Search Results (22)

Early weaning in intensive lamb production improves reproductive efficiency but predisposes lambs to diarrhea, oxidative stress, and intestinal barrier dysfunction, highlighting the need for non-antibiotic strategies to protect gut health. This study evaluated whether a sheep-derived mixed probiotic could alleviate early weaning–induced intestinal injury and clarified its potential molecular mechanisms. Early weaning reduced body weight, average daily gain and feed efficiency, increased diarrhea, decreased plasma and colonic catalase (CAT), glutathione peroxidase (GSH-PX), and superoxide dismutase (SOD) activities, increased malondialdehyde (MDA), elevated interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), reduced interleukin-10 (IL-10) and transforming growth factor-β (TGF-β), increased plasma and mucosal immunoglobulin A, M, and G (IgA, IgM, IgG), and increased colonic lipopolysaccharide (LPS) with reduced diamine oxidase (DAO). Intestinally, EW induced villus atrophy, deeper crypts, lower villus height-to-crypt depth ratios, goblet cell loss, higher histopathological scores, and decreased colonic mucin 2, zonula occludens-1, claudin-1, and occludin. Probiotic supplementation partially reversed these alterations, restoring antioxidant enzyme activities, improving villus architecture and barrier protein expression, and rebalancing cytokine and immunoglobulin profiles. Transcriptomic and network analyses showed that early weaning activated Cytokine–cytokine receptor, NF-κB, TNF and Th17 pathways, whereas probiotics suppressed a weaning-responsive inflammatory gene module, downregulated key hub genes, and enhanced peroxisome proliferator-activated receptor (PPAR) signaling. These results show that supplementing early-weaned lambs with a mixed probiotic generated from sheep is an efficient nutritional strategy to reduce intestinal oxidative and inflammatory damage associated with weaning and to enhance their health and performance. Full article

Patients with multiple traumas, particularly those with traumatic brain injury (TBI), are among the most challenging cases in intensive care medicine. Although early orotracheal intubation and invasive mechanical ventilation (IMV) are essential for airway protection and neurological treatment, they significantly increase the risk of lower respiratory tract infection (LRTI), including ventilator-associated pneumonia (VAP) and ventilator-associated tracheobronchitis (VAT). These complications are particularly prevalent among neurocritical patients due to the distinctive interaction between the brain, lungs and immune system. This narrative review examines the current evidence on the mechanisms underlying the brain–lung–immune axis; the diagnostic challenges in identifying respiratory infections in mechanically ventilated TBI patients; and optimal approaches to empirical or quasi-targeted antimicrobial therapy based on diagnostic algorithms and rapid molecular techniques. Severe TBI induces neurogenic inflammation, autonomic dysregulation, and immunosuppression, thereby increasing susceptibility to pulmonary infections. The ‘triple hit hypothesis’ best explains this cascade: sympathetic hyperactivity (first hit), iatrogenic ventilatory injury (second hit), and intestinal dysbiosis with systemic immune dysregulation (third hit). VAP diagnosis remains challenging due to the lack of universal criteria, the overlap with systemic inflammatory response syndrome, and the low specificity of radiological and clinical signs. VAT may represent an intermediate stage within a continuum of ventilator-associated infection. Recent evidence supports the selective use of nebulized antibiotics for VAT, advocating an individualized, locally adapted empirical approach to VAP treatment. Syndromic molecular panels can accelerate the identification of pathogens, enabling the earlier and more appropriate selection of antimicrobials and improving outcomes while preserving stewardship. Understanding the brain–lung–immune axis and improving diagnostic accuracy are essential to enhancing the treatment of respiratory infections in neurocritical care. Integrating clinical assessment, biomarkers and rapid microbiological testing enables timely, targeted therapy and reduces the misuse of antimicrobials. Full article

