Multi-omics analyses of radiation survivors identify radioprotective microbes and metabolites

Creatine-mediated ferroptosis inhibition is involved in the intestinal radioprotection of daytime-restricted feeding

Ionizing radiation-induced intestinal injury (IRIII) is a catastrophic disease lack of sufficient medical countermeasures currently. Regulation of the gut microbiota through dietary adjustments is a potential strategy to mitigate IRIII. Time-restricted feeding (TRF) is an emerging behavioral nutrition intervention with pleiotropic health benefits. Whether this dietary pattern influences the pathogenesis of IRIII remains vague. We evaluated the impact of TRF on intestinal radiosensitivity in this study and discovered that only daytime TRF (DTRF), not nighttime TRF, could ameliorate intestinal damage in mice that received a high dose of IR. Faecal metagenomic and metabolomic studies revealed that the intestinal creatine level was increased by approximate 9 times by DTRF, to which the Bifidobacterium pseudolongum enrichment contribute. Further investigations showed that creatine could activate the energy sensor AMP-activated protein kinase in irradiated enterocytes and induce phosphorylation of acetyl-CoA carboxylase, resulting in reduced production of polyunsaturated fatty acids and reduced ferroptosis after IR. The administration of creatine mitigated IRIII and reduced bacteremia and proinflammatory responses. Blockade of creatine import compromised the ferroptosis inhibition and mitigation of DTRF on IRIII. Our study demonstrates a radioprotective dietary mode that can reshape the gut microbiota and increase intestinal creatine, which can suppress IR-induced ferroptosis, thereby providing effective countermeasures for IRIII prevention.

Raffinose-metabolizing bacteria impair radiation-associated hematopoietic recovery via the bile acid/FXR/NF-κB signaling pathway

Radiation-associated hematopoietic recovery (RAHR) is critical for mitigating lethal complications of acute radiation syndrome (ARS), yet therapeutic strategies remain limited. Through integrated multi-omics analysis of a total body irradiation (TBI) mouse model, we identify Bacteroides acidifaciens-dominated gut microbiota as key mediators of RAHR impairment. 16S ribosomal rRNA sequencing revealed TBI-induced dysbiosis characterized by Bacteroidaceae enrichment, while functional metagenomics identified raffinose metabolism as the most significantly perturbed pathway. Notably, raffinose supplementation (10% w/v) recapitulated radiation-induced microbiota shifts and delayed bone marrow recovery. Fecal microbiota transplantation (FMT) revealed a causative role for raffinose-metabolizing microbiota, particularly Bacteroides acidifaciens, in delaying RAHR progression. Mechanistically, B. acidifaciens-mediated bile acid deconjugation activated FXR, subsequently suppressing NF-κB-dependent hematopoietic recovery. Therapeutic FXR inhibition via ursodeoxycholic acid (UDCA) had been shown to be a viable method for rescuing RAHR. Our results delineated a microbiome-bile acid-FXR axis as a master regulator of post-irradiation hematopoiesis. Targeting B. acidifaciens or its metabolic derivatives could represent a translatable strategy to mitigate radiation-induced hematopoietic injury.

MIIST305 mitigates gastrointestinal acute radiation syndrome injury and ameliorates radiation-induced gut microbiome dysbiosis

High-dose radiation exposure results in gastrointestinal (GI) acute radiation syndrome identified by the destruction of mucosal layer, intestinal growth barrier dysfunction, and aberrant inflammatory responses. Further, radiation causes gut microbiome dysbiosis characterized by diminished microbial diversity, mostly commensal bacteria, and the spread of bacterial pathogens that trigger the recruitment of immune cells and the production of pro-inflammatory factors that lead to further GI tissue damage. Currently, there are no U.S. Food and Drug Administration (FDA) approved countermeasures that can treat radiation-induced GI injuries. To meet this critical need, Synedgen Inc. has developed a glycopolymer radiomitigator (MIIST305) that is specifically targeted to the GI tract, which acts by intercalating into the mucus layer and the glycocalyx of intestinal epithelial cells that could potentially ameliorate the deleterious effects of radiation. Male C57BL/6J adult mice were exposed to 13 Gy partial body X-irradiation with 5% bone marrow shielding and MIIST305 was administered on days 1, 3, and 5 post-irradiation. Approximately 85% of the animals survived the irradiation exposure and were apparently healthy until the end of the 30-day study period. In contrast, no control, Vehicle-treated animals survived past day 10 at this radiation dose. We show that MIIST305 improved intestinal epithelial barrier function and suppressed systemic inflammatory responses mediated by radiation-induced pro-inflammatory cytokines. Taxonomic profiling and community structure of the fecal and colonic mucosa microbiota demonstrated that MIIST305 treatment increased microbial diversity and restored abundance of beneficial commensal bacteria, including Lactobacillus and Bifidobacterium genera while suppressing potentially pathogenic bacteria Enterococcus and Staphylococcus compared with Vehicle-treated animals. In summary, MIIST305 is a novel GI-targeted therapeutic that greatly enhances survival in mice exposed to lethal radiation and protects the GI tract from injury by restoring a balanced gut microbiota and reducing pro-inflammatory responses. Further development of this drug as an FDA-approved medical countermeasure is of critical importance.

Wheat bran supplementation improved polystyrene degradation efficiency of Zophobas atratus larvae by alleviating intestinal injury caused by polystyrene-intake

Wheat bran supplementation significantly improves the polystyrene consumption capacity of Zophobas atratus larvae. However, the underlying mechanism remains unclear, limiting further advancements in degradation efficiency. This study seeks to clarify the mechanism by analyzing intestinal morphology, gut microbiota structure, gene transcription, and targeted metabolites. Specifically, histopathology results demonstrated that wheat bran supplementation alleviated polystyrene-induced intestinal injury in larvae. From a genetic perspective, genes related to annexins and tight junction proteins were upregulated in intestinal tissues. These genetic changes positively correlated with increased levels of short-chain fatty acids, eicosanoids, and beneficial bacteria (e.g., Latilactobacillus curvatus). Moreover, wheat bran supplementation alleviated gut microbiota dysbiosis, suppressed pathogenic bacteria, reduced over upregulation of NADPH oxidase activity related genes, and up-regulated genes linked to the intestinal immune system process pathway, thereby mitigating the intestinal injury. It also upregulated genes associated with the aromatase activity pathway, promoting the degradation of polystyrene and its intermediates. In summary, wheat bran supplementation enhanced the polystyrene degradation efficiency of Z. atratus larvae by upregulating genes linked to the aromatase activity pathway and mitigating intestinal injury (through modulation of intestinal gene transcription, microbiota structure, and metabolites). Our findings offer new insights into improving the efficiency of insect-mediated plastic biodegradation.

Unusual MurC Ligase and Peptidoglycan Discovered in Lachnospiraceae Using a Fluorescent L-Amino Acid Based Selective Labeling Probe

Developing selective labeling probes for specific bacterial taxa can not only facilitate the study of target bacteria but also deepen our understanding of the microbial diversity at structural and molecular levels. The availability of such probes, however, remains very limited. In this study, by exploiting the variation of amino acids in peptidoglycan stem peptide, we designed a fluorescent L-amino acid probe and found that it can selectively target the family Lachnospiraceae (a major Gram-positive family in murine gut microbiome) in vivo. The following in vitro test using two Roseburia species belonging to this family validated labeling by the probe. We then discovered that the labeling site is the first amino acid (L-alanine in most bacteria), which links the stem peptide with N-acetylmuramic acid, a process catalyzed by a highly conserved enzyme MurC. An enzyme assay of Roseburia MurC demonstrated its ability to conjugate a fluorescent L-amino acid and other non-L-Ala amino acids to UDP-N-acetylmuramic acid. Subsequent X-ray crystallography analysis uncovered a substantially enlarged inner space in this enzyme, which can partially explain its tolerance to these atypical substrates. The resulting unusual peptidoglycan structures lead to significantly reduced activation of the NOD immune receptors, suggesting a new mechanism for the host to accommodate these highly abundant commensals.

Cannabinoid-2 receptor depletion promotes non-alcoholic fatty liver disease in mice via disturbing gut microbiota and tryptophan metabolism

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. NAFLD encompasses a spectrum of liver damage starting with liver steatosis and lipid disorders presented as the hallmark. Cannabinoid-2 receptor (CB2R) is the receptor of endocannabinoids mainly expressed in immune cells. Our preliminary study revealed the preventative role of CB2R in liver injury related to lipid metabolism. In this study, we aimed to explore the role of CB2R in NAFLD and the underlying mechanism related to microbial community. High-fat diet-induced NAFLD model was established in mice. We found that hepatic CB2R expression was significantly reduced in NAFLD mice and CB2R-/- mice fed with normal chow. Interestingly, cohousing with or transplanted with microbiota from WT mice, or treatment with an antibiotic cocktail ameliorated the NAFLD phenotype of CB2R-/- mice. The gut dysbiosis in CB2R-/- mice including increased Actinobacteriota and decreased Bacteroidota was similar to that of NAFLD patients and NAFLD mice. Microbial functional analysis and metabolomics profiling revealed obviously disturbed tryptophan metabolism in NAFLD patients and NAFLD mice, which were also seen in CB2R-/- mice. Correlation network showed that the disordered tryptophan metabolites such as indolelactic acid (ILA) and xanthurenic acid in CB2R-/- mice were mediated by gut dysbiosis and related to NAFLD severity indicators. In vitro and in vivo validation experiments showed that the enriched tryptophan metabolites ILA aggravated NAFLD phenotypes. These results demonstrate the involvement of CB2R in NAFLD, which is related to gut microbiota-mediated tryptophan metabolites. Our findings highlight CB2R and the associated microbes and tryptophan metabolites as promising targets for the treatment of NAFLD.

