Polysaccharides from soybean residue fermented by Neurospora crassa alleviate DSS-induced gut barrier damage and microbiota disturbance in mice

Compound prebiotics as prophylactic and adjunctive treatments ameliorate DSS-induced colitis through gut microbiota modulation effects

The prophylactic and adjunctive impacts of compound prebiotics (CP), comprising galacto-oligosaccharides, fructo-oligosaccharides, and isomalto-oligosaccharides, on colitis remain unclear. This study aimed to elucidate the effects of CP on dextran sodium sulfate (DSS)-induced colitis via modulation of the gut microbiota. Mice received prophylactic CP (PCP) for three weeks and DSS in the second week. In the third week, therapeutic CP, mesalazine, and a combination of CP and mesalazine (CPM) were administered to mice with DSS-induced colitis. The administration of PCP and CPM was found to ameliorate colitis, as evidenced by increases in body weight and colon length, elevation of the anti-inflammatory cytokine IL-10, and reductions in the disease activity index, histological scores, and levels of pro-inflammatory cytokines in mice with DSS-induced colitis on days 14 or 21. Furthermore, an increase in the relative abundance of probiotics (Ligilactobacillus, Bifidobacterium, and Limosilactobacillus), alpha diversity indices, short-chain fatty acids (SCFA) contents, and microbial network complexity was observed following PCP or CPM treatment. Correlation analysis revealed positive associations between these probiotics and both SCFA and IL-10, and negative associations with pro-inflammatory cytokines. This study highlighted the potential of CP as novel prophylactic and adjunctive treatments for alleviating DSS-induced intestinal inflammation and maintaining gut microbiota homeostasis.

Dietary inulin alleviated constipation induced depression and anxiety-like behaviors: Involvement of gut microbiota and microbial metabolite short-chain fatty acid

Chronic constipation has been associated with depression-like behavior. Previous study identified the crucial role of gut microbiota in the development of constipation and depression. Dietary inulin (INU) could regulate gut microbiota. Whether INU treatment could ameliorate constipation induced depression was not clear. For this purpose, male CD-1 mice were administered diphenoxylate (20 mg/kg body weight/day) to induce constipation. We found that INU (10 % in standard diet) alleviated the diphenoxylate-induced constipation, manifested as the increase weight and moisture content of feces. Furthermore, the associated depression and anxiety-like behavior disorders were improved by inhibiting neuro-inflammation and preventing synaptic ultrastructure damage under INU treatment. Moreover, INU pretreatment improved the diphenoxylate-induced gut barrier damage by upregulating tight junction protein expression. INU also reshaped gut microbiota in constipation mice by increasing the relative abundance of Bacteroides and Proteobacteria and downregulating the abundance of Muribacalum and Melaminabacteria. The effects of INU on diphenoxylate-induced depression were abolished by gut microbiota depletion via antibiotic treatment. In addition, INU increased the concentration of short chain fatty acids (SCFAs) in feces contents. Meanwhile, supplementation of SCFAs could also partly improve diphenoxylate-induced depression. In conclusion, INU intake was a potential nutritional intervention strategy to prevent constipation induced depression via microbiota-gut-SCFAs axis.

EPA and DHA Alleviated Chronic Dextran Sulfate Sodium Exposure-Induced Depressive-like Behaviors in Mice and Potential Mechanisms Involved

Patients with ulcerative colitis (UC) have higher rates of depression. However, the mechanism of depression development remains unclear. The improvements of EPA and DHA on dextran sulfate sodium (DSS)-induced UC have been verified. Therefore, the present study mainly focused on the effects of EPA and DHA on UC-induced depression in C57BL/6 mice and the possible mechanisms involved. A forced swimming test and tail suspension experiment showed that EPA and DHA significantly improved DSS-induced depressive-like behavior. Further analysis demonstrated that EPA and DHA could significantly suppress the inflammation response of the gut and brain by regulating the NLRP3/ASC signal pathway. Moreover, intestine and brain barriers were maintained by enhancing ZO-1 and occludin expression. In addition, EPA and DHA also increased the serotonin (5-HT) concentration and synaptic proteins. Interestingly, EPA and DHA treatments increased the proportion of dominant bacteria, alpha diversity, and beta diversity. In conclusion, oral administration of EPA and DHA alleviated UC-induced depressive-like behavior in mice by modulating the inflammation, maintaining the mucosal and brain barriers, suppressing neuronal damage and reverting microbiota changes.

