Feruloylated oligosaccharides and ferulic acid alter gut microbiome to alleviate diabetic syndrome

Feruloylated arabinoxylan from wheat bran inhibited M1-macrophage activation and enhanced M2-macrophage polarization

The effects of feruloylated arabinoxylan (AX) on typically activated inflammatory macrophages (M1) and alternatively anti-inflammatory macrophages (M2) and its possible mechanisms were investigated. The results revealed that feruloylated AX was composed of 37.63% arabinose and 52.23% xylose, with a weight-average molecular weight of 1.1374 × 10⁴ Da, and bound ferulic acid content of 10.84 mg/g. Besides, feruloylated AX (50-1000 μg/mL) markedly downregulated the mRNA expressions of NO, IL-1β, TNF-α, IL-6, and IL-23a, and reduced the phosphorylation levels of p38, ERK, and JNK in M1. In contrast, the mRNA expressions of Arg-1, Mrc-1, and CCL22 were significantly upregulated by feruloylated AX (50-1000 μg/mL), and the phosphorylation level of AKT was significantly increased in M2. Overall, our results indicated that feruloylated AX could have an inhibitory or a promoting effect on already activated macrophages, and MAPK or PI3K signaling pathways might be involved in this regulation.

Metformin inhibits tumor growth and affects intestinal flora in diabetic tumor-bearing mice

Many studies have found that diabetes increases the risk of some cancers such as hepatocellular carcinoma. However, there are few studies on the relationship between the two diseases and their effects on intestinal flora. Therefore, we used streptozotocin and high-fat diet to establish a mouse model of type 2 diabetes, and then inoculated the Huh-7 hepatocellular carcinoma cells to obtain mouse diabetic tumor model. Mice inoculated with Huh-7 cells alone served as control. The tumor size in the diabetic tumor group was significantly higher than that in the tumor group. Our study also showed that the expression levels of inflammation-related factors (TNFα, IL-1β, IL-6, TLR4 and MCP1) in the diabetic tumor group were significantly higher than that in the tumor group. We found that metformin alleviated blood glucose level, reduced the expressions of inflammation-related factors and retarded xenograft tumor growth in the diabetic tumor group, but it couldn't reduce the tumor growth in the tumor group. Subsequent studies found that the content of some short chain fatty acids (SCFAs) including acetic acid, propionic acid and isobutyric acid decreased significantly in diabetic tumor group. Metformin increased short chain fatty acid levels (acetic acid, butyic acid and valeric acid) and enriched the abundance of SCFA-producing bacterial genera such as Ruminococcaceae, Clostridiales, Anaerovorax, Odoribacter and Marvinbryantia. In conclusion, type 2 diabetes could promote the growth of hepatoma cells in mice. Metformin could inhibit the growth of tumor under the condition of diabetes and play a role in the intestinal homeostasis in mice.

Omnifarious fruit polyphenols: an omnipotent strategy to prevent and intervene diabetes and related complication?

Diabetes mellitus is a metabolic syndrome which cannot be cured. Recently, considerable interest has been focused on food ingredients to prevent and intervene in complications of diabetes. Polyphenolic compounds are one of the bioactive phytochemical constituents with various biological activities, which have drawn increasing interest in human health. Fruits are part of the polyphenol sources in daily food consumption. Fruit-derived polyphenols possess the anti-diabetic activity that has already been proved either from in vitro studies or in vivo studies. The mechanisms of fruit polyphenols in treating diabetes and related complications are under discussion. This is a comprehensive review on polyphenols from the edible parts of fruits, including those from citrus, berries, apples, cherries, mangoes, mangosteens, pomegranates, and other fruits regarding their potential benefits in preventing and treating diabetes mellitus. The signal pathways of characteristic polyphenols derived from fruits in reducing high blood glucose and intervening hyperglycemia-induced diabetic complications were summarized.