Targeting CCR5 with miltefosine as a therapeutic strategy for thrombocytopenia

Thrombocytopenia remains a challenging clinical condition with limited treatment options. Here, we demonstrated that miltefosine stimulated megakaryocyte (MK) differentiation in vitro. Miltefosine significantly accelerated platelet recovery, enhanced platelet function, and boosted MK production and differentiation in irradiated mice. RNA sequencing revealed association of CCR5, MAPK, and JAK2/STAT3 signaling pathways in miltefosine-mediated MK differentiation. Molecular docking, drug affinity responsive target stability (DARTS), and surface plasmon resonance (SPR) assays confirmed direct binding of miltefosine to CCR5. Inhibition of CCR5 disrupted miltefosine's effects on MK differentiation and activation of MAPK and JAK2/STAT3 signaling pathways, as well as key transcription factors GATA1, EGR1, and TAL1. Similarly, blockade of the MAPK or JAK2/STAT3 signaling pathways hindered miltefosine-induced MK differentiation and transcription factor activation. Our findings establish CCR5 as a therapeutic target for thrombocytopenia and identify miltefosine as a CCR5 agonist that promotes MK differentiation and platelet production via MAPK and JAK2/STAT3 signaling.

Unveiling the Anti-Aging Potential of 3HB: Lifespan Extension and Cellular Senescence Delay

BACKGROUND/OBJECTIVE

Aging is a significant risk factor for chronic diseases and disability, yet effective anti-aging interventions remain elusive. We explored the potential of 3-hydroxybutyrate (3HB), an endogenous metabolite with established safety, to modulate longevity in mice.

METHODS

In this study, we employed 2BS and WI-38 cell models, a yeast model, and naturally aging mouse models to investigate the effects of 3HB on aging in various systems. Additionally, we utilized RNA sequencing and metabolomics technologies to explore the potential mechanisms underlying the action of 3HB.

RESULTS

Our findings demonstrate that 3HB supplementation effectively delays cellular senescence, extending yeast lifespan by 51.3% and the median lifespan of naturally senescent mice by 21.0%. Notably, 3HB prolonged healthy lifespan in mice while mitigating age-related tissue morphology changes and organ senescence. Mechanistically, we identified that 3HB's anti-aging properties are mediated through its ability to delay cellular senescence and metabolic reprogramming, while promoting the production of beneficial metabolites like trigoneline and isoguvacine.

CONCLUSIONS

These findings highlight the promising therapeutic potential of 3HB as an anti-aging intervention and provide novel insights into its underlying mechanisms.

Electron-beam FLASH whole brain irradiation induced a unique changes of intestinal flora

BACKGROUND

Whole-brain radiotherapy (WBRT) is an important way to treat multiple metastases. Ultra-high dose rate (FLASH) can avoid neurotoxicity caused by conventional irradiation, it has attracted much attention. This study aims to study the difference of irradiation-induced intestinal flora between conventional dose rate and FLASH WBRT.

METHODS

WBRT with 10 Gy was performed with electron-beam conventional irradiation (2 Gy/s) and electron-beam FLASH (eFLASH) irradiation (230 Gy/s). The intestinal feces and whole brain of mice were isolated after behavioral evaluation at 1st, 3rd and 10th weeks post-irradiation. HE staining and immunofluorescence were used to access the level of brain damage. The differences in intestinal microbes and transcription levels were detected by 16S rRNA gene sequencing and transcriptome sequencing, respectively.

RESULTS

eFLASH irradiation significantly reduced radiation neurotoxicity and had a long-term protective effect on cognitive function and learning and memory ability. Compared with conventional irradiation, eFLASH irradiation not only up-regulated the expression of genes related to neuronal regeneration and digestive system, but also induced more abundant intestinal microflora, especially the "probiotics" such as Lachnospiraceae and others, which were proved to play a role in radiation protection, increased significantly after eFLASH irradiation. The up-regulated microbiota after eFLASH irradiation was significantly positively correlated with genes related to neuronal development and regeneration, while significantly negatively correlated with genes related to inhibitory synapses. Additionally, conventional irradiation down-regulated microbial metabolism-related pathways, while FLASH did not.

CONCLUSIONS

In summary, we explored the unique gut microbiota changes induced by eFLASH WBRT for the first time, providing a theoretical basis for exploring the mechanism of action of FLASH.

Gut commensal Lachnospiraceae bacteria contribute to anti-colitis effects of Lactiplantibacillus plantarum exopolysaccharides

The probiotic Lactiplantibacillus plantarum (L. plantarum) could ameliorate colitis. Alterations in the composition of gut microbiota (GM) have been proved in cases of colitis. The exopolysaccharides from L. plantarum HMPM2111 (LPE) could be effective in colitis through altering the composition of the GM. These effects were linked to inhibiting intestinal inflammation, regulating the TXNIP/NLRP3 inflammasome axis, and attenuating colonic barrier dysfunction. The combination of fecal microbiota transplantation (FMT) and antibiotic inducement showed that gut bacteria susceptible to vancomycin were inversely associated with colitis features and were necessary for the anti-inflammatory effects of LPE. The elevated abundances of gut commensal Lachnospiraceae bacteria were associated with the restoration of colitis treated by LPE. Metabolomics analysis showed that colitis mice treated with LPE had higher levels of propionate and tryptophan metabolites generated from gut bacteria. The administration of these metabolites protected colitis and resulted in a reduction in inflammatory responses. The outcomes of our investigation emerge the significance of the GM in controlling the protective implications of LPE against colitis. Lachnospiraceae bacteria, together with downstream metabolites, contribute substantially to protection. This work elucidates the essential function of the GM-metabolite axis in producing comprehensive protection versus colitis and identifies prospective treatment targets.

Mucosal Microbiome Markers of Complete Pathologic Response to Neoadjuvant Therapy in Rectal Carcinoma

Abstract

The intestinal microbiome contributes to colorectal carcinogenesis, disease progression, and response to therapy. Pathologic complete response is the therapeutic goal of neoadjuvant chemoradiation in rectal carcinoma. Nonoperative management has become an accepted strategy, and markers of complete treatment response are needed. Intestinal commensal bacteria contribute to treatment response and radiation colitis, and microbiome-targeted therapies have shown promise in clinical trials. We investigated the relationship among mucosa-associated bacteria, neoadjuvant therapy response, and radiation colitis symptoms in 57 patients who received neoadjuvant regimens with no therapy, chemotherapy only, or chemoradiation. The design was a retrospective cohort study. Microbiome profiling was performed by 16S rDNA sequencing of formalin-fixed, paraffin-embedded tissue at the proximal margin of resection. Global β diversity differed according to neoadjuvant therapy modality and was associated with radiation colitis. Taxonomic differences were detectable at phylum and lower classification levels, and radiation-induced colitis was associated with enrichment of the Bacillaceae family. Taxonomic features, including reduced Streptococcus, Lachnospiraceae, and Bacillaceae, were enriched in complete histopathologic responders to neoadjuvant therapy. Taxon-based prediction of metabolic pathways identified enrichment of prokaryotic NAD+ biosynthesis and salvage pathways in complete responders. Mucosal microbiome responses to multimodal neoadjuvant therapy reflect symptomatic radiation colitis, histopathologic evidence of radiation injury, and pathologic treatment response. Posttreatment microbiome β diversity markers of complete pathologic response may be useful in decisions to manage rectal carcinoma nonoperatively.

Significance

Posttreatment markers of the complete response of rectal carcinoma to neoadjuvant chemoradiation are needed to guide decisions about surgical resection. We found that mucosal microbiome β diversity, bacterial metabolic capacities, and specific taxonomic groups distinguished between complete and incomplete responders. The mucosal microbiome provides markers for complete pathologic response.

Delayed Impact of Ionizing Radiation Depends on Sex: Integrative Metagenomics and Metabolomics Analysis of Rodent Colon Content

There is an escalating need to comprehend the long-term impacts of nuclear radiation exposure since the permeation of ionizing radiation has been frequent in our current societal framework. A system evaluation of the microbes that reside inside a host's colon could meet this knowledge gap since the microbes play major roles in a host's response to stress. Indeed, our past study suggested that these microbes might break their symbiotic association with moribund hosts to form a pro-survival condition exclusive to themselves. In this study, we undertook metagenomics and metabolomics assays regarding the descending colon content (DCC) of adult mice. DCCs were collected 1 month and 6 months after 7 Gy or 7.5 Gy total body irradiation (TBI). The assessment of the metagenomic diversity profile in DCC found a significant sex bias caused by TBI. Six months after 7.5 Gy TBI, decreased Bacteroidetes were replaced by increased Firmicutes in males, and these alterations were reflected in the functional analysis. For instance, a larger number of networks linked to small chain fatty acid (SCFA) synthesis and metabolism were inhibited in males than in females. Additionally, bioenergy networks showed regression dynamics in females at 6 months post-TBI. Increased accumulation of glucose and pyruvate, which are typical precursors of beneficial SCFAs coupled with the activated networks linked to the production of reactive oxygen species, suggest a cross-sex energy-deprived state. Overall, there was a major chronic adverse implication in male mice that supported the previous literature in suggesting females are more radioresistant than males. The sex-biased chronic effects of TBI should be taken into consideration in designing the pertinent therapeutics.

