Review: Effect of Gut Microbiota and Its Metabolite SCFAs on Radiation-Induced Intestinal Injury

Metabolism of quercitrin in the colon and its beneficial regulatory effects on gut microbiota

BACKGROUND

Quercitrin is a dietary flavonoid widely found in plants with various physiological activities. However, whether quercitrin alters gut microbiota in vivo is not well understood. The aim of this study was to investigate metabolism of quercitrin in the colon and its regulation on gut microbiota in mice.

RESULTS

Herein, 22 flavonoids related to quercitrin metabolism were identified based on ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). Gas chromatography and 16S rDNA gene sequencing were used to investigate short-chain fatty acid (SCFA) content and diversity of composition of gut microbiota, respectively. The results showed that quercitrin significantly alters the beta-diversity of the gut microbiota, probiotics such as Akkermansia and Lactococcus were significantly increased, and the production of propanoate, isovalerate and hexanoate of the quercitrin group were enhanced significantly. The Spearman's association analysis provided evidence that Gardnerella and Akkermansia have obvious correlations with most of quercitrin metabolites and SCFAs.

CONCLUSION

Quercitrin and its metabolites in the colon altered the structure of the mice gut microbiota and increased the content of SCFAs. Our experiments provide valuable insights into quercitrin research and application. © 2024 Society of Chemical Industry.

Alginate Oligosaccharides Enhance Antioxidant Status and Intestinal Health by Modulating the Gut Microbiota in Weaned Piglets

Alginate oligosaccharides (AOSs), which are an attractive feed additive for animal production, exhibit pleiotropic bioactivities. In the present study, we investigated graded doses of AOS-mediated alterations in the physiological responses of piglets by determining the intestinal architecture, barrier function, and microbiota. A total of 144 weaned piglets were allocated into four dietary treatments in a completely random design, which included a control diet (CON) and three treated diets formulated with 250 mg/kg (AOS250), 500 mg/kg (AOS500), and 1000 mg/kg AOS (AOS1000), respectively. The trial was carried out for 28 days. Our results showed that AOS treatment reinforced the intestinal barrier function by increasing the ileal villus height, density, and fold, as well as the expression of tight junction proteins, especially at the dose of 500 mg/kg AOS. Meanwhile, supplementations with AOSs showed positive effects on enhancing antioxidant capacity and alleviating intestinal inflammation by elevating the levels of antioxidant enzymes and inhibiting excessive inflammatory cytokines. The DESeq2 analysis showed that AOS supplementation inhibited the growth of harmful bacteria Helicobacter and Escherichia_Shigella and enhanced the relative abundance of Faecalibacterium and Veillonella. Collectively, these findings suggested that AOSs have beneficial effects on growth performance, antioxidant capacity, and gut health in piglets.

Microbiome in radiotherapy: an emerging approach to enhance treatment efficacy and reduce tissue injury

Radiotherapy is a widely used cancer treatment that utilizes powerful radiation to destroy cancer cells and shrink tumors. While radiation can be beneficial, it can also harm the healthy tissues surrounding the tumor. Recent research indicates that the microbiota, the collection of microorganisms in our body, may play a role in influencing the effectiveness and side effects of radiation therapy. Studies have shown that specific species of bacteria living in the stomach can influence the immune system's response to radiation, potentially increasing the effectiveness of treatment. Additionally, the microbiota may contribute to adverse effects like radiation-induced diarrhea. A potential strategy to enhance radiotherapy outcomes and capitalize on the microbiome involves using probiotics. Probiotics are living microorganisms that offer health benefits when consumed in sufficient quantities. Several studies have indicated that probiotics have the potential to alter the composition of the gut microbiota, resulting in an enhanced immune response to radiation therapy and consequently improving the efficacy of the treatment. It is important to note that radiation can disrupt the natural balance of gut bacteria, resulting in increased intestinal permeability and inflammatory conditions. These disruptions can lead to adverse effects such as diarrhea and damage to the intestinal lining. The emerging field of radiotherapy microbiome research offers a promising avenue for optimizing cancer treatment outcomes. This paper aims to provide an overview of the human microbiome and its role in augmenting radiation effectiveness while minimizing damage.

Microbial imbalance in Chinese children with diarrhea or constipation

Diarrhea and constipation are common health concerns in children. Numerous studies have identified strong association between gut microbiota and digestive-related diseases. But little is known about the gut microbiota that simultaneously affects both diarrhea and constipation or their potential regulatory mechanisms. Stool samples from 618 children (66 diarrhea, 138 constipation, 414 healthy controls) aged 0-3 years were collected to investigate gut microbiota changes using 16S rRNA sequencing. Compared with healthy, children with diarrhea exhibited a significant decrease in microbial diversity, while those with constipation showed a marked increase (p < 0.05). Significantly, our results firstly Ruminococcus increased in constipation (p = 0.03) and decreased in diarrhea (p < 0.01) compared to healthy controls. Pathway analysis revealed that Ruminococcus highly involved in the regulation of five common pathways (membrane transport, nervous system, energy metabolism, signal transduction and endocrine system pathways) between diarrhea and constipation, suggesting a potential shared regulatory mechanism. Our finding firstly reveals one core microorganisms that may affect the steady balance of the gut in children with diarrhea or constipation, providing an important reference for potential diagnosis and treatment of constipation and diarrhea.

Effects of combined ciprofloxacin and Neulasta therapy on intestinal pathology and gut microbiota after high-dose irradiation in mice

Introduction

Treatments that currently exist in the strategic national stockpile for acute radiation syndrome (ARS) focus on the hematopoietic subsyndrome, with no treatments on gastrointestinal (GI)-ARS. While the gut microbiota helps maintain host homeostasis by mediating GI epithelial and mucosal integrity, radiation exposure can alter gut commensal microbiota which may leave the host susceptible to opportunistic pathogens and serious sequelae such as sepsis. To mitigate the effects of hematopoietic ARS irradiation, currently approved treatments exist in the form of colony stimulating factors and antibiotics: however, there are few studies examining how these therapeutics affect GI-ARS and the gut microbiota. The aim of our study was to examine the longitudinal effects of Neulasta and/or ciprofloxacin treatment on the gut microbiota after exposure to 9.5 Gy 60Co gamma-radiation in mice.

Methods

The gut microbiota of vehicle and drug-treated mice exposed to sham or gamma-radiation was characterized by shotgun sequencing with alpha diversity, beta diversity, and taxonomy analyzed on days 2, 4, 9, and 15 post-irradiation.

Results

No significant alpha diversity differences were observed following radiation, while beta diversity shifts and taxonomic profiles revealed significant alterations in Akkermansia, Bacteroides, and Lactobacillus. Ciprofloxacin generally led to lower Shannon diversity and Bacteroides prevalence with increases in Akkermansia and Lactobacillus compared to vehicle treated and irradiated mice. While Neulasta increased Shannon diversity and by day 9 had more similar taxonomic profiles to sham than ciprofloxacin-or vehicle-treated irradiated animals. Combined therapy of Neulasta and ciprofloxacin induced a decrease in Shannon diversity and resulted in unique taxonomic profiles early post-irradiation, returning closer to vehicle-treated levels over time, but persistent increases in Akkermansia and Bacteroides compared to Neulasta alone.