Enzymatic Production of Xylo-oligosaccharides from Destarched Wheat Bran and the Impact of Their Degree of Polymerization and Substituents on Their Utilization as a Carbon Source by Probiotic Bacteria

The enzymatic production of xylo-oligosaccharides (XOs) from destarched wheat bran with a GH11 xylanase was studied. Xylo-oligosaccharides (XOs) produced were separated into different fractions according to their degree of polymerization (DP) and the nature of their substituents: arabinoxylo-oligosaccharides (AXOs) with a DP from 2 to 3 and DP from 2 to 6 and feruloylated arabinoxylo-oligosaccharides (FAXOs) esterified by ferulic and p-coumaric acids with a DP from 3 to 6. Both AXOs (short and long DP) and FAXOs stimulated the growth of Bifidobacterium adolescentis, Faecalibacterium prausnitzii, and Prevotella copri similarly but not Lactobacillus rhamnosus. The utilization of AXOs and FAXOs as a carbon source resulted in the increase in turbidity, decrease in pH, and production of short-chain fatty acids (SCFAs) in the culture broth. The highest amount of SCFAs was produced by F. prausnitzii using FAXOs. Results suggest that FAXOs and AXOs have the potential to be considered as prebiotics.

GuanXinNing Tablet Attenuates Alzheimer's Disease via Improving Gut Microbiota, Host Metabolites, and Neuronal Apoptosis in Rabbits

Based on accumulating evidence, Alzheimer's disease (AD) is related to hypercholesterolemia, gut microbiota, and host metabolites. GuanXinNing Tablet (GXN) is an oral compound preparation composed of two Chinese herbs, Salvia miltiorrhiza Bge. and Ligusticum chuanxiong Hort., both of which exert neuroprotective effects. Nevertheless, the effect of GXN on AD is unknown. In the present study, we investigated whether GXN alters cholesterol, amyloid-beta (Aβ), gut microbiota, serum metabolites, oxidative stress, neuronal metabolism activities, and apoptosis in an AD model rabbit fed a 2% cholesterol diet. Our results suggested that the GXN treatment significantly reduced cholesterol levels and Aβ deposition and improved memory and behaviors in AD rabbits. The 16S rRNA analysis showed that GXN ameliorated the changes in the gut microbiota, decreased the Firmicutes/Bacteroidetes ratio, and improved the abundances of Akkermansia and dgA-11_gut_group. ¹H-NMR metabolomics found that GXN regulated 12 different serum metabolites, such as low-density lipoprotein (LDL), trimethylamine N-oxide (TMAO), and glutamate (Glu). In addition, the ¹H-MRS examination showed that GXN remarkably increased N-acetyl aspartate (NAA) and Glu levels while reducing myo-inositol (mI) and choline (Cho) levels in AD rabbits, consequently enhancing neuronal metabolism activities. Furthermore, GXN significantly inhibited oxidative stress and neuronal apoptosis. Taken together, these results indicate that GXN attenuates AD via improving gut microbiota, host metabolites, and neuronal apoptosis.

Supplemental L-Arginine Improves the Embryonic Intestine Development and Microbial Succession in a Chick Embryo Model