Proteomics and lipidomics of human umbilical cord mesenchymal stem cells exposed to ionizing radiation

OBJECTIVES

Mesenchymal stem cell (MSC)-based therapies exhibit beneficial effects on various forms of tissue damage, including ionizing radiation-induced lesions. However, whether ionizing radiation affects the functions of human umbilical cord mesenchymal stem cells (hucMSCs) remains unclear. This study aimed to investigate the effect and possible mechanisms of ionizing radiation on the proliferation and differentiation of hucMSCs.

METHODS

The hucMSCs were divided into the 1 Gy group (exposure to a single dose (1 Gy) of X-ray radiation (1 Gy/min) for 14 days) and control (without radiation treatment) group. The proliferation, apoptosis, and adipogenic and osteogenic differentiation abilities of hucMSCs in the two groups were evaluated. Moreover, the lipidomics and proteomics analyses were conducted to explore crucial lipids and proteins by which ionizing radiation affected the functions of hucMSCs. In addition, the effects of BYSL on radiation-treated hucMSCs were explore, as well as the involved potential mechanisms.

RESULTS

X-ray radiation treatment inhibited proliferation, promoted apoptosis, and decreased adipogenic and osteogenic differentiation abilities of hucMSCs. Key lipids, such as triglyceride (TG) and phosphatidylcholine (PC), and hub proteins (BYSL, MRTO4, and RRP9) exhibited significant differences between the 1 Gy group and control group. Moreover, BYSL, MRTO4, and RRP9 were significantly correlated with TG and PC. BYSL overexpression evidently promoted the cell proliferation, adipogenic and osteogenic differentiation abilities of radiation-treated hucMSCs, as well as the protein expression levels of p-GSK-3β/GSK-3β and β-catenin, while suppressed cell apoptosis. However, the GSK-3β inhibitor (1-Az) treatment reversed the protein expression levels of p-GSK-3β/GSK-3β, β-catenin and BYSL, as well as the cell proliferation, apoptosis, adipogenic and osteogenic differentiation abilities of radiation-treated hucMSCs.

CONCLUSIONS

Our findings reveal that the proliferation and differentiation of hucMSCs are suppressed by radiation, which may be associated with the changes of key lipids (TG and PC) and proteins (BYSL, MRTO4, and RRP9). Furthermore, BYSL promotes adipogenic and osteogenic differentiation abilities of radiation-treated hucMSCs via GSK-3β/β-catenin pathway. These findings help explain the response of hucMSCs to radiation and have clinical implications for improving the outcomes of MSC-based therapies after radiotherapy.

Bacillus Coagulans BC99 Protects Ionizing Radiation-Induced Intestinal Injury and Modulates Gut Microbiota and Metabolites in Mice

The gastrointestinal tract is highly sensitive to ionizing radiation (IR), which causes radiation-induced intestinal injury (RIII). There are no effective drugs available for RIII in routine clinical treatment, which is a major limiting factor during the process of radiotherapy for pelvic abdominal malignancies. In this study, we aimed to elucidate the potential of probiotic Bacillus coagulans BC99 (B.coagulans BC99) in preventing RIII. C57BL/6J mice were gavage-administered with B.coagulans BC99 for 30 days and then exposed to a single dose of 12 Gy x-ray whole abdominal irradiation (WAI). B.coagulans BC99 treatment could mitigate RIII by preventing weight loss, maintaining the integrity of intestinal structure and barrier, improving inflammatory symptoms, modulating oxidative stress, and regulating the composition of gut microbiota, thereby reestablishing intestinal homeostasis. In addition, the potential radioprotective mechanism of B.coagulans BC99 was closely related to the gut microbiota-derived metabolites. This study offers a novel perspective for advancing probiotic-based treatments for RIII and enhancing strategies for the prevention of RIII.

Diet-microbiome interactions in cancer

Diet impacts cancer in diverse manners. Multiple nutritional effects on tumors are mediated by dietary modulation of commensals, residing in mucosal surfaces and possibly also within the tumor microenvironment. Mechanistically understanding such diet-microbiome-host interactions may enable to develop precision nutritional interventions impacting cancer development, dissemination, and treatment responses. However, data-driven nutritional strategies integrating diet-microbiome interactions are infrequently incorporated into cancer prevention and treatment schemes. Herein, we discuss how dietary composition affects cancer-related processes through alterations exerted by specific nutrients and complex foods on the microbiome. We highlight how dietary timing, including time-restricted feeding, impacts microbial function in modulating cancer and its therapy. We review existing and experimental nutritional approaches aimed at enhancing microbiome-mediated cancer treatment responsiveness while minimizing adverse effects, and address challenges and prospects in integrating diet-microbiome interactions into precision oncology. Collectively, mechanistically understanding diet-microbiome-host interactomes may enable to achieve a personalized and microbiome-informed optimization of nutritional cancer interventions.

Gut microbiota and gastrointestinal tumors: insights from a bibliometric analysis

Introduction

Despite the growing number of studies on the role of gut microbiota in treating gastrointestinal tumors, the overall research trends in this field remain inadequately characterized.

Methods

A bibliometric analysis was conducted using publications retrieved from the Web of Science Core Collection (up to September 30, 2024). Analytical tools including VOSviewer, CiteSpace, and an online bibliometric platform were employed to evaluate trends and hotspots.

Results

Analysis of 1,421 publications revealed significant geographical disparities in research output, with China and the United States leading contributions. Institutionally, the University of Adelaide, Zhejiang University, and Shanghai Jiao Tong University were prominent contributors. Authorship analysis identified Hannah R. Wardill as the most prolific author, while the International Journal of Molecular Sciences emerged as a leading journal. Rapidly growing frontiers include "proliferation," "inhibition," "immunotherapy," "drug delivery," and "tumorigenesis."

Discussion

This study provides a comprehensive overview of research trends and highlights emerging directions, aiming to advance scientific and clinical applications of gut microbiota in gastrointestinal tumor therapy.

The emerging role of IL-22 as a potential radiosensitivity biomarker for radiation-induced intestinal injury

Considering the beneficial role played by IL-22 in alleviating radiation-induced intestinal injury through its promotion of epithelial regeneration, it was hypothesized that individuals with elevated IL-22 levels might display either minimal intestinal injury or increased resistance following ionizing irradiation exposure. To assess the impact of IL-22 on intestinal radiosensitivity, IL-22 expression levels was detected in serum of normal mice. Mice naturally with high or low levels of IL-22 or pretreated with IL-22 or anti-IL-22 were subjected to 10 Gy of total abdominal radiation (TAI). Daily observation, morphometric analysis, quantitative reverse transcriptase polymerase chain reaction, immunohistochemistry and western blot were employed to measure weight loss, survival rate, cell proliferation and death, and DNA damage. Furthermore, influence of IL-22 pretreatment on survival of intestinal organoid exposed to 6 Gy X-rays was evaluated. The results showed that IL-22 expression levels were varied between individuals. Surprisingly, mice with high IL-22 levels displayed exacerbated intestinal injury manifesting as increased weight loss, reduced regeneration capacity and more cell apoptosis. Notably, a strong positive correlation between weight loss and IL-22 expression level was observed. Additionally, pretreatment with IL-22 resulted in increased mortality accompanied by enhanced cell apoptosis and DNA damage in crypt of early exposure, as well as diminished survival of intestinal organoid, while pretreatment with anti-IL-22 antibody alleviated the intestinal injury. In this study, we established a direct link between IL-22 and radiosensitivity, suggesting IL-22 could be used as a potential biomarker for predicting individual intestinal radiosensitivity prior to radiation exposure.

Flammulina velutipes residue Polysaccharide Alleviates Immunosuppression and Intestinal Injury by Modulating Gut Microbiota and Associated Metabolites

This study elucidated the mechanisms underlying the immunoregulatory and gut-microbiota-modulating effects of Flammulina velutipes residue polysaccharide (FVRP) using cyclophosphamide (CTX)-induced mouse models. FVRP supplementation alleviated CTX-induced intestinal damage and boosted antioxidant enzyme activity and cytokine secretion. Additionally, FVRP enhanced the diversity and total species richness of the gut microbiota, promoting the proliferation of beneficial bacteria (e.g., Prevotellaceae), while reducing the abundance of CTX-derived bacteria (Lachnospiraceae and Rikenellaceae). FVRP facilitates the accumulation of short-chain fatty acids. Untargeted metabolomic analyses of cecal content revealed that FVRP treatment notably restored the levels of 32 endogenous metabolites altered by CTX. Based on a pseudosterility mice model, fecal microbiota transplantation (FMT), and fecal filtrate transplantation (FFT), gut microbiota and associated metabolites were demonstrated to play a crucial role in the immunomodulatory and protective effects of FVRP against intestinal injury. In conclusion, FVRP exhibits significant potential as an immune enhancer and natural therapeutic agent for alleviating intestinal inflammatory conditions.