Discussion

This study provides a framework for the identification of microbial elements that may influence radiosensitivity, biodosimetry and the efficacy of potential therapeutics. Moreover, increased survival from H-ARS using these therapeutics may affect the symptoms and appearance of what may have been subclinical GI-ARS.

Vitamin A deficiency suppresses CEACAM1 to impair colonic epithelial barrier function via downregulating microbial-derived short-chain fatty acids

Vitamin A (VA) plays an essential role in modulating both the gut microbiota and gut barrier function. Short-chain fatty acids (SCFAs), as metabolites of the gut microbiota, protect the physiological intestinal barrier; however, they are compromised when VA is deficient. Thus, there is an urgent need to understand how and which SCFAs modulate colonic epithelial barrier integrity in VA deficiency (VAD). Herein, compared with normal VA rats (VAN), at the beginning of pregnancy, we confirmed that the colonic desmosome junction was impaired in the VAD group, and the amounts of acetate, propionate, and butyrate declined because of the decreased abundance of SCFA-producing bacteria (Romboutsia, Collinsella, and Allobaculum). The differentially expressed genes correlated with the gut barrier and the histone deacetylase complex between the VAD and VAN groups were enriched by RNA sequencing. In the VAD group, the expression levels of colonic CEA cell adhesion molecule 1 (CEACAM1) were down-regulated, and the levels of histone deacetylase 1 (HDAC1) and HDAC3 were up-regulated. Intriguingly, the above changes in the VAD groups were rescued by VA supplementation in the early postnatal period. Further study indicated that in Caco-2 cells, butyrate treatment significantly repressed the enrichment of HDAC3 on the promoter of the CEACAM1 gene to induce its expression. Our findings support that butyrate intervention can alleviate the impairment of colonic barrier function caused by VAD, and timely postnatal VA intervention may reverse the damage caused by VAD on gut barrier integrity during pregnancy.

Review of yeast culture concerning the interactions between gut microbiota and young ruminant animals

Microorganisms inhabit the gastrointestinal tract of ruminants and regulate body metabolism by maintaining intestinal health. The state of gastrointestinal health is influenced not only by the macro-level factors of optimal development and the physiological structure integrity but also by the delicate equilibrium between the intestinal flora and immune status at the micro-level. Abrupt weaning in young ruminants causes incomplete development of the intestinal tract resulting in an unstable and unformed microbiota. Abrupt weaning also induced damages to the microecological homeostasis of the intestinal tract, resulting in the intestinal infections and diseases, such as diarrhea. Recently, nutritional and functional yeast culture has been researched to tackle these problems. Herein, we summarized current known interactions between intestinal microorganisms and the body of young ruminants, then we discussed the regulatory effects of using yeast culture as a feed supplement. Yeast culture is a microecological preparation that contains yeast, enriched with yeast metabolites and other nutrient-active components, including β-glucan, mannan, digestive enzymes, amino acids, minerals, vitamins, and some other unknown growth factors. It stimulates the proliferation of intestinal mucosal epithelial cells and the reproduction of intestinal microorganisms by providing special nutrient substrates to support the intestinal function. Additionally, the β-glucan and mannan effectively stimulate intestinal mucosal immunity, promote immune response, activate macrophages, and increase acid phosphatase levels, thereby improving the body's resistance to several disease. The incorporation of yeast culture into young ruminants' diet significantly alleviated the damage caused by weaning stress to the gastrointestinal tract which also acts an effective strategy to promote the balance of intestinal flora, development of intestinal tissue, and establishment of mucosal immune system. Our review provides a theoretical basis for the application of yeast culture in the diet of young ruminants.

Development of small intestinal barrier function and underlying mechanism in Chinese indigenous and Duroc piglets during suckling and weaning periods

This study explored the developmental changes in small intestinal barrier function and the potential regulatory roles of intestinal microbiota and metabolites in different breeds of piglets during suckling and weaning periods. Taoyuan black (TB), Xiangcun black (XB), and Duroc (DR) piglets (10 litters per breed; half male and half female) were selected for sampling to evaluate the intestinal barrier-related indexes and intestinal microbiota and metabolites at 1, 10, 21 (weaned), and 24 (3 d after weaning) d old. The results showed that weaning led to severe shedding of small intestinal microvilli and sparse microvilli arrangement. D-lactate level in the ileum of TB and XB piglets during suckling and weaning periods was lower (P < 0.01) than that of DR piglets, as well as the ileal diamine oxidase level at 1 d old. The expression level of mucin 1 was higher (P < 0.05) in the ileum of TB and XB piglets than that of DR piglets, and it was the highest in the ileum of TB piglets at 21 d old. The expression levels of mucin 2 and mucin 13 were higher (P < 0.10) in TB and XB piglets than those of DR piglets at 21 d old, whereas mucin 2 and mucin 13 in the ileum of TB and XB piglets were higher (P < 0.05) than those of DR piglets at 24 d old. TB and XB piglets had a lower relative abundance of Escherichia_Shigella at 21 and 24 d old, but they had higher Streptococcus at 1 and 24 d old than DR piglets (P < 0.01). Differential metabolites between the three breeds of piglets were mainly related to oxidative phosphorylation, steroid biosynthesis, and bile acid synthesis. Collectively, these findings suggest that different pig breeds present differences in the development of the small intestinal barrier function. Compared with DR piglets, TB and XB piglets had higher intestinal permeability during the suckling period and a stronger intestinal mechanical barrier after weaning. Moreover, intestinal microbiota and metabolites are the key factors for developing small intestinal barrier functions in different breeds of piglets.

The gut microbiota regulates the depressive-type behaviors and inflammatory processes after severe burn injuries in mice

An emerging number of studies have recently revealed the correlation between burn injuries and psychological disorders. Gut microbiota and inflammatory factors may play a vital role in this process. Nevertheless, there are few studies conducted to disclose the potential mechanism of the gut microbiota between depression and burn injuries. In this study, we constructed a burn model of C57BL/6 mice, which showed that the symptom of depression became more and more severe with the burn of mice lasted longer. Meanwhile, there are significant differences of composition of gut microbiota among mice before and after burn. Then, we tested the inflammatory factors in the brain and peripheral blood, which showed an increased expression of Iba1, VWF, TNF-α and IL-6, and a decreased expression of IL-10 in burn mice. In addition, the expression of zonula occludens-1 (ZO-1) in cecum showed a down-regulation in burn mice, which indicated impaired intestinal barrier function. Lastly, the crossing fecal microbiota transplantation (FMT) and cohousing experiment were conducted to determine the functions of cross-transplantation of fecal microbiota on the depressive-type behaviours in burned mice. According to the score of Tail suspension test (TST), the burn mice were divided into two groups: Resilient mice (no-depressed mice) and Abnormal mice (depressed mice). After abnormal mice were transplanted with fecal microbiota of resilient mice, the symptom of depression was improved, and the expression of TNF-α, IL-6 and IL-10 return to normal levels (P < 0.05). On the contrary, after resilient mice were transplanted with fecal microbiota of abnormal mice both the TST scores and inflammatory factor developed depressive-type changes. In conclusion, our study demonstrated the changes of gut microbiota and inflammatory factors in depressed burn mice and non-depressed burn mice. The gut microbiota dysbiosis could impaired intestinal barrier function and lead to neuroinflammation, and this phenomenon could be significantly mitigated by FMT.