Early colonization of intestinal microbiota plays an important role in intestinal development. However, the microbial succession at an embryonic stage and its assembly patterns induced by prenatal nutrition are unknown. In the present study, we used a chick embryo model to investigate the effects of in ovo feeding (IOF) of L-arginine (Arg) on the intestinal development and microbial succession of embryos. A total of 216 fertile eggs were randomly distributed into 2 groups including the non-injected control group and IOF of Arg group with 7 mg/egg. The results showed that IOF Arg increased the intestinal index, absolute weight of jejunum, and improved jejunal morphology in terms of villus width and surface area (p < 0.05). The relative mRNA expressions of mTOR and 4E-BP1 were up-regulated and accompanied by higher contents of Mucin-2 in the Arg group (p < 0.05). There was a significant elevation in contents of serum glucose and high-density lipoprotein cholesterol, whereas there was a decreased low-density lipoprotein cholesterol in the Arg group (p < 0.05). Additionally, Proteobacteria and Firmicutes were major intestinal bacteria species at the embryonic stage. However, Arg supplementation targeted to shape assembly patterns of microbial succession and then changed microbial composition (p = 0.05). Meanwhile, several short-chain fatty acids (SCFAs)-producing bacteria, such as Roseburia, Blautia, and Ruminococcus were identified as biomarkers in the Arg group (LDA > 3, p < 0.05). Accordingly, significant elevated concentrations of SCFAs, including lactic acid and formic acid, were observed in the Arg group (p < 0.05), accompanied by the higher concentration of butyric acid (0.05 < p < 0.10). In conclusion, prenatal Arg supplementation improved embryonic intestine development by regulating glucose and lipid homeostasis to supply more energy for chick embryos. The possible mechanism could be the roles of Arg in shaping the microbial assembly pattern and succession of the embryonic intestine, particularly the enrichment of potential probiotics. These findings may contribute to exploring nutritional strategies to establish health-promoting microbiota by manipulating prenatal host-microbe interactions for the healthy development of neonates.

Impact of Plant-Based Meat Alternatives on the Gut Microbiota of Consumers: A Real-World Study

Eating less meat is increasingly seen as a healthier, more ethical option. This is leading to growing numbers of flexitarian consumers looking for plant-based meat alternatives (PBMAs) to replace at least some of the animal meat they consume. Popular PBMA products amongst flexitarians, including plant-based mince, burgers, sausages and meatballs, are often perceived as low-quality, ultra-processed foods. However, we argue that the mere industrial processing of ingredients of plant origin does not make a PBMA product ultra-processed by default. To test our hypothesis, we conducted a randomised controlled trial to assess the changes to the gut microbiota of a group of 20 participants who replaced several meat-containing meals per week with meals cooked with PBMA products and compared these changes to those experienced by a size-matched control. Stool samples were subjected to 16S rRNA sequencing. The resulting raw data was analysed in a compositionality-aware manner, using a range of innovative bioinformatic methods. Noteworthy changes included an increase in butyrate metabolising potential-chiefly in the 4-aminobutyrate/succinate and glutarate pathways-and in the joint abundance of butyrate-producing taxa in the intervention group compared to control. We also observed a decrease in the Tenericutes phylum in the intervention group and an increase in the control group. Based on our findings, we concluded that the occasional replacement of animal meat with PBMA products seen in flexitarian dietary patterns can promote positive changes in the gut microbiome of consumers.

Cyanidin-3-O-glucoside and its phenolic metabolites ameliorate intestinal diseases via modulating intestinal mucosal immune system: potential mechanisms and therapeutic strategies

The incidence of the intestinal disease is globally increasing, and the intestinal mucosa immune system is an important defense line. A potential environmental cause to regulate gut health is diet. Cyanidin-3-O-glucoside is a natural plant bioactive substance that has shown rising evidence of improving intestinal disease and keeping gut homeostasis. This review summarized the intestinal protective effect of Cyanidin-3-O-glucoside in vivo and in vitro and discussed the potential mechanisms by regulating the intestinal mucosal immune system. Cyanidin-3-O-glucoside and phenolic metabolites inhibited the presence and progression of intestinal diseases and explained from the aspects of repairing the intestinal wall, inhibiting inflammatory reaction, and regulating the gut microbiota. Although the animal and clinical studies are inadequate, based on the accumulated evidence, we propose that the interaction of Cyanidin-3-O-glucoside with the intestinal mucosal immune system is at the core of most mechanisms by which affect host gut diseases. This review puts forward the potential mechanism of action and targeted treatment strategies.

