Dihydroquercetin supplement alleviates colonic inflammation potentially through improved gut microbiota community in mice

Gut dysbiosis exacerbates inflammatory liver injury induced by environmentally relevant concentrations of nanoplastics via the gut-liver axis

As an emerging and potentially threatening pollutant, nanoplastics (NPs) have received considerable global attention. Due to their physical properties and diminutive size, NPs ingestion can more easily cross biological barriers and enter the human and animal body. Despite reports of hepatotoxicity associated with NPs, their impact and potential underlying mechanisms remain elusive. In this study, we investigated the impact of NPs at concentrations found in the environment on the gut flora, intestinal barrier function, liver pyroptosis, and inflammation in mice following 12 weeks of exposure. To further validate the involvement of gut flora in inflammatory liver damage caused by NPs, we utilized antibiotics to remove the intestinal flora and performed fecal microbiota transplantation. We confirmed that NPs exposure altered the gut microbiota composition, with a notable rise in the proportions of Alloprevotella and Ileibacterium while causing a decrease in the relative proportions of Dubosiella. This disruption also affected the gut barrier, increasing lipopolysaccharides in circulation and promoting liver pyroptosis. Importantly, mice receiving fecal transplants from NPs-treated mice showed intestinal barrier damage, liver pyroptosis, and inflammation. However, NPs effects on the intestinal barrier and liver pyroptosis were attenuated by antibiotics depletion of the commensal microbiota. In summary, our current research revealed that extended exposure to environmentally relevant concentrations of NPs resulted in inflammatory damage to the liver. Additionally, we have identified for the first time that imbalances in intestinal flora are crucial in liver pyroptosis induced by NPs.

Unraveling the protective mechanisms and bioactive components of litchi polysaccharides in intestinal health

In recent years, the rise in intestinal disease has driven the hunt for safer, cost-effective alternatives to traditional, side-effect-laden medications. Litchi polysaccharide (LP), derived from litchi pulp, has emerged as a potential intestinal protector, but its efficacy has not been well-established. Our study have demonstrated LP significantly preserves the integrity of the intestinal barrier in both Caenorhabditis elegans model and antibiotic-exposed mice. Furthermore, LP regulates the gut microbiota, promoting the dominance of beneficial bacteria such as Anaerostipes and Lachnoclostridium in antibiotic-exposed mice and elevating the levels of short-chain fatty acids (SCFAs). LP2-a, a key component making up 11.13 % of LP and with a molecular weight of 72,477 Da, has been isolated and identified as the main active agent. Its molecular structure, featuring galactose and arabinose and possessing a main chain composed of specific sugar units and side chains, is crucial for its protective effects. In C. elegans, LP2-a regulates the expression of intestinal structure-related genes, including up-regulating the expression of act-5 and down-regulating the levels of ajm-1, erm-1, and zoo-1, protecting the integrity of the intestinal barrier. This study provides a theoretical foundation for the potential use of LP, particularly LP2-a, in the treatment of intestinal diseases.

Lactobacillus complex fermentation of whey protein to reduce foodborne allergy symptoms in mice

Bovine whey protein, a common ingredient in foods for infants and young children, represents the primary source of nutrition for this demographic. However, bovine whey protein contains β-lactoglobulin (β-LG), which is not found in human whey protein, and some α-lactalbumin (α-LA) with a different amino acid sequence, which has the potential to cause allergic reactions. Eating bovine whey protein can cause allergic reactions in the human immune system. This phenomenon refers to an allergy to bovine whey protein. It is estimated that this condition affects 1.9% to 4.9% of infants globally. Lactobacilli possess a robust protein hydrolysis system capable of disrupting epitopes associated with whey protein allergies while yielding hydrolyzed products and bioactive peptides. This process represents a safe and effective approach to reducing the allergenicity of milk. Consequently, we established a mouse model for whey protein allergy and evaluated the effects of fermented whey protein produced by Lactobacillus on allergic symptoms in mice using ELISA, real-time fluorescence quantitative PCR (RT-qPCR), and HE staining techniques. Furthermore, we analyzed the intestinal flora of allergic mice through 16S rDNA sequencing to elucidate the relationship between Lactobacillus-mediated alterations in gut microbiota and allergic phenotypes within this study. The results showed that compared with the whey protein group, the levels of immunoglobulin E (IgE), histamine and mast cell protease in the serum of mice in the lactic acid bacteria fermented whey protein group were significantly increased, and the secretion of T helper 2 (Th2) type cytokines was inhibited, the production of T helper 1 (Th1) type cytokines was promoted, and the inflammation caused by sensitized mice was significantly alleviated. Furthermore, the fermentation of whey protein by Lactobacillus resulted in an improvement in the intestinal flora of mice, accompanied by promotion of the growth of probiotics such as Lactobacillus, Odoribacter and Bacteroides. This effectively alleviated the allergic reaction in mice. The findings of this experiment provide a theoretical basis for the development of hypoallergenic dairy products and offer a certain degree of guidance for the clinical treatment of allergic diseases.

TENS improves CFL injury rat and regulates the intestinal microbiota

AIM

This study revealed the mechanism of transcutaneous electrical nerve stimulation (TENS) for improving the calcaneofibular ligament (CFL) injury rats by regulating the intestinal microbiota.

METHODS

After 1, 2, and 3 weeks of TENS treatment, the improvement of CFL injury rats model and the expressions of IL-1β/NF-κB/IL-17 signaling pathway were measured. Then the intestinal microbiota was analyzed by 16S rDNA sequencing and its functions related to improve CFL injury rat were analyzed.

RESULTS

TENS could improved the athletic ability of CFL injury rats and reduced the expressions of IL-1β/NF-κB by regulating the IL-17 signaling pathway. By 16S rDNA sequencing analysis, the TENS treatment improved the intestinal dysbacteriosisof CFL injury rats and decrease pathogenic bacteria Ruminococcus and Dubosiella. The changed intestinal microbiota maybe relative with the ankle injury, whereas the increase in probiotics (Bacteroides and Lactobacillus) was relative with anti-inflammation.

CONCLUSION

TENS could down-regulate the expressions of IL-1β/NF-κB to improve CFL injury rat. TENS could change the intestinal microbiota of CFL rats and the changed bacteria whose function related to anti-inflammation could improve CFL rat. The intestinal microbiota could become a potential treatment for CFL injury.

Preventive effects of taxifolin on dental caries in vitro and in vivo

OBJECTIVES

The present study aimed to explore the inhibitory effect of taxifolin (TAX) on Streptococcus mutans (S. mutans) in vitro and evaluated the anti-caries efficacy of TAX in vivo.

DESIGN

The anti-microbial and anti-biofilm properties of TAX were examined on the S. mutans, and the results were preliminarily verified by quantitative real-time PCR. Polarized light microscopy and transverse microradiography were used to detect the effect of TAX on inhibiting enamel demineralization. The effect of TAX on the remineralization of demineralized enamel was analyzed by a microhardness tester, atomic force microscope, and transverse microradiography. The rat dental caries model was constructed to explore the anti-caries effect of TAX in vivo.

RESULTS

The minimum inhibitory concentration of TAX against S. mutans was 1 mg/mL. The 1 mg/mL TAX impeded the biofilm formation, destroyed the biofilm structure, and effectively prevented enamel demineralization caused by S. mutans. Both the 0.5 mg/mL and 1 mg/mL TAX-treated groups exhibited a higher percentage of surface microhardness recovery, along with lower surface roughness, mineral loss, and lesion depth. Additionally, 1 mg/mL TAX demonstrated the ability to inhibit the initiation and progression of caries in rats, while also proving to be biologically safe.

CONCLUSIONS

TAX had a significant inhibitory effect on S. mutans, could inhibit enamel demineralization and promote remineralization of demineralized enamel, and showed a promising anti-caries effect in vivo.

5-aminosalicylic acid alleviates colitis and protects intestinal barrier function by modulating gut microbiota in mice

5-aminosalicylic acid (5-ASA) is widely used in the treatment of ulcerative colitis (UC), but its anti-inflammatory mechanism is complex and has not been fully understood. DSS model was used to test the effect of 5-ASA. Tight junction and Ki-67 were detected by western blot, immunofluorescence, and immunohistochemistry or qPCR. 16S rRNA gene sequencing of gut microbiota and subsequent bioinformatics and statistical analysis were performed to identify the specific bacteria which were associated with the treatment effect of 5-ASA. GC-MS was performed to test short-chain fatty acids (SCFAs). Antibiotic-treated mice were used to demonstrate the key role of endogenous gut microbiota. Here, we found that 5-ASA alleviated dextran sulfate sodium (DSS)-induced colitis in mice. Moreover, 5-ASA significantly repaired the intestinal barrier. At the molecular level, 5-ASA markedly raised the expression of tight junction proteins including JAM-A and occludin and cell proliferation marker Ki-67 in mice. In addition, bacterial 16S rRNA gene sequencing and bioinformatics analysis showed that 5-ASA significantly modulated the DSS-induced gut bacterial dysbiosis. In detail, it stimulated the growth of protective bacteria belonging to Faecalibaculum and Dubosiella, which were negatively correlated with colitis parameters, and blocked the expansion of pro-inflammatory bacteria such as Escherichia-Shigella and Oscillibacter, which were positively correlated with colitis in mice. Meanwhile, 5-ASA increased the cecal acetate level. Most notably, 5-ASA was no longer able to treat colitis and reverse gut barrier dysfunction in antibiotic-treated mice that lacked endogenous gut microbiota. Our data suggested that the anti-inflammatory activity of 5-ASA required the inherent intestinal flora, and the gut microbiota was a potential and effective target for the treatment of ulcerative colitis.