Impact of the ONCOBIOME network in cancer microbiome research

The European Union-sponsored ONCOBIOME network has spurred an international effort to identify and validate relevant gut microbiota-related biomarkers in oncology, generating a unique and publicly available microbiome resource. ONCOBIOME explores the effects of the microbiota on gut permeability and metabolism as well as on antimicrobial and antitumor immune responses. Methods for the diagnosis of gut dysbiosis have been developed based on oncomicrobiome signatures associated with the diagnosis, prognosis and treatment responses in patients with cancer. The mechanisms explaining how dysbiosis compromises natural or therapy-induced immunosurveillance have been explored. Through its integrative approach of leveraging multiple cohorts across populations, cancer types and stages, ONCOBIOME has laid the theoretical and practical foundations for the recognition of microbiota alterations as a hallmark of cancer. ONCOBIOME has launched microbiota-centered interventions and lobbies in favor of official guidelines for avoiding diet-induced or iatrogenic (for example, antibiotic- or proton pump inhibitor-induced) dysbiosis. Here, we review the key advances of the ONCOBIOME network and discuss the progress toward translating these into oncology clinical practice.

Significant changes in gut microbiota and SCFAs among patients with newly diagnosed acute myeloid leukemia

The purpose of this study was to identify whether the gut microbiota and metabolites of newly diagnosed acute myeloid leukemia (AML) patients displayed specific characteristic alterations and whether these changes could be used as potential biomarkers for predicting the disease. Notably, the gut microbiota and metabolites of AML patients exhibited significant structural and quantitative alterations at the time of their initial diagnosis. Beneficial bacteria, including Faecalibacterium, Collinsella, Lacticaseibacillus, and Roseburia, as well as butyric acid and acetic acid, were found to be considerably reduced in newly diagnosed AML patients. In contrast, Enterococcus and Lactobacillus, especially Enterococcus, were significantly enriched. Further investigation indicated that Enterococcus could serve as a potential intestinal marker, showing a strong negative correlation with the levels of acetic and butyric acid. Importantly, assays aimed at identifying AML demonstrated that Enterococcus, butyric acid, and acetatic acid exhibited excellent predictive effectiveness. Colonizing Enterococcus from patients were isolated for pathogen investigation, which revealed that these bacteria possess several strong virulence factors and multiple drug-resistance gene characteristics. Therefore, we speculate that the increase of Enterococcus may contribute to the development and progression of AML.

Research progress on fecal microbiota transplantation in tumor prevention and treatment

The application of fecal microbiota transplantation (FMT) as a therapeutic strategy to directly modify the makeup of the gut microbiota has made significant progress in the last few decades. The gut microbiota, a sizable microbial community present in the human gut, is essential for digestion, immunomodulation, and nutrition absorption. Alternatively, a growing body of research indicates that gut microbiota is a key contributor to cancer, and intratumoral bacteria are considered to be crucial "accomplices" in the development and metastasis of malignancies. The exceptional clinical effectiveness of FMT in treating melanoma patients has been adequately established in earlier research, which has created new avenues for the diagnosis and treatment of cancer and sparked an increasing interest in the treatment and prevention of other cancers. However, further research on the function and mechanisms of the gut microbiota is required to properly comprehend the impact and role of these organisms in tumor regulation. In this article, we present a detailed account of the influence of FMT on the entire course of cancer patients' illness and treatment, from tumor development, metastasis, and invasion, to the impact and application of treatment and prognosis, as well as address the associated mechanisms.

Role of gut microbiota in predicting chemotherapy-induced neutropenia duration in leukemia patients

Background

Acute leukemia is an aggressive malignancy with high morbidity and mortality, and chemotherapy is the primary treatment modality. However, chemotherapy often induces neutropenia (chemotherapy-induced neutropenia, CIN), increasing the risk of infectious complications and mortality. Current research suggests that gut microbiota may play a significant role in chemotherapy's efficacy and side effects.

Objective

This study aimed to investigate whether gut microbiota can predict the duration of chemotherapy-induced neutropenia in leukemia patients.

Methods

We included 56 leukemia patients from the Hematology Department of the Second Affiliated Hospital of Nanchang University, collecting fecal samples 1 day before and 1 day after chemotherapy. The diversity and community structure of gut microbiota were analyzed using 16S rRNA gene sequencing. Patients were divided into two groups based on the duration of neutropenia post-chemotherapy: Neutropenia ≤7 Days Group (NLE7 Group) and Neutropenia > 7 Days Group (NGT7 Group). Comparative analysis identified characteristic microbiota.

Results

After chemotherapy, gut microbiota diversity significantly decreased (p < 0.05). In the NGT7 Group, the relative abundance of Enterococcus before chemotherapy was significantly higher than in the NLE7 Group (p < 0.05). ROC curve analysis showed that the relative abundance of Enterococcus had high predictive accuracy for the duration of neutropenia (AUC = 0.800, 95% CI: 0.651-0.949).

Conclusion

The abundance of Enterococcus before chemotherapy can predict the duration of chemotherapy-induced neutropenia. These findings provide new evidence for gut microbiota as a predictive biomarker for chemotherapy side effects and may guide personalized treatment for leukemia patients.

The influence of the microbiome on radiotherapy and DNA damage responses

Colorectal cancer (CRC) is one of the most prevalent cancers in terms of diagnosis and mortality. Radiotherapy (RT) remains a mainstay of CRC therapy. As RT relies on DNA damage to promote tumor cell death, the activity of cellular DNA damage repair pathways can modulate cancer sensitivity to therapy. The gut microbiome has been shown to influence intestinal health and is independently associated with CRC development, treatment responses and outcomes. The microbiome can also modulate responses to CRC RT through various mechanisms such as community structure, toxins and metabolites. In this review we explore the use of RT in the treatment of CRC and the molecular factors that influence treatment outcomes. We also discuss how the microbiome can promote radiosensitivity versus radioprotection to modulate RT outcomes in CRC. Understanding the molecular interaction between the microbiome and DNA repair pathways can assist with predicting responses to RT. Once described, these connections between the microbiome and RT response can also be used to identify actionable targets for therapeutic development.

Mechanisms of action of intestinal microorganisms and advances in head and neck tumors

In the last decade, it has been discovered that intestinal flora can affect various organ-specific cancers by altering the body's energy balance, synthesizing genetic toxins and small signaling molecules, and initiating and modulating immune responses. In this review, we will focus on elucidating the role of intestinal flora based on its molecular mechanisms and its possible impact on head and neck cancers in the near future, and explore how it may be a novel approach to treating head and neck cancers in the future.

Gut microbiota as a new target for anticancer therapy: from mechanism to means of regulation

In order to decipher the relationship between gut microbiota imbalance and cancer, this paper reviewed the role of intestinal microbiota in anticancer therapy and related mechanisms, discussed the current research status of gut microbiota as a biomarker of cancer, and finally summarized the reasonable means of regulating gut microbiota to assist cancer therapy. Overall, our study reveals that the gut microbiota can serve as a potential target for improving cancer management.

Purine metabolism in bone marrow microenvironment inhibits hematopoietic stem cell differentiation under microgravity

BACKGROUND

Spaceflight and microgravity environments have been shown to cause significant health impairments, including bone loss, immune dysfunction, and hematopoietic disorders. Hematopoietic stem cells (HSCs), as progenitors of the hematopoietic system, are critical for the continuous renewal and regulation of immune cells. Therefore, elucidating the regulatory mechanisms governing HSC fate and differentiation in microgravity environments is of paramount importance.

METHODS

In this study, hindlimb unloading (HU) was employed in mice to simulate microgravity conditions. After 28 days of HU, cells were isolated for analysis. Flow cytometry and colony-forming assays were utilized to assess changes in HSC proliferation and differentiation. Additionally, transcriptomic and untargeted metabolomic sequencing were performed to elucidate alterations in the metabolic pathways of the bone marrow microenvironment and their molecular regulatory effects on HSCs fate.

RESULTS

Our findings revealed that 28 days of HU impaired hematopoietic function, leading to multi-organ damage and hematological disorders. The simulated microgravity environment significantly increased the HSCs population in the bone marrow, particularly within the long-term and short-term subtypes, while severely compromising the differentiation capacity of hematopoietic stem/progenitor cells. Transcriptomic analysis of HSCs, combined with metabolomic profiling of bone marrow supernatants, identified 1,631 differentially expressed genes and 58 metabolites with altered abundance. Gene set enrichment analysis indicated that HU suppressed key pathways, including hematopoietic cell lineage and MAPK signaling. Furthermore, integrated analyses revealed that metabolites affected by HU, particularly hypoxanthine enriched in the purine metabolism pathway, were closely associated with hematopoietic cell lineage and MAPK signaling pathways. Molecular docking simulations and in vitro experiments confirmed that hypoxanthine interacts directly with core molecules within these pathways, influencing their expression.

CONCLUSIONS

These findings demonstrate that hypoxanthine in the bone marrow supernatant acts as a signaling mediator under microgravity, influencing HSCs fate by modulating hematopoietic cell lineage and MAPK signaling pathways. This study offers novel insights into the impact of microgravity on HSC fate and gene expression, underscoring the pivotal role of bone marrow microenvironmental metabolic changes in regulating key signaling pathways that determine hematopoietic destiny.

