Effects of potassium diformate on growth performance, apparent digestibility of nutrients, serum biochemical indices, and intestinal microflora in Cherry Valley ducks.

This study was performed to investigate the effects of potassium diformate (KDF) on growth performance, apparent digestibility of nutrients, serum biochemical indices, and intestinal microflora of Cherry Valley ducks. In total, 144 female healthy 1-day-old Cherry Valley ducks were divided into 3 groups with 6 replicates per group and 8 ducks per replicate according to the principle of similar body weight. The control group was fed a basic diet. In the 2 experimental groups, 0.8% and 1.2% KDF was added to the basic diet, respectively. The trial period was 6 wk and the pretrial period was 3 wk. The final weight and ADG were significantly higher in the 0.8% KDF group than in the control group (P < 0.05). The feed-to-gain ratio was significantly lower in both KDF groups than in the control group (P < 0.05). The apparent digestibility of CP was significantly higher in both KDF groups than in the control group (P < 0.05). The apparent digestibility of calcium was also significantly higher in the 0.8% KDF group (P < 0.05). The serum levels of alkaline phosphatase, cholesterol, and total protein were significantly lower in the 0.8% KDF group than in the control group (P < 0.05), the IgM content was significantly higher (P < 0.05), the low-density lipoprotein cholesterol, triglyceride, and urea levels were significantly lower (P < 0.01), and the glucose level was significantly higher (P < 0.01). The serum total protein level was significantly higher in the 1.2% KDF group than in the control group (P < 0.05). The relative abundance of Firmicutes and Patescibacteria in the gut of ducks was significantly higher in the 0.8% KDF group than in the control group (P < 0.05), the relative abundance of unclassified Erysipelotrichaceae and Lactobacillus was significantly higher (P < 0.01), and the relative abundance of Fusobacteriota was significantly lower (P < 0.05). However, the relative abundance of Firmicutes in the gut of ducks was significantly higher in the 1.2% KDF group than in the control group (P < 0.05). The relative abundance of unclassified Erysipelotrichaceae and Clostridium sensu stricto 1 was significantly higher (P < 0.01), as was the relative abundance of Fusobacteriota and Proteobacteria (P < 0.05). These findings indicate that the addition of 0.8% KDF to the diet can improve the growth performance of Cherry Valley ducks, promote the absorption of nutrients, change the structure of the microflora in the cecum, and increase the relative abundance of dominant bacteria. It was also shown that there was a significant difference between the 0.8% and 1.2% KDF levels which suggest that the safety margin for overdosing is quite low.

Heat-treated and/or lysozyme-treated Enterococcus faecalis (FK-23) improves the progression of renal disease in a unilateral ischemia-reperfusion injury rat model.

The prevalence of chronic kidney disease (CKD) is increasing owing to the elderly population. Here, we investigated the effects of heat-treated Enterococcus faecalis (FK-23) and lysozyme-treated FK-23 (LFK) on the progression of CKD in rats. A CKD model was established using male Wistar rats by subjecting them to right nephrectomy (1K), followed by ischemia and reperfusion (IR). FK-23 or LFK was fed ad libitum as a mixed diet after right nephrectomy. Animals subjected to renal ischemia-reperfusion injury (IRI) showed increased plasma creatinine and blood urea nitrogen levels. Furthermore, in the kidneys, collagen accumulation and α-smooth muscle actin, indicative of fibroblast activation and fibrosis-related gene and protein expression, increased 3 weeks after IRI. FK-23 and LFK suppressed the increase in the mRNA levels of some of these genes. The increase in oxidative stress markers, 4-hydroxy-2-nonenal, endothelial nitric oxide synthase, and nitrotyrosine in the kidney, as well as increased plasma uremic toxins after IRI, were also ameliorated by FK-23 and LFK. Metagenomic analysis of fecal samples revealed that gut microbial alteration caused by IRI was also ameliorated by LFK treatment. These results suggest that Enterococcus faecalis ingredients may improve CKD progression by suppressing oxidative stress and correcting the balance of the intestinal microflora.

Effects of Aeromonas infection on the immune system, physical barriers and microflora structure in the intestine of juvenile grass carp (Ctenopharyngodon idella).