Modulating Effects of Turmeric Polysaccharides on Immune Response and Gut Microbiota in Cyclophosphamide-Treated Mice

Turmeric, a traditional medicinal herb, is commonly used as a dietary and functional ingredient. This study aimed to investigate the effect of turmeric polysaccharides (TPs) on intestinal immunity and gut microbiota in cyclophosphamide (Cy)-induced immunosuppressed BALB/c mice. We verified that the oral administration of TPs-0 and TPs-3 (200 and 400 mg/kg, bw) improved thymus and spleen indexes, increased the whole blood immune cells (WBC) and lymph count index, and stimulated the secretion of serum immunoglobulin IgG. More importantly, TPs-0 and TPs-3 could repair intestinal immune damage and reduce intestinal inflammation. The specific mechanism is ameliorating the intestinal pathological damage, promoting CD4+ T cell secretion, regulating the expression of related cytokines, and reducing the level of critical proteins in the NF-κB/iNOS pathway. Interestingly, the intake of TPs-0 and TPs-3 significantly increased the content of short-chain fatty acids (SCFAs). Moreover, TPs-0 and TPs-3 relieved the intestinal microbiota disorder via the proliferation of the abundance of Lactobacillus and Bacteroides and the inhibition of Staphylococcus. Cumulatively, our study suggests that TPs-0 and TPs-3 can relieve intestinal immune damage by repairing the immune barrier and regulating intestinal flora disorders. TPs have potential applications for enhancing immunity as a functional food.

The Potential Role of Probiotics, Especially Butyrate Producers, in the Management of Gastrointestinal Mucositis Induced by Oncologic Chemo-Radiotherapy

Many clinical studies have now highlighted how the composition of the intestinal microbiota can regulate the effects of many oncological therapies. In particular, the modulation of microbial composition has been shown to enhance their efficacy and reduce potential side effects. Numerous adverse events induced by chemotherapy and radiotherapy appear to be strongly associated with an alteration in the intestinal microbiota caused by these treatments. This supports the hypothesis that the modulation or correction of the microbiota may decrease the toxic impact of therapies, improving patient compliance and quality of life. Among the most debilitating disorders related to oncological treatments is certainly mucositis, and recent clinical data highlight how the deficiency of short-chain fatty acids, especially butyrate, and specifically the lack of certain bacterial groups responsible for its production (butyrate producers), is strongly associated with this disorder. It is hypothesized that restoring these elements may influence the onset and severity of adverse events. Therefore, the intake of probiotics, especially butyrate producers, and specifically Clostridium butyricum (CBM588), currently the only cultivable and usable strain with a history of data proving its safety, could be a valuable ally in oncological therapies, reducing the associated discomfort and improving compliance, efficacy, and quality of life for patients.

Effects of radiofrequency field from 5G communication on fecal microbiome and metabolome profiles in mice

With the rapid development of 5G networks, the influence of the radiofrequency field (RF) generated from 5G communication equipment on human health is drawing increasing attention in public. The study aimed at assessing the effects of long-term exposure to 4.9 GHz (one of the working frequencies of 5G communication) RF field on fecal microbiome and metabolome profiles in adult male C57BL/6 mice. The animals were divided into Sham group and radiofrequency group (RF group). For RF group, the mice were whole body exposed to 4.9 GHz RF field for three weeks, 1 h/d, at average power density (PD) of 50 W/m2. After RF exposure, the mice fecal samples were collected to detect gut microorganisms and metabolites by 16S rRNA gene sequencing and LC-MS method, respectively. The results showed that intestinal microbial compositions were altered in RF group, as evidenced by reduced microbial diversity and changed microbial community distribution. Metabolomics profiling identified 258 significantly differentially abundant metabolites in RF group, 57 of which can be classified to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Besides, functional correlation analysis showed that changes in gut microbiota genera were significantly correlated with changes in fecal metabolites. In summary, the results suggested that altered gut microbiota and metabolic profile are associated with 4.9 GHz radiofrequency exposure.

Astragalus polysaccharide promotes the regeneration of intestinal stem cells through HIF-1 signalling pathway

Ionizing radiation (IR)-induced intestinal injury is usually accompanied by high lethality. Intestinal stem cells (ISCs) are critical and responsible for the regeneration of the damaged intestine. Astragalus polysaccharide (APS), one of the main active ingredients of Astragalus membranaceus (AM), has a variety of biological functions. This study was aimed to investigate the potential effects of APS on IR-induced intestine injury via promoting the regeneration of ISCs. We have established models of IR-induced intestinal injury and our results showed that APS played great radioprotective effects on the intestine. APS improved the survival rate of irradiated mice, reversed the radiation damage of intestinal tissue, increased the survival rate of intestinal crypts, the number of ISCs and the expression of intestinal tight junction-related proteins after IR. Moreover, APS promoted the cell viability while inhibited the apoptosis of MODE-K. Through organoid experiments, we found that APS promoted the regeneration of ISCs. Remarkably, the results of network pharmacology, RNA sequencing and RT-PCR assays showed that APS significantly upregulated the HIF-1 signalling pathway, and HIF-1 inhibitor destroyed the radioprotection of APS. Our findings suggested that APS promotes the regeneration of ISCs through HIF-1 signalling pathway, and it may be an effective radioprotective agent for IR-induced intestinal injury.

What Makes the Gut-Lung Axis Working? From the Perspective of Microbiota and Traditional Chinese Medicine

Background

An increasing number of studies have proved that gut microbiota is involved in the occurrence and development of various lung diseases and can interact with the diseased lung. The concept of the gut-lung axis (GLA) provides a new idea for the subsequent clinical treatment of lung diseases through human microbiota. This review aims to summarize the microbiota in the lung and gut and the interaction between them from the perspectives of traditional Chinese medicine and modern medicine.

Method

We conducted a literature search by using the search terms "GLA," "gut microbiota," "spleen," and "Chinese medicine" in the databases PubMed, Web of Science, and CNKI. We then explored the mechanism of action of the gut-lung axis from traditional Chinese medicine and modern medicine.

Results

The lung and gut microbiota enable the GLA to function through immune regulation, while metabolites of the gut microbiota also play an important role. The spleen can improve the gut microbiota to achieve the regulation of the GLA.

Conclusion

Improving the gut microbiota through qi supplementation and spleen fortification provides a new approach to the clinical treatment of lung diseases by regulating the GLA. Currently, our understanding of the GLA is limited, and more research is needed to explain its working principle.