Soluble dietary fibers from solid-state fermentation of wheat bran by the fungus Cordyceps cicadae and their effects on colitis mice

Ulcerative colitis is a chronic inflammatory disease with a complex pathogenesis for which there is no definitive therapeutic agent. Fermentation, as a green and efficient bioprocessing technique, has been shown to enhance the biological activity of food ingredients. Soluble dietary fiber isolated from plants is thought to have the potential to prevent and alleviate ulcerative colitis. This work was designed to study the differences in the chemical properties of the soluble dietary fiber from wheat bran fermented by Isaria cicadae Miq. (FSDF) and the unfermented soluble dietary fiber from wheat bran (UFSDF) and their effects on colitis mice. The results showed that FSDF and UFSDF differed in molecular weight, monosaccharide compositions, and surface morphology. In addition, supplementation with UFSDF and FSDF ameliorated the symptoms of DSS-induced colitis in mice by attenuating body weight loss, decreasing the disease activity index and splenic index, shortening the length of the colon, and attenuating colonic tissue damage. UFSDF and FSDF also increased the production of the anti-inflammatory cytokine IL-10 and inhibited the expression of IL-6, IL-1β, and TNF-α. The results of gut flora and short-chain fatty acid analyses showed that UFSDF and FSDF improved the diversity of gut microbiota, up-regulated the abundance of some beneficial bacteria such as Akkermansia and Muribaculaceae, increased the levels of acetic acid, propionic acid, and butyric acid, and restored dextran sodium sulfate (DSS)-induced dysbiosis of the intestinal flora in mice. These findings provide guidance for the development of FSDF and UFSDF as functional foods for the relief of ulcerative colitis.

Integrated metabolomics and transcriptomics revealed the anti-constipation mechanisms of xylooligosaccharides from corn cobs

Xylooligosaccharides (XOSs) have recently garnered interest for their potential as an anti-constipation agent. In this study, we investigated the effects of XOSs derived from corn cobs on constipation in mice through a comprehensive analysis of both the metabolome and transcriptome. Our multi-omics approach revealed that XOSs primarily modulated butanoate metabolism and steroid hormone biosynthesis pathways, as well as key signaling pathways such as PPAR and NF-kappa B. Notably, we observed a decrease in inflammatory biomarker expression and an elevation of butyric acid metabolite levels with XOSs treatment. A deeper analysis of gene expression and metabolite alterations highlighted significant changes in genes encoding critical enzymes and metabolites involved in these pathways. Overall, these findings underscore the considerable potential of XOSs derived from corn cobs as a dietary supplement for effectively alleviating constipation.

Recent progress in plant-derived polysaccharides with prebiotic potential for intestinal health by targeting gut microbiota: a review

Natural products of plant origin are of high interest and widely used, especially in the food industry, due to their low toxicity and wide range of bioactive properties. Compared to other plant components, the safety of polysaccharides has been generally recognized. As dietary fibers, plant-derived polysaccharides are mostly degraded in the intestine by polysaccharide-degrading enzymes secreted by gut microbiota, and have potential prebiotic activity in both non-disease and disease states, which should not be overlooked, especially in terms of their involvement in the treatment of intestinal diseases and the promotion of intestinal health. This review elucidates the regulatory effects of plant-derived polysaccharides on gut microbiota and summarizes the mechanisms involved in targeting gut microbiota for the treatment of intestinal diseases. Further, the structure-activity relationships between different structural types of plant-derived polysaccharides and the occurrence of their prebiotic activity are further explored. Finally, the practical applications of plant-derived polysaccharides in food production and food packaging are summarized and discussed, providing important references for expanding the application of plant-derived polysaccharides in the food industry or developing functional dietary supplements.

Carnobacterium maltaromaticum boosts intestinal vitamin D production to suppress colorectal cancer in female mice

Carnobacterium maltaromaticum was found to be specifically depleted in female patients with colorectal cancer (CRC). Administration of C. maltaromaticum reduces intestinal tumor formation in two murine CRC models in a female-specific manner. Estrogen increases the attachment and colonization of C. maltaromaticum via increasing the colonic expression of SLC3A2 that binds to DD-CPase of this bacterium. Metabolomic and transcriptomic profiling unveils the increased gut abundance of vitamin D-related metabolites and the mucosal activation of vitamin D receptor (VDR) signaling in C. maltaromaticum-gavaged mice in a gut microbiome- and VDR-dependent manner. In vitro fermentation system confirms the metabolic cross-feeding of C. maltaromaticum with Faecalibacterium prausnitzii to convert C. maltaromaticum-produced 7-dehydrocholesterol into vitamin D for activating the host VDR signaling. Overall, C. maltaromaticum colonizes the gut in an estrogen-dependent manner and acts along with other microbes to augment the intestinal vitamin D production to activate the host VDR for suppressing CRC.

Characterization and the cholesterol-lowering effect of dietary fiber from fermented black rice (Oryza sativa L.)