Grass carp (Ctenopharyngodon idella) is an intensively cultured and economically important herbivorous fish species in China, but its culture is often impacted by Aeromonas pathogens such as Aeromonas hydrophila and Aeromonas veronii. In this study, healthy grass carp were separately infected with A. hydrophila or A. veronii for 12, 24, 48 or 72 h. The results showed that the mRNA expression levels of intestinal inflammatory factors (tnf-α, il-1ß and il-8), complement factors (c3 and c4), antimicrobial peptides (hepcidin, nk-lysin and ß-defensin-1), immunoglobulins (igm and igt), and immune pathway-related signaling molecules (tlr1, tlr2, tlr4, myd88, irak4, irak1, traf6, nf-κb p65 and ap-1) were differentially upregulated in response to A. hydrophila and A. veronii challenge. Additionally, the expression levels of the intestinal pro-apoptotic genes tnfr1, tnfr2, tradd, caspase-8, caspase-3 and bax were significantly increased, whereas the expression of the inhibitory factor bcl-2 was significantly downregulated, indicating that Aeromonas infection significantly induced apoptosis in the intestine of grass carp. Moreover, the expression of intestinal tight junction proteins (occludin, zo-1, claudin b and claudin c) was significantly decreased after infection with Aeromonas. Histopathological analysis indicated the Aeromonas challenge caused severe damage to the intestinal villi with adhesions and detachment of intestinal villi accompanied by severe inflammatory cell infiltration at 12 h and 72 h. The 16S rRNA sequencing results showed that Aeromonas infection significantly altered the structure of the intestinal microflora of the grass carp at the phylum (Proteobacteria, Fusobacteria, Bacteroidetes and Firmicutes) and genus (Proteus, Cetobacterium, Bacteroides, and Aeromonas) levels. Take together, the findings of this study revealed that Aeromonas infection induces an intestinal immune response, triggers cell apoptosis, destroys physical barriers and alters microflora structure in the intestine of juvenile grass carp; the results will help to reveal the pathogenesis of intestinal bacterial diseases in grass carp.

[Effects of "brain-gut coherence" method of acupuncture on motor function and intestinal microflora in the patients with cerebral ischemic stroke].

OBJECTIVE: To observe the clinical effect of "brain-gut coherence" method of acupuncture on cerebral ischemic stroke (CIS) and explore its action mechanism. METHODS: A total of 82 patients with CIS were randomly divided into an observation group (41 cases, 3 cases dropped out, 2 cases discontinued) and a control group (41 cases, 4 cases dropped out, 2 cases excluded). The conventional basic treatment was administered in the two groups. Additionally, in the observation group, "brain-gut coherence" method of acupuncture was delivered. The stimulating points included the parietal and temporal anterior oblique line on the affected side, Zhongwan (CV 12), Guanyuan (CV 4), and bilateral Tianshu (ST 25), Zusanli (ST 36), Shangjuxu (ST 37) and Xiajuxu (ST 39). In the control group, the routine acupuncture was operated at Baihui (GV 20), Yintang (GV 24+), bilateral Fengchi (GB 20) and Zusanli (ST 36), and Hegu (LI 4), Jianyu (LI 15), Quchi (LI 11), Waiguan (TE 5), Futu (ST 32), Sanyinjiao (SP 6) and Taichong (LR 3) on the affected side. Acupuncture stimulation lasted 30 min each time, once daily, and for 5 days a week. The intervention for 4 weeks was required. The scores of Fugl-Meyer assessment scale (FMA), Berg balance scale (BBS) and the modified Barthel index (MBI), as well as the score of gastrointestinal symptoms were compared before and after treatment in the two groups. The neutrophil count (NUE) and the content of the serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) were detected before and after treatment in the two groups. Using 16S rRNA gene sequencing, the structure and relative abundance of intestinal microflora was detected before and after treatment; and with the enzyme linked immunosorbent assay (ELISA) adopted, the levels of intestinal fatty acid-binding protein (iFABP), D-lactate (D-LA), lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP), tumor necrosis factor-α(TNF-α), interleukin (IL)-1ß and IL-6 in the serum were detected before and after treatment in the two groups. RESULTS: After treatment, the scores of FMA, BBS and MBI were increased (P<0.05), and the scores of gastrointestinal symptoms were decreased (P<0.05) compared with those before treatment in the two groups. Compared with the control group, the scores of FMA, BBS and MBI were higher (P<0.05) and the score of gastrointestinal symptoms was lower (P<0.05) in the observation group after treatment. NEU and the content of serum NT-proBNP were reduced in the two groups (P<0.05), and the content of serum NT-proBNP in the observation group was lower than that of the control group (P<0.05) after treatment. Chao1, Ace, Sobs and Shannon indexes were increased after treatment compared with those before treatment in the two groups (P<0.05); and these indexes in the observation group were higher when compared with the control group (P<0.05). After treatment, the relative abundance of Bacteroidaceae, Enterobacteriaceae, Oscillospiraceae, Streptococcaceae and Sutterellaceae was reduced in comparison with that before treatment in the two groups (P<0.05); and the relative abundance of these microflora was lower in the observation group when compared with the control group (P<0.05). After treatment, the relative abundance of Lachnospiraceae, Ruminococcaceae, Bifidobacteriaceae and Coriobacteriaceae was increased in comparison with that before treatment in the two groups (P<0.05); and the relative abundance of these microflora was elevated in the observation group when compared with the control group (P<0.05). After treatment, the levels of iFABP, D-LA, LPS, LBP, TNF-α, IL-1ß and IL-6 were reduced when compared with those before treatment in the two groups (P<0.05), and these levels of the observation group were lower than those of the control group (P<0.05). CONCLUSION: "Brain-gut coherence" method of acupuncture can improve the motor function and gastrointestinal function of the patients with cerebral ischemic stroke, which may be related to modulating the structure of intestinal microflora, alleviating inflammatory reactions and accelerating the intestinal barrier repair.