Exploring the growing phase forest musk deer (Moschus berezovskii) dietary energy requirements based on growth performance and gut microbiota analysis

The forest musk deer (FMD) farming industry is currently experiencing rapid growth, yet the dietary energy requirements for FMD remain unclear. Therefore, we explored the optimal dietary digestible energy (DE) for growing phase FMD by providing three diets with different DE levels and analyzing changes in gut microbiota. A total of 20 six-month-old FMD were used in a 62-day trial. Animals were fed either traditional feed (CON, 10.38 MJ/kg DE) or pelleted diets with low (L, 8.87 MJ/kg), medium (M, 10.38 MJ/kg), or high (H, 11.86 MJ/kg) DE levels. The results showed that feeding pelleted diets significantly reduced the incidence of diarrhea (P < 0.05). The average daily gain in the H group was significantly higher than in the M group, and the M group was higher than both the L and CON groups (P < 0.05). Additionally, the H group showed the highest nutrient digestibility and the greatest increase in body measurements (P < 0.05). Analysis of fecal microbiota revealed that α-diversity and the relative abundance of Firmicutes increased with higher dietary energy levels, while the relative abundance of Bacteroidetes decreased. Beneficial bacteria such as Akkermansia and Lachnospira were significantly enriched in the H group. In conclusion, our findings suggest that pelleted diets are suitable for growing phase FMD, with an optimal dietary DE level of 11.86 MJ/kg.

IMPORTANCE

This study underscores the significance of identifying the optimal dietary digestible energy (DE) for growing forest musk deer (FMD). Pelleted diets with a DE level of 11.86 MJ/kg enhanced growth performance, nutrient digestibility, and gut health, while reducing diarrhea and enriching beneficial gut bacteria, offering valuable insights for improving FMD farming practices.

Fecal metabolomic analysis of the role of gut microbiota and short-chain fatty acids in the therapeutic mechanism of Timosaponin AIII in Sjögren's syndrome

INTRODUCTION/OBJECTIVES

Sjogren's syndrome (SS) is a chronic inflammatory and difficult-to-treat autoimmune disease. Timosaponin AIII (TAIII), a plant-derived steroidal saponin, effectively inhibits cell proliferation, induces apoptosis, and exhibits anti-inflammatory properties. This study explored the mechanisms of action of TAIII in SS treatment by studying gut microbiota and short-chain fatty acids (SCFAs) using fecal metabolomics.

METHODS

The model group used non-obese diabetic (NOD) mice. The treatment group was classified into TAIII and hydroxychloroquine groups. The gut microbiota, SCFAs, and metabolites were analyzed using 16S rRNA sequencing, gas chromatography-mass spectrometry analysis, and liquid chromatography-mass spectrometry, respectively.

RESULTS

TAIII effectively alleviated dry mouth in NOD mice, slowed the progression of salivary gland tissue injury, reduced inflammatory factor expression, and increased the levels of aquaporins 1 and 5. TAIII regulated SCFA content and tryptophan metabolism by altering the abundance of the Rikenellaceae_RC9_gut_group, thereby reducing the inflammatory response. TAIII can improve imbalances in the gut microbiota and the metabolic levels of related SCFAs and tryptophan, thereby reducing the level of inflammation.

CONCLUSION

The significant differences observed in the abundance of the Rikenellaceae_RC9_gut_group between the treatment and control groups indicated the potential relationship between bacteria and metabolites in SS. Key Points • The safe and effective treatment of SS with traditional Chinese medicine • Multi-means study on intestinal flora, short-chain fatty acids, and metabonomics.

Nanoscale Liposomes Co-Loaded with Irinotecan Hydrochloride and Thalidomide for Colorectal Cancer Synergistic Therapy

Irinotecan hydrochloride (CPT-11) is one of the first-line drugs used in the clinical treatment of colorectal cancer (CRC). However, the concomitant adverse effect of delayed diarrhea has hindered its clinical use. CPT-11 combined with Thalidomide (THA) therapy is considered a palliative strategy. To optimize the synergistic treatment of CPT-11 and THA, co-loaded liposomes are constructed using cholesterol, lecithin, and 1, 2-Distearoyl-sn-glycero-3-phosphoethanolamine-Poly(ethylene glycol) (DSPE-PEG) as the "immune and gut microbiota regulator." The co-loaded liposomes, which possess good stability, are prepared by the solvent injection method. After the treatment with the co-loaded liposomes, tumor growth in CRC-bearing mice is significantly inhibited. In particular, the co-loaded liposomes demonstrate favorable diarrhea-relieving effects through the modulation of inflammatory cytokines and gut microbiota. These findings suggest that the co-loaded liposomes have great potential as a combined drug-delivery platform for CRC therapy.

Oral colon-retentive inulin gels protect against radiation-induced hematopoietic and gastrointestinal injury by improving gut homeostasis

Ionizing radiation-induced injury often occurs in nuclear accidents or large-dose radiotherapy, leading to acute radiation syndromes characterized by hematopoietic and gastrointestinal injuries even to death. However, current radioprotective drugs are only used in hospitals with unavoidable side effects. Here, we heated the aqueous solution of inulin, a polysaccharide dietary fiber, forming colon-retentive gel as a radiation protector in radiotherapy. Mouse models were established after 60Co γ-ray irradiation of the total body or abdomen. Inulin gels were orally administered to the mice every day from 3 days pre-radiation to 3 days post-radiation. The hematopoietic system was well protected with good blood cell recovery and cell proliferation in the femur and spleen. Oral inulin gels increased the relative abundances of key commensal microorganisms including f_Lachnospiraceae, Akkermansia, Blautia, and short-chain fatty acid metabolites. The secretion of the anti-inflammation cytokines IL-22 and IL-10 in the intestinal cells also increased. Similarly, the expression of the tight junction proteins claudin-1 and occludin in the gut mucosa was affected. In an orthotopic murine colorectal cancer model, oral inulin gels followed by 10-Gy abdomen radiation improved the radiotherapy efficiency with low attenuated radiation injury. Taken the data together, these results suggest that oral inulin gels are a bioactive material against ionizing radiation-induced injury.

Butyrate-engineered yeast activates Nppa and Sgcg genes and reduces radiation-induced heart damage via the gut-heart axis

Radiotherapy is a method of treating cancer through radiation aimed at killing cancer cells or inhibiting their growth. However, radiotherapy has numerous side effects because it kills tumors while causing damage to normal cells or tissues. The literature shows that radiation can cause damage to heart tissue. This study found that engineered yeast that produced butyrate can maintain small intestinal barrier function by recovering GPR109A to reduce intestinal damage caused by abdominal irradiation in mice. We unexpectedly found that engineered yeast could mitigate irradiation-induced heart damage via the gut-heart axis. Mechanistically, engineered yeast enhanced taurine and nicotinamide metabolism by increasing the relative abundance of Akkermansia and Lachnospiraceae_NK4A136; then, yeast modulated cardiac function by activating the Sgcg and Nppa genes to attenuate cardiac damage induced by abdominal irradiation. Finally, we confirmed that engineered yeast mitigated cardiac damage caused by total body irradiation, which protected other vital organs through the intestinal tract. This study has a profound impact on cancer treatment, the emergence of engineered yeast will alleviate radiotherapy side effects and benefit patients.

Integrative multi-omics analysis of radionuclide-induced intestinal injury reveals the radioprotective role of L-citrulline through histone H3-mediated Cxcl3

BACKGROUND

The widespread application of nuclear technology has markedly heightened the risk of extensive, uncontrolled exposure to radiation. Nevertheless, in contrast to external irradiation, the biological impacts and countermeasures against internal irradiation from radionuclides remain inadequately characterized.

METHODS

Mice were administered yttrium-90 (Y90) carbon microspheres via gavage at different dosages (0-5.0 mCi) to establish a radionuclides exposure model. A multi-omics analysis was employed to access alterations in gut microbiota, fecal and colonic metabolites profiles, and intestinal mRNA expression post-irradiation. The function of significant metabolite was validated at both cellular levels and organismal levels. Additionally, ChIP-Seq and RNA-Seq techniques were utilized to investigate the molecular mechanism underlying the actions of key metabolite.

RESULTS

Exposure to Y90 resulted in intestinal damage and hematological impairment. Multi-omics analysis revealed significant alternations of gut microbiota, fecal metabolites, colonic metabolites, and intestinal mRNA expression following internal radiation exposure. Notably, L-citrulline was identified as a metabolite with changes observed in both fecal and colonic tissues, demonstrating radioprotective properties in vitro and in vivo. Mechanistically, L-citrulline facilitated the citrullination of histone H3 at the 17th site (H3Cit17), and multiple mRNAs including C-X-C motif chemokine ligand 3 (Cxcl3), were transcriptionally regulated by H3Cit17 post L-citrulline treatment. Furthermore, Cxcl3 conferred protective effects for intestinal epithelial cells against ionizing radiation.

CONCLUSIONS

The research offers critical perspectives on the intestinal and gut microbiota's reaction to radionuclides exposure. It underscores the promise of L-citrulline as a radioprotective compound, which may have substantial ramifications for the formulation of strategies to mitigate radiation exposure.

Tumor microbiome: roles in tumor initiation, progression, and therapy

Over the past few years, the tumor microbiome is increasingly recognized for its multifaceted involvement in cancer initiation, progression, and metastasis. With the application of 16S ribosomal ribonucleic acid (16S rRNA) sequencing, the intratumoral microbiome, also referred to as tumor-intrinsic or tumor-resident microbiome, has also been found to play a significant role in the tumor microenvironment (TME). Understanding their complex functions is critical for identifying new therapeutic avenues and improving treatment outcomes. This review first summarizes the origins and composition of these microbial communities, emphasizing their adapted diversity across a diverse range of tumor types and stages. Moreover, we outline the general mechanisms by which specific microbes induce tumor initiation, including the activation of carcinogenic pathways, deoxyribonucleic acid (DNA) damage, epigenetic modifications, and chronic inflammation. We further propose the tumor microbiome may evade immunity and promote angiogenesis to support tumor progression, while uncovering specific microbial influences on each step of the metastatic cascade, such as invasion, circulation, and seeding in secondary sites. Additionally, tumor microbiome is closely associated with drug resistance and influences therapeutic efficacy by modulating immune responses, drug metabolism, and apoptotic pathways. Furthermore, we explore innovative microbe-based therapeutic strategies, such as engineered bacteria, oncolytic virotherapy, and other modalities aimed at enhancing immunotherapeutic efficacy, paving the way for microbiome-centered cancer treatment frameworks.