Intestinal overexpression of Pla2g10 alters the composition, diversity and function of gut microbiota in mice

The intestinal microbiota is important for the health of the host and recent studies have shown that some genes of the host regulated the composition of the intestinal microbiota. Group 10 phospholipase A2 (PLA2G10) is a member of the lipolytic enzyme family PLA2, which hydrolyze the ester bond at the sn-2 position of phospholipids to produce free fatty acids and lysophospholipids. PLA2G10 is secreted into the intestinal lumen, but its impact on the gut microbiota remains unclear. In this study, we generated intestine-specific Pla2g10 knock-in mice, and used 16S RNA sequencing to compare their gut microbiota with that of their wild-type (WT) littermates. Results showed that gut-specific Pla2g10 knock-in induced both PLA2G10 mRNA and protein levels in the colon. Moreover, intestinal Pla2g10 overexpression reduced the α-diversity of the gut microbiota relative to that of WT mice. The abundance of Bacteroidetes was lower in the Pla2g10 knock-in mice than that in the control mice, while the ratio of Firmicutes/Bacteroidetes was higher. Furthermore, the abundance of the genus Allobaculum was reduced, whereas the abundance of beneficial bacteria genera, including Enterorhabdus, Dubosiella, and Lactobacillus, was increased by host intestinal Pla2g10 overexpression. In summary, intestinal Pla2g10 overexpression increased the proportions of beneficial bacterial in the colonic chyme of mice, providing a potential therapeutic target for future improvement of the gut microbiota.

Dihydroquercetin attenuated Prevotella copri-caused intestinal injury by modulating gut microbiota and bile acids in weaned piglets

Gut microbiota disruption during the weaning process is a significant factor of intestinal injury. Our previous studies have suggested that Prevotella may play a critical role in causing intestinal inflammation. This study aimed to clarify the impact of Prevotella copri on intestinal injury and the protecting effect by dihydroquercetin (DHQ) in weaned piglets. A total of 108 healthy Duroc × Landrace × Yorkshire weaned piglets, aged 21 d, were randomly allocated into 3 groups with 6 replicates and 6 piglets per replicate. The piglets were the following diets for 28 d: 1) a basal diet, 2) basal diet containing 1.0 × 108 CFU/kg P. copri, 3) basal diet supplemented with 1.0 × 108 CFU/kg P. copri and 100 mg/kg DHQ. Results showed that P. copri decreased significantly the average daily gain (ADG) (P < 0.001), which was recovered by supplementation of DHQ with decreased serum levels of malondialdehyde (MDA), interleukin (IL)-2 and IL-8 but increased total superoxide dismutase (T-SOD) activity and IL-10 in weaned piglets (P < 0.001). Moreover, DHQ increased the expression of tight junction proteins (claudin-2, occludin and tight junction protein zonula occludens protein-1 (ZO-1) and the mRNA expression of glutathione peroxidase 4 (GPX-4) in ileum (P < 0.001). Intestinal flora analysis showed that P. copri increased the relative abundance of Prevotella (P = 0.026) and Eubacterium coprostanoligenes group (P < 0.001), but decreased the relative abundance of Lachnospiraceae NK4A136 group (P < 0.001), while supplementation of DHQ reduced the relative abundance of Prevotella (P = 0.026). Metabolomics results indicated that P. copri enhanced the content of 12-OH bile acid, but decreased the contents of glycodeoxycholic acid (GDCA) and glycochenodeoxycholic acid (GCDCA) (P < 0.001), while DHQ reduced the 12-OH bile acid content (P < 0.001) and increased the GDCA content (P = 0.020). In summary, P. copri caused intestinal injury and reduced growth performance in weaned piglets, and DHQ showed a protective effect by modulating gut microbiota and bile acids metabolism.

Dachaihu decoction ameliorates abnormal behavior by regulating gut microbiota in rats with propionic acid-induced autism

Background

Autism spectrum disorder (ASD) is an early-onset neurodevelopmental disorder, usually accompanied by gut microbiota dysregulation. Gut microbiota homeostasis is considered effective for ASD. Reportedly, Dachaihu decoction (DCHD) can efficiently regulate gut microbiota and inflammation. However, the mechanisms underlying the effects of DCHD in the treatment of ASD remain unclear.

Objective

This study investigated the potential effects and mechanisms of DCHD in treating ASD.

Methods

In the animal experiment, propionic acid was administered to construct an ASD rat model. The ASD rats were treated with DCHD, and the efficacy was assessed using the behavioral detections, such as open field test, elevated plus maze test, novel object recognition test. Additionally, the levels of IL-6, TNF-α, IL-10, T-SOD, MDA, GSH and CAT were determined using kits, and histological staining was used to evaluate brain morphology. Moreover, tight junction proteins (ZO-1 and occludin) expression levels were evaluated using RT-qPCR, whereas Iba1 expression level was assessed by immunofluorescence staining. The 16S rRNA sequencing and metabolomic analysis of feces revealed the potential targets of DCHD against ASD. In a small human trail, the clinical scales ADOS-2 and Autism Behavior Checklist (ABC) assessed autism severity. Gastrointestinal problems and brain function were evaluated based on food intolerance and event-related potential, respectively.

Results

DCHD significantly improved autism-like behaviors and increased antioxidant enzyme activity, decreased inflammation and enhanced the intestinal barrier by the animal experiment. Furthermore, the DCHD treatment altered the gut microbiota profile, with increased probiotics Adlercreutzia, Parvibacter, Turicibacter, and Christensenellaceae. Further, DCHD increased the beneficial metabolite indole-3-acetate and decreased the cognitive impairment-related metabolites asymmetric dimethylarginine and homogentisic acid. Meanwhile, the small clinical trial revealed that DCHD significantly alleviated the core symptoms of ASD, with decreased ADOS-2 and ABC scale scores. DCHD also decreased the levels of specific egg white/yolk and milk IgG antibodies and shortened the MMN and P3b latencies.

Conclusion

This study demonstrated that DCHD may alleviate ASD via inhibiting oxidative stress, reducing inflammation, and modulating the gut microbiota in rats. Combined with human trial, DCHD may be a promising drug for treating ASD. This study provides a scientific rationale for treating mental disorders related to gut microbiota dysbiosis.

Non-starch polysaccharides from Castanea mollissima Bl. ameliorate metabolic syndrome by remodeling barrier function, microbial community, and metabolites in high-fat-diet/streptozotocin-induced diabetic mice

Non-starch polysaccharides have been demonstrated to have significant benefits in treating some chronic metabolic diseases such as hyperglycemia. However, the preventive effect of non-starch polysaccharides from Castanea mollissima Bl. (CMNSP) on type 2 diabetes mellitus (T2DM) remain underexplored. The objective of this study was to investigate the effect of CMNSP on glucose and lipid metabolism, intestinal barrier, gut microbiota and their metabolites in high fat diet/streptozotocin-induced T2DM mice. The results revealed that CMNSP significantly mitigated hyperglycemia, insulin resistance, hyperlipidemia, and prevented pancreatic atrophy, hepatic steatosis and enhanced the expression at mRNA level and corresponding protein of PI3K/AKT/Glut2 signaling pathway in liver. Moreover, CMNSP enhanced the level of SCFAs and restored intestinal barrier damage and gut microbiota disturbance in diabetic mice. Further fecal metabolomics analysis identified that CMNSP primarily influenced the metabolic pathways such as Primary bile acid biosynthesis and Taurine and hypotaurine metabolism, and were significantly correlated with changes in dominant bacterial genera including Bacteroides and Lactobacillus.

Dihydroquercetin Ameliorates Neuronal Ferroptosis in Rats After Subarachnoid Hemorrhage via the PI3K/AKT/Nrf2/HO-1 Pathway

Subarachnoid hemorrhage (SAH) is a specific type of stroke. Dihydroquercetin (DHQ), a flavonoid, is known for its various pharmacological properties. This study aimed to explore the roles and mechanisms of DHQ in influencing the progression of SAH. A rat SAH model was established using the endovascular perforation technique. Following SAH induction, DHQ was administered orally 1 h later. Assessments included SAH scores, neurological function, brain swelling, blood-brain barrier (BBB) integrity, neuronal damage, apoptosis levels, inflammation, and indicators of ferroptosis using various treatments. The HT22 cells were exposed to hemin to simulate SAH-like conditions under in vitro settings. Cell counting kit-8 assays, flow cytometry, enzyme?linked immunosorbent assay, BODIPY 581/591 C11 staining, western blot analysis, and biochemical kits were employed to evaluate the potential effects of DHQ. Moreover, the mechanisms responsible for the protective effect of DHQ were examined by western blot analysis. The in vivo findings revealed that DHQ mitigated neurological impairments, brain swelling, BBB disruption, and neuronal injury at 24 h post-SAH. DHQ also reduced neuronal degeneration, inflammation, and ferroptosis following SAH. The in vitro findings revealed that DHQ enhanced cell survival and reduced ferroptosis at 24 h following hemin exposure. Mechanistically, DHQ activated phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling in SAH rats and hemin-treated HT22 cells to exert neuroprotective effects. In conclusion, this study reveals that DHQ can effectively decrease BBB permeability, brain edema, neurological dysfunctions, and ferroptosis post-SAH by activating the PI3K/AKT/Nrf2/HO-1 pathway.

Bifidobacterium longum JBLC-141 alleviates hypobaric hypoxia-induced intestinal barrier damage by attenuating inflammatory responses and oxidative stress

Hypobaric hypoxia exposure occurs at high altitudes, including plateaus, and affects normal intestinal function and microbiota composition. Exposure induces an intestinal inflammatory response and oxidative stress injury, ultimately disrupting intestinal homeostasis and causing barrier damage. Thus, due to its anti-inflammatory, antioxidative, and intestinal microbiota-regulating properties, Bifidobacterium longum is a potentially effective probiotic intervention to protect the intestinal barrier during low-pressure hypoxia on plateaus. However, its mechanism of action is not fully defined. In this study, we investigate the mechanism by which B. longum intervenes in intestinal barrier damage caused by plateau low-pressure hypoxia. To this end, an in vivo model is established by exposing rats to a simulated low-pressure hypoxic plateau environment. The experimental rats were subsequently supplemented with a B. longum strain (JBLC-141) extracted from the feces of healthy adults in Bama, Guangxi. B. longum JBLC-141 mitigates the effects of plateau low-pressure hypoxia on the rat intestinal barrier. This is achieved by activating the intestinal Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway, alleviating plateau hypoxia-induced intestinal oxidative stress injury. B. longum JBLC-141 also attenuates the inflammatory response and upregulates the expression of the tight junction proteins claudin-1, occludin, and zonula occludens-1. Furthermore, it reduces intestinal permeability, effectively ameliorating and repairing the barrier histological damage induced by the plateau low-pressure hypoxic environment. In addition, B. longum JBLC-141 positively regulates the intestinal microbiota, increasing the relative abundance of beneficial bacteria while reducing that of pathogenic bacteria and maintaining intestinal flora homeostasis in rats.