Effects of Dietary Ferulic Acid on the Intestinal Microbiota and the Associated Changes on the Growth Performance, Serum Cytokine Profile, and Intestinal Morphology in Ducks

The present study investigated the effects of ferulic acid (FA) on the growth performance, serum cytokine profile, intestinal morphology, and intestinal microbiota in ducks at the growing stage. 300 female Linwu ducks at 28 days of age with similar body weights were randomly divided into five groups. Each group contained six replicates of 10 birds. The dietary treatments were corn-soybean-based diet supplemented with FA at the concentrations of 0 (control), 100, 200, 400, and 800 mg/kg diet. The results demonstrated that dietary FA at the levels of 200, 400, and 800 mg/kg increased the average daily gain (P = 0.01), 400 and 800 mg/kg FA increased the final body weight (P = 0.02), 100, 200, and 800 mg/kg FA increased the serum glutathione (P = 0.01), and 100, 400, and 800 mg/kg FA increased the glutathione peroxidase activities in birds (P < 0.01). Additionally, 200, 400, and 800 mg/kg dietary FA lowered the serum levels of interleukin-2 (P = 0.02) and interleukin-6 (P = 0.04). Moreover, the morphometric study of the intestines indicated that 400 mg/kg FA decreased the crypt depth in jejunum (P = 0.01) and caecum (P = 0.04), and increased the ratio of villus height to crypt depth in jejunum (P = 0.02). Significant linear and/or quadratic relationships were found between FA concentration and the measured parameters. 16S rRNA sequencing revealed that dietary FA increased the populations of genera Faecalibacterium, Paludicola, RF39, and Faecalicoccus in the cecum (P < 0.05), whereas decreased the populations of Anaerofilum and UCG-002 (P < 0.05). The Spearman correlation analysis indicated that phylum Proteobacteria were negatively, but order Oscillospirales, and family Ruminococcaceae were positively related to the parameters of the growth performance. Phylum Bacteroidetes, class Negativicutes and family Rikenellaceae were negatively associated with the parameters of the antioxidative capability. And phylum Cyanobacteria, Elusimicrobia, and Bacteroidetes, class Bacilli, family Rikenellaceae, and genus Prevotella were positively associated with the parameters of the immunological capability. Thus, it was concluded that the supplementations of 400 mg/kg FA in diet was able to improve the growth performance, antioxidative and immunological capabilities, intestinal morphology, and modulated the gut microbial construction of Linwu ducks at the growing stage.

Characterization of Feruloyl Esterase from Bacillus pumilus SK52.001 and Its Application in Ferulic Acid Production from De-Starched Wheat Bran

Feruloyl esterase (FAE; EC 3.1.1.73) catalyzes the hydrolysis of the 4-hydroxy-3-methoxycinnamoyl group in an esterified sugar to assist in waste biomass degradation or to release ferulic acid (FA). An FAE-producing strain was isolated from humus soil samples and identified as Bacillus pumilus SK52.001. The BpFAE gene from B. pumilus SK52.001 was speculated and heterogeneously expressed in Bacillus subtilis WB800 for the first time. The enzyme exists as a monomer with 303 amino acids and a molecular mass of 33.6 kDa. Its specific activity was 377.9 ± 10.3 U/ (mg protein), using methyl ferulate as a substrate. It displays an optimal alkaline pH of 9.0, an optimal temperature of 50 °C, and half-lives of 1434, 327, 235, and 68 min at 50, 55, 60, and 65 °C, respectively. Moreover, the purified BpFAE released 4.98% FA of the alkali-acidic extractable FA from de-starched wheat bran (DSWB). When the DSWB was enzymatically degraded by the synergistic effect of the BpFAE and commercial xylanase, the FA amount reached 49.47%. It suggested that the alkaline BpFAE from B. pumilus SK52.001, which was heterologously expressed in B. subtilis WB800, possesses great potential for biomass degradation and achieving high-added value FA production from food by-products.

Broccoli microgreens juice reduces body weight by enhancing insulin sensitivity and modulating gut microbiota in high-fat diet-induced C57BL/6J obese mice

PURPOSE

This study aimed to explore the protective effect of broccoli microgreens juice (BMJ) during C57BL/6J mice obesity development.

METHODS

The obese model mice, induced by feeding high-fat diet (HFD), were treated with BMJ by gavage for 10 weeks. Melbine was gavaged at 300 mg/(kg bw)/d, as a positive control group.