Butyrate affects bacterial virulence: a new perspective on preventing enteric bacterial pathogen invasion

Enteric bacterial pathogens are a major threat to intestinal health. With the widespread use of antibiotics, bacterial resistance has become a problem, and there is an urgent need for a new treatment to reduce dependence on antibiotics. Butyrate can control enteric bacterial pathogens by regulating the expression of their virulence genes, promoting the posttranslational modification of their proteins, maintaining an anaerobic environment, regulating the host immune system and strengthening the intestinal mucosal barrier. Here, this review describes the mechanisms by which butyrate regulates the pathogenicity of enteric bacterial pathogens from various perspectives and discusses the prospects and limitations of butyrate as a new option for the control of pathogenic bacteria.

Oral compound probiotic supplements can improve the quality of life for patients with lung cancer during chemotherapy: A randomized placebo-controlled study

BACKGROUND

Chemotherapy is an important approach for lung cancer patients. The study was designed to evaluate the feasibility of the compound probiotic supplements in improving the quality of life for lung cancer patients undergoing chemotherapy.

METHODS

This randomized, double-blind, placebo-controlled trial enrolled chemotherapy-naive patients with lung cancer who were scheduled to receive platinum-based doublet chemotherapy. All eligible patients were randomly administered (1:1) compound probiotic supplements (group BP-1) or placebo (group C) for two chemotherapy cycles. The EORTC QLQ C30 questionnaire scores were evaluated before the first, second, and third cycles of chemotherapy. The primary endpoint was the difference in the EROTC QLQ C30 questionnaire score between the two groups after two cycles of chemotherapy.

RESULTS

A total of 110 patients were recruited from March 2021 to January 2022. After undergoing two cycles of chemotherapy, group BP-1 were significantly better in various dimensions of the overall quality of life, role function, nausea and vomiting, appetite loss, constipation, and diarrhea relative to group C (76.90 ± 18.31 vs. 58.89 ± 17.17; 93.33 ± 11.58 vs. 85.93 ± 15.06; 0.00 ± 0.00 vs. 27.04 ± 29.15; 6.67 ± 13.53 vs. 22.22 ± 18.80; 0.95 ± 5.63 vs. 28.15 ± 22.42; 2.86 ± 9.47 vs. 15.56 ± 16.82; p < 0.05, respectively). The incidence of nausea and vomiting, appetite loss, constipation, and diarrhea in group BP-1 was significantly lower than in group C (0% vs. 71.43%, 16.67% vs. 57.14%, 2.38% vs. 63.27%, and 7.14% vs. 42.86%, respectively, p < 0.001).

CONCLUSIONS

Compound probiotic supplements can improve the quality of life and relieve chemotherapy-related gastrointestinal side effects for lung cancer patients receiving platinum-based doublet chemotherapy. (Chinese Clinical Trial Registry: ChiCTR1800019269).

Effects of ginseng on short-chain fatty acids and intestinal microbiota in rats with spleen-qi deficiency based on gas chromatography-mass spectrometry and 16s rRNA technology

RATIONALE

Spleen-qi deficiency syndrome, a common weakness syndrome in traditional Chinese medicine, results from insufficient spleen-qi levels. For centuries, ginseng has been relied upon as a traditional Chinese medicine to treat spleen-qi deficiency syndrome. Until now, the mechanism feature of ginseng in treating temper deficiency through intestinal bacteria and short-chain fatty acid (SCFA) metabolites has not been fully elucidated.

METHODS

This study established a rat model of spleen-qi deficiency via multi-factor compound modeling that involved fatigue injury and a controlled diet. The content of SCFAs between different treatment groups was determined by gas chromatography-mass spectrometry. And the 16s rRNA sequencing technology was applied to reveal the effects of ginseng on the intestinal microecological environment of the rats.

RESULTS

It was found that the ginseng treatment group exhibited the most remarkable regulatory effect on propionic acid, surpassing all other administration groups. Ginseng increased the relative abundance of beneficial bacteria and decreased that of harmful bacteria at the genus level in rats with spleen-qi deficiency syndrome. And propionic acid is significantly positively correlated with Lactobacillus level and significantly negatively correlated with uncultured_bacterium_f_Muribaculaceae (p < 0.05). n-Butyric acid is negatively correlated with the Faecalibaculum level (p < 0.01). n-Valeric acid is significantly negatively correlated with the Romboutsia level (p < 0.01).

CONCLUSION

The mechanism of ginseng treatment for spleen-qi deficiency is elucidated from the perspective of gut microbiota and its metabolite SCFAs. It provides a new way for further development and utilization of ginseng and a theoretical basis.

Mitigation of acute radiation syndrome (ARS) with human umbilical cord blood

PURPOSE

The growing concern over potential unintended nuclear accidents or malicious activities involving nuclear/radiological devices cannot be overstated. Exposure to whole-body doses of radiation can result in acute radiation syndrome (ARS), colloquially known as "radiation sickness," which can severely damage various organ systems. Long-term health consequences, such as cancer and cardiovascular disease, can develop many years post-exposure. Identifying effective medical countermeasures and devising a strategic medical plan represents an urgent, unmet need. Various clinical studies have investigated the therapeutic use of umbilical cord blood (UCB) for a range of illnesses, including ARS. The objective of this review is to thoroughly discuss ARS and its sub-syndromes, and to highlight recent findings regarding the use of UCB for radiation injury. UCB, a rich source of stem cells, boasts numerous advantages over other stem cell sources, like bone marrow, owing to its ease of collection and relatively low risk of severe graft-versus-host disease. Preclinical studies suggest that treatment with UCB, and often UCB-derived mesenchymal stromal cells (MSCs), results in improved survival, accelerated hematopoietic recovery, reduced gastrointestinal tract damage, and mitigation of radiation-induced pneumonitis and pulmonary fibrosis. Interestingly, recent evidence suggests that UCB-derived exosomes and their microRNAs (miRNAs) might assist in treating radiation-induced damage, largely by inhibiting fibrotic pathways.

CONCLUSION

UCB holds substantial potential as a radiation countermeasure, and future research should focus on establishing treatment parameters for ARS victims.

Mitigative and anti-inflammatory effects of Trichostatin A against radiation-induced gastrointestinal toxicity and gut microbiota alteration in mice

PURPOSE

Radiation-induced gastrointestinal injury (RIGI) is a serious side effect of abdominal and pelvic radiotherapy, which often limits the treatment of gastrointestinal and gynaecological cancers. RIGI is also observed during accidental radiological or nuclear scenarios with no approved agents available till date to prevent or mitigate RIGI in humans. Trichostatin A (TSA), an epigenetic modulator, has been currently in clinical trials for cancer treatment and is also well known for its antibiotic and antifungal properties.

METHODS

In this study, partial body (abdominal) irradiation mice model was used to investigate the mitigative effect of TSA against gastrointestinal toxicity caused by gamma radiation. Mice were checked for alterations in mean body weight, diarrheal incidence, disease activity index and survival against 15 Gy radiation. Structural abnormalities in intestine and changes in microbiota composition were studied by histopathology and 16S rRNA sequencing of fecal samples respectively. Immunoblotting and biochemical assays were performed to check protein nitrosylation, expression of inflammatory mediators, infiltration of inflammatory cells and changes in pro-inflammatory cytokine.