With the widespread use of ionizing radiation (IR) in medical and industrial settings, irradiation has become increasingly common, posing significant risks to human health. Among the various organs affected, the gut is particularly sensitive to radiation-induced damage, leading to conditions such as radiation-induced intestinal damage (RIID). Recent studies have emphasized the critical role of gut microbiota and its metabolites in mitigating radiation-induced injury. This review discusses the effects of IR on the mammalian and human gut microbiota. We examine the dynamics of gut microbiota composition during and after irradiation, and emphasize the protective role of the gut flora and the metabolites in the pathophysiological mechanisms exhibited during radiation injury. In addition, this article investigates how specific metabolites, such as short-chain fatty acids and indole derivatives, may contribute to the mitigation of inflammation and promotion of gut barrier integrity. In addition, various therapeutic strategies based on modulating the gut microbiota, such as probiotics, antibiotics, and fecal microbiota transplantation, are discussed to understand their potential to prevent or mitigate RIID. Understanding the interactions between IR, gut microbiota and their metabolites provides new avenues for developing innovative therapeutic approaches to improve patient outcomes during and after radiotherapy. Future research directions could focus on optimizing microbiota-based therapies and exploring the role of diet and lifestyle in enhancing intestinal health during irradiation. Full article

Objective: Yinchenhao decoction (YCHD), a classical herbal formula comprising Artemisia capillaris, Gardenia jasminoides, and Rheum palmatum, has been clinically used for over 1000 years to treat cholestasis. However, its mechanism of action remains undefined. This study aimed to elucidate YCHD’s therapeutic mechanisms against cholestasis, with a focus on the gut microbiota-mediated regulation of the farnesoid X receptor (FXR)–fibroblast growth factor 15 (FGF15) pathway. Methods: An alpha-naphthyl isothiocyanate (ANIT)-induced cholestasis mouse model was established. Mice received YCHD (3/9 g/kg) for 7 days. 16S rRNA sequencing, targeted LC/MS (bile acid (BA) quantification), untargeted GC/MS (fecal metabolite detection), qPCR/Western blot (FXR pathway analysis), fecal microbiota transplantation (FMT), and antibiotic depletion were employed to dissect the gut–liver axis interactions. Results: YCHD alleviated cholestatic liver injury by reducing serum biomarkers, restoring BA homeostasis via FXR-FGF15 activation, and suppressing hepatic Cyp7a1-mediated BA synthesis. It remodeled gut microbiota, enriched FXR-activating secondary BAs (CDCA, DCA, CA), and restored the intestinal barrier integrity. Antibiotic cocktail abolished YCHD’s efficacy, while FMT from YCHD-treated mice enhanced its therapeutic effects, confirming microbiota dependency. Conclusions: YCHD mitigates cholestasis through gut microbiota-driven FXR activation and direct hepatobiliary regulation. These findings bridge traditional medicine and modern pharmacology, highlighting microbiome modulation as a therapeutic strategy for cholestatic liver diseases. Full article

Background/Objectives: Overuse or misuse of antibiotics could cause adverse effects such as gut microbiota dysbiosis and intestinal barrier dysfunction. Probiotic intervention could effectively alleviate these symptoms. However, the precise efficacy of Bifidobacterium animalis subsp. lactis PB200 (B. lactis PB200) in mitigating antibiotic-induced intestinal injury remains unclear. Objective: The aim of this study was to systematically evaluate the effects of B. lactis PB200 on intestinal barrier injury and gut microbiota dysbiosis in a murine model of antibiotic-induced intestinal injury. Methods: BALB/c mice were administered ceftriaxone sodium via oral gavage for seven consecutive days, followed by probiotic intervention daily via gastric gavage for 4 weeks. Results: The results indicated that B. lactis PB200 played a positive role in enhancing intestinal barrier function, as evidenced by the restored intestinal morphology, and elevated the expression of tight junctions including ZO-1, Claudin-4 and Occludin (2.76-fold, 4.39-fold, and 2.61-fold, respectively) compared to that in the Model group. B. lactis PB200 normalized the levels of serum pro- and anti-inflammatory factors, including IL-1β, IL-6, TNF-α and IL-10, and elevated the diversity and richness of gut microbiota. B. lactis PB200 significantly elevated the levels of propionic acid and butyric acid, with increases of 1.67-fold and 2.82-fold, respectively, compared to the Model group. Notably, B. lactis PB200 reduced the abundance of Enterocloster and increased the abundance of Parabacteroides, promoting the rebalance of gut microbiota. Conclusions: Taken together, these findings highlighted the significant potential of B. lactis PB200 in alleviating intestinal barrier damage and restoring the balance of gut microbiota caused by an antibiotic. Full article