Lactobacillus acidophilus 6074 Fermented Jujube Juice Ameliorated DSS-induced Colitis via Repairing Intestinal Barrier, Modulating Inflammatory Factors, and Gut Microbiota

Lactobacillus acidophilus L. acidophilus Lactobacillus, Bifidobacterium, and Akkermansia, This study aimed to explore the ameliorative effects and underlying mechanisms of oral administration Lactobacillus acidophilus 6074 fermented jujube juice (LAFJ) on dextran sulfate sodium (DSS)-induced colitis in mice. In this study, jujube juice was used as a substrate and fermented by L. acidophilus 6074 to investigate its effects on gut microbiota, intestinal barrier function, oxidative stress, inflammatory factors, and short-chain fatty acids (SCFAs) in mice with colitis and to reveal its potential mechanism for alleviating colitis. The results demonstrated that fermentation caused significant changes in the nutrients and nonnutrients of jujube juice, mainly in organic acids (malic acid, lactic acid, citric acid, and succinic acid) and free amino acids (Thr, Met, Ser, Ile, and Lys). High-dose LAFJ (20 mL/kg/day) significantly reduced the disease activity index (DAI), improved histopathological morphology, and increased colon length in colitis mice. LAFJ alleviated colon damage and preserved the integrity of the colonic mucosal barrier by promoting the expression of colonic tight junction proteins occludin, claudin-1, and zonula occluden-1 (ZO-1). Furthermore, LAFJ inhibited the production of proinflammatory factors and attenuated oxidative stress. Gut microbiota of mice revealed that LAFJ increased beneficial bacteria such as Lactobacillus, Bifidobacterium, and Akkermansia, promoted the production of SCFAs, and inhibited the growth of harmful microorganisms. Overall, LAFJ could reshape and restore gut microbiota imbalance caused by intestinal inflammation and alleviate the development of colitis, which may become a novel dietary intervention.

In vivo absorption, in vitro simulated digestion, and fecal fermentation properties of Imperata cylindrica polysaccharides and their effects on gut microbiota

Recently we have investigated polysaccharide from Imperata cylindrica (ICP) for its physicochemical structure and biological activities. However, the digestion characteristics have yet to be understood. This study investigated the digestion and metabolism characteristics of ICP through in vivo fluorescence tracking, in vitro simulated digestion, fecal fermentation experiments, and microbial sequencing. The results showed that ICP significant distribution in the gastrointestinal tract and kidneys. ICP underwent slight degradation during simulated gastric and intestinal digestion. During fecal fermentation, the utilization degree of ICP and the concentration of short-chain fatty acids (SCFAs) increased. ICP promoted the increase of beneficial microbial abundance. To understand the impact of ICP on the integrity and health of intestinal tissues, molecular docking was employed to preliminarily predict the interaction between ICP and key proteins. The results revealed that ICP could recognize and bind to key proteins through high-affinity targeting binding sites.

Assessment of progression of pulmonary fibrosis based on metabonomics and analysis of intestinal microbiota

The main purpose of this study was to explore the changes of biomarkers in different developmental stages of bleomycin-induced pulmonary fibrosis (PF) in rats via comprehensive pathophysiology, UPLC-QTOF/MS metabonomic technology, and 16S rRNA gene sequencing of intestinal microbiota. The rats were randomly divided into normal control and 1-, 2- and 4-week model group. The rat model of PF was established by one-time intratracheal instillation of bleomycin. The levels of inflammatory and fibrosis-related factors such as hydroxyproline (HYP), type III procollagen (COL-III), type IV collagen (COL-IV), hyaluronidase (HA), laminin (LN), interleukin (IL)-1β, IL-6, malondialdehyde (MDA) increased and superoxide dismutase (SOD) decreased as the PF cycle progressed. In the 1-, 2- and 4-week model group, 2, 19 and 18 potential metabolic biomarkers and 3, 16 and 12 potential microbial biomarkers were detected, respectively, which were significantly correlated. Glycerophospholipid metabolism pathway was observed to be an important pathway affecting PF at 1, 2 and 4 weeks; arginine and proline metabolism pathways significantly affected PF at 2 weeks. Linoleic acid metabolism pathway exhibited clear metabolic abnormalities at 2 and 4 weeks of PF, and alpha-linolenic acid metabolism pathway significantly affected PF at 4 weeks.

Oat anthranilamides regulates high-fat diet-induced intestinal inflammation by the TLR4/NF-κb signalling pathway and gut microbiota

Oat anthranilamides have demonstrated antioxidant and anti-inflammatory effects; however, the precise mechanism of action remains unclear. This study investigated the impact of oat anthranilamide B (AVN B) on high-fat diet (HFD)-induced intestinal inflammation in mice and its underlying mechanisms. The results indicated that AVN B supplementation mitigated weight gain and reduced inflammatory and oxidative stress markers in serum, liver, and intestines. It improved intestinal barrier dysfunction by upregulating the expression levels of Occludin and MUC2 while simultaneously reducing intestinal inflammation by inhibiting the TLR4/NF-κB signalling pathway. Additionally, AVN B treatment improved gut microbiota composition. It increased the abundance of beneficial flora and the production of short-chain fatty acids (SCFAs), especially propionate and butyrate, associated with reduced production of pro-inflammatory factors and enhanced intestinal protection. The findings provide scientific evidence for the potential of AVN B as an anti-inflammatory agent.

Integrated gut microbiota and serum pharmacochemistry reveal the mechanisms of wine steaming in alleviating rhubarb diarrhea

BACKGROUND

Long-term use of rhubarb (RH) can cause adverse gastrointestinal reactions (such as diarrhea), whereas RH steaming with wine (PRH) can alleviate RH-induced diarrhea. However, the potential material basis and mechanisms by which wine steaming alleviates diarrhea caused by RH remain unclear.

PURPOSE

To reveal the potential material basis and underlying mechanisms of wine steaming in alleviating diarrhea caused by RH from the perspective of small intestinal flora and immune function.

METHODS

The major anthraquinone/anthrone components were detected using high-performance liquid chromatography (HPLC). Constipation model mice were replicated using loperamide hydrochloride and were administered RH and PRH for six consecutive weeks. Histopathological observation (duodenum, jejunum, and ileum) was performed using hematoxylin-eosin (HE) staining, and the serum levels of inflammatory cytokines, immunoglobulin G (IgG), and immunoglobulin A (IgA) were examined. CD4+, CD8+, and Treg cells counts in peripheral blood were determined using flow cytometry; The protein expression of Toll-like receptor 4 (TLR4) and nuclear factor kappa-B (NF-κB) was determined using immunohistochemistry (IHC) and western blot (WB). The small intestine contents and feces were analyzed by 16 S rRNA sequencing and the contents of short chain fatty acids (SCFAs) in feces were determined using gas chromatography-mass spectrometry (GC-MS). Ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) was used to analyze the blood absorption compounds and endogenous metabolites.

RESULTS

The levels of the major anthraquinone/anthrone components were decreased in PRH. RH and PRH both increased the wet fecal weight at 12 h (WFW-12) and fecal water rate (FWR), alleviated the dry and black fecal morphology, and relieved small intestine injuries in the second week. In the fourth week, although RH and PRH alleviated the abnormal levels of indicators in the model mice (fecal water rate, immune cells percentage, and TLR4/NF-κB expression), minor small intestinal damage was observed. Compared to that at the fourth week, RH and PRH increased the levels of WFW-12, FWR, inflammatory cytokines, and TLR4/NF-κB expression, and decreased the levels of IgG/IgA and immune cells with extended administration (sixth week). Further, damage to the small intestine worsened (severe ileal damage) and different degrees of loose stools were observed in RH- and PRH-administered mice in the sixth week. Compared with those in the control group, the levels of WFW-12, FWR, inflammatory cytokines, TLR4/NF-κB expression, IgG/IgA, and immune cell percentage were significantly different in the RH-H and PRH-H mice at the sixth week (except for CD8+in PRH-H). Further, RH and PRH disturbed the gut microbiota (GM) (Lactobacillus and Dubosiella decreased, Aerococcus and Corynebacterium increased) and obviously reduced the content of SCFAs (acetic acid, butyric acid, and isobutyric acid). However, almost all the results indicated a lower impact of PRH than that of RH. Metabolic pathways mainly involved in glycerophospholipid metabolism were identified along with a total of 21 blood absorption components, including anthraquinones, anthrones, flavanols, and tannins. The correlation analysis showed a positive correlation of pathogenic bacteria (Aerococcus and Corynebacterium) with inflammatory cytokines, TLR4/NF-κB, LysoPC(20:0/0:0), and PE (16:0/20:4(8Z,11Z,14Z,17Z)) and a negative correlation with immune cells and SCFAs (acetic acid and isobutyric acid); however, the opposite results were observed for beneficial bacteria (Lactobacillus and Dubosiella).

CONCLUSION

Overall, PRH can alleviate RH-induced diarrhea by recovering the GM imbalance and abnormal levels of GM-mediated SCFAs, alleviating the decrease in cellular immune function and abnormal expression of TLR4/NF-κB, thereby suppressing the release of inflammatory factors, possibly, through its lower content of anthraquinones. This study explored for the first time the processing mechanism of wine steaming in alleviating RH-induced diarrhea from the aspects of small intestinal flora and small intestinal immune function.