Black rice was fermented with Neurospora crassa, after which the dietary fiber (DF) extracted from it was characterized and evaluated for its cholesterol-lowering effect in mice. The findings demonstrated that fermentation increased the level of soluble DF from 17.27% ± 0.12 to 29.69% ± 0.26 and increased the adsorption capacity of DF for water, oil, cholesterol, glucose and sodium cholate. The fermented DF had a more loose and porous structure than that extracted from unfermented rice. Additionally, feeding with DF from the fermented black rice significantly reduced body weight, lowered total cholesterol levels and improved the lipid profile in mice gavaged with a high dose (5 g per kg bw) or a low dose (2.5 g per kg·bw). ELISA showed that the hepatic expression of typical proteins and enzymes that are involved in cholesterol metabolism was regulated by the fermented rice DF, leading to reduced cholesterol production and increased cholesterol clearance. The fermented DF also modified the gut microbiota composition (e.g. Firmicutes reduced and Akkermansia increased), which promoted the production of short-chain fatty acids. In conclusion, fermentation can modify the structure and function of DF in black rice and the fermented dietary fiber has excellent cholesterol lowering effects possibly by cholesterol adsorption, cholesterol metabolism modulation, and intestinal microflora regulation.

Smilax china L. Polysaccharide Alleviates Dextran Sulphate Sodium-Induced Colitis and Modulates the Gut Microbiota in Mice

This work aimed to investigate the preventive effect of Smilax china L. polysaccharide (SCP) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. Smilax china L. polysaccharide was isolated by hot water extraction, ethanol precipitation, deproteinization, and purification using DEAE-cellulose column chromatography to yield three polysaccharides: SCP_C, SCP_A, and SCP_N. Acute colitis was induced by administering 3% (w/v) DSS in drinking water for 7 days. Sulfasalazine, SCP_C, SCP_A, and SCP_N were administered by gavage for 9 days. SCP_C, SCP_A, and SCP_N could significantly improve symptoms, as evidenced by the declining disease activity index (DAI), decreased spleen weight, increased length of the colon, and improved colonic histology. Moreover, SCP_C, SCP_A, and SCP_N increased serum glutathione and decreased the levels of pro-inflammatory cytokines, malondialdehyde, nitric oxide, and myeloperoxidase in colon tissues. Additionally, SCP_C, SCP_A, and SCP_N modulated gut microbiota via ascending the growth of Lachnospiraceae, Muribaculaceae, Blautia, and Mucispirillum and descending the abundance of Akkermansiaceae, Deferribacteraceae, and Oscillibacter in mice with UC. The results suggested that Smilax china L. polysaccharide ameliorates oxidative stress, balances inflammatory cytokines, and modulates gut microbiota, providing an effective therapeutic strategy for UC in mice.

Fucoidan Ameliorated Dextran Sulfate Sodium-Induced Ulcerative Colitis by Modulating Gut Microbiota and Bile Acid Metabolism

Gut dysbiosis and bile acid (BA) metabolism disturbance are involved in the pathogenesis of ulcerative colitis. This study aimed to investigate the effect of fucoidan on BA metabolism and gut microbiota in dextran sulfate sodium-induced colitis mice. Our results showed that fucoidan effectively suppressed colonic inflammation and repaired the gut barrier. In addition, fucoidan increased the relative abundance of the Lachnospiraceae family, such as Turicibacter, Muribaculum, Parasutterella, and Colidextribacter, followed by an increase in short-chain fatty acids, especially in butyrate. Moreover, fucoidan modulated bile acid metabolism by elevating cholic acid, ursodeoxycholic acid, deoxycholic acid, and lithocholic acid and decreasing β-muricholic acid, which led to activation of FXR and TGR5 and further enhanced the gut barrier and suppressed colonic inflammation. Our results revealed that the effect of fucoidan alleviating colitis was largely mediated by gut microbiota, which was confirmed by the fecal transplantation experiment. Collectively, these findings provided the basis for fucoidan as a potential functional food for colitis.

Safety evaluation of Neurospora crassa mycoprotein for use as a novel meat alternative and enhancer

Cultivation of filamentous fungi to produce sustainable, nutrient rich meat replacements has recently attracted significant commercial and research interest. Here, we report evidence for the safety and nutritional value of Neurospora crassa mycoprotein, a whole mycelium food ingredient produced by fermentation and minimal downstream processing. N. crassa has a long history of human use in fermented foods and in molecular biology research. A survey of studies that used N. crassa in animal feed revealed no adverse effects to the health of the animals. Furthermore, a review of the literature found no reports of confirmed allergenicity or toxicity in humans involving N. crassa. Genomic toxigenicity analysis and in vitro testing did not identify any toxins in N. crassa mycoprotein. Two independent genomic allergenicity studies did not identify proteins that would be considered a particular risk for allergenic potential. Furthermore, nutritional analysis demonstrated that N. crassa mycoprotein is a good source of complete protein and is rich in fiber, potassium, and iron. Taken together, the presented data and the history of human use without evidence of human or animal harm indicate that foods containing N. crassa can generally be regarded as safe.