Escherichia coli Activate Extraintestinal Antibody Response and Provide Anti-Infective Immunity.

The effects of intestinal microflora on extraintestinal immune response by intestinal cytokines and metabolites have been documented, but whether intestinal microbes stimulate serum antibody generation is unknown. Here, serum antibodies against 69 outer membrane proteins of Escherichia coli, a dominant bacterium in the human intestine, are detected in 141 healthy individuals of varying ages. Antibodies against E. coli outer membrane proteins are determined in all serum samples tested, and frequencies of antibodies to five outer membrane proteins (OmpA, OmpX, TsX, HlpA, and FepA) are close to 100%. Serum antibodies against E. coli outer membrane proteins are further validated by Western blot and bacterial pull-down. Moreover, the present study shows that OstA, HlpA, Tsx, NlpB, OmpC, YfcU, and OmpA provide specific immune protection against pathogenic E. coli, while HlpA and OmpA also exhibit cross-protection against Staphylococcus aureus infection. These finding indicate that intestinal E. coli activate extraintestinal antibody responses and provide anti-infective immunity.

Influence of increasing acclimation temperature on growth, digestion, antioxidant capacity, liver transcriptome and intestinal microflora of Ussruri whitefish Coregonus ussuriensis Berg.

For effective restoration, conservation of Ussruri whitefish Coregonus ussuriensis Berg and coping with global climate change, effects of environmental temperature on Ussruri whitefish urgently need to be explored. In current study, the effects of different acclimation temperatures on the growth, digestive physiology, antioxidant ability, liver transcriptional responses and intestinal microflora patterns of Ussruri whitefish were investigated. Ussruri whitefish (15.20 g ± 1.23 g) were reared for 42 days under different acclimation temperatures, i.e., 10, 13, 16, 19, 22 and 25 °C, respectively. Result first determined 28 °C as the semi-lethal temperature in order to design the temperature gradient test. Highest main gain rate (MGR) and specific growth rate (SGR) were observed in fish group having acclimation temperature of 19 °C. Significantly decrease (P < 0.05) in triglyceride (TG) content appeared at 19 °C as compared to the 10 °C and 13 °C temperature groups. 19 °C notablely increased protease activities of stomach and intestine and intestinal lipase and amylase activities. 19 °C group obtained the highest activities of chloramphnicol acetyltransferase (CAT) and total antioxidant capacity (T-AOC) and higher activities of superoxide dismutase (SOD). The intestinal microflora composition was most conducive to maintaining overall intestinal health when the temperature was 19 °C, compared to 10 °C and 25 °C. Ussruri whitefish exposed to 10 °C and 25 °C possessed the lower Lactobacillus abundance compared to exposure to 19 °C. Temperature down to 10 °C or up to 25 °C, respectively, triggered cold stress and heat stress, which leading to impairment in intestinal digestion, liver antioxidant capacity and intestinal microflora structure. Liver transcriptome response to 10 °C, 19 °C and 25 °C revealed that Ussruri whitefish might require the initiation of endoplasmic reticulum stress to correct protein damage from cold-temperature and high-temperature stress, and it was speculated that DNAJB11 could be regarded as a biomarker of cold stress response.Based on the quadratic regression analysis of MGR and SGR against temperature, the optimal acclamation temperature were, respectively, 18.0 °C and 18.1 °C. Our findings provide valuable theoretical insights for an in-depth understanding of temperature acclimation mechanisms and laid the foundation for conservation and development of Ussruri whitefish germplasm resources.