Optimization of a gelatin/carboxymethylcellulose-based probiotic microcapsule and its application in preventing dextran sodium sulfate-induced colitis in mice

Oral administration of probiotics has demonstrated substantial potential in alleviating colitis. However, most of the ingested microorganisms struggle to survive the harsh conditions of the gastrointestinal tract, leading to decreased efficacy. In the present study, using double emulsification (W1/O/W2) and complex coacervation methods, we developed a gelatin/carboxymethyl cellulose (CMC)-based probiotic microcapsule and analyzed the efficacy of encapsulated probiotics in preventing dextran sodium sulfate (DSS)-induced colitis in mice. Our results reveal that nearly 90% of the encapsulated probiotics remained viable after 30-day storage at 4°C and approximately 38.1% of viable bacteria (4.0 × 108 cfu/g) survived after 4-h simulated gastrointestinal digestion. In a DSS-induced colitis model, pretreatment with probiotics exerted significant protective effects, with the bacterial microcapsule-treated group having superior outcomes to those of the bacterial suspension plus empty carrier group. Probiotic treatments, especially those administered in the encapsulated form, significantly increased fecal short-chain fatty acid contents, and altered the intestinal microbial composition. The family Muribaculaceae, dominant bacteria in the mouse gut, may be the key microorganism involved in the BM regulation process. Our study presents an alternative approach to treating colitis using probiotics. PRACTICAL APPLICATION: The encapsuled probiotic showed remarkable storage stability at 4°C, maintained good vitality after simulated digestion, and gained superior outcomes in preventing colitis. Our results offer an alternative approach for the probiotic preparations aiming to prevent the intestinal inflammation.

Shatianyu (Citrus grandis L. Osbeck) whole fruit alleviated loperamide-induced constipation via enhancing gut microbiota-mediated intestinal serotonin secretion and mucosal barrier homeostasis

This study aims to explore the effects of Shatianyu (Citrus grandis L. Osbeck) whole fruit powder (SWFP) enriched in flavonoids and dietary fiber on loperamide-induced constipation after a 4-week administration in the diet, together with possible microbiota-mediated mechanisms. The SWFP intervention shortened the first defecation time and increased defecation frequency; it also increased the serum serotonin (5-HT) level and decreased the LPS level in constipation mice. SWFP promoted the development of colonic enterochromaffin cells (ECs) and upregulated the expression of 5-HT synthetic rate-limiting enzyme (Tph1) in ECs. Furthermore, SWFP downregulated the expression of colonic TLR-4, TNF-α and IL-1β and upregulated the expression of tight junction proteins. Besides promoting 5-HT secretion in ECs, butyrate was proved to play a positive role in enhancing intestinal barrier homeostasis through FFAR2/3. Notably, SWFP increased both the fecal butyrate contents and colonic FFAR3 expression in a dose-related manner. Likewise, SWFP enriched butyrate-production related microbes, such as Ruminococcus_torques_group, Ruminococcus, Dubosiella and Parasutterella. Thus, SWFP might alleviate constipation by regulating the microbiota to produce butyrate, thereby enhancing colonic 5-HT secretion and the FFAR3-mediated anti-inflammatory pathway.

Hydrolyzed protein formula improves the nutritional tolerance by increasing intestinal development and altering cecal microbiota in low-birth-weight piglets

Background

Prematurity or low birth weight (LBW), poses a significant challenge in global health. Exploring appropriate and effective nutritional interventions is crucial for the growth and development of LBW infants. Hydrolyzed protein formula has been suggested as a potential solution to prevent intestinal dysfunction and improve digestion and absorption in infants.

Objectives

This study aimed to investigate the benefits of hydrolyzed protein formula on feeding intolerance, intestinal morphological development, and microbiota in a LBW piglet model.

Methods

A total of 24 male piglets (3 d of age, 0.95-1.25 kg average BW) were assigned (8 pens/diet; 1 pigs/pen) into three dietary treatments and fed with a basic formula (BF), standard premature infant formula (SF) and hydrolyzed protein formula (HF) respectively, for 7 d. After the piglets sacrifice, growth performance, amino acid metabolism and intestinal morphology were assessed. 16S rRNA sequencing and microbial metabolic phenotypes analyzed the effects of different formula treatments on intestinal flora structure of LBW piglets.

Results

The HF diet reduced the rates of diarrhea and milk vomiting were reduced by 20.44% (p > 0.05) and 58.44% (p > 0.05), and decreased the crypt depth in the ileum while increasing the ratio of villus height/crypt depth and the mRNA expressions of y+LAT1 and b0,+AT in the ileum (p < 0.05). HF increased the final body weight, serum Thr and essential amino acid contents, and CAT2 and b0,+AT mRNA expressions in ileal mucosa compared with the SF diet (p < 0.05). Microbiota sequencing results showed that the colonic microbial richness indices (Chao1, ACE, and observed species), the diversity indices (Shannon and Simpson), and the phyla Actinobacteriota, unidentified_Bacteria, Acidobacteriota and Actinobacteria, the genus Rubrobacter and RB41 were reduced (p < 0.05) in SF and HF groups. Microbial metabolic phenotypes analysis showed a reduction in the richness of biofilm-forming bacteria (p < 0.05).

Conclusion

In summary, hydrolyzed protein formula had better nutrition and tolerance in LBW suckling piglets by improving amino acid transport and intestinal development, and regulating gut microbial communities.

FMT and TCM to treat diarrhoeal irritable bowel syndrome with induced spleen deficiency syndrome- microbiomic and metabolomic insights

BACKGROUND

Diarrheal irritable bowel syndrome (IBS-D) is a functional bowel disease with diarrhea, and can be associated with common spleen deficiency syndrome of the prevelent traditional Chinese medicine (TCM) syndrome. Fecal microbiota transplantation (FMT) could help treating IBS-D, but may provide variable effects. Our study evaluated the efficacy of TCM- shenling Baizhu decoction and FMT in treating IBS-D with spleen deficiency syndrome, with significant implications on gut microbiome and serum metabolites.

METHODS

The new borne rats were procured from SPF facility and separated as healthy (1 group) and IBS-D model ( 3 groups) rats were prepared articially using mother's separation and senna leaf treatment. 2 groups of IBS-D models were further treated with TCM- shenling Baizhu decoction and FMT. The efficacy was evaluated by defecation frequency, bristol stool score, and intestinal tight junction proteins (occludin-1 and claudin-1) expression. Microbiomic analysis was conducted using 16 S rRNA sequencing and bioinformatics tools. Metabolomics were detected in sera of rats by LC-MS and annotated by using KEGG database.

RESULTS

Significant increment in occludin-1 and claudin-1 protein expression alleviated the diarrheal severity in IBS-D rats (P < 0.05) after treatment with FMT and TCM. FMT and TCM altered the gut microbiota and regulated the tryptophan metabolism, steroid hormone biosynthesis and glycerophospholipid metabolism of IBS-D rats with spleen deficiency syndrome.The microbial abundance were changed in each case e.g., Monoglobus, Dubosiella, and Akkermansia and othe metabolic profiles.

CONCLUSION

FMT and TCM treatment improved the intestinal barrier function by regulating gut microbiota and improved metabolic pathways in IBS-D with spleen deficiency syndrome.

Dietary Dihydroquercetin Alleviated Colitis via the Short-Chain Fatty Acids/miR-10a-5p/PI3K-Akt Signaling Pathway

Gut microbiota provides an important insight into clarifying the mechanism of active substances with low bioavailability, but its specific action mechanism varied case by case and remained unclear. Dihydroquercetin (DHQ) is a bioactive flavonoid with low bioavailability, which showed beneficial effects on colitis alleviation and gut microbiota modulation. Herein, we aimed to explore the microbiota-dependent anticolitis mechanism of DHQ in sight of gut microbiota metabolites and their interactions with microRNAs (miRNAs). Dietary supplementation of DHQ alleviated dextran sulfate sodium-induced colitis phenotypes and improved gut microbiota dysbiosis. Fecal microbiota transplantation further revealed that the anticolitis activity of DHQ was mediated by gut microbiota. To clarify how the modulated gut microbiota alleviated colitis in mice, the tandem analyses of the microbiome and targeted metabolome were performed, and altered profiles of metabolite short-chain fatty acids (SCFAs) and bile acids and their producers were observed in DHQ-treated mice. In addition, SCFA treatment showed anticolitis activity compared to that of bile acids, along with the specific inhibition on the phosphoinositide-3-kinase (PI3K)-protein kinase B (Akt) pathway. Subsequently, the colonic miRNA profile of mice receiving SCFA treatment was sequenced, and a differentially expressed miR-10a-5p was identified. Both prediction analysis and dual-luciferase reporter assay indicated that miR-10a-5p directly bind to the 3'-untranslated regions of gene pik3ca, inhibit the PI3K-Akt pathway activation, and lead to colitis alleviation. Together, we proposed that gut microbiota mediated the anticolitis activity of DHQ through the SCFAs/miR-10a-5p/PI3K-Akt axis, and it provided a novel insight into clarifying the microbiota-dependent mechanism via the interaction between metabolites and miRNAs.

Aged Gut Microbiome Induces Metabolic Impairment and Hallmarks of Vascular and Intestinal Aging in Young Mice

Aging, an independent risk factor for cardiometabolic diseases, refers to a progressive deterioration in physiological function, characterized by 12 established hallmarks. Vascular aging is driven by endothelial dysfunction, telomere dysfunction, oxidative stress, and vascular inflammation. This study investigated whether aged gut microbiome promotes vascular aging and metabolic impairment. Fecal microbiome transfer (FMT) was conducted from aged (>75 weeks old) to young C57BL/6 mice (8 weeks old) for 6 weeks. Wire myography was used to evaluate endothelial function in aortas and mesenteric arteries. ROS levels were measured by dihydroethidium (DHE) staining and lucigenin-enhanced chemiluminescence. Vascular and intestinal telomere function, in terms of relative telomere length, telomerase reverse transcriptase expression and telomerase activity, were measured. Systemic inflammation, endotoxemia and intestinal integrity of mice were assessed. Gut microbiome profiles were studied by 16S rRNA sequencing. Some middle-aged mice (40-42 weeks old) were subjected to chronic metformin treatment and exercise training for 4 weeks to evaluate their anti-aging benefits. Six-week FMT impaired glucose homeostasis and caused vascular dysfunction in aortas and mesenteric arteries in young mice. FMT triggered vascular inflammation and oxidative stress, along with declined telomerase activity and shorter telomere length in aortas. Additionally, FMT impaired intestinal integrity, and triggered AMPK inactivation and telomere dysfunction in intestines, potentially attributed to the altered gut microbial profiles. Metformin treatment and moderate exercise improved integrity, AMPK activation and telomere function in mouse intestines. Our data highlight aged microbiome as a mechanism that accelerates intestinal and vascular aging, suggesting the gut-vascular connection as a potential intervention target against cardiovascular aging and complications.