Whole Abdominal Pencil Beam Scanned Proton FLASH Increases Acute Lethality

PURPOSE

Ultrahigh dose-rate FLASH radiation therapy has emerged as a modality that promises to reduce normal tissue toxicity while maintaining tumor control. Previous studies of gastrointestinal toxicity using passively scattered FLASH proton therapy (PRT) have, however, yielded mixed results, suggesting that the requirements for gastrointestinal sparing by FLASH are an open question. Furthermore, the more clinically relevant pencil beam scanned (PBS) FLASH PRT has not yet been assessed in this context, despite differences in the spatiotemporal dose-rate distributions compared with passively scattered PRT. Here, to our knowledge, we provide the first report on the effects of PBS FLASH PRT on acute gastrointestinal injury in mice after whole abdominal irradiation.

METHODS AND MATERIALS

Whole abdominal irradiation was performed on C57BL/6J mice using the entrance channel of the Bragg curve of a 250 MeV PBS proton beam at field-averaged dose rates of 0.6 Gy/s for conventional (CONV) and 80 to 100 Gy/s for FLASH PRT. A 2D strip ionization chamber array was used to measure the dose and dose rate for each mouse. Survival was assessed at 14 Gy. Intestines were harvested and processed as Swiss rolls for analysis using a novel artificial intelligence-based crypt assay to quantify crypt regeneration 4 days after irradiation.

RESULTS

Survival was significantly reduced after 14 Gy FLASH PRT compared with CONV (P < .001). Our artificial intelligence-based crypt assays demonstrated no significant difference in intestinal crypts/cm or crypt depth between groups 4 days after irradiation. Furthermore, we found no significant difference in 5-ethynyl-2'-deoxyuridine+ cells/crypt or Olfactomedin4+ intestinal stem cells with FLASH relative to CONV PRT.

CONCLUSIONS

Overall, our data demonstrate significantly impaired survival after abdominal PBS FLASH PRT without apparent differences in intestinal histology 4 days after irradiation.

Anti-Inflammatory Resveratrol Protects Mice From Early Mortality After Haematopoietic Stem Cell Transplantation

The occurrence of inflammation subsequent to haematopoietic stem cell transplantation is associated with an elevated risk of transplant-related mortality (TRM). However, the duration of inflammation and the potential efficacy of anti-inflammatory agents in reducing TRM remain uncertain. We performed a comprehensive investigation to examine the post-transplantation alterations of inflammatory mediators and to ascertain the correlation between inflammation level and TRM through the neutrophil-lymphocyte ratio, ELISAs and cytometric bead array. The findings revealed that the 30-day interval following transplantation is characterised by the most pronounced inflammatory response in both human and murine subjects, thereby elevating the risk of TRM. The inflammation is primarily caused by myeloid bias during haematopoietic reconstitution, which is a commonly overlooked aspect in clinical transplantation, additionally, a lesser extent of irradiation-induced injury. The administration of the anti-inflammatory agent resveratrol has the potential to reduce systemic inflammation and TRM by suppressing the NOD-like receptor signalling pathway and slowing down granulocyte implantation in HSCT mice. This approach did not impair the differentiation potential of haematopoietic stem cells. These findings demonstrate that the 30-day post-transplant period represents an opportunity to facilitate HSCT colonisation, mitigate transplant-related adverse effects, and potentially reap the benefits of anti-inflammatory treatments.

Studies on the alleviating effect of Bifidobacterium lactis V9 on dextran sodium sulfate-induced colitis in mice

Background

Inflammatory bowel disease (IBD) has become a global public health problem with complex pathogenesis and limited therapeutic options. We aimed to investigate the potential mechanisms by which Bifidobacterium lactis V9 (V9) alleviated colitis in a dextran sodium sulfate-induced colitis model mice.

Methods

Mice were induced to develop colitis by drinking DSS solution to induce colitis. The expression of the relevant factors in the blood supernatant of the mice was determined by ELISA. RT-qPCR and Western blotting were used to detect mRNA and protein expression of target genes. The fecal microbiota was analyzed by 16S rRNA sequencing. Intestinal metabolites were analyzed by untargeted metabolomics.

Results

V9 effectively improved the overall symptoms of the colitis model mice. H&E showed that V9 re-stored the intestinal tissue structure. ELISA showed that V9 decreased the levels of IL-6, IL-22, and TNF-α and increased IL-10, SP, VIP, and 5-HT. V9 increased the expression of AHR, CYP1A1, MUC2, Claudin-3, Occludin, and ZO-1, and decreased 5-hydroxytryptamine transporter and Claudin-2. V9 increased the abundance of gut microbiota in colitis mice to promote the growth of beneficial bacteria. V9 increased tryptophan metabolites, and short-chain fatty acids, and improved gut inflammation.

Conclusion

V9 attenuates intestinal inflammation, improves the mucosal barrier, modulates intestinal microecology and exerts a protective effect in a mouse model of DSS-induced colitis.

Multi-omics analysis combined with network pharmacology revealed the mechanisms of rutaecarpine in chronic atrophic gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Tetradium ruticarpum (A.Juss.) T.G.Hartley is a traditional Chinese medicine with a history of thousands of years, which plays an important role in the relief of gastric pain, indigestion, vomiting and diarrhea. Rutaecarpine (RUT) is one of the major active constituents of Tetradium ruticarpum (A.Juss.) T.G.Hartley with potential therapeutic activity in chronic atrophic gastritis (CAG). However, the mechanism of RUT to improve CAG is not well understood.

AIM OF THIS STUDY

This study aimed to evaluate the efficacy of RUT in treating CAG and its underlying mechanism.

MATERIALS AND METHODS

The CAG model of SD rats was established by induction with 0.1% ammonia and 20 mmol/L sodium deoxycholate solution, accompanied with irregular fasting cycle. The efficacy of RUT in treating CAG was assessed through pathological examination and serum biochemical indices including PP, IL-6, MTL, TNF-α, PG I, SS, PG II, IL-10 and GAS-17. Following this, network pharmacology, 16s rRNA sequencing, transcriptomics, and broadly targeted metabolomics were conducted to unravel the underlying mechanisms of RUT's action in CAG treatment. Ultimately, molecular docking, western blotting, and immunohistochemistry were employed to validate the critical targets and pathways involved in RUT's therapeutic approach for CAG.

RESULTS

RUT significantly improved body weight, gastric juice pH and gastric histologic injury in CAG rats. The results of serum biochemical indices showed that RUT significantly inhibited the expression levels of SS, GAS-17, IL-6 and TNF-α, and increased the levels of MTL, PP, PGI, PGII and IL-10. In addition, RUT apparently increased the expression of mucosal barrier proteins such as ZO-1, E-cadherin and claudin-4 and occludin. Network pharmacology in combination with transcriptomics revealed that the MAPK signaling pathway was the most important pathway for RUT treatment of CAG. Further analysis suggested that by regulating linoleic acid metabolism, metabolic pathways, etc. mainly related to energy metabolism, RUT intervention effectively ameliorated gastric tissue metabolic disorders in CAG rats. The 16S rRNA gene-based microbiota analysis revealed that RUT altered the composition of the intestinal microbiota and decreased the relative abundance of unclassified_Muribaculaceae. PICRUST analysis suggested that the differential bacteria may be involved in energy metabolism pathway regulation for the improvement of CAG. A comprehensive analysis of the transcriptome and metabolome showed that the RUT improved the differential metabolites through the regulation of TGER2, CBR1 and CTPS1 targets.

CONCLUSION

These findings indicated that RUT's mechanism of action in treating CAG was related to modulating the gut microbiota, influencing energy metabolism, and inhibiting the MAPK signaling pathway. This provided new insights into how RUT exerts its therapeutic effects on CAG.

Elucidation of the mechanism of berberine against gastric mucosa injury in a rat model with chronic atrophic gastritis based on a combined strategy of multi-omics and molecular biology

Background

Berberine (BBR) is widely used to treat gastrointestinal diseases. However, the pharmacological mechanism of action of BBR in anti-chronic atrophic gastritis (CAG) remains unclear. This study aimed to investigate the mechanism of action of BBR in CAG by integration of molecular biology and multi-omics studies strategy.

Methods

The CAG model was established by alternating drinking water of 0.1% ammonia and 20 mmol/L sodium deoxycholate, accompanied by an irregular diet. Serum biochemical indices including PGI, PGII, GAS-17, IL-6, IL-1β, and TNF-α were analyzed. HE and AB-PAS staining were employed to assess pathological damage in gastric tissue. The underlying molecular mechanism of BBR in CAG treatment was explored via the integration of network pharmacology, transcriptomics, widely targeted metabolomics and intestinal flora analysis. Finally, relevant key targets and pathway were verified.