Reduced glutathione (GSH) is a main nonenzymatic antioxidant, but its effects and underlying mechanisms on growth and intestinal health in weaned piglets still require further assessment. A total of 180 weaned piglets were randomly allotted to 5 groups: a basal diet (CON), and a basal diet supplemented with antibiotic chlortetracycline (ABX), 50 (GSH1), 65 (GSH2), or 100 mg/kg GSH (GSH3). Results revealed that dietary GSH1, GSH2, and ABX improved body weight and the average daily gain of weaned piglets, and ABX decreased albumin content but increased aspartate aminotransferase (AST) activity and the ratio of AST to alanine transaminase levels in plasma. GSH2 significantly decreased glucose content but increased the content of triglyceride and cholesterol in the plasma. Both GSH1 and GSH2 improved the jejunal mucosa architecture (villus height, crypt depth, and the ratio of villus height to crypt depth), tight junction protein (ZO-1 and Occludin), and antioxidant capacity (CAT and MDA), and the effects were superior to ABX. Dietary GSH improved the jejunal barrier by probably inhibiting the myosin light chain kinas pathway to up-regulate the transcript expression of tight junction protein (ZO-1 and Occludin) and Mucins. Through the proteomics analysis of the jejunal mucosa using 4D-DIA, the KEGG pathway enrichment analysis showed that differentiated proteins were significantly enriched in redox homeostasis-related pathways such as glutathione metabolism, cytochrome P450, the reactive oxygen species metabolic pathway, the oxidative phosphorylation pathway, and the phosphatidylinositol 3-kinase-serine/threonine kinase pathway in GSH2 vs. CON and in GSH2 vs. ABX. The results of proteomics and qRT-PCR showed that GSH supplementation might dose-dependently promote growth performance and that it alleviated the weaning stress-induced oxidative injury of the jejunal mucosa in piglets by activating SIRTI and Akt pathways to regulate GPX4, HSP70, FoxO1. Therefore, diets supplemented with 50–65 mg/kg GSH can promote the growth of and relieve intestinal oxidative injury in weaned piglets. Full article

The increasing incidence of multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium (S. Tm), known for causing invasive enteric infections, presents a significant public health challenge. Given the diminishing efficacy of existing antibiotics, it is imperative to explore novel alternatives for the treatment of MDR S. Tm infections. Here, we identified esculetin (EST), a natural coumarin abundant in dietary foods and herbs, as a compound exhibiting broad-spectrum antibacterial properties against a range of MDR bacteria. Our findings demonstrate that EST effectively inhibited the proliferation and expansion of MDR S. Tm in both in vitro experiments and animal models. Specifically, EST significantly downregulated the type 3 secretion system-1 (T3SS-1) virulence expression of MDR S. Tm, thereby preventing its invasion into intestinal epithelial cells. In S. Tm-infected mice, we observed cecal injury characterized by the upregulation of inflammatory cytokines, a reduction in goblet cell numbers, a decreased expression of tight junction proteins, and microbial dysbiosis. Conversely, EST treatment ameliorated these pathological changes induced by S. Tm infection and reduced oxidative stress by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, thereby improving intestinal barrier function. These results suggest that dietary coumarins or a targeted plant-based diet may offer a promising strategy to counteract MDR bacteria-induced enteric diseases. Full article