The dose-dependent mechanism behind the protective effect of lentinan against acute alcoholic liver injury via proliferating intestinal probiotics

Acute alcoholic liver injury (AALI) is a widespread disease that can develop into hepatitis, liver fibrosis, and cirrhosis. In severe cases, it can be life-threatening, while drug treatment presents various side effects. This study characterized the structure of natural lentinan (LNT) from the Qinba Mountain area and investigated the protective mechanism of different LNT doses (100 mg kg-1, 200 mg kg-1, and 400 mg kg-1) on AALI. The results showed that LNT was a glucose-dominated pyran polysaccharide with a triple-helical structure and a molecular weight (Mw) of 7.56 × 106 Da. An AALI mouse model showed that all the LNT doses protected liver function, reduced hepatic steatosis, alleviated oxidative stress and inflammatory response, and stimulated probiotic proliferation. Low-dose LNT increased anti-oxidant-associated beneficial bacteria, medium-dose LNT improved liver swelling and promoted anti-oxidant-associated probiotics, and high-dose LNT increased the probiotics that helped protect liver function and anti-oxidant and anti-inflammatory properties. All the LNT doses inhibited pathogenic growth, including Oscillospiraceae, Weeksellaceae, Streptococcaceae, Akkermansiaceae, Morganellaceae, and Proteus. These results indicated that the protective effect of LNT against AALI was mediated by the proliferation of various intestinal probiotics and was related to the consumption doses. These findings offer new strategies for comprehensively utilizing Lentinula edodes from the Qinba Mountain area and preventing AALI using natural food-based substances.

Christensenella minuta protects and restores intestinal barrier in a colitis mouse model by regulating inflammation

Christensenella minuta DSM 22607 has recently been suggested as a potential microbiome-based therapy for inflammatory bowel disease (IBD) because it displays strong anti-inflammatory effects both in vitro and in vivo. Here, we aimed to decipher the mechanism(s) underlying the DSM 22607-mediated beneficial effects on the host in a mouse model of chemically induced acute colitis. We observed that C. minuta plays a key role in the preservation of the epithelial barrier and the management of DNBS-induced inflammation by inhibiting interleukin (IL)-33 and Tumor necrosis factor receptor superfamily member 8 (Tnfrsf8) gene expression. We also showed that DSM 22607 abundance was positively correlated with Akkermansia sp. and Dubosiella sp. and modulated microbial metabolites in the cecum. These results offer new insights into the biological and molecular mechanisms underlying the beneficial effects of C. minuta DSM 22607 by protecting the intestinal barrier integrity and regulating inflammation.

Anti-obesogenic effect of lupin-derived protein hydrolysate through modulation of adiposopathy, insulin resistance and gut dysbiosis in a diet-induced obese mouse

The prevalence of obesity is increasingly widespread, resembling a global epidemic. Lifestyle changes, such as consumption of high-energy-dense diets and physical inactivity, are major contributors to obesity. Common features of this metabolic pathology involve an imbalance in lipid and glucose homeostasis including dyslipidemia, insulin resistance and adipose tissue dysfunction. Moreover, the importance of the gut microbiota in the development and susceptibility to obesity has recently been highlighted. In recent years, new strategies based on the use of functional foods, in particular bioactive peptides, have been proposed to counteract obesity outcomes. In this context, the present study examines the effects of a lupin protein hydrolysate (LPH) on obesity, dyslipidemia and gut dysbiosis in mice fed a high-fat diet (HFD). After 12 weeks of LPH treatment, mice gained less weight and showed decreased adipose dysfunction compared to the HFD-fed group. HFD-induced dyslipidemia (increased triglycerides, cholesterol and LDL concentration) and insulin resistance were both counteracted by LPH consumption. Discriminant analysis differentially distributed LPH-treated mice compared to non-treated mice. HFD reduced gut ecological parameters, promoted the blooming of deleterious taxa and reduced the abundance of commensal members. Some of these changes were corrected in the LPH group. Finally, correlation analysis suggested that changes in this microbial population could be responsible for the improvement in obesity outcomes. In conclusion, this is the first study to show the effect of LPH on improving weight gain, adiposopathy and gut dysbiosis in the context of diet-induced obesity, pointing to the therapeutic potential of bioactive peptides in metabolic diseases.

Integrated bioinformatics and multiomics reveal Liupao tea extract alleviating NAFLD via regulating hepatic lipid metabolism and gut microbiota

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) poses a significant global public health concern. Liupao tea (LPT) is a Chinese national geographical indication product renowned for its lipid-lowering properties. However, the precise mechanisms and active constituents contributing to the efficacy of LPT against NAFLD remain unclear.

PURPOSE

This study aims to comprehensively explore the therapeutic potential of Liupao tea extract (LPTE) in alleviating NAFLD through an integrated strategy.

METHODS

Initially, network pharmacology analysis was conducted based on LPTE chemical ingredient analysis, identifying core targets and key components. Potential active ingredients were validated through chemical standards based on LC-MS/MS. To confirm the pharmacological efficacy of LPTE in NAFLD, NAFLD mice models were employed. Alterations in hepatic lipid metabolism were comprehensively elucidated through integration of metabolomics, lipidomics, network pharmacology analysis, and real-time PCR analysis. To further explore the binding interactions between key components and core targets, molecular docking and microscale thermophoresis (MST) analysis were employed. Furthermore, to investigate LPTE administration effectiveness on gut microbiota in NAFLD mice, a comprehensive approach was employed. This included Metorigin analysis, 16S rRNA sequencing, molecular docking, and fecal microbiome transplantation (FMT).

RESULTS

Study identified naringenin, quercetin, luteolin, and kaempferol as the potential active ingredients of LPTE. These compounds exhibited therapeutic potential for NAFLD by targeting key proteins such as PTGS2, CYP3A4, and ACHE, which are involved in the metabolic pathways of hepatic linoleic acid (LA) and glycerophospholipid (GP) metabolism. The therapeutic effectiveness of LPTE was observed to be comparable to that of simvastatin. Furthermore, LPTE exhibited notable efficacy in alleviating NAFLD by influencing alterations in gut microbiota composition (Proteobacteria phylum, Lactobacillus and Dubosiella genus) that perhaps impact LA and GP metabolic pathways.

CONCLUSION

LPTE could be effective in preventing high-fat diet (HFD)-induced NAFLD by modulating hepatic lipid metabolism and gut microbiota. This study firstly integrated bioinformatics and multi-omics technologies to identify the potential active components and key microbiota associated with LPTE's effects, while also primally elucidating the action mechanisms of LPTE in alleviating NAFLD. The findings offer a conceptual basis for LPTE's potential transformation into an innovative pharmaceutical agent for NAFLD prevention.

Therapeutic modulation of the kynurenine pathway in severe mental illness and comorbidities: A potential role for serotonergic psychedelics

Mounting evidence points towards a crucial role of the kynurenine pathway (KP) in the altered gut-brain axis (GBA) balance in severe mental illness (SMI, namely depression, bipolar disorder, and schizophrenia) and cardiometabolic comorbidities. Preliminary evidence shows that serotonergic psychedelics and their analogues may hold therapeutic potential in addressing the altered KP in the dysregulated GBA in SMI and comorbidities. In fact, aside from their effects on mood, psychedelics elicit therapeutic improvement in preclinical models of obesity, metabolic syndrome, and vascular inflammation, which are highly comorbid with SMI. Here, we review the literature on the therapeutic modulation of the KP in the dysregulated GBA in SMI and comorbidities, and the potential application of psychedelics to address the altered KP in the brain and systemic dysfunction underlying SMI and comorbidities. Psychedelics might therapeutically modulate the KP in the altered GBA in SMI and comorbidities either directly, via altering the metabolic pathway by influencing the rate-limiting enzymes of the KP and affecting the levels of available tryptophan, or indirectly, by affecting the gut microbiome, gut metabolome, metabolism, and the immune system. Despite promising preliminary evidence, the mechanisms and outcomes of the KP modulation with psychedelics in SMI and systemic comorbidities remain largely unknown and require further investigation. Several concerns are discussed surrounding the potential side effects of this approach in specific cohorts of individuals with SMI and systemic comorbidities.

Cadmium in Market Pork Kidneys: A Study on Cadmium Bioavailability and the Health Effects Based on Mouse Models

Edible offal of farmed animals can accumulate cadmium (Cd). However, no studies have investigated Cd bioavailability and its health effects. Here, based on mouse models, market pork kidney samples exhibited high Cd relative bioavailability of 74.5 ± 11.2% (n = 26), close to 83.8 ± 7.80% in Cd-rice (n = 5). This was mainly due to high vitamin D3 content in pork kidney, causing 1.7-2.3-fold up-regulated expression of duodenal Ca transporter genes in mice fed pork kidney compared to mice fed Cd-rice, favoring Cd intestinal absorption via Ca transporters. However, although pork kidney was high in Cd bioavailability, subchronic low-dose (5% in diet) consumption of two pork kidney samples having 0.48 and 0.97 μg Cd g-1 dw over 35 d did not lead to significant Cd accumulation in the tissue of mice fed Cd-free rice but instead remarkably decreased Cd accumulation in the tissue of mice fed Cd-rice (0.48 μg Cd g-1) by ∼50% and increased abundance of gut probiotics (Faecalibaculum and Lactobacillus). Overall, this study contributed to our understanding of the bioavailability and health effects associated with Cd in edible offal, providing mechanistic insights into pork kidney consumption safety based on Cd bioavailability.