RESULTS

BMJ supplementation significantly reduced white adipose tissues (WAT) mass, the body weight and adipocyte size, and increased water intake in HFD-fed mice. Moreover, it improved glucose tolerance, reduced insulin level and HOMA-IR value, and alleviated insulin resistance. Compared with the HFD group, BMJ supplementation significantly increased the relative abundance of Bacteroidetes and decreased the ratio of Firmicutes to Bacteroidetes at the phylum level, and enriched Bacteroides_acidifaciens at the species level. These changes in the composition of gut microbiota are associated with the production of short-chain fatty acids (SCFAs), and reduced LPS levels, and had an obvious anti-inflammatory effect.

CONCLUSIONS

These findings suggested that the protective effects of BMJ on diet-induced obesity may be involved in gut microbiota-SCFAs-LPS-inflammatory axis. In addition, BMJ can enhance liver antioxidant capacity and reduce liver fat accumulation. Consequently, these results sustain BMJ as a novel functional food for obesity, on the basis of its opposing effects on HFD-induced obesity in mice.

Feruloylated Arabinoxylan and Oligosaccharides: Chemistry, Nutritional Functions, and Options for Enzymatic Modification

Cereal brans and grain endosperm cell walls are key dietary sources of different types of arabinoxylan. Arabinoxylan is the main group of hemicellulosic polysaccharides that are present in the cell walls of monocot grass crops and hence in cereal grains. The arabinoxylan polysaccharides consist of a backbone of β-(1→4)-linked xylopyranosyl residues, which carry arabinofuranosyl moieties, hence the term arabinoxylan. Moreover, the xylopyranosyl residues can be acetylated or substituted by 4-O-methyl-d-glucuronic acid. The arabinofuranosyls may be esterified with a feruloyl group. Feruloylated arabinoxylo-oligosaccharides exert beneficial bioactivities via prebiotic, immunomodulatory, and/or antioxidant effects. New knowledge on microbial enzymes that catalyze specific structural modifications of arabinoxylans can help us understand how these complex fibers are converted in the gut and provide a foundation for the production of feruloylated arabinoxylo-oligosaccharides from brans or other cereal grain processing sidestreams as functional food ingredients. There is a gap between the structural knowledge, bioactivity data, and enzymology insight. Our goal with this review is to present an overview of the structures and bioactivities of feruloylated arabinoxylo-oligosaccharides and review the enzyme reactions that catalyze specific changes in differentially substituted arabinoxylans.

Gut microbiota, key to unlocking the door of diabetic kidney disease

This review discusses the influence of gut microbiota dysbiosis on diabetic kidney disease through metabolite profile changes and immune and inflammatory mechanisms. We also elaborate on the mechanism of dysbiosis in the onset and development of other kidney diseases.

This review presents scientific evidence on the pathophysiologic links between gut microbiota and diabetic kidney disease (DKD), highlighting the influence of gut microbiota dysbiosis on DKD through metabolite profile changes and immunologic mechanisms.

Gut Microbiota of Chinese Obese Children and Adolescents With and Without Insulin Resistance

OBJECTIVE

The intestinal flora of gut microbiota in obese Chinese children and adolescents with and without insulin resistance (IR) was analyzed, as well as associations between the gut microbiota and two serum cytokines related to glucose metabolism, adropin and angiopoietin-like 4 (ANGPTL4).

METHODS

Clinical data, fecal bacterial composition, glucose-related hormones, and serum adipokines (adropin and ANGPTL4) were analyzed in 65 Chinese children with exogenous obesity. The composition of the gut microbiota was determined by 16S rRNA-based metagenomics and IR was calculated using the homeostasis model assessment (HOMA).