RESULTS

TSA administration to C57Bl/6 mice improved radiation induced mean body weight loss, maintained better health score, reduced disease activity index and promoted survival. The 16S rRNA sequencing of fecal DNA demonstrated that TSA influenced the fecal microbiota dynamics with significant alterations in the Firmicutes/Bacteriodetes ratio. TSA effectively mitigated intestinal injury, down-regulated NF-κB, Cox-2, iNOS expression, inhibited PGE2 and protein nitrosylation levels in irradiated intestine. The upregulation of NLRP3-inflammasome complex and infiltrations of inflammatory cells in the inflamed intestine were also prevented by TSA. Subsequently, the myeloperoxidase activity in intestine alongwith serum IL-18 levels was found reduced.

CONCLUSION

These findings provide evidence that TSA inhibits inflammatory mediators, alleviates gut dysbiosis, and promotes structural restoration of the irradiated intestine. TSA, therefore, can be considered as a potential agent for mitigation of RIGI in humans.

The role of the symbiotic microecosystem in cancer: gut microbiota, metabolome, and host immunome

The gut microbiota is not just a simple nutritional symbiosis that parasitizes the host; it is a complex and dynamic ecosystem that coevolves actively with the host and is involved in a variety of biological activities such as circadian rhythm regulation, energy metabolism, and immune response. The development of the immune system and immunological functions are significantly influenced by the interaction between the host and the microbiota. The interactions between gut microbiota and cancer are of a complex nature. The critical role that the gut microbiota plays in tumor occurrence, progression, and treatment is not clear despite the already done research. The development of precision medicine and cancer immunotherapy further emphasizes the importance and significance of the question of how the microbiota takes part in cancer development, progression, and treatment. This review summarizes recent literature on the relationship between the gut microbiome and cancer immunology. The findings suggest the existence of a "symbiotic microecosystem" formed by gut microbiota, metabolome, and host immunome that is fundamental for the pathogenesis analysis and the development of therapeutic strategies for cancer.

Identification and Characterization of a Potential Probiotic, Clostridium butyricum G13, Isolated from the Intestine of the Mud Crab (Scylla paramamosain)

The butyrate-producing bacterium Clostridium butyricum has been proven to be important in improving the growth and health benefits of aquatic animals. In this study, C. butyricum G13 was isolated for the first time from the gut of the mud crab (Scylla paramamosain). The results of this study showed that C. butyricum G13 could produce a high concentration of butyric acid and grow well in a wide range of pHs (4 to 9) and NaCl (1 to 2.5%) and bile salt (0.2 to 1.0%) concentrations. In vitro characterization revealed that C. butyricum G13 is a Gram-positive and gamma-hemolytic bacterium sensitive to most antibiotics and shows hydrophobicity and the capacity to degrade starch. In vitro fermentation using mud crab gut contents showed that C. butyricum G13 alone or in combination with galactooligosaccharides (GOS) and/or resistant starch (RS) significantly increased butyric acid production and beneficially affected the abundance and diversity of intestinal microbiota. In addition, C. butyricum G13 can improve the survival rate of mud crabs and effectively maintain the normal structure of gut morphology after infection with Vibrio parahaemolyticus. In conclusion, C. butyricum G13 can be considered a potential probiotic that improves the immune capacity and confers health benefits on mud crabs. IMPORTANCE With the development of society, more and more aquatic animals are demanded. Intensification in the aquaculture scale is facing problems, such as disease outbreaks, eutrophication of water bodies, and misuse of antibiotics. Among these challenges, disease outbreak is the most important factor directly affecting aquaculture production. It is crucial to explore new approaches effective for the prevention and control of diseases. Probiotics have been widely used in aquaculture and have shown beneficial effects on the host. In this study, the butyrate-producing bacterium Clostridium butyricum G13 was isolated for the first time from the intestine of the mud crab through in vitro fermentation. The bacterium has probiotic properties and changes the gut microbiota to be beneficial to hosts in vitro as well as protecting hosts from Vibrio parahaemolyticus infection in vivo. The outcomes of this study indicate that C. butyricum G13 can be used as a potential probiotic in mud crab aquaculture.

Gastrointestinal Dysfunction in Neurological and Neurodegenerative Disorders

Increasing research links the gut microbiome to neurodegenerative disorders. The gut microbiome communicates with the central nervous system via the gut-brain axis and affects behavioral and cognitive phenotypes. Dysbiosis (a dysfunctional microbiome) drives increased intestinal permeability and inflammation that can negatively affect the brain via the gut-brain axis. Healthier metabolic and lipid profiles and cognitive phenotypes are observed in individuals with more distinct microbiomes. In this review, we discuss the role of the gut microbiome and gut-brain axis in neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease and related animal models, in cancer and cancer treatments, and in metabolic syndrome. We also discuss strategies to improve the gut microbiome and ultimately brain function. Because healthier cognitive phenotypes are observed in individuals with more distinct microbiomes, increased efforts are warranted to develop therapeutic strategies for those at increased risk of developing neurological disorders and patients diagnosed with those disorders.

Oral Microalgae-Nano Integrated System against Radiation-Induced Injury

The increasing applications of ionizing radiation in society raise the risk of radiation-induced intestinal and whole-body injury. Astaxanthin is a powerful antioxidant to reduce the reactive oxygen generated from radiation and the subsequent damage. However, the oral administration of astaxanthin remains challenging owing to its low solubility and poor bioavailability. Herein, we facilely construct an orally used microalgae-nano integrated system (SP@ASXnano) against radiation-induced intestinal and whole-body injury, combining natural microalgae Spirulina platensis (SP) with astaxanthin nanoparticles (ASXnano). SP and ASXnano show complementation in drug delivery to improve distribution in the intestine and blood. SP displays limited gastric drug loss, prolonged intestinal retention, constant ASXnano release, and progressive degradation. ASXnano improves drug solubility, gastric stability, cell uptake, and intestinal absorption. SP and ASXnano have synergy in many aspects such as anti-inflammation, microbiota protection, and fecal short-chain fatty acid up-regulation. In addition, the system is ensured with biosafety for long-term administration. The system organically combines the properties of microalgae and nanoparticles, which was expected to expand the medical application of SP as a versatile drug delivery platform.

Population response of intestinal microbiota to acute Vibrio alginolyticus infection in half-smooth tongue sole (Cynoglossus semilaevis)

Introduction

Vibriosis causes enormous economic losses of marine fish. The present study investigated the intestinal microbial response to acute infection of half-smooth tongue sole with different-dose Vibrio alginolyticus within 72 h by metagenomic sequencing.

Methods

The inoculation amount of V. alginolyticus for the control, low-dose, moderate-dose, and high-dose groups were 0, 8.5 × 101, 8.5 × 104, and 8.5 × 107 cells/g respectively, the infected fish were farmed in an automatic seawater circulation system under a relatively stable temperature, dissolved oxygen and photoperiod, and 3 ~ 6 intestinal samples per group with high-quality DNA assay were used for metagenomics analysis.