Common dietary emulsifiers promote metabolic disorders and intestinal microbiota dysbiosis in mice

Dietary emulsifiers are linked to various diseases. The recent discovery of the role of gut microbiota-host interactions on health and disease warrants the safety reassessment of dietary emulsifiers through the lens of gut microbiota. Lecithin, sucrose fatty acid esters, carboxymethylcellulose (CMC), and mono- and diglycerides (MDG) emulsifiers are common dietary emulsifiers with high exposure levels in the population. This study demonstrates that sucrose fatty acid esters and carboxymethylcellulose induce hyperglycemia and hyperinsulinemia in a mouse model. Lecithin, sucrose fatty acid esters, and CMC disrupt glucose homeostasis in the in vitro insulin-resistance model. MDG impairs circulating lipid and glucose metabolism. All emulsifiers change the intestinal microbiota diversity and induce gut microbiota dysbiosis. Lecithin, sucrose fatty acid esters, and CMC do not impact mucus-bacterial interactions, whereas MDG tends to cause bacterial encroachment into the inner mucus layer and enhance inflammation potential by raising circulating lipopolysaccharide. Our findings demonstrate the safety concerns associated with using dietary emulsifiers, suggesting that they could lead to metabolic syndromes.

Functional evaluation of pure natural edible Ferment: protective function on ulcerative colitis

Purpose

To investigate the therapeutic efficiency of a novel drink termed "Ferment" in cases of ulcerative colitis (UC) and its influence on the gut microbiota.

Method

In this study, we developed a complex of mixed fruit juice and lactic acid bacteria referred to as Ferment. Ferment was fed to mice for 35 days, before inducing UC with Dextran Sulfate Sodium Salt. We subsequently investigated the gut microbiome composition using 16S rRNA sequencing.

Result

After Ferment treatment, mouse body weight increased, and animals displayed less diarrhea, reduced frequency of bloody stools, and reduced inflammation in the colon. Beneficial bacteria belonging to Ileibacterium, Akkermansia, and Prevotellacea were enriched in the gut after Ferment treatment, while detrimental organisms including Erysipelatoclostridium, Dubosiella, and Alistipes were reduced.

Conclusion

These data place Ferment as a promising dietary candidate for enhancing immunity and protecting against UC.

Lycium barbarum polysaccharide remodels colon inflammatory microenvironment and improves gut health

Aim

Disturbed intestinal microbiota has been implicated in the inflammatory microenvironment of the colon, which usually results in ulcerative colitis (UC). Given the limitations of these drugs, it is important to explore alternative means of protecting the gut health from UC. This study aimed to investigate the potential of polysaccharides as beneficial nutrients in the regulation of the gut microbiota, which determines the inflammatory microenvironment of the colon.

Materials and methods

Mice were treated with dextran sulfate sodium (DSS) to evaluate the effects and mechanisms of Lycium barbarum polysaccharide (LBP) in remodeling the inflammatory microenvironment and improving gut health. Body weight and disease activity indices were monitored daily. Hematoxylin and eosin staining was used to analyze colon dynamics. The levels of inflammatory indicators and expression of MUC-2, claudin-1, ZO-1, and G-protein-coupled receptor 5 (TGR5) were determined using assay kits and immunohistochemistry, respectively. 16S rRNA high-throughput sequencing of the intestinal microbiota and liquid chromatography-tandem mass spectrometry for related bile acids were used.

Results

LBP significantly improved the colonic tissue structure by upregulating MUC-2, claudin-1, and ZO-1 protein expression. The bacterial genus Dubosiella was dominant in healthy mice, but significantly decreased in mice treated with DSS. LBP rehabilitated Dubosiella in the sick guts of DSS mice to a level close to that of healthy mice. The levels of other beneficial bacterial genera Akkermansia and Bifidobacterium were also increased, whereas those of the harmful bacterial genera Turicibacter, Clostridium_sensu_stricto_1, Escherichia-Shigella, and Faecalibaculum decreased. The activity of beneficial bacteria promoted the bile acids lithocholic and deoxycholic acids in mice with UC, which improved the gut barrier function through the upregulation of TGR5.

Conclusion

The inflammatory microenvironment in the gut is determined by the balance of the gut microbiota. LBP showed great potential as a beneficial nutrient for rehabilitating Dubosiella which is dominant in the gut of healthy mice. Nutrient-related LBP may play an important role in gut health management.

Bacillus licheniformis ameliorates Aflatoxin B1-induced testicular damage by improving the gut-metabolism-testis axis

Global aflatoxin B1 (AFB1) contamination is inevitable, and it can significantly damage testicular development. However, the current mechanism is confusing. Here, by integrating the transcriptome, microbiome, and serum metabolome, we comprehensively explain the impact of AFB1 on testis from the gut-metabolism-testis axis. Transcriptome analysis suggested that AFB1 exposure directly causes abnormalities in testicular inflammation-related signalling, such as tumor necrosis factor (TNF) pathway, and proliferation-related signalling pathways, such as phosphatidylinositide 3-kinases-protein kinase B (PI3K-AKT) pathway, which was verified by immunofluorescence. On the other hand, we found that upregulated inflammatory factors in the intestine after AFB1 exposure were associated with intestinal microbial dysbiosis, especially the enrichment of Bacilli, and enrichment analysis showed that this may be related to NLR family pyrin domain containing 3 (NLRP3)-mediated NOD-like receptor signalling. Also, AFB1 exposure caused blood metabolic disturbances, manifested as decreased hormone levels and increased oxidative stress. Significantly, B. licheniformis has remarkable AFB1 degradation efficiency (> 90%). B. licheniformis treatment is effective in attenuating gut-testis axis damage caused by AFB1 exposure through the above-mentioned signalling pathways. In conclusion, our findings indicate that AFB1 exposure disrupts testicular development through the gut-metabolism-testis axis, and B. licheniformis can effectively degrade AFB1.

Protective Mechanism of Polysaccharide ORP-1 Isolated from Oudemansiella raphanipes against Age-Related Cognitive Decline through the Microbiota-Gut-Brain Axis

Age-related cognitive decline is primarily attributed to the progressive weakening of synaptic function and loss of synapses, while age-related gut microbial dysbiosis is known to impair synaptic plasticity and cognitive behavior by metabolic alterations. To improve the health of the elderly, the protective mechanisms of Oudemansiella raphanipes polysaccharide (ORP-1) against age-related cognitive decline are investigated. The results demonstrate that ORP-1 and its gut microbiota-derived metabolites SCFAs restore a healthy gut microbial population to handle age-related gut microbiota dysbiosis mainly by increasing the abundance of beneficial bacteria Dubosiella, Clostridiales, and Prevotellaceae and reducing the abundance of harmful bacteria Desulfovibrio, strengthen intestinal barrier integrity by abolishing age-related alterations of tight junction (TJ) and mucin 2 (MUC2) proteins expression, diminish age-dependent increase in circulating inflammatory factors, ameliorate cognitive decline by reversing memory- and synaptic plasticity-related proteins levels, and restrain hyperactivation of microglia-mediated synapse engulfment and neuroinflammation. These findings expand the understanding of prebiotic-microbiota-host interactions.

Crude Tieguanyin oolong tea polysaccharides regulate intestinal immune and gut microflora in dextran sulfate sodium-induced mice colitis

BACKGROUND

The global incidence and prevalence of inflammatory bowel diseases (IBDs) have been increasing. Epidemiological studies, clinical trials, and animal experiments have indicated a negative association between the consumption of tea and IBD. This study aims to investigate the protective effects of crude Tieguanyin oolong tea polysaccharides (CTPS) on experimental colitis, while also exploring the underlying mechanisms.

RESULTS

The administration of CTPS significantly alleviated IBD in the mouse model, and was found to regulate T-cell mediated immune responses in the colon by modulating cytokine production associated with T cells. Furthermore, CTPS demonstrated a positive impact on the gut microbiota, reversing the increase in pathogenic Helicobacter and enhancing the relative abundances of beneficial bacteria such as Akkermansia, Lachnospiraceae, and Odoribacter. Oral administration of CTPS also led to an improvement in intestinal metabolism, specifically by increasing the levels of short-chain fatty acids.

CONCLUSION

This study provides the first in vivo evidence of the protective effects of CTPS on colitis in mice. The effects are likely facilitated through the regulation of T cell-mediated responses and modulation of the gut microbiota, suggesting that CTPS may be a potential preventive and therapeutic approach for IBD. © 2023 Society of Chemical Industry.

Regulation of Gut Microbiota and Microbial Metabolome of Kefir Supernatant against Fusobacterium nucleatum and DSS-Coinduced Colitis

The aim of this study was to investigate the intervention effect of kefir supernatant (KS) on the initiation and progression of an ulcerative colitis (UC) murine model. We established an UC murine model by orally administrating with 109 CFUs of Fusobacterium nucleatum for 3 weeks and 3% dextran sulfate sodium (DSS) treatment in the third week. KS was used to intervene in this colitis model. Our results showed that KS supplementation ameliorated the symptoms, restrained the secretion of pro-inflammatory cytokines (TNF-α, IL-6, and IL-17F), promoted the release of anti-inflammatory cytokines (IL-4 and IL-10), and ameliorated oxidative stress. Furthermore, the increased number of goblet cells and upregulated expression of MUC2, occludin and claudin-1 indicated that the colon barrier was protected by KS. Additionally, KS supplementation mitigated gut microbiota dysbiosis in the UC murine model, leading to an increase in the abundance of Blautia and Akkermansia and a decrease in the level of Bacteroides. The altered gut microbiota also affected colon metabolism, with differential metabolites mainly associated with the biosynthesis of the l-arginine pathway. This study revealed that KS supplementation restored the community structure of gut microbiota, altered the biosynthesis of l-arginine, and thereby modulated the process of colonic inflammation.