Inflammation accelerating intestinal fibrosis: from mechanism to clinic.

Intestinal fibrosis is a prevalent complication of IBD that that can frequently be triggered by prolonged inflammation. Fibrosis in the gut can cause a number of issues, which continue as an ongoing challenge to healthcare systems worldwide. The primary causes of intestinal fibrosis are soluble molecules, G protein-coupled receptors, epithelial-to-mesenchymal or endothelial-to-mesenchymal transition, and the gut microbiota. Fresh perspectives coming from in vivo and in vitro experimental models demonstrate that fibrogenic pathways might be different, at least to some extent, independent of the ones that influence inflammation. Understanding the distinctive procedures of intestinal fibrogenesis should provide a realistic foundation for targeting and blocking specific fibrogenic pathways, estimating the risk of fibrotic consequences, detecting early fibrotic alterations, and eventually allowing therapy development. Here, we first summarize the inflammatory and non-inflammatory components of fibrosis, and then we elaborate on the underlying mechanism associated with multiple cytokines in fibrosis, providing the framework for future clinical practice. Following that, we discuss the relationship between modernization and disease, as well as the shortcomings of current studies. We outline fibrosis diagnosis and therapy, as well as our recommendations for the future treatment of intestinal fibrosis. We anticipate that the global review will provides a wealth of fresh knowledge and suggestions for future fibrosis clinical practice.

The mitigative role of novel aflatoxin-degrading enzymes in diverse broiler performance indicators and gut microbiota following the consumption of diets contaminated with aflatoxins.

BACKGROUND: This study aims to explore both the toxic effects of aflatoxins (AFs) and the protective effects of degrading enzymes (DE) on broilers exposed to AFs. RESULTS: The findings reveal that a diet contaminated with 69.15 µg kg-1 of aflatoxin B1 had significant adverse effects on broilers. Specifically, it led to a reduction in average daily gain, dressed yield percentage, half-eviscerated yield with giblet yield percentage, eviscerated yield percentage, as well as serum superoxide dismutase (SOD), glutathione peroxidase activity and liver SOD activity (P < 0.05). Conversely, the diet increased the feed conversion ratio, liver index, serum glutamic oxaloacetic transaminase levels and malondialdehyde levels in both serum and liver (P < 0.05). Additionally, AFs disrupted the intestinal microflora significantly (P < 0.05), altering the relative abundance of Enterococcus, Lactobacillus and Escherichia in broiler jejunum. The addition of DE to AF-contaminated feed mitigated these negative effects and reduced the residues of aflatoxin B1, aflatoxin B2 and aflatoxin M1 in the liver and duodenum (P < 0.05). We also observed that broilers fed the diet pelleted at 80 °C exhibited improved dressing percentage and water holding capacity compared to those on the 75 °C diet. CONCLUSION: In summary, DE serves as an effective feed additive for mitigating AF contamination in poultry production. © 2024 Society of Chemical Industry.

Intestinal microflora promotes Th2-mediated immunity through NLRP3 in damp and heat environments.

Background: With the worsening of the greenhouse effect, the correlation between the damp-heat environment (DH) and the incidence of various diseases has gained increasing attention. Previous studies have demonstrated that DH can lead to intestinal disorders, enteritis, and an up-regulation of NOD-like receptor protein 3 (NLRP3). However, the mechanism of NLRP3 in this process remains unclear. Methods: We established a DH animal model to observe the impact of a high temperature and humidity environment on the mice. We sequenced the 16S rRNA of mouse feces, and the RNA transcriptome of intestinal tissue, as well as the levels of cytokines including interferon (IFN)-γ and interleukin (IL)-4 in serum. Results: Our results indicate that the intestinal macrophage infiltration and the expression of inflammatory genes were increased in mice challenged with DH for 14 days, while the M2 macrophages were decreased in Nlrp3 -/- mice. The alpha diversity of intestinal bacteria in Nlrp3 -/- mice was significantly higher than that in control mice, including an up-regulation of the Firmicutes/Bacteroidetes ratio. Transcriptomic analysis revealed 307 differentially expressed genes were decreased in Nlrp3 -/- mice compared with control mice, which was related to humoral immune response, complement activation, phagocytic recognition, malaria and inflammatory bowel disease. The ratio of IFN-γ/IL-4 was decreased in control mice but increased in Nlrp3 -/- mice. Conclusions: Our study found that the inflammation induced by DH promotes Th2-mediated immunity via NLRP3, which is closely related to the disruption of intestinal flora.