Light pollution is a potential risk for intestinal health in humans and animals. The gut microbiota is associated with the development of intestinal inflammation induced by extended exposure to light, but the underlying mechanism is not yet clear. The results of this study showed that extended exposure to light (18L:6D) damaged intestinal morphology, downregulated the expression of tight junction proteins, and upregulated the expression of the NLRP3 inflammasome and the concentration of pro-inflammatory cytokines. In addition, extended exposure to light significantly decreased the abundance of Lactobacillus, Butyricicoccus, and Sellimonas and increased the abundance of Bifidobacterium, unclassified Oscillospirales, Family_XIII_UCG-001, norank_f__norank_o__Clostridia_vadinBB60_group, and Defluviitaleaceae_UCG-01. Spearman correlation analysis indicated that gut microbiota dysbiosis positively correlated with the activation of the NLRP3 inflammasome. The above results indicated that extended exposure to light induced intestinal injury by NLRP3 inflammasome activation and gut microbiota dysbiosis. Antibiotic depletion intestinal microbiota treatment and cecal microbiota transplantation (CMT) from the 12L:12D group to 18L:6D group indicated that the gut microbiota alleviated intestinal inflammatory injury induced by extended exposure to light via inhibiting the activation of the NLRP3 inflammasome. In conclusion, our findings indicated that the gut microbiota can alleviate intestinal inflammation induced by extended exposure to light via inhibiting the activation of the NLRP3 inflammasome. Full article

This study investigated the effects of an antibiotic cocktail on intestinal microbial composition, mechanical barrier structure, and immune functions in early broilers. One-day-old healthy male broiler chicks were treated with a broad-spectrum antibiotic cocktail (ABX; neomycin, ampicillin, metronidazole, vancomycin, and kanamycin, 0.5 g/L each) or not in drinking water for 7 and 14 days, respectively. Sequencing of 16S rRNA revealed that ABX treatment significantly reduced relative Firmicutes, unclassified Lachnospiraceae, unclassified Oscillospiraceae, Ruminococcus torques, and unclassified Ruminococcaceae abundance in the cecum and relative Firmicutes, Lactobacillus and Baccillus abundance in the ileum, but significantly increased richness (Chao and ACE indices) and relative Enterococcus abundance in the ileum and cecum along with relatively enriched Bacteroidetes, Proteobacteria, Cyanobacteria, and Enterococcus levels in the ileum following ABX treatment for 14 days. ABX treatment for 14 days also significantly decreased intestinal weight and length, along with villus height (VH) and crypt depth (CD) of the small intestine, and remarkably increased serum LPS, TNF-α, IFN-γ, and IgG levels, as well as intestinal mucosa DAO and MPO activity. Moreover, prolonged use of ABX significantly downregulated occludin, ZO-1, and mucin 2 gene expression, along with goblet cell numbers in the ileum. Additionally, chickens given ABX for 14 days had lower acetic acid, butyric acid, and isobutyric acid content in the cecum than the chickens treated with ABX for 7 days and untreated chickens. Spearman correlation analysis found that those decreased potential beneficial bacteria were positively correlated with gut health-related indices, while those increased potential pathogenic strains were positively correlated with gut inflammation and gut injury-related parameters. Taken together, prolonged ABX application increased antibiotic-resistant species abundance, induced gut microbiota dysbiosis, delayed intestinal morphological development, disrupted intestinal barrier function, and perturbed immune response in early chickens. This study provides a reliable lower-bacteria chicken model for further investigation of the function of certain beneficial bacteria in the gut by fecal microbiota transplantation into germ-free or antibiotic-treated chickens. Full article

The abnormality in N6-methyladenosine (m6A) methylation is involved in the course of Alzheimer’s disease (AD), while the intervention of 27-Hydroxycholesterol (27-OHC) can affect the m6A methylation modification in the brain cortex. Disordered gut microbiota is a key link in 27-OHC leading to cognitive impairment, and further studies have found that the abundance of Roseburia intestinalis in the gut is significantly reduced under the intervention of 27-OHC. This study aims to investigate the association of 27-OHC, Roseburia intestinalis in the gut, and brain m6A modification in the learning and memory ability injury. In this study, 9-month-old male C57BL/6J mice were treated with antibiotic cocktails for 6 weeks to sweep the intestinal flora, followed by 27-OHC or normal saline subcutaneous injection, and then Roseburia intestinalis or normal saline gavage were applied to the mouse. The 27-OHC level in the brain, the gut barrier function, the m6A modification in the brain, and the memory ability were measured. From the results, we observed that 27-OHC impairs the gut barrier function, causing a disturbance in the expression of m6A methylation-related enzymes and reducing the m6A methylation modification level in the brain cortex, and finally leads to learning and memory impairment. However, Roseburia intestinalis supplementation could reverse the negative effects mentioned above. This study suggests that 27-OHC-induced learning and memory impairment might be linked to brain m6A methylation modification disturbance, while Roseburia intestinalis, as a probiotic with great potential, could reverse the damage caused by 27-OHC. This research could help reveal the mechanism of 27-OHC-induced neural damage and provide important scientific evidence for the future use of Roseburia intestinalis in neuroprotection. Full article