Effects of potassium sorbate on systemic inflammation and gut microbiota in normal mice: A comparison of continuous intake and washout period

Potassium sorbate (PS) is a widely used food preservative in the field of food industry. However, the effects of continuous intake and washout period of PS on host health are still unclear. In this study, to investigate long-term effect and after-effect of different concentrations and time points of PS, healthy mice were orally exposed to 150 mg/kg, 500 mg/kg and 1000 mg/kg of PS for 10 weeks, and washout treatment for another 5 weeks, respectively. The results indicated that PS intake for 10 weeks had no obvious effects on organs and adipose tissue, nor did it noteworthily interfere with glucolipid metabolism in the serum. However, it caused inflammatory cell infiltration in the liver, increased serum interleukin (IL)-1β level, changed abundances of gut microbiota but failed to promote the production of short chain fatty acids in the gut. After washout period for 5 weeks, liver inflammation and IL-1β level were decreased, and gut environment developed towards a healthier condition. Specifically, PS washout significantly increased abundance of Lachnospiraceae_NK4A136_group and the production of isobutyric acid. This study confirmed washout period eliminated negative effects from continuous intake of PS, which provided positive evidence for its safety.

Exclusive Enteral Nutrition Beneficially Modulates Gut Microbiome in a Preclinical Model of Crohn's-like Colitis

Exclusive enteral nutrition (EEN) is an established dietary treatment for Crohn's disease (CD) by alleviating inflammation and inducing remission. However, the mechanisms of action of EEN are incompletely understood. As CD is associated with gut microbiome dysbiosis, we investigated the effect of EEN on the microbiome in a rat model of CD-like colitis. The rat model of CD-like colitis was established by an intracolonic instillation of TNBS at 65 mg/kg in 250 µL of 40% ethanol. Sham control rats were instilled with saline. Rats were fed ad libitum with either regular pellet food or EEN treatment with a clear liquid diet (Ensure). Rats were euthanized at 7 days. Fecal pellets were collected from the distal colon for 16S rRNA sequencing analysis of gut microbiota. In addition, colon tissues were taken for histological and molecular analyses in all the groups of rats. EEN administration to TNBS-induced CD rats significantly improved the body weight change, inflammation scores, and disease activity index. The mRNA expression of IL-17A and interferon-γ was significantly increased in the colonic tissue in TNBS rats when fed with regular food. However, EEN treatment significantly attenuated the increase in IL-17A and interferon-γ in TNBS rats. Our 16S rRNA sequencing analysis found that gut microbiota diversity and compositions were significantly altered in TNBS rats, compared to controls. However, EEN treatment improved alpha diversity and increased certain beneficial bacteria such as Lactobacillus and Dubosiella and decreased bacteria such as Bacteroides and Enterorhabdus in CD-like rats, compared to CD-like rats with the regular pellet diet. In conclusion, EEN treatment increases the diversity of gut microbiota and the composition of certain beneficial bacteria. These effects may contribute to the reduced inflammation by EEN in the rat model of CD-like colitis.

Gut microbiota and liver metabolomics reveal the potential mechanism of Lactobacillus rhamnosus GG modulating the liver toxicity caused by polystyrene microplastics in mice

Microplastics (MPs) are known to cause liver toxicity as they can spread through the food chain. Most researches on their toxicity have focused on individual organs, neglecting the crucial "gut-liver axis"-a bidirectional communication pathway between the gut and liver. Probiotics have shown promise in modulating the effects of environmental pollutants. In this study, we exposed mice to Lactobacillus rhamnosus GG (LGG, 100 mg/kg b.w./d) and/or polystyrene microplastics (PS-MPs, 5 mg/kg b.w./d) for 28 d via gavage to investigate how probiotics influence live toxicity through the gut-liver axis. Our results demonstrated that PS-MPs induced liver inflammation (increased IL-6 and TNF-α) and disrupted lipid metabolism. However, when combined with LGG, these effects were alleviated. LGG also improved colon health, rectifying ciliary defects and abnormal mucus secretion caused by PS-MPs. Furthermore, LGG improved gut microbiota dysbiosis induced by PS-MPs. Metabolomics and gene expression analysis (Cyp7a1 and Cyp7b1) indicated that LGG modulated bile acid metabolism. In summary, LGG appears to protect the liver by maintaining gut homeostasis, enhancing gut barrier integrity, and reducing the liver inflammation. These findings confirm the potential of LGG to modulate liver toxicity caused by PS-MPs through the gut-liver axis, offering insights into probiotics' application for environmental pollutant detoxification.

Prebiotic inulin controls Th17 cells mediated central nervous system autoimmunity through modulating the gut microbiota and short chain fatty acids

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demyelination occurring in the central nervous system (CNS). Inulin is a common prebiotic that can improve metabolic disorders by modulating the gut microbiota. However, its capacity to affect CNS autoimmunity is poorly recognized. Experimental autoimmune encephalomyelitis (EAE) is a classical mouse model of MS. Herein, we found that oral administration of inulin ameliorated the severity EAE in mice, accompanied by reductions in inflammatory cell infiltration and demyelination in the CNS. These reductions were associated with decreased proportion and numbers of Th17 cells in brain and spleen. Consistent with the findings, the serum concentrations of IL-17, IL-6, and TNF-α were reduced in inulin treated EAE mice. Moreover, the proliferation of auto-reactive lymphocytes, against MOG35-55 antigen, was attenuated ex vivo. Mechanistically, inulin treatment altered the composition of gut microbiota. It increased Lactobacillus and Dubosiella whereas decreased g_Prevotellaceae_NK3B31_group at the genus level, alongside with elevated concentration of butyric acid in fecal content and serum. In vitro, butyrate, but not inulin, could inhibit the activation of MOG35-55 stimulated lymphocytes. Furthermore, fecal microbiota transplantation assay confirmed that fecal contents of inulin-treated normal mice had an ameliorative effect on EAE mice. In contrast, antibiotic cocktail (ABX) treatment diminished the therapeutic effect of inulin in EAE mice as well as the reduction of Th17 cells, while supplementation with Lactobacillus reuteri restored the amelioration effect. These results confirmed that the attenuation of inulin on Th17 cells and inflammatory demyelination in EAE mice was dependent on its modulation on gut microbiota and metabolites. Our findings provide a potential therapeutic regimen for prebiotic inulin supplementation in patients with multiple sclerosis.

Heat-moisture treatment enhances the ordered degree of starch structure in whole chestnut flour and alters its gut microbiota modulation in mice fed with high-fat diet

Currently, chestnuts attract more attention among consumers due to its rich nutritional functions, but systematic evaluation on the effect of thermal processing on its nutritional value is still limited. In this work, based on results of microstructural properties that heat-moisture treatment (HMT) could enhance the total ordered degree of starch structure in whole chestnut flour (CN) and promote the formation of anti-enzymatic component, in vitro experiment was then conducted and confirmed that HMT could significantly reduce the predicted glycemic index (pGI) of CN from 75.6 to 64.3 and improve its dietary fiber content from 7.06 to 13.42 g/100 g (p < 0.05). Further dietary intervention studies with CN and heat-moisture treated CN (HMT-CN) supplementation on the high-fat diet (HFD) consuming mice were discussed in terms of gut microbiota and its metabolites changes. The results showed that both CN and HMT-CN significantly resisted the weight gain induced by HFD, while HMT-CN had better serum lipid regulation effect. However, they had different effects on the gut metabolism pathways, among which CN inhibited the production of stearamine by promoting the proliferation of Dubosiella, while HMT-CN contributed to the growth of Lachnoclostridium, Desulfovibrio, and Faecalibaculum which stimulated the formation of associated metabolites including jwh-018-d11, valylproline, tetranor-12(S)-HETE, and PA (3:0/18:0). Overall, these discoveries could provide basic data for the effective utilization of CN in food industry processing.

Tissue Lipid Profiles of Rainbow Trout, Oncorhynchus mykiss, Cultivated under Environmental Variables on a Diet Supplemented with Dihydroquercetin and Arabinogalactan

Reared rainbow trout are vulnerable to environmental stressors, in particular seasonal water warming, which affects fish welfare and growth and induces a temperature response, which involves modifications in tissue lipid profiles. Dietary supplements of plant origin, including the studied mix of a flavonoid, dihydroquercetin and a polysaccharide, arabinogalactan (25 and 50 mg per 1 kg of feed, respectively), extracted from larch wood waste, were shown to facilitate stress tolerance in fish and also to be beneficial for the safety of natural ecosystems and the sustainability of aquaculture production. This four-month feeding trial aimed to determine the effects of the supplement on liver and muscle lipid accumulation and the composition in rainbow trout reared under environmental variables. During periods of environmental optimum for trout, a consistent increase in energy lipid stores, particularly triacylglycerols (2.18 vs. 1.49-fold over a growing season), and an overall increase in lipid saturation due to lower levels of PUFAs, such as eicosapentaenoic (20:5n-3), docosahexaenoic (22:6n-3) and arachidonic (20:4n-6) acids, were observed in both control and supplement-fed fish, respectively. However, in fish stressed by an increase in ambient temperature, dietary supplementation with dihydroquercetin and arabinogalactan reduced mortality (3.65 in control vs. 2.88% in supplement-fed fish, p < 0.05) and alleviated the high-temperature-induced inhibition of lipid accumulation. It also stabilised the membrane phospholipid ratio and moderated the fatty acid composition of fish muscle and liver, resulting in higher levels of n-3 PUFAs and their precursors. Thus, the natural compounds tested are beneficial in accelerating fish tolerance to environmental stressors, reducing mortality and thermal response, and moderately improving fillet quality attributes by increasing the protein/lipid ratio and the abundance of fatty acids essential for human nutrition.