Uncovering the characteristics of the gut microbiota in patients with ischemic stroke and hemorrhagic stroke.

This study aimed to explore the gut microbiota characteristics of ischemic and hemorrhagic stroke patients. A case-control study was conducted, and high-throughput sequencing of the V4-V5 region of 16S rRNA was used to analyze the differences in gut microbiota. The results showed that Proteobacteria was significantly increased in the ischemic stroke group compared with the healthy control group, while Fusobacteria was significantly increased in the hemorrhagic stroke group. In the ischemic stroke group, Butyricimonas, Alloprevotella, and Escherichia were significantly more abundant than in the healthy control group. In the hemorrhagic stroke group, Atopobium, Hungatella, Eisenbergiella, Butyricimonas, Odonbacter, Lachnociostridium, Alistipes, Parabacteroides, and Fusobacterium were significantly more abundant than in the healthy control group. Additionally, Alloprevotella, Ruminococcus, and Prevotella were significantly more abundant in the ischemic stroke group than in the hemorrhagic stroke group. The gut microbiota of ischemic and hemorrhagic stroke patients has significant diversity characteristics. These results provide new theoretical basis for exploring the prevention and treatment of different types of stroke through gut microbiota research.

Network analysis of microbiome and metabolome to explore the mechanism of raw rhubarb in the protection against ischemic stroke via microbiota-gut-brain axis.

Ischemic stroke (IS) has attracted worldwide attention due to the high mortality and disability rate. Raw rhubarb (RR) is a traditional medicinal plant and whole-food that has been used in China for its various pharmacological activities, such as antioxidant and anti-inflammatory properties. Recent pharmacological research has shown the role of RR against IS, but its mechanism of action remains unclear, particularly in the context of the brain-gut axis. To address this gap in knowledge, the present study was conducted in the middle cerebral artery occlusion/reperfusion (MCAO/R) model with the aim of investigating the effects of RR on regulating the intestinal microbiota barrier and metabolism and thereby reducing inflammatory response so as to improve the IS. The results showed that pre-treatment of RR attenuated cerebral infarct area and inflammation response in MCAO rats. Furthermore, RR also improved intestinal barrier function, including the integrity and permeability of the intestinal barrier. Additionally, RR intervention significantly attenuated gut microbiota dysbiosis caused by ischemic stroke, especially the increased Firmicutes. Notably, the pseudo-germ-free (PGF) rats further demonstrated that the anti-stroke effect of RR might rely on intestinal microbiota. In addition, the UPLC/Q-Orbitrap-MS-Based metabolomics revealed the disrupted metabolic profiles caused by MCAO/R, and a total of 11 differential metabolites were modulated by RR administration, especially bile acids. Further correlation analysis and network pharmacology analysis also demonstrated a strong association between specific bacteria, such as Firmicutes and bile acids. In conclusion, our work demonstrated that RR could effectively ameliorate ischemic stroke by modulating the microbiota and metabolic disorders.

Faecalibacterium prausnitzii Supplementation Prevents Intestinal Barrier Injury and Gut Microflora Dysbiosis Induced by Sleep Deprivation.

Sleep deprivation (SD) leads to impaired intestinal barrier function and intestinal flora disorder, especially a reduction in the abundance of the next generation of probiotic Faecalibacterium prausnitzii (F. prausnitzii). However, it remains largely unclear whether F. prausnitzii can ameliorate SD-induced intestinal barrier damage. A 72 h SD mouse model was used in this research, with or without the addition of F. prausnitzii. The findings indicated that pre-colonization with F. prausnitzii could protect against tissue damage from SD, enhance goblet cell count and MUC2 levels in the colon, boost tight-junction protein expression, decrease macrophage infiltration, suppress pro-inflammatory cytokine expression, and reduce apoptosis. We found that the presence of F. prausnitzii helped to balance the gut microbiota in SD mice by reducing harmful bacteria like Klebsiella and Staphylococcus, while increasing beneficial bacteria such as Akkermansia. Ion chromatography analysis revealed that F. prausnitzii pretreatment increased the fecal butyrate level in SD mice. Overall, these results suggested that incorporating F. prausnitzii could help reduce gut damage caused by SD, potentially by enhancing the intestinal barrier and balancing gut microflora. This provides a foundation for utilizing probiotics to protect against intestinal illnesses.