Results

The acute infections with V. alginolyticus at high, medium, and low doses caused the change of different-type leukocytes at 24 h, whereas the joint action of monocytes and neutrophils to cope with the pathogen infection only occurred in the high-dose group at 72 h. The metagenomic results suggest that a high-dose V. alginolyticus infection can significantly alter the intestinal microbiota, decrease the microbial α-diversity, and increase the bacteria from Vibrio and Shewanella, including various potential pathogens at 24 h. High-abundance species of potential pathogens such as V. harveyii, V. parahaemolyticus, V. cholerae, V. vulnificus, and V. scophthalmi exhibited significant positive correlations with V. alginolyticus. The function analysis revealed that the high-dose inflection group could increase the genes closely related to pathogen infection, involved in cell motility, cell wall/ membrane/envelope biogenesis, material transport and metabolism, and the pathways of quorum sensing, biofilm formation, flagellar assembly, bacterial chemotaxis, virulence factors and antibiotic resistances mainly from Vibrios within 72 h.

Discussion

It indicates that the half-smooth tongue sole is highly likely to be a secondary infection with intestinal potential pathogens, especially species from Vibrio and that the disease could become even more complicated because of the accumulation and transfer of antibiotic-resistance genes in intestinal bacteria during the process of V. alginolyticus intensified infection.

Adhesive Ergothioneine Hyaluronate Gel Protects against Radiation Gastroenteritis by Alleviating Apoptosis, Inflammation, and Gut Microbiota Dysbiosis

Radiation gastroenteritis represents one of the most prevalent and hazardous complications of abdominopelvic radiotherapy, which not only severely reduces patients' life quality but also restricts radiotherapy efficacy. However, there is currently no clinically available oral radioprotector for this threatening disease due to its complex pathogenesis and the harsh gastrointestinal environment. To this end, this study developed a facile but effective oral radioprotector, ergothioneine hyaluronate (EGT@HA) gel, protecting against radiation gastroenteritis by synergistically regulating oxidative stress, inflammation, and gut microbiota. In vitro and cellular experiments verified the chemical stability and free radical scavenging ability of EGT and its favorable cellular radioprotective efficacy by inhibiting intracellular reactive oxidative species (ROS) generation, DNA damage, mitochondrial damage, and apoptosis. At the in vivo level, EGT@HA with prolonged gastrointestinal residence mitigated radiation-induced gastrointestinal tissue injury, apoptosis, neutrophil infiltration, and gut flora dysbiosis. For the first time, this work investigated the protective effects of EGT@HA gel on radiation gastroenteritis, which not only hastens the advancement of the novel gastrointestinal radioprotector but also provides a valuable gastrointestinal radioprotection paradigm by synergistically modulating oxidative stress, inflammation, and gut microbiota disturbance.

Exploring the Involvement of Gut Microbiota in Cancer Therapy-Induced Cardiotoxicity

Trillions of microbes in the human intestinal tract, including bacteria, viruses, fungi, and protozoa, are collectively referred to as the gut microbiome. Recent technological developments have led to a significant increase in our understanding of the human microbiome. It has been discovered that the microbiome affects both health and the progression of diseases, including cancer and heart disease. Several studies have indicated that the gut microbiota may serve as a potential target in cancer therapy modulation, by enhancing the effectiveness of chemotherapy and/or immunotherapy. Moreover, altered microbiome composition has been linked to the long-term effects of cancer therapy; for example, the deleterious effects of chemotherapy on microbial diversity can, in turn, lead to acute dysbiosis and serious gastrointestinal toxicity. Specifically, the relationship between the microbiome and cardiac diseases in cancer patients following therapy is poorly understood. In this article, we provide a summary of the role of the microbiome in cancer treatment, while also speculating on a potential connection between treatment-related microbial changes and cardiotoxicity. Through a brief review of the literature, we further explore which bacterial families or genera were differentially affected in cancer treatment and cardiac disease. A deeper understanding of the link between the gut microbiome and cardiotoxicity caused by cancer treatment may help lower the risk of this critical and potentially fatal side effect.

Gut microbiota is associated with response to 131I therapy in patients with papillary thyroid carcinoma

PURPOSE

Radioactive iodine (¹³¹I) therapy is a conventional post-surgery treatment widely used for papillary thyroid carcinoma (PTC). Since ¹³¹I is orally administered, we hypothesize that it may affect gut microbiome. This study aims to investigate alterations of intestinal microbiome caused by ¹³¹I therapy in PTC patients and explore its association with response to ¹³¹I therapy.

METHODS

Fecal samples of 60 PTC patients pre- and post-¹³¹I therapy were collected to characterize the ¹³¹I therapy-induced gut microbiota alterations using 16S rRNA gene sequencing. According to the inclusion criteria, sequence data of 40 out of the 60 patients, divided into excellent response (ER) group and non-excellent response (NER) group, were recruited to investigate the possible connection between gut microbiota and response to ¹³¹I therapy. Multivariate binary logistic regression was employed to construct a predictive model for response to ¹³¹I therapy.

RESULTS

Microbial richness, diversity, and composition were tremendously altered by ¹³¹I therapy. A significant decline of Firmicutes to Bacteroides (F/B) ratio was observed post-¹³¹I therapy. ¹³¹I therapy also led to changes of gut microbiome-related metabolic pathways. Discrepancies in β diversity were found between ER and NER groups both pre- and post-¹³¹I therapy. Furthermore, a predictive model for response to ¹³¹I therapy with a p value of 0.003 and an overall percentage correct of 80.0% was established, with three variables including lymph node metastasis, relative abundance of g_Bifidobacterium and g_Dorea. Among them, g_Dorea was identified to be an in independent predictor of response to ¹³¹I therapy (p = 0.04).

CONCLUSION

For the first time, the present study demonstrates the gut microbial dysbiosis caused by ¹³¹I therapy in post-surgery PTC patients and reveals a previously undefined role of gut microbiome as predictor for ¹³¹I ablation response. G_Dorea and g_Bifidobacterium may be potential targets for clinical intervention to improve response to ¹³¹I in post-operative PTC patients.

TRIAL REGISTRATION

ChiCTR2100048000. Registered 28 June 2021.

New Insights into the Relationship between Gut Microbiota and Radiotherapy for Cancer

Cancer is the second most common cause of death among humans in the world, and the threat that it presents to human health is becoming more and more serious. The mechanisms of cancer development have not yet been fully elucidated, and new therapies are changing with each passing day. Evidence from the literature has validated the finding that the composition and modification of gut microbiota play an important role in the development of many different types of cancer. The results also demonstrate that there is a bidirectional interaction between the gut microbiota and radiotherapy treatments for cancer. In a nutshell, the modifications of the gut microbiota caused by radiotherapy have an effect on tumor radiosensitivity and, as a result, affect the efficacy of radiotherapy and show a certain radiation toxicity, which leads to numerous side effects. What is of new research significance is that the "gut-organ axis" formed by the gut microbiota may be one of the most interesting potential mechanisms, although the relevant research is still very limited. In this review, we combine new insights into the relationship between the gut microbiota, cancer, and radiotherapy. Based on our current comprehensive understanding of this relationship, we give an overview of the new cancer treatments based on the gut microbiota.