RESULTS

The 65 obese subjects were divided into two groups: insulin sensitive (IS) (n=40, 57.5% males) or IR (n=25, 60% males). Principal coordinates analysis revealed that the gut microbiota samples from the IS group clustered together and separated partly from the IR group (p=0.008). By Mann-Whitney U-test, at a phylum level, a reduction of Firmicutes and an increase of Bacteroidetes in the IR subjects was observed. LEfSe analysis revealed that IS subject, when compared to their IR counterparts, harbored members of the order Coriobacteriales, Turicibacterales, Pasteurellales and family Turicibacteraceae, that were significantly more abundant. In contrast, the IR subjects had members of family Peptococcaceae that were significantly more prevalent than the IS subjects (all p<0.05). Spearman's correlation analysis revealed that serum ANGPTL4 was positively associated with genus Bacteroides, Butyricimonas, and Alistipes, and adropin was positively associated with genus Anaerostipes and Alistipes, and negatively associated with genus Blautia (all p<0.05).

CONCLUSION

In obese children, the gut microbiome in IR subjects was significantly discordant from the IS subjects, and the abundance of some metabolism-related bacteria correlated with the serum concentrations of adropin and ANGPTL4. These observations infer that the gut microbiota may be involved in the regulation of glucose metabolism in obesity.

Feruloylated Oligosaccharides Alleviate Central Nervous Inflammation in Mice Following Spinal Cord Contusion

As one of the empirical models of the chronic central inflammatory response, a spinal cord injury (SCI) deteriorates the neuronal survival and results in irreversible motor and sensory dysfunction below the injury area. Our previous studies have reported that maize bran feruloylated oligosaccharides (FOs) exert significant anti-inflammatory activities both in diabetes and colitis. However, no direct evidence of FOs alleviating central nervous inflammation was stated. This study aimed to investigate the therapeutic effect of FOs on SCI and its potential mechanism. Our results indicated that 4 weeks of FO administration effectively mitigated the inflammatory response via decreasing the number of microglia (labelled with Iba1), result in the expression of IL-1α, IL-2, IL-6, IL-18 and TNF-α downregulating, but the level of IL-10 and BDNF increases in the injured spinal cord. Moreover, FOs enhanced neuronal survival, ameliorated the scar cavities, and improved behaviors, including Basso mouse scale (BMS) scores and the gait of mice after SCI. Together, these results demonstrated that administration of FOs showed superior functional recovery effects in a SCI model. Also, FOs may modulate inflammatory activities by regulating the expression of proinflammatory factors, decreasing the production of inflammatory cells, and promoting functional recovery through the MAPK pathway following SCI.

Hypoglycemic Effect of Prolamin from Cooked Foxtail Millet (Setaria italic) on Streptozotocin-Induced Diabetic Mice

Millet proteins have been demonstrated to possess glucose-lowering and lipid metabolic disorder modulation functions against diabetes; however, the molecular mechanisms underlying their anti-diabetic effects remain unclear. The present study aimed to investigate the hypoglycemic effect of prolamin from cooked foxtail millet (PCFM) on type 2 diabetic mice, and explore the gut microbiota and serum metabolic profile changes that are associated with diabetes attenuation by PCFM. Our diabetes model was established using a high-fat diet combined with streptozotocin before PCFM or saline was daily administrated by gavage for 5 weeks. The results showed that PCFM ameliorated glucose metabolism disorders associated with type 2 diabetes. Furthermore, the effects of PCFM administration on gut microbiota and serum metabolome were investigated. 16S rRNA gene sequencing analysis indicated that PCFM alleviated diabetes-related gut microbiota dysbiosis in mice. Additionally, the serum metabolomics analysis revealed that the metabolite levels disturbed by diabetes were partly altered by PCFM. Notably, the decreased D-Glucose level caused by PCFM suggested that its anti-diabetic potential can be associated with the activation of glycolysis and the inhibition of gluconeogenesis, starch and sucrose metabolism and galactose metabolism. In addition, the increased serotonin level caused by PCFM may stimulate insulin secretion by pancreatic β-cells, which contributed to its hypoglycemic effect. Taken together, our research demonstrated that the modulation of gut microbiota composition and the serum metabolomics profile was associated with the anti-diabetic effect of PCFM.