Protective Mechanism of Eurotium amstelodami from Fuzhuan Brick Tea against Colitis and Gut-Derived Liver Injury Induced by Dextran Sulfate Sodium in C57BL/6 Mice.

The study explored the potential protective impact of the probiotic fungus Eurotium amstelodami in Fuzhuan brick tea on ulcerative colitis, along with the underlying mechanism. A spore suspension of E. amstelodami was administered to C57BL/6 mice to alleviate DSS-induced colitis. The findings indicated that administering E. amstelodami evidently enhanced the ultrastructure of colonic epithelium, showing characteristics such as enhanced TJ length, reduced microvilli damage, and enlarged intercellular space. After HLL supplementation, the activation of the liver inflammation pathway, including TLR4/NF-kB and NLRP3 inflammasome caused by DSS, was significantly suppressed, and bile acid metabolism, linking liver and gut, was enhanced, manifested by restoration of bile acid receptor (FXR, TGR5) level. The dysbiosis of the gut microbes in colitis mice was also restored by HLL intervention, characterized by the enrichment of beneficial bacteria (Lactobacillus, Bifidobacterium, Akkermansia, and Faecalibaculum) and fungi (Aspergillus, Trichoderma, Wallemia, Eurotium, and Cladosporium), which was closely associated with lipid metabolism and amino acid metabolism, and was negatively correlated with inflammatory gene expression. Hence, the recovery of gut microbial community structure, implicated deeply in the inflammatory index and metabolites profile, might play a crucial role in the therapeutic mechanism of HLL on colitis.

Synergistic impact of Gui Zhi Shao Yao Zhi Mu Decoction and leflunomide on gut microbiota in rheumatoid arthritis: insights from 16S rDNA sequencing.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disease with complex pathogenesis, including alterations in the gut microbiota. Gui Zhi Shao Yao Zhi Mu Decoction (GSZD), a traditional Chinese herbal formula, has shown efficacy in RA treatment, but its impact on intestinal microflora remains unclear. This study aimed to investigate the effects of GSZD combined with leflunomide on the gut microbiota of RA patients. METHODS: The study enrolled 48 RA patients who were randomly assigned to either a control group receiving leflunomide or a treatment group receiving GSZD combined with leflunomide for 12 weeks. Gut microbiota composition was analyzed pre- and post-intervention using 16S rDNA sequencing. Changes in microbial diversity, abundance, and metabolic functions were assessed. RESULTS: Post-treatment, both groups exhibited significant alterations in gut microbiota composition. GSZD combined with leflunomide led to an increased Bacteroidetes/Firmicutes ratio and a reduction in Actinobacteria compared to leflunomide alone. This was associated with beneficial shifts in microbial genera and metabolic pathways, suggesting improved gut health and systemic immune modulation. CONCLUSION: GSZD combined with leflunomide significantly modulates the gut microbiota in RA patients. This study provides insights into the mechanisms underlying the therapeutic effects of GSZD and highlights the potential of integrating traditional Chinese medicine with conventional treatments in managing RA.

Roles of ß-catenin in innate immune process and regulating intestinal flora in Qi river crucian carp (Carassius auratus).

In mammals, ß-catenin participates in innate immune process through interaction with NF-κB signaling pathway. However, its role in teleost immune processes remains largely unknown. We aimed to clarify the function of ß-catenin in the natural defense mechanism of Qi river crucian carp (Carassius auratus). ß-catenin exhibited a ubiquitous expression pattern in adult fish, as indicated by real-time PCR analysis. Following lipopolysaccharide (LPS), Polyinosinic-polycytidylic acid (polyI: C) and Aeromonas hydrophila (A. hydrophila) challenges, ß-catenin increased in gill, intestine, liver and kidney, indicating that ß-catenin likely plays a pivotal role in the immune response against pathogen infiltration. Inhibition of the ß-catenin pathway using FH535, an inhibitor of Wnt/ß-catenin pathway, resulting in pathological damage of the gill, intestine, liver and kidney, significant decrease of innate immune factors (C3, defb3, LYZ-C, INF-γ), upregulation of inflammatory factors (NF-κB, TNF-α, IL-1, IL-8), and downregulation of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities, increase of Malondialdehyde (MDA) content. Following A. hydrophila invasion, the mortality rate in the FH535 treatment group exceeded that of the control group. In addition, the diversity of intestinal microflora decreased and the community structure was uneven after FH535 treatment. In summary, our findings strongly suggest that ß-catenin plays a vital role in combating pathogen invasion and regulating intestinal flora in Qi river crucian carp.