Gut microbiota: a new avenue to reveal pathological mechanisms of constipation

Constipation is very pervasive all over the world. It is a common multifactorial gastrointestinal disease, and its etiology and pathomechanism are not completely clear. Now, increasing evidence shows that intestinal flora is closely related to constipation. Intestinal flora is the largest microbiota in the human body and has powerful metabolic functions. Intestinal flora can produce a variety of metabolites, such as bile acids, short-chain fatty acids, tryptophan metabolites, and methane, which have important effects on intestinal motility and secretion. The host can also monitor the intestinal flora and regulate gut dysbacteriosis in constipation. To explore the relationship between intestinal flora and host, the combination of multiomics technology has become the powerful and effective method. Furthermore, the homeostasis restoration of intestinal flora also provides a new strategy for the treatment of constipation. This review aims to explore the interaction between intestinal flora and host in constipation, which contributes to disclose the pathogenesis of constipation and the development of novel drugs for the treatment of constipation from the perspective of intestinal flora. KEY POINTS: • This review highlights the regulation of gut microbiota on the intestinal motility and secretion of host. • The current review gives an insight into the role of the host on the recognition and regulation of intestinal ecology under constipation. • The article also introduces some novel methods of current gut microbiota research and gut microbiota-based constipation therapies.

Archaea Microbiome Dysregulated Genes and Pathways as Molecular Targets for Lung Adenocarcinoma and Squamous Cell Carcinoma

The human microbiome is a vast collection of microbial species that exist throughout the human body and regulate various bodily functions and phenomena. Of the microbial species that exist in the human microbiome, those within the archaea domain have not been characterized to the extent of those in more common domains, despite their potential for unique metabolic interaction with host cells. Research has correlated tumoral presence of bacterial microbial species to the development and progression of lung cancer; however, the impacts and influences of archaea in the microbiome remain heavily unexplored. Within the United States lung cancer remains highly fatal, responsible for over 100,000 deaths every year with a 5-year survival rate of roughly 22.9%. This project attempts to investigate specific archaeal species' correlation to lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) incidence, patient staging, death rates across individuals of varying ages, races, genders, and smoking-statuses, and potential molecular targets associated with archaea microbiome. Archaeal species abundance was assessed across lung tissue samples of 527 LUAD patients, 479 LUSC patients, and 99 healthy individuals. Nine archaeal species were found to be of significantly altered abundance in cancerous samples as compared to normal counterparts, 6 of which are common to both LUAD and LUSC subgroups. Several of these species are of the taxonomic class Thermoprotei or the phylum Euryarchaeota, both known to contain metabolic processes distinct from most bacterial species. Host-microbe metabolic interactions may be responsible for the observed correlation of these species' abundance with cancer incidence. Significant microbes were correlated to patient gene expression to reveal genes of altered abundance with respect to high and low archaeal presence. With these genes, cellular oncogenic signaling pathways were analyzed for enrichment across cancer and normal samples. In comparing gene expression between LUAD and adjacent normal samples, 2 gene sets were found to be significantly enriched in cancers. In LUSC comparison, 6 sets were significantly enriched in cancer, and 34 were enriched in normals. Microbial counts across healthy and cancerous patients were then used to develop a machine-learning based predictive algorithm, capable of distinguishing lung cancer patients from healthy normal with 99% accuracy.

Research progress on the mechanism of radiation enteritis

Radiation enteritis (Re) is one of the most common complications of radiation therapy for abdominal tumors. The efficacy of cancer treatment by radiation is often limited by the side effects of Re. Re can be acute or chronic. Treatment of acute Re is essentially symptomatic. However, chronic Re usually requires surgical procedures. The underlying mechanisms of Re are complex and have not yet been elucidated. The purpose of this review is to provide an overview of the pathogenesis of Re. We reviewed the role of intestinal epithelial cells, intestinal stem cells (ISCs), vascular endothelial cells (ECs), intestinal microflora, and other mediators of Re, noting that a better understanding of the pathogenesis of Re may lead to better treatment modalities.

The Role of the Human Gut Microbiome in Inflammatory Bowel Disease and Radiation Enteropathy

The human gut microbiome plays a key role in regulating host physiology. In a stable state, both the microbiota and the gut work synergistically. The overall homeostasis of the intestinal flora can be affected by multiple factors, including disease states and the treatments given for those diseases. In this review, we examine the relatively well-characterised abnormalities that develop in the microbiome in idiopathic inflammatory bowel disease, and compare and contrast them to those that are found in radiation enteropathy. We discuss how these changes may exert their effects at a molecular level, and the possible role of manipulating the microbiome through the use of a variety of therapies to reduce the severity of the underlying condition.

LMWP (S3-3) from the Larvae of Musca domestica Alleviate D-IBS by Adjusting the Gut Microbiota

Diarrhea-based Irritable Bowel Syndrome (D-IBS) and diarrhea are both associated with ecological imbalance of the gut microbiota. Low Molecular Weight Peptides (LMWP) from the larvae of Musca domestica have been shown to be effective in the treatment of diarrhea and regulation of gut microbiota. Meanwhile, the single polypeptide S3-3 was successfully isolated and identified from LMWP in our previous studies. It remains unclear exactly whether and how LMWP (S3-3) alleviate D-IBS through regulating gut microbiota. We evaluated the gut microbiota and pharmacology to determine the regulation of gut microbiota structure and the alleviating effect on D-IBS through LMWP (S3-3). The rates of loose stools, abdominal withdrawal reflex (AWR) and intestinal tract motility results revealed that LMWP (S3-3) from the larvae of Musca domestica had a regulating effect against diarrhea, visceral hypersensitivity and gastrointestinal (GI) dysfunction in D-IBS model mice. Additionally, 16S rRNA gene sequencing was utilized to examine the gut microbiota, which suggests that LMWP induce structural changes in the gut microbiota and alter the levels of the following gut microbiota: Bacteroidetes, Proteobacteria and Verrucomicrobia. LMWP putatively functioned through regulating 5-HT, SERT, 5-HT2AR, 5-HT3AR and 5-HT4R according to the results of ELISA, qRT-PCR and IHC. The findings of this study will contribute to further understanding how LMWP (S3-3) attenuate the effects of D-IBS on diarrhea, visceral hypersensitivity and GI dysfunction.