The impact of dioctyl phthalate exposure on multiple organ systems and gut microbiota in mice

Dioctyl phthalate, commonly known as bis(2-ethylhexyl) phthalate (DEHP), is a widely used plasticizer in various industries and has been shown to directly or indirectly impact human health. However, there is a lack of comprehensive studies evaluating the potential health risks associated with DEHP accumulation in different organs across various age groups. This study aimed to assess the effects of low (50 mg/kg·bw) and high (500 mg/kg·bw) doses of DEHP on five different organs in mice at young (4-week-old) and aged (76-week-old) life stages. Our findings revealed that both low and high doses of DEHP exposure led to significant dose-dependent inflammation in the liver, spleen, and kidney. Furthermore, regardless of age, DEHP exposure resulted in elevated activity of alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in the liver, as well as increased levels of creatinine (Cr) and urea in the kidney. Moreover, analysis of the fecal microbiota using 16S rRNA sequencing demonstrated that DEHP exposure disrupted the homeostasis of the gut microbiota, characterized by an increased abundance of pathogenic bacteria such as Desulfovibrio and Muribaculum, and a decreased abundance of beneficial bacteria like Lactobacillus. This study provides compelling evidence that DEHP at different concentrations can induce damage to multiple organs and disrupt gut microbiota composition. These findings lay the groundwork for further investigations into DEHP toxicity in various human organs, contributing to a better understanding of the potential health risks associated with DEHP exposure.

Sodium alginate/poly(vinyl alcohol)/taxifolin nanofiber mat promoting diabetic wound healing by modulating the inflammatory response, angiogenesis, and skin flora

Diabetes-related ulcers are still a therapeutic problem because of their susceptibility to infection, ongoing inflammation, and diminished vascularization. The design and development of novel dressings are clinically urgent for the treatment of chronic wounds due to diabetic ulcers. In this study, we made taxifolin (TAX) loaded sodium alginate (SA)/poly(vinyl alcohol) (PVA) nanofibers for the treatment of chronic wounds. The SA/PVA/TAX nanofibers that have been created are smooth and bead-free, with good thermal stability, hydrophilicity, and mechanical properties. The release profile indicated a sustained drug release, with a cumulative release rate of 64.6 ± 3.7 % at 24 h. In vitro experiments have shown that SA/PVA/TAX has good antibacterial activity, antioxidant activity, and biocompatibility. In vivo experiments have shown that SA/PVA/TAX exhibits desirable biochemical properties and is involved in the diabetic wound healing process by promoting cell proliferation (Ki67), angiogenesis (CD31, VEGFA), and alleviating inflammation (CD68). Western blotting experiments suggest that SA/PVA/TAX may promote diabetic wound healing by inhibiting the TLR4/NF-κB/NLRP3 signaling pathway and upregulating the expression of VEGFA and PDGFA. The 16S rRNA sequencing results showed that SA/PVA/TAX increased the wound surface flora's diversity and reversed the skin microbiota's structural imbalance. Therefore, SA/PVA/TAX can promote diabetic wound healing by modulating the inflammatory response, angiogenesis, and skin flora and has the potential to be an excellent wound dressing.

Chronic Exposure to Drinking Water As, Pb, and Cd at Provisional Guideline Values Reduces Weight Gain in Male Mice via Gut Microflora Alterations and Intestinal Inflammation

Few studies have investigated the long-term effect of exposure to arsenic (As), lead (Pb), and cadmium (Cd) via drinking water at the provisional guideline values on gut microflora. In this study, male and female mice were exposed to water As, Pb, or Cd at 10, 10, or 5 μg L-1 for 6 months. At the end of the exposure, the net weight gain of male mice exposed to As and Pb (9.91 ± 1.35 and 11.2 ± 1.50 g) was significantly (p < 0.05) lower compared to unexposed control mice (14.1 ± 3.24 g), while this was not observed for female mice. Relative abundance of Akkermansia, a protective gut bacterium against intestinal inflammation, was reduced from 29.7% to 3.20%, 4.83%, and 17.0% after As, Pb, and Cd exposure in male mice, which likely caused chronic intestinal inflammation, as suggested by 2.81- to 9.60-fold higher mRNA levels of pro-inflammatory factors in ileal enterocytes of male mice. These results indicate that long-term exposure to drinking water As, Pb, and Cd at concentrations equivalent to the China provisional guideline values can cause loss of protective bacteria and lead to chronic intestinal inflammation, thereby affecting body weight gain in male mice.

The alleviating effect of ellagic acid on DSS-induced colitis via regulating gut microbiomes and gene expression of colonic epithelial cells

The anti-inflammatory effect of ellagic acid (EA) and its possible underlying mechanism in dextran sulfate sodium (DSS)-induced mouse chronic colonic inflammation were studied. It was observed that EA administration significantly alleviated the colonic inflammation phenotypes, including decreasing the disease activity index (DAI), enhancing the body weight loss, and improving the shortened length of the colon and pathological damage of colon tissue. Additionally, EA reshaped the constitution of the gut microbiota by elevating the ratio of Bacteroidetes along with Bacteroides and Muribaculaceae, while decreasing the proportion of Firmicutes. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) revealed that the metabolic function of the gut microbiota was also changed. Furthermore, mouse colon transcriptome analysis showed that the tight junction and peroxisome proliferator-activated receptor (PPAR) signaling pathways were activated and the expressions of related genes were upregulated after EA intervention. These results showed that EA could remodel the gut bacterial composition, change the intestinal epithelial cell gene expressions in mice, and consequently improve the colonic inflammatory symptoms.

Sodium butyrate ameliorates diabetic retinopathy in mice via the regulation of gut microbiota and related short-chain fatty acids

BACKGROUND

Diabetic retinopathy (DR) development is associated with disturbances in the gut microbiota and related metabolites. Butyric acid is one of the short-chain fatty acids (SCFAs), which has been found to possess a potential antidiabetic effect. However, whether butyrate has a role in DR remains elusive. This study aimed to investigate the effect and mechanism of sodium butyrate supplementation on DR.

METHODS

C57BL/6J mice were divided into three groups: Control group, diabetic group, and diabetic with butyrate supplementation group. Type 1 diabetic mouse model was induced by streptozotocin. Sodium butyrate was administered by gavage to the experimental group daily for 12 weeks. Optic coherence tomography, hematoxylin-eosin, and immunostaining of whole-mount retina were used to value the changes in retinal structure. Electroretinography was performed to assess the retinal visual function. The tight junction proteins in intestinal tissue were evaluated using immunohistochemistry. 16S rRNA sequencing and LC-MS/MS were performed to determine the alteration and correlation of the gut microbiota and systemic SCFAs.

RESULTS

Butyrate decreased blood glucose, food, and water consumption. Meanwhile, it alleviated retinal thinning and activated microglial cells but improved electroretinography visual function. Additionally, butyrate effectively enhanced the expression of ZO-1 and Occludin proteins in the small intestine. Crucially, only butyric acid, 4-methylvaleric acid, and caproic acid were significantly decreased in the plasma of diabetic mice and improved after butyrate supplementation. The deeper correlation analysis revealed nine genera strongly positively or negatively correlated with the above three SCFAs. Of note, all three positively correlated genera, including norank_f_Muribaculaceae, Ileibacterium, and Dubosiella, were significantly decreased in the diabetic mice with or without butyrate treatment. Interestingly, among the six negatively correlated genera, Escherichia-Shigella and Enterococcus were increased, while Lactobacillus, Bifidobacterium, Lachnospiraceae_NK4A136_group, and unclassified_f_Lachnospiraceae were decreased after butyrate supplementation.

CONCLUSION

Together, these findings demonstrate the microbiota regulating and diabetic therapeutic effects of butyrate, which can be used as a potential food supplement alternative to DR medicine.

Ketogenic diet protects MPTP-induced mouse model of Parkinson's disease via altering gut microbiota and metabolites

The ketogenic diet (KD) is a low-carbohydrate, high-fat regime that is protective against neurodegenerative diseases. However, the impact of KD on Parkinson's disease (PD) and its mechanisms remains unclear. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD was fed with KD for 8 weeks. Motor function and dopaminergic neurons were evaluated. Inflammation in the brain, plasma, and colon tissue were also measured. Fecal samples were assessed by 16S rDNA gene sequencing and untargeted metabolomics. We found that KD protected motor dysfunction, dopaminergic neuron loss, and inflammation in an MPTP mouse model of PD. 16S rDNA sequencing revealed that MPTP administration significantly increased Citrobacter, Desulfovibrio, and Ruminococcus, and decreased Dubosiella, whereas KD treatment reversed the dysbiosis. Meanwhile, KD regulated the MPTP-induced histamine, N-acetylputrescine, d-aspartic acid, and other metabolites. Fecal microbiota transplantation using feces from the KD-treated mice attenuated the motor function impairment and dopaminergic neuron loss in antibiotic-pretreated PD mice. Our current study demonstrates that KD played a neuroprotective role in the MPTP mouse model of PD through the diet-gut microbiota-brain axis, which may involve inflammation in the brain and colon. However, future research is warranted to explore the explicit anti-inflammatory mechanisms of the gut-brain axis in PD models fed with KD.

New Insights of Biological Functions of Natural Polyphenols in Inflammatory Intestinal Diseases

The intestine is critically crucial for nutrient absorption and host defense against exogenous stimuli. Inflammation-related intestinal diseases, including enteritis, inflammatory bowel disease (IBD), and colorectal cancer (CRC), are heavy burdens for human beings due to their high incidence and devastating clinical symptoms. Current studies have confirmed that inflammatory responses, along with oxidative stress and dysbiosis as critical pathogenesis, are involved in most intestinal diseases. Polyphenols are secondary metabolites derived from plants, which possess convincible anti-oxidative and anti-inflammatory properties, as well as regulation of intestinal microbiome, indicating the potential applications in enterocolitis and CRC. Actually, accumulating studies based on the biological functions of polyphenols have been performed to investigate the functional roles and underlying mechanisms over the last few decades. Based on the mounting evidence of literature, the objective of this review is to outline the current research progress regarding the category, biological functions, and metabolism of polyphenols within the intestine, as well as applications for the prevention and treatment of intestinal diseases, which might provide ever-expanding new insights for the utilization of natural polyphenols.