Resveratrol ameliorates DSS-induced ulcerative colitis by acting on mouse gut microbiota.

OBJECTIVE AND DESIGN: Ulcerative colitis (UC) is a multi-faceted, recurrent immune disorder caused by dextran sulfate sodium (DSS). The intestinal microbiota has multiple functions in the host, so UC requires long-term potent medication. The effect of resveratrol (RSV) has seldom been reported, and this study researched that. Herein, the effect of RSV and Grape seed oil that anti-inflammatory ability in experimental mice was explored, also why RSV altered Gut Microbiota has been researched. MATERIALS AND METHODS: In this experiment, the effects of experimental drugs on colon length in mice with DSS-induced colitis were compared. H&E Staining was performed on serial sections of colon tissues and histological scores were determined for all groups. The expression of cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) in the colon tissue of mice was detected by immunohistochemical staining. In the end, the α-diversity index, sobs index, and rarefaction curve of the cecal and colon microbiota of different groups of mice were measured. Bray-Curtis-based Venn diagram of PCoA (principal coordinate analysis) and OTUs distribution in mouse gut microbiota were obtained. RESULTS: The results showed that the use of 40 mg/kg RSV (high dose) significantly reduced the severity of UC. The use of 10 mg/kg RSV (low dose) significantly reduced the effect of shortened colon length in DSS mice. Compared with the DSS-treated group, the levels of COX-2 and TNF-α in the colon tissues of RSV + DSS-treated mice were significantly decreased. According to this experiment, 19 mouse gut microbiota species had a relative abundance greater than 0.1%, with Beerella, Bacteroides, Helicobacter, Oscillator, and cecum pylori being more abundant in the colon than in the colon. A higher relative abundance of Lachnospira NK4A136 was observed in DSS and RSV groups compared with the control group, whereas the opposite was observed for Alloprevotella. This proves that resveratrol increases the uniformity and diversity of gut microbes to a certain extent, and has a protective effect on the gut.

Multi-omics analysis of miRNA-mediated intestinal microflora changes in crucian carp Carassius auratus infected with Rahnella aquatilis.

Infection by an emerging bacterial pathogen Rahnella aquatilis caused enteritis and septicemia in fish. However, the molecular pathogenesis of enteritis induced by R. aquatilis infection and its interacting mechanism of the intestinal microflora associated with microRNA (miRNA) immune regulation in crucian carp Carassius auratus are still unclear. In this study, C. auratus intraperitoneally injected with R. aquatilis KCL-5 was used as an experimental animal model, and the intestinal pathological changes, microflora, and differentially expressed miRNAs (DEMs) were investigated by multi-omics analysis. The significant changes in histopathological features, apoptotic cells, and enzyme activities (e.g., lysozyme (LYS), alkaline phosphatase (AKP), alanine aminotransferase (ALT), aspartate transaminase (AST), and glutathione peroxidase (GSH-Px)) in the intestine were examined after infection. Diversity and composition analysis of the intestinal microflora clearly demonstrated four dominant bacteria: Proteobacteria, Fusobacteria, Bacteroidetes, and Firmicutes. A total of 87 DEMs were significantly screened, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the potential target genes were mainly involved in the regulation of lipid, glutathione, cytosine, and purine metabolism, which participated in the local immune response through the intestinal immune network for IgA production, lysosome, and Toll-like receptor (TLR) pathways. Moreover, the expression levels of 11 target genes (e.g., TLR3, MyD88, NF-κB, TGF-ß, TNF-α, MHC II, IL-22, LysC, F2, F5, and C3) related to inflammation and immunity were verified by qRT-PCR detection. The correlation analysis indicated that the abundance of intestinal Firmicutes and Proteobacteria was significantly associated with the high local expression of miR-203/NF-κB, miR-129/TNF-α, and miR-205/TGF-ß. These findings will help to elucidate the molecular regulation mechanism of the intestinal microflora, inflammation, and immune response-mediated miRNA-target gene axis in cyprinid fish.

Chitosan oligosaccharide improves intestinal homeostasis to achieve the protection for the epithelial barrier of female Drosophila melanogaster via regulating intestinal microflora.