Lactobacilli have been widely used as probiotics because of their benefits for intestinal health and physiological functions. Among a variety of Lactobacillus genera, Limosilactobacillus reuteri has been studied for its ability to exert anti-inflammatory functions and its role in controlling metabolic disorders, as well as the production of the antimicrobial compound reuterin. However, the effects and mechanisms of L. reuteri on enhancing immune responses in the immunosuppressed states have been relatively understudied. In this study, we isolated an immunomodulatory strain, namely, L. reuteri KBL346 (KBL346), from a fecal sample of a 3-month-old infant in Korea. We evaluated the immunostimulatory activity and hematopoietic function of KBL346 in macrophages and cyclophosphamide (CPA)-induced immunosuppressed mice. KBL346 increased the phagocytic activity against Candida albicans MYA-4788 in macrophages, and as biomarkers for this, increased secretions of nitric oxide (NO) and prostaglandin E₂ (PGE₂) were confirmed. Also, the secretions of innate cytokines (TNF-α, IL-1β, and IL-6) were increased. In CPA-induced immunosuppressed mice, KBL346 at a dosage of 10¹⁰ CFU/kg protected against spleen injury and suppressed levels of immune-associated parameters, including NK cell activity, T and B lymphocyte proliferation, CD4⁺ and CD8⁺ T cell abundance, cytokines, and immunoglobulins in vivo. The effects were comparable or superior to those in the Korean red ginseng positive control group. Furthermore, the safety assessment of KBL346 as a probiotic was conducted by evaluating its antibiotic resistance, hemolytic activity, cytotoxicity, and metabolic characteristics. This study demonstrated the efficacy and safety of KBL346, which could potentially be used as a supplement to enhance the immune system. Full article

The involvement of alterations in gut microbiota composition due to the use of antibiotics has been widely observed. However, a clear picture of the influences of gentamicin, which is employed for the treatment of bacterial diarrhea in animal production, are largely unknown. Here, we addressed this problem using piglet models susceptible to enterotoxigenic Escherichia coli (ETEC) F4, which were treated with gentamicin. Gentamicin significantly alleviated diarrhea and intestinal injury. Through 16s RNS sequencing, it was found that gentamicin increased species richness but decreased community evenness. Additionally, clear clustering was observed between the gentamicin-treated group and the other groups. More importantly, with the establishment of a completely different microbial structure, a novel metabolite composition profile was formed. KEGG database annotation revealed that arachidonic acid metabolism and vancomycin resistance were the most significantly downregulated and upregulated pathways after gentamicin treatment, respectively. Meanwhile, we identified seven possible targets of gentamicin closely related to these two functional pathways through a comprehensive analysis. Taken together, these findings demonstrate that gentamicin therapy for diarrhea is associated with the downregulation of arachidonic acid metabolism. During this process, intestinal microbiota dysbiosis is induced, leading to increased levels of the vancomycin resistance pathway. An improved understanding of the roles of these processes will advance the conception and realization of new therapeutic and preventive strategies. Full article