Results

The results showed that BBR exerted therapeutic effects in improving CAG via alleviating inflammation response, maintaining the gastric mucosal barrier's integrity and repairing gastric mucosal tissues. Network pharmacology showed that the treatment of CAG by BBR mainly involved in inflammatory response, apoptosis, angiogenesis and metabolic processes. Furthermore, 234 different expression genes were identified in the gastric tissue transcriptome, which were mainly involved in biological processes such as cell adhesion, angiogenesis, apoptosis, cell migration and lipids metabolism by regulating the MAPK signaling pathway. Metabolomics results showed that 125 differential metabolites were also identified, while the pathways were mainly involved in D-glutamine and D-glutamate metabolism, and tyrosine metabolism, etc. Integrating transcriptomics and metabolomics analyses indicated that BBR directly regulated Carnitine C3:0, LPC (0:0/20:3), L-Glutamic Acid and FFA (15:0) by acting on SLC25A20, PNLIPRP1, PLA2G4C, GSR, GFPT2, GCLM, CTPS1, ACSL1, ACOT4 and ACOT2. 16S rRNA sequencing revealed that BBR could restore the balance of gut microbiota dysbiosis by significantly regulating the relative abundance of unclassified_Muribaculaceae and Lactobacillus_johnsonii.

Conclusion

This study demonstrated that BBR alleviates CAG through the regulation of the MAPK signaling pathway, metabolic disorders and gut microbiota dysbiosis, thereby revealing the complex mechanism of BBR in relation to alleviating CAG from multiple levels and perspectives.

Akkermansia muciniphila exacerbates acute radiation-induced intestinal injury by depleting mucin and enhancing inflammation

Dysbiosis of gut microbiota plays a crucial role in acute radiation-induced intestinal injury. However, studies on the influence of gut microbiota on acute radiation-induced intestinal injury are inconsistent. In this study, we established an acute radiation-induced intestinal injury mouse model and performed fecal microbiota transplantation to explore the role of the gut microbiota in acute radiation-induced intestinal injury. We observed a significant increase in Akkermansia muciniphila following irradiation, whereas fecal microbiota transplantation effectively reduced A. muciniphila levels. Contrary to expectations, A. muciniphila supplementation increased acute radiation-induced intestinal injury and mortality. Mechanistically, postradiation A. muciniphila upregulates mucin metabolism genes and consumes mucin, thinning the mucosal barrier and promoting the adhesion and translocation of potential pathogens to epithelial cells, thus exacerbating acute radiation-induced intestinal injury. This enables A. muciniphila to use mucin as an energy source. Additionally, A. muciniphila increases the inflammatory macrophage changes and secretion of inflammatory cytokines, leading to a decrease in epithelial stem cell density and inhibition of goblet cell differentiation, further exacerbating acute radiation-induced intestinal injury. Our findings suggest that in certain intestinal environments, the addition of A. muciniphila may worsen radiation-induced intestinal damage; thus, alternative approaches to reverse the dysbiosis associated with radiotherapy should be explored.

Exercise ameliorates osteopenia in mice via intestinal microbial-mediated bile acid metabolism pathway

Rationale: Physical exercise is essential for skeletal integrity and bone health. The gut microbiome, as a pivotal modulator of overall physiologic states, is closely associated with skeletal homeostasis and bone metabolism. However, the potential role of intestinal microbiota in the exercise-mediated bone gain remains unclear. Methods: We conducted microbiota depletion and fecal microbiota transplantation (FMT) in ovariectomy (OVX) mice and aged mice to investigate whether the transfer of gut ecological traits could confer the exercise-induced bone protective effects. The study analyzed the gut microbiota and metabolic profiles via 16S rRNA gene sequencing and LC-MS untargeted metabolomics to identify key microbial communities and metabolites responsible for bone protection. Transcriptome sequencing and RNA interference were employed to explore the molecular mechanisms. Results: We found that gut microbiota depletion hindered the osteogenic benefits of exercise, and FMT from exercised osteoporotic mice effectively mitigated osteopenia. Comprehensive profiling of the microbiome and metabolome revealed that the exercise-matched FMT reshaped intestinal microecology and metabolic landscape. Notably, alterations in bile acid metabolism, specifically the enrichment of taurine and ursodeoxycholic acid, mediated the protective effects on bone mass. Mechanistically, FMT from exercised mice activated the apelin signaling pathway and restored the bone-fat balance in recipient MSCs. Conclusion: Our study underscored the important role of the microbiota-metabolic axis in the exercise-mediated bone gain, heralding a potential breakthrough in the treatment of osteoporosis.

Microbiota-Induced Radioprotection: A Novel Approach to Enhance Human Radioresistance with In-Situ Genetically Engineered Gut Bacteria

The high sensitivity of living organic forms to space radiation remains the critical issue during spaceflight, to which they will be chronically exposed during months of interplanetary or even decades of interstellar spaceflight. In the human body, all actively dividing and poorly differentiated cells are always close to being damaged by radiological or chemical agents. The chronic exposure to ionizing radiation primarily causes changes in blood counts and intestinal damage such as fibrosis, obliterative vasculitis, changes in the gut microbiota, and atrophy or degeneration of muscle fibers. The project “MISS: Microbiome Induced Space Suit” was presented at the Giant Jamboree of the International Genetically Engineered Machine Competition 2021, with the aim to investigate the ability of the novel microbiota-mediated approach to enhance human resistance to ionizing radiation. The key innovative part of the project was the idea to create a novel radioprotector delivery mechanism based on human gut microbiota with the function of outer membrane vesicles (OMVs) secretion. The project concept proposed the feasibility of genetically modifying the human microbiota in situ through the delivery of genetic constructs to the host’s crypts using silicon nanoparticles with chemically modified surfaces. In this perspective, we discuss the advances in modifying microbiota-mediated secretory activity as a promising approach for radioprotection and as an alternative to hormone therapy and other health conditions that currently require continuous drug administration. Future clinical trials of in situ methods to genetic engineering the crypt microbiota may pave the way for indirect regulation of human cells.

Dietary methionine supplementation promotes mice hematopoiesis after irradiation

BACKGROUND

With the increasing risk of nuclear exposure, more attention has been paid to the prevention and treatment of acute radiation syndrome (ARS). Although amino acids are key nutrients involved in hematopoietic regulation, the impacts of amino acids on bone marrow hematopoiesis following irradiation and the associated mechanisms have not been fully elucidated. Hence, it is of paramount importance to study the changes in amino acid metabolism after irradiation and their effects on hematopoiesis as well as the related mechanisms.

METHODS

The content of serum amino acids was analyzed using metabolomic sequencing. The survival rate and body weight of the irradiated mice were detected after altering the methionine content in the diet. Extracellular matrix (ECM) protein analysis was performed via proteomics analysis. Inflammatory factors were examined by enzyme-linked immunosorbent assay (ELISA). Flow cytometry, Western blotting, and immunofluorescence were employed to determine the mechanism by which S100 calcium-binding protein A4 (S100A4) regulates macrophage polarization.

RESULTS

The survival time of irradiated mice was significantly associated with alterations in multiple amino acids, particularly methionine. A high methionine diet promoted irradiation tolerance, especially in the recovery of bone marrow hematopoiesis, yet with dose limitations. Folate metabolism could partially alleviate the dose bottleneck by reducing the accumulation of homocysteine. Mechanistically, high methionine levels maintained the abundance of ECM components, including collagens and glycoproteins, in the bone marrow post-irradiation, among which the level of S100A4 was significantly changed. S100A4 regulated macrophage polarization via the STAT3 pathway, inhibited bone marrow inflammation and facilitated the proliferation and differentiation of hematopoietic stem/progenitor cells.

CONCLUSIONS

We have demonstrated that an appropriate elevation in dietary methionine enhances irradiation tolerance in mice and explains the mechanism by which methionine regulates bone marrow hematopoiesis after irradiation.

Lithocholic acid phenocopies anti-ageing effects of calorie restriction

Calorie restriction (CR) is a dietary intervention used to promote health and longevity1,2. CR causes various metabolic changes in both the production and the circulation of metabolites1; however, it remains unclear which altered metabolites account for the physiological benefits of CR. Here we use metabolomics to analyse metabolites that exhibit changes in abundance during CR and perform subsequent functional validation. We show that lithocholic acid (LCA) is one of the metabolites that alone can recapitulate the effects of CR in mice. These effects include activation of AMP-activated protein kinase (AMPK), enhancement of muscle regeneration and rejuvenation of grip strength and running capacity. LCA also activates AMPK and induces life-extending and health-extending effects in Caenorhabditis elegans and Drosophila melanogaster. As C. elegans and D. melanogaster are not able to synthesize LCA, these results indicate that these animals are able to transmit the signalling effects of LCA once administered. Knockout of AMPK abrogates LCA-induced phenotypes in all the three animal models. Together, we identify that administration of the CR-mediated upregulated metabolite LCA alone can confer anti-ageing benefits to metazoans in an AMPK-dependent manner.

Radiation-Resistant Bacteria Deinococcus radiodurans-Derived Extracellular Vesicles as Potential Radioprotectors

The increasing use of radiation presents a risk of radiation exposure, making the development of radioprotectors necessary. In the previous study, it is investigated that Deinococcus radiodurans (R1-EVs) exert the antioxidative properties. However, the radioprotective activity of R1-EVs remains unclear. In the present study, the protective effects of R1-EVs against total body irradiation (TBI)-induced acute radiation syndrome (ARS) are investigated. To assess R1-EVs' radioprotective efficacy, ARS is induced in mice with 8 Gy of TBI, and protection against hematopoietic (H)- and gastrointestinal (GI)-ARS is evaluated. The survival rate of irradiated mice group decreases substantially after irradiation. In contrast, pretreatment with R1-EVs increases the survival rates of the mice. The administration of R1-EVs provides effective protection against radiation-induced death of bone marrow cells and splenocytes by scavenging reactive oxygen species (ROS). Additionally, R1-EVs protect both intestinal stem and epithelial cells from radiation-induced apoptosis. R1-EVs stimulate the production of short-chain fatty acids in the gastrointestinal tract, suppress proinflammatory cytokines, and increase regulatory T cells in pretreated mice versus the irradiation-only group. Proteomic analysis shows that the R1-EV proteome is significantly enriched with proteins involved in oxidative stress response. These findings highlight R1-EVs as potent radioprotectors with applications against radiation damage and ROS-mediated diseases.