Chitosan oligosaccharide (COS) is a new type of marine functional oligosaccharide with biological activities such as regulating intestinal microflora and improving intestinal immunity. In this study, female Drosophila melanogaster was used as a model organism to evaluate the effect of COS on intestinal injury by H2O2 induction, and its mechanism was explored through the analysis of intestinal homeostasis. The results showed that 0.25% of COS could effectively prolong the lifespan of stressed female D. melanogaster by increasing its antioxidant capacity and maintaining intestinal homeostasis, which included protecting the mechanical barrier, promoting the chemical barrier, and regulating the biological barrier by affecting its autophagy and the antioxidant signaling pathway. Additionally, the protective effect of COS on the intestinal barrier and homeostasis of D. melanogaster under oxidative stress status is directly related to its regulation of the intestinal microflora, which could decrease excessive autophagy and activate the antioxidant system to promote health. IMPORTANCE: The epithelial barrier plays an important role in the organism's health. Chitosan oligosaccharide (COS), a new potential prebiotic, exhibits excellent antioxidant capacity and anti-inflammatory effects. Our study elucidated the protective mechanisms of COS on the intestinal barrier of Drosophila melanogaster under oxidative stress, which could provide new insights into COS application in various industries, such as food, agriculture, and medicine.

Asiaticoside ameliorates DSS-induced colitis in mice by inhibiting inflammatory response, protecting intestinal barrier and regulating intestinal microecology.

Ulcerative colitis (UC) is one of the most prevalent inflammatory bowel diseases and poses a serious threat to human health. Currently, safe and effective preventive measures are unavailable. In this study, the protective effects of asiaticoside (AS) on dextran sodium sulfate (DSS)-induced colitis in mice and the underlying molecular mechanism were investigated. In this experiment, colitis was induced in mice with DSS. Subsequently, the role of AS in colitis and its underlying mechanisms were examined using H&E staining, immunofluorescence staining, western blot, Elisa, FMT, and other assays. The results showed that AS significantly attenuated the related symptoms of DSS-induced colitis in mice. In addition, AS inhibited the activation of signaling pathways TLR4/NF-κB and MAPK reduced the release of inflammatory factors, thereby attenuating the inflammatory response in mice. AS administration also restored the permeability of the intestinal barrier by increasing the levels of tight junction-associated proteins (claudin-3, occludin, and ZO-1). In addition, AS rebalanced the intestinal flora of DSS-treated mice by increasing the diversity of the flora. AS can alleviate DSS-induced ulcerative colitis in mice by maintaining the intestinal barrier, thus inhibiting the signaling pathways TLR4/NF-κB and MAPK activation, reducing the release of inflammatory factors, and regulating intestinal microecology.

Selective breeding of cold-tolerant black soldier fly (Hermetia illucens) larvae: Gut microbial shifts and transcriptional patterns.

The larvae of black soldier fly (BSFL) convert organic waste into insect proteins used as feedstuff for livestock and aquaculture. BSFL production performance is considerably reduced during winter season. Herein, the intraspecific diversity of ten commercial BSF colonies collected in China was evaluated. The Bioforte colony was subjected to selective breeding at 12 °C and 16 °C to develop cold-tolerant BSF with improved production performance. After breeding for nine generations, the weight of larvae, survival rate, and the dry matter conversion rate significantly increased. Subsequently, intestinal microbiota in the cold-tolerant strain showed that bacteria belonging to Morganella, Dysgonomonas, Salmonella, Pseudochrobactrum, and Klebsiella genera were highly represented in the 12 °C bred, while those of Acinetobacter, Pseudochrobactrum, Enterococcus, Comamonas, and Leucobacter genera were significantly represented in the 16 °C bred group. Metagenomic revealed that several animal probiotics of the Enterococcus and Vagococcus genera were greatly enriched in the gut of larvae bred at 16 °C. Moreover, bacterial metabolic pathways including carbohydrate, lipid, amino acids, and cofactors and vitamins, were significantly increased, while organismal systems and human diseases was decreased in the 16 °C bred group. Transcriptomic analysis revealed that the upregulated differentially expressed genes in the 16 °C bred groups mainly participated in Autophagy-animal, AMPK signaling pathway, mTOR signaling pathway, Wnt signaling pathway, FoxO signaling pathway, Hippo signaling pathway at day 34 under 16 °C conditions, suggesting their significant role in the survival of BSFL. Taken together, these results shed lights on the role of intestinal microflora and gene pathways in the adaptation of BSF larvae to cold stress.