The gut microbiota, as a major source of opportunistic pathogens, poses a great threat to systemic infection, whereas the role of the gut microbiota in sepsis is underestimated. Here, we aimed to explore the effects of different gut microbiota patterns (namely, enterotypes) in cecal ligation and puncture (CLP)-induced murine sepsis. To achieve this purpose, we built four kinds of enterotypes by exposing mice to different types of antibiotics (azithromycin, amoxicillin, metronidazole, and levofloxacin). The results showed that antibiotic exposure induced different enterotypes, which, in turn, led to varying levels of systemic inflammation in septic mice, with amoxicillin-associated enterotypes exhibiting the most severe inflammation, followed by metronidazole, azithromycin, and levofloxacin. Specifically, the amoxicillin-associated enterotype was characterized by an abundance of intestinal opportunistic pathogens, including Enterobacteriaceae, Sutterellaceae, and Morganellaceae. This enterotype played a significant role in promoting the pathogenic potential of the gut microbiota, ultimately contributing to the development of severe systemic inflammation. Furthermore, the amoxicillin-associated enterotype exaggerated the sepsis-related liver injury, as evidenced by higher levels of alanine aminotransferase, aspartate transaminase, and hepatic malondialdehyde. The results of the RNA sequencing and the fecal suspension intraperitoneal injection sepsis model indicated that the amoxicillin-associated enterotype provoked acute hepatic immune responses and led to more significant metabolic compensation in the event of sepsis. Collectively, we concluded that the gut microbiota was one crucial factor for heterogeneity in sepsis, where the modulated gut microbiota likely prevented or reduced the serious consequences of sepsis, at least in gut-derived sepsis. Full article

Peripartum antibiotics can negatively impact the developing gut microbiome and are associated with necrotizing enterocolitis (NEC). The mechanisms by which peripartum antibiotics increase the risk of NEC and strategies that can help mitigate this risk remain poorly understood. In this study, we determined mechanisms by which peripartum antibiotics increase neonatal gut injury and evaluated whether probiotics protect against gut injury potentiated by peripartum antibiotics. To accomplish this objective, we administered broad-spectrum antibiotics or sterile water to pregnant C57BL6 mice and induced neonatal gut injury to their pups with formula feeding. We found that pups exposed to antibiotics had reduced villus height, crypt depth, and intestinal olfactomedin 4 and proliferating cell nuclear antigen compared to the controls, indicating that peripartum antibiotics impaired intestinal proliferation. When formula feeding was used to induce NEC-like injury, more severe intestinal injury and apoptosis were observed in the pups exposed to antibiotics compared to the controls. Supplementation with the probiotic Lactobacillus rhamnosus GG (LGG) reduced the severity of formula-induced gut injury potentiated by antibiotics. Increased intestinal proliferating cell nuclear antigen and activation of the Gpr81-Wnt pathway were noted in the pups supplemented with LGG, suggesting partial restoration of intestinal proliferation by probiotics. We conclude that peripartum antibiotics potentiate neonatal gut injury by inhibiting intestinal proliferation. LGG supplementation decreases gut injury by activating the Gpr81-Wnt pathway and restoring intestinal proliferation impaired by peripartum antibiotics. Our results suggest that postnatal probiotics may be effective in mitigating the increased risk of NEC associated with peripartum antibiotic exposure in preterm infants. Full article

Replacing antibiotics with probiotics has become an important way to safely and effectively prevent and treat some gastrointestinal diseases. This study was conducted to investigate whether Lactobacillus salivarius WZ1 (L.S) could reduce the inflammatory injury to the mouse jejunum induced by Escherichia coli (ETEC) K88. Forty Kunming mice were randomly divided into four groups with 10 mice in each group. From day 1 to day 14, the control group and the E. coli group were administered with normal saline each day, while the L.S group and the L.S + E. coli group were gavaged with Lactobacillus salivarius WZ1 1 × 10⁸ CFU/mL each day. On the 15th day, the E. coli group and the L.S + E. coli group were intragastrically administered ETEC K88 1 × 10⁹ CFU/mL and sacrificed 24 h later. Our results show that pretreatment with Lactobacillus salivarius WZ1 can dramatically protect the jejunum morphological structure from the changes caused by ETEC K88 and relieve the morphological lesions of the jejunum, inhibiting changes in the mRNA expressions of TNF-α, IL-1β and IL-6 and the protein expressions of TLR4, NF-κB and MyD88 in the intestinal tissue of mice caused by ETEC K88. Moreover, pretreatment with Lactobacillus salivarius WZ1 also increased the relative abundance of beneficial genera such as Lactobacillus and Bifidobacterium and decreased the abundance of harmful genera such as Ralstonia and Helicobacter in the gut. These results demonstrate that Lactobacillus salivarius WZ1 can inhibit the inflammatory damage caused by ETEC K88 in mouse jejunum by regulating the TLR4/NF-κB/MyD88 inflammatory pathway and gut microbiota. Full article