Systemic inflammatory response to daily exposure to microcystin-LR and the underlying gut microbial mechanisms

Cyanobacterial toxins have raised global concerns due to potential chronic disease implications from daily drinking water exposure, which remain largely unknown despite extensive research on their acute effects. To understand the mechanisms underlying microcystin-LR (MC-LR)-induced inflammation-associated diseases. Mice were exposed to MC-LR for one year at concentrations comparable to human environmental exposure levels. Comprehensive pathological observation and multi-omics approaches based on 16S rRNA gene sequencing, untargeted metabolomics, transcriptomics and proteomics were conducted across various organs. Daily exposure to MC-LR induced intestinal microbial dysbiosis and colitis-like changes. It also caused systemic chronic inflammation marked by elevated serum levels of inflammatory cytokines, inflammation-associated pathological changes, and identification of infection-related genes/proteins within the gut-brain-spleen-liver axis. Furthermore, multi-omics analysis across organs suggested that Muribaculaceae may promote a systemic infection-inflammatory response, relying on kynurenine metabolites signaling in peripheral tissues. In contrast, Lachnospiraceae may act an opposing role, dependent on intestinal indole derivatives via the neuroimmunomodulation pathway. A fecal microbiota transplantation experiment confirmed that alterations in Muribaculaceae and Lachnospiraceae resulting from exposure to MC-LR triggered the local and systemic chronic inflammation in mice. This study light on the potential strategies employed by gut microbial community in regulating MC-induced inflammation-associated chronic diseases under repeated exposure through drinking water.

Alterations in Gut Microbiota Correlate With Hematological Injuries Induced by Radiation in Beagles

Dynamics of gut microbiota and their associations with the corresponding hematological injuries postradiation remain to be elucidated. Using single whole-body exposure to 60Co-γ ray radiation at the sublethal dose of 2.5 Gy, we developed a beagle model of acute radiation syndrome (ARS) and then monitored the longitudinal changes of gut microbiome and hematology for 45 days. We found that the absolute counts of circulating lymphocytes, neutrophils, and platelets were sharply declined postradiation, accompanied by a largely shifted composition of gut microbiome that manifested as a significantly increased ratio of Firmicutes to Bacteroidetes. In irradiated beagles, alterations in hematological parameters reached a nadir on day 14, sustaining for 1 week, which were gradually returned to the normal levels thereafter. However, no structural recovery of gut microbiota was observed throughout the study. Fecal metagenomics revealed that irradiation increased the relative abundances of genus Streptococcus, species Lactobacillus animalis and Lactobacillus murinus, but decreased those of genera Prevotella and Bacteroides. Metagenomic functions prediction demonstrated that 26 altered KEGG pathways were significantly enriched on Day 14 and 35 postradiation. Furthermore, a total of 43 bacterial species were found to correlate well with hematological parameters by Spearman's analysis. Our results provide an insight into the longitudinal changes in intestinal microbiota at different clinical stages during ARS in canine. Several key microbes those tightly associated with the hematological alterations may serve as biomarkers to discriminate the different phases of host with ARS.

Rifaximin alleviates irinotecan-induced diarrhea in mice model

BACKGROUND

Irinotecan is a chemotherapeutic drug widely used to treat solid tumors. However, its effectiveness is limited by the severely delayed onset of diarrhea. This study aimed to confirm the protective effects of the non-systemic oral antibiotic rifaximin on irinotecan-induced mucositis in mice model.

MATERIALS AND METHODS

Six to eight week-old BALB/c mice were treated with saline, irinotecan (50 mg/kg, i.p. once daily), rifaximin (50 mg/kg, p.o. twice daily), or irinotecan + rifaximin for 9 consecutive days. Signs of diarrhea, bloody diarrhea, and body weight were monitored daily. Intestinal tissues were harvested for histopathological analysis and quantitative PCR. SN38 and SN38G concentration in intestine were detected using LC-MS analysis. Intestinal bacteria β-glucuronidase (BGUS) activity was detected using mouse feces. We performed 16S rRNA sequencing to investigate the gut microbiota composition. Gut permeability was tested in vivo by measuring the fluorescein isothiocyanate-dextran intensity in the serum.

RESULTS

Rifaximin reduced the frequency of delayed diarrhea and attenuated the severity of diarrhea caused by irinotecan in mice. Rifaximin significantly inhibited SN38 exposure in intestine and irinotecan-induced increase in BGUS activity. Rifaximin alleviated intestinal mucosal inflammation, prevented intestinal epithelial damage caused by irinotecan, and maintained gut barrier function. Moreover, the consecutive use of rifaximin did not cause a disorder in gut microbiota and reduced irinotecan-induced Firmicutes expansion. More importantly, rifaximin inhibited the expansion of some microbiota (such as Blautia, Eggerthella, and f_Enterobacteriaceae) and promoted an increase in beneficial microbiota (such as Lactobacillus intestinalis, Lachnospiraceae NK4A136 group, and f_Oscillospiraceae).

CONCLUSIONS

Preventive use of rifaximin is a feasible method to protect against irinotecan-induced diarrhea.

A sex-dependent salivary bacterium influences oral mucositis severity after allogeneic hematopoietic cell transplantation

The success of allogeneic hematopoietic cell transplantation (alloHCT) in curing hematologic disorders is limited by its short- and long-term toxicities. One such toxicity is oral mucositis (OM), causing pain, speech/swallowing difficulty, and prolonged hospitalization. Although conditioning chemoradiotherapy is the direct cause of OM, potential host-intrinsic mediators of mucosal injury remain elusive. We hypothesized that the oral microbiota may influence OM severity. We used a validated comprehensive scoring system based on specialized Oral Medicine examinations to longitudinally quantify OM severity in alloHCT recipients. High-throughput multi-site profiling of the oral microbiota was performed in parallel. We identify a sex-dependent commensal bacterium, Oribacterium asaccharolyticum, whose presence in saliva before transplantation is associated with more severe OM 14 days after transplantation. The sex predilection of this species correlated with higher uric acid levels in men. Our findings represent the first sex-dependent microbiota-mediated pathway in OM pathogenesis and introduce novel targets for preventative interventions.

Taurine ameliorates radiation-induced oxidative stress in bone marrow mesenchymal stromal cells and promotes osteogenesis

Osteoradionecrosis of the jaw (ORNJ) is a severe complication following head and neck radiotherapy that significantly impacts the quality of life of patients. Currently, there is a lack of comprehensive understanding of the microenvironmental factors involved in ORNJ. In this study, we reveal the activation of taurine metabolism in irradiated mandibular stromal cells using scRNA-Seq and demonstrate a decrease in taurine levels in irradiated bone marrow mesenchymal stromal cells (BMSCs) through metabolomics. Compared with unirradiated BMSCs, taurine uptake in irradiated BMSCs increases. Taurine concentrations in the peripheral blood and jaws of irradiated mice are significantly lower than those in unirradiated mice (P = 0.0064 and 0.0249 respectively). Supplementation with taurine promotes osteogenic differentiation, reduces oxidative stress, and decreases DNA damage in irradiated BMSCs. Oral administration of taurine significantly improves the survival rate of irradiated mice and enhances osteogenesis in irradiated jaws. Our study highlights the role of taurine in the recovery from radiation-induced jaw injury, and suggests its potential as a non-invasive therapeutic option for combating ORNJ.

Dietary restriction and fasting alleviate radiation-induced intestinal injury by inhibiting cGAS/STING activation

Radiation injury to the intestine is one of the most common complications in patients undergoing abdominal or pelvic cavity radiotherapy, limiting the clinical application of this treatment. Evidence shows the potential benefits of dietary restriction in improving metabolic profiles and age-related diseases. The present study investigated the effects and mechanisms of dietary restriction in radiation-induced intestinal injury. The mice were randomly divided into the control group, 10 Gy total abdominal irradiation (TAI) group, and groups pretreated with 30% caloric restriction (CR) for 7 days or 24 h fasting before TAI. After radiation, the mice were returned to ad libitum. The mice were sacrificed 3.5 days after radiation, and tissue samples were collected. CR and fasting reduced radiation-induced intestinal damage and promoted intestinal recovery by restoring the shortened colon length, improving the impaired intestinal structure and permeability, and remodeling gut microbial structure. CR and fasting also significantly reduced mitochondrial damage and DNA damage, which in turn reduced activation of the cyclic GMP-AMP synthase/stimulator of interferon gene (cGAS/STING) pathway and the production of type I interferon and other chemokines in the jejunum. Since the cGAS/STING pathway is linked with innate immunity, we further showed that CR and fasting induced polarization to immunosuppressive M2 macrophage, decreased CD8+ cytotoxic T lymphocytes, and downregulated proinflammatory factors in the jejunum. Our findings indicated that CR and fasting alleviate radiation-induced intestinal damage by reducing cGAS/STING-mediated harmful immune responses.