A Class IIb Bacteriocin Plantaricin NC8 Modulates Gut Microbiota of Different Enterotypes in vitro

The gut microbiota is engaged in multiple interactions affecting host health. Bacteriocins showed the ability of impeding the growth of intestinal pathogenic bacteria and modulating gut microbiota in animals. Few studies have also discovered their regulation on human intestinal flora using an in vitro simulated system. However, little is known about their effect on gut microbiota of different enterotypes of human. This work evaluated the modification of the gut microbiota of two enterotypes (ET B and ET P) by the class IIb bacteriocin plantaricin NC8 (PLNC8) by using an in vitro fermentation model of the intestine. Gas chromatography results revealed that PLNC8 had no influence on the gut microbiota’s production of short-chain fatty acids in the subjects’ samples. PLNC8 lowered the Shannon index of ET B’ gut microbiota and the Simpson index of ET P’ gut microbiota, according to 16S rDNA sequencing. In ET B, PLNC8 enhanced the abundance of Bacteroides, Bifidobacterium, Megamonas, Escherichia-Shigella, Parabacteroides, and Lactobacillus while decreasing the abundance of Streptococcus. Prevotella_9, Bifidobacterium, Escherichia-Shigella, Mitsuokella, and Collinsella were found more abundant in ET P. The current study adds to our understanding of the impact of PLNC8 on the human gut microbiota and lays the groundwork for future research into PLNC8’s effects on human intestinal disease.

Associations Between Disordered Microbial Metabolites and Changes of Neurotransmitters in Depressed Mice

Backgrounds

Many pieces of evidence demonstrated that there were close relationships between gut microbiota and depression. However, the specific molecular mechanisms were still unknown. Here, using targeted metabolomics, this study was conducted to explore the relationships between microbial metabolites in feces and neurotransmitters in prefrontal cortex of depressed mice.

Methods

Chronic unpredictable mild stress (CUMS) model of depression was built in this study. Targeted liquid chromatography-mass spectrometry analysis was used to detect the microbial metabolites in feces and neurotransmitters in prefrontal cortex of mice. Both univariate and multivariate statistical analyses were applied to identify the differential microbial metabolites and neurotransmitters and explore relationships between them.

Results

Ninety-eight differential microbial metabolites (mainly belonged to amino acids, fatty acids, and bile acids) and 11 differential neurotransmitters (belonged to tryptophan pathway, GABAergic pathway, and catecholaminergic pathway) were identified. Five affected amino acid-related metabolic pathways were found in depressed mice. The 19 differential microbial metabolites and 10 differential neurotransmitters were found to be significantly correlated with depressive-like behaviors. The two differential neurotransmitters (tyrosine and glutamate) and differential microbial metabolites belonged to amino acids had greater contributions to the overall correlations between microbial metabolites and neurotransmitters. In addition, the significantly decreased L-tyrosine as microbial metabolites and tyrosine as neurotransmitter had the significantly positive correlation (r = 0.681, p = 0.0009).

Conclusions

These results indicated that CUMS-induced disturbances of microbial metabolites (especially amino acids) might affect the levels of neurotransmitters in prefrontal cortex and then caused the onset of depression. Our findings could broaden the understanding of how gut microbiota was involved in the onset of depression.

Marine Chitooligosaccharide Alters Intestinal Flora Structure and Regulates Hepatic Inflammatory Response to Influence Nonalcoholic Fatty Liver Disease

In this study, C57BL/6 mice were given an HFHSD diet for 8 weeks to induce hepatic steatosis and then given COSM solution orally for 12 weeks. The study found that the HFHSD diet resulted in steatosis and insulin resistance in mice. The formation of NAFLD induced by HFHSD diet was related to the imbalance of intestinal flora. However, after COSM intervention, the abundance of beneficial bacteria increased significantly, while the abundance of harmful bacteria decreased significantly. The HFHSD diet also induced changes in intestinal bacterial metabolites, and the content of short-chain fatty acids in cecal contents after COSM intervention was significantly higher than that in the model group. In addition, COSM not only improved LPS levels and barrier dysfunction in the ileum and colon but upregulated protein levels of ZO-1, occludin, and claudin in the colon and downregulated the liver LPS/TLR4/NF-κB inflammatory pathway. We concluded that the treatment of marine chitooligosaccharide COSM could improve the intestinal microflora structure of the fatty liver and activate an inflammatory signaling pathway, thus alleviating the intrahepatic lipid accumulation induced by HFHSD.

Alterations in Intestinal Antioxidant and Immune Function and Cecal Microbiota of Laying Hens Fed on Coated Sodium Butyrate Supplemented Diets

This study was designed to evaluate the effects of dietary coated sodium butyrate (CSB) on the intestinal antioxidant, immune function, and cecal microbiota of laying hens. A total of 720 52-week-old Huafeng laying hens were randomly allocated into five groups and fed a basal diet supplemented with CSB at levels of 0 (control), 250 (S250), 500 (S500), 750 (S750), and 1000 (S1000) mg/kg for eight weeks. The results revealed that CSB supplementation quadratically decreased the malondialdehyde content and increased the superoxide dismutase activity of the jejunum as well as the total antioxidative capacity activity of the ileum (p < 0.05). Dietary CSB supplementation linearly decreased the diamine oxidase and D-lactic acid content of the serum (p < 0.05). Compared with the control group, the addition of CSB resulted in linear and/or quadratic effects on the mRNA expression of inflammatory cytokines TNF-α, IL-6, and IL-10 in the jejunum and ileum (p < 0.05). The short-chain fatty acid concentrations increased quadratically as supplemental CSB improved (p < 0.05). Additionally, dietary CSB levels had no effect on microbial richness estimators, but ameliorated cecal microbiota by raising the abundance of probiotics and lowering pathogenic bacteria enrichment. In conclusion, our results suggest that dietary supplementation with CSB could improve the intestinal health of laying hens via positively influencing the antioxidant capacity, inflammatory cytokines, short-chain fatty acids, and gut microbiota. In this study, 500 mg/kg CSB is the optimal supplement concentration in the hens’ diet.

Preventive effect of sanguinarine on intestinal injury in mice exposed to whole abdominal irradiation

Intestinal injury is one of the major side effects that are induced by medical radiation exposure, and has limited effective therapies. In this study, we investigated the beneficial effects of sanguinarine (SAN) on intestinal injury induced by ionizing radiation (IR) both in vitro and in vivo. Mice were exposed to whole abdominal irradiation (WAI) to mimic clinical scenarios. SAN was injected intraperitoneally to mitigate IR-induced injury. Histological examination was performed to assess the tissue injuries of the spleen and small intestine. A small intestinal epithelial cell line-6 (IEC-6) was analyzed for its viability and apoptosis in vitro under different treatments. Inflammation-related pathways and serum inflammatory cytokines were detected via Western blot analysis and ELISA, respectively. High-throughput sequencing was used to characterize the gut microbiota profile. High-performance liquid chromatography was performed to assess short-chain fatty acid contents in the colon. In vitro, SAN pretreatment protected cell viability and reduced apoptosis in IEC-6 cells. In vivo, SAN pretreatment protected immune organs, alleviated intestinal injury, and promoted intestinal recovery. SAN also reduced the levels of inflammatory cytokines, suppressed high mobility group box 1 (HMGB1)/ Toll-like receptor 4 (TLR4) pathway activation, and modulated gut microbiota composition. Our findings demonstrate that the beneficial properties of SAN alleviated intestinal radiation injury. Thus, SAN represents a therapeutic option for protecting against IR-induced intestinal injury in preclinical settings.