth, proliferation, migration, and invasion via the PI3K/AKT pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Amorphophalli Rhizoma (APR) is widely used as an adjuvant treatment for advanced and metastatic triple-negative breast cancer (TNBC), but its effects, potential active ingredients, and mechanism of action on estrogen receptor-positive (ER+) and human epidermal growth factor receptor-positive (HER2+) breast cancer cells were not reported.

AIM OF THE STUDY

The present study investigated the effects and mechanism of APR on ER+ and HER2+ breast cancer cells.

MATERIALS AND METHODS

Rotary evaporation was used to prepare different extracts of APR. Cell activity was assessed using the cell counting kit-8 (CCK-8) method. Wound healing assays were used to assess cell migration, and a cell invasion assay was performed using a Transwell chamber with Matrigel matrix. A xenograft model was used to analyze the inhibitory effects of APR on tumor growth. Bioinformatics analyses were used to explore the potential mechanism of APR in breast cancer. RT-qPCR and Western blotting were performed to reveal the molecular mechanism.

RESULTS

The ethyl acetate extract of APR showed the strongest tumor inhibitory effect on ER+ and HER2+ breast cancer cells compared to petroleum ether or N-butanol extracts. APR inhibited ER+ and HER2+ breast cancer cell growth, proliferation, migration, and invasion via the phosphatidylinositol-3 kinase (PI3K)/AKT pathway.

CONCLUSIONS

APR had a significant inhibitory effect on ER+ and HER2+ breast cancer cells via the PI3K/AKT signaling pathway. Therefore, APR may be useful for preventing ER+ and HER2+ breast tumor growth, proliferation, migration, and invasion.

Ultrasound Viscoelastic Properties of Biomass Polysaccharide Hydrogels as Evaluated by Rheometer Equipped with Sono-Device

A viscoelastic rheometer was equipped with a sono-device and a water bath to enable measurement of storage moduli G′ and loss moduli G″ of biomass polysaccharide hydrogels such as Kanten agarose, κ-carrageenan, and konjac glucomannan under ultrasound (US) exposure. The action of low power of 43 kHz US on their hydrogels significantly decreased G′ of Kanten agarose and carrageenan after a few seconds of US exposure 0.1% strain. When US with 20 W output power was exposed under mechanical strain at 0.1%, lower values were obtained cyclically for 3 min US intervals. The values then reverted to the original moduli values when US was stopped in cases of Kanten agarose and carrageenan hydrogels. As G″ values were increased during US operation, the anhydro-L-galactose segments in their hydrogels were unable to relax the external US forces within the gel sufficiently, thereby leading to gel structure collapse at a higher strain percentage. These results suggest that US exposure induced deformational change in the hydrogel structure formed by hydrogen-bonded cross-links. However, US deformation was less in the case of deacetylated cross-linkage in konjac glucomannan hydrogel.

Chemical Profiling and Evaluation of Antioxidant and Anticancer Potential of Tuber Crop Amorphophallus commutatus var. wayanadensis

Cancer and cancer-related diseases are a global health concern in the present scenario. Functional food and nutraceuticals are considered as a boon towards cancer management. Amorphophallus commutatus var. wayanadensis (ACW) is an herbaceous plant used by the local communities of Wayanad, India, for food and primary healthcare. Various radical scavenging and reducing power assays were undertaken to evaluate the antioxidant activity of methanolic extract of ACW (MEAC). In vitro anticancer activity was evaluated against HT-29 cell line by MTT assay, morphological analysis, DNA fragmentation assay and cell cycle analysis. Caspase and COX-2 enzyme assays were conducted to examine the underlying mechanism. Studies on Ehrlich Ascites Carcinoma (EAC) transplanted mice models was carried out to evaluate the in-vivo antioxidant and anticancer potential of MEAC. The major bioactive nutraceutical compound present in MEAC was isolated by bioactivity-guided fractionation. MEAC showed significant in vitro antioxidant activity. Further, MEAC promoted cytotoxicity against HT-29 cells by activating caspase-3 dependent apoptotic pathway with a cell cycle arrest at the G1/S phase and subsequent down regulation of COX-2 pathway. The potential antitumor activity of MEAC was further confirmed in EAC tumor bearing mice models in which treatment with MEAC increased the levels of antioxidant enzymes, improved the hematological profile towards normal and also augmented the life span of tumor bearing mice. β-sitosterol isolated from ACW induces anticancer activity via caspase-dependent pathway. Our study confirmed the antioxidant and anticancer activities of ACW, which proposes the medicinal importance of this plant as a preventive and supportive therapy for arising tumors.

Impacts of konjac glucomannan with different modification of degradation or deacetylation on the stress resistance and fitness in Caenorhabditis elegans

The impact of modification in molecules or deacetylation of konjac glucomannan (KGM) on the stress resistance in vivo has rarely been studied systematically. This research studied the effects of KGM with different molecular weights and degrees of deacetylation on the stress resistance and physical fitness of Caenorhabditis elegans. After the nematodes were incubated with different modified KGM, the survival rate of nematodes under oxidative and heat stress, as well as the fertility and locomotion were measured. KGM(2-5) can significantly prolong the mean and maximum lifespan of nematodes in the presence of paraquat. Under heat stress, all partially degraded konjac glucomannan (PDKGM) showed the significant extension of survival rates. Da(1-3) improved the survival rates of nematodes under oxidative stress. Furthermore, genes expression showed that KGM(2-5) and Da(1-3) upregulated the expression of sod-3, hsp-16.2, and atf-7. Taken together, molecular weight reduction or deacetylation of KGM have a significant impact on the stress resistance in vivo. PDKGM applied in stress resistance will be suggested not to exceed 200 kDa and deacylation of KGM will be suggested to be below 50%.

Recent advances in biotransformation, extraction and green production of D-mannose

D-mannose is a natural and biologically active monosaccharide. It is the C-2 epimer of glucose and a component of a variety of polysaccharides in plants. In addition, D-mannose also naturally exists in some cells of the human body and participates in the immune regulation of cells as a prebiotic. Its good physiological benefits to human health and wide application in the food and pharmaceutical industries have attracted widespread attention. Therefore, in-depth research on preparation methods of D-mannose has been widely developed. This article summarizes the main production methods of D-mannose in recent years, especially the in-depth excavation from biomass raw materials such as coffee grounds, konjac flour, acai berry, etc., to provide new ideas for the green manufacture of D-mannose.

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Various methods of recent mannose production were comprehensively summarized.

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The new technical progress of obtaining mannose from biomass as emphatically discussed.

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Discuss various preparation methods including different pretreatments, enzymatic hydrolysis, etc.

A chromosome-level genome assembly of Amorphophallus konjac provides insights into konjac glucomannan biosynthesis

Amorphophallus konjac, a perennial herb in the Araceae family, is a cash crop that can produce a large amount of konjac glucomannan. To explore mechanisms underlying such large genomes in the genus Amorphophallus as well as the gene regulation of glucomannan biosynthesis, we present a chromosome-level genome assembly of A. konjac with a total genome size of 5.60 Gb and a contig N50 of 1.20 Mb. Comparative genomic analysis reveals that A. konjac has undergone two whole-genome duplication (WGD) events in quick succession. Two recent bursts of transposable elements are identified in the A. konjac genome, which contribute greatly to the large genome size. Our transcriptomic analysis of the developmental corms characterizes key genes involved in the biosynthesis of glucomannan and related starches. High expression of cellulose synthase-like A, Cellulose synthase-like D, mannan-synthesis related 1, GDP-mannose pyrophosphorylase and phosphomannomutase fructokinase contributes to glucomannan synthesis during the corm expansion period while high expression of starch synthase, starch branching enzyme and phosphoglucomutase is responsible for starch synthesis in the late corm development stage. In conclusion, we generate a high-quality genome of A. konjac with different sequencing technologies. The expansion of transposable elements has caused the large genome of this species. And the identified key genes in the glucomannan biosynthesis provide valuable candidates for molecular breeding of this crop in the future.

Effects of Konjaku Flour on the Gut Microbiota of Obese Patients

OBJECTIVE

Gut microbiota have been thought to play a role in the emergence of obesity and metabolic disorders, thus dietary fiber may be an effective strategy for the management of obesity by modulating the gut microbiota. The aim of the present study was to investigate the effects of konjaku flour (KF) supplementation on treating obesity and regulating intestinal microbiota in obese adults.

METHODS

In a 5-week, randomized, double-blind, place-controlled trial, sixty-nine obese volunteers aged 25 to 35 with body mass index ≥28 kg/m² were randomly assigned to receive KF or placebo (lotus root starch). Obesity index, blood parameters, and gut microbiota were analyzed.

RESULTS

KF remarkably reduced the body mass index (BMI), fat mass, percentage body fat (PBF), serum triglyceride (TG), glycated hemoglobin A1c (HbA1c), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels in the patients (p <0.05 or p <0.01). Meanwhile, high-throughput sequencing and bioinformatics analysis showed that the konjac flour treatment notably increased the α-diversity and changed the β-diversity of intestinal microflora in patients (p <0.01). Moreover, konjac flour could also evidently increase the abundance of some of the beneficial microorganisms related to obesity of patients, such as Lachnospiraceae, Roseburia, Solobacterium, R. inulinivorans, Clostridium perfringens, and Intestinimonas butyriciproducens, and reduce the abundance of the harmful microorganisms, such as Lactococcus, Bacteroides fragilis, Lactococcus garvieae, B. coprophilus, B. ovatus, and B. thetaiotaomicron (p <0.01). Specifically, C. perfringens was significantly negatively correlated with serum total cholesterol (TC) (p <0.01).

CONCLUSION

These results suggested that KF can achieve positive effects on treating obesity, which manifest on reducing BMI, fat mass, blood glucose, and blood lipid, improving hepatic function, and also regulating intestinal microfloral structure. Therefore, changes in gut microbiota may explain in part the effects of KF.