Intestinal Flora Research Articles

CO-RELATION BETWEEN THE GUT MICROBIOTA AND BRAIN

The relationship between your gut and your brain refers to a neurological pathway that exists among your gastrointestinal tract and brain. They are linked in numerous methods, whether physiologically or through biochemistry. The human gut is home for a wide variety of living organisms, including microbes, viruses, bacteria, fungus, and archaea. The term "microbiome" refers to these all together. The bacteria which inhabit the gastrointestinal tracts of people along with other creatures are known as the gut microbiota, intestinal flora, A number of bacteria have been related to illnesses, whereas other microbes are crucial for additional aspects of well- being. Individuals with a range of neurological disorders, including depression, bipolar disorder, schizophrenia, have been discovered to have notable changes in the chemical makeup of their gut microbes. Microbes in the gut are additionally connected to various mental health conditions. KeyWords: Gut microflora, Probiotics, Vagus nerve, Neurotransmitters,

Dietary supplementation of distiller's grains yeast cultures improves performance and immunity by altering the intestinal flora of broilers.

Distiller's grains are a by-product of liquor production with a higher yield than liquor. Developing and utilizing distiller's grains well could alleviate the problem of scarce feed resources. Our present experiment was conducted with 6000 yellow-feathered broilers to study the effects of adding distiller's grains yeast cultures (DGYC) to the diet on growth performance and immunity of broilers. The broilers were divided into five groups, receiving different DGYC concentrations during two stages. Growth performance, intestinal microorganisms and immune organ development were measured. The results showed that groups B and D, supplemented with medium and high concentrations of DGYC, respectively, had significantly improved growth performance compared to the control group (P < 0.05). Group D also showed higher immune organ index (P < 0.01), increased serum total protein, high-density lipoprotein and immunoglobulin levels (P < 0.05) and lower levels of low-density lipoprotein, triglycerides, interleukin 1β and tumor necrosis factor α (P < 0.05). Hematoxylin and eosin staining confirmed improved immune organ development in group D (P < 0.05). Furthermore, in high-concentration group D, levels of short-chain fatty acids (SCFA; acetic, propionic and butyric acids) in cecal chyme were significantly increased (P < 0.05). The richness (Chao1) and diversity (Faith-pd) index of cecal microbiota were significantly higher in group D compared to the control group (P < 0.05). The microbial composition in group D differed from the control and medium-concentration group B. Seven bacteria (Clostridia-UCG-014, UCG-009, DTU089, UCG-010, Campylobacter, Harryflintia, Shuttleworthia) showed significant differences (P < 0.05). After DGYC feeding, DTU089 decreased, while other SCFA-producing bacteria increased (P < 0.05). Subsequently, KEGG function and corresponding signal pathway predictions were performed on bacteria with significant differences. Group D exhibited a higher enrichment of immune function pathways (P < 0.01) and showed significant changes in four immune signaling pathways according to the signal pathway heatmap. Our data suggest that high concentrations of DGYC can be applied as a feed additive for broilers that promotes growth, improves intestinal health and enhances certain immunity. © 2024 Society of Chemical Industry.

Fresh bamboo juice regulates the diversity of intestinal microflora in mice by promoting the function of ILC2 cells to mediate intestinal protection

Background and aimUlcerative colitis (UC) is a growing global health concern, with current treatments facing challenges like drug dependence and side effects. Fresh bamboo juice (FBJ), known for its antimicrobial and potential immune-modulating properties, has shown promise as a natural therapeutic agent. The present study aimed to explore the protective effects of FBJ against colitis and further analyze the changes of gut microbiota composition, metabolite profiles, and underlying immune mechanisms. Materials and MethodsA colitis model in mice was established using DSS to investigate the effectiveness of FBJ. Intestinal tissue and fecal samples were also collected for 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS) analysis. Additionally, immunofluorescence and flow cytometry were employed to detect the proliferation and function of group 2 innate lymphoid cells (ILC2). Enzyme-linked immunosorbent assay (ELISA) was used to measure the cytokines secreted by immune cells. ResultsFBJ demonstrated significant therapeutic effects against DSS-induced colitis in mice. At the genus level, the abundance of Bacteroides, Akkermansia and unassigned bacteria in the bamboo juice group increased compared with the DSS group. In contrast, the abundance of Alloprevotella, Lactobacillus, Lachnospiraceae_NK4A136_group and Ruminococcaceae_UCG-014 significantly decreased. FBJ partially restored the balance of gut microbiota, as evidenced by the increased levels of beneficial bacteria. Metabolome analysis revealed significant alterations in fecal metabolites, including 3-Hydroxypyridine, Pyridoxine, SM(d18:1/16:0), and DL-Methionine sulfoxide were remarkably altered. Dysregulation of pathways such as Vitamin B6 metabolism, sphingolipid metabolism, and tyrosine metabolism was observed, which may contribute to protection against colitis. Flow cytometry and immunofluorescence showed a significant reduction in the proportion of ILC2 cells following FBJ treatment in the DSS group (1.82 % v.s. 3.18 %, P < 0.05). ELISA showed that the FBJ group had lower levels of IL-5, IL-6, IL-10, IL-13, IL-33, TNF-α, IFN-γ in intestinal tissue. ConclusionsOur findings demonstrate that FBJ exerts a protective effect against colitis, primarily by modulating the intestinal flora and metabolite profiles in mice with colitis. Furthermore, the observed alterations in bacterial flora and metabolites likely affect ILC2 function and cytokine production, thereby mediating the protective effects against colitis through modulation of the immune system.

The Effect of Organic Vegetable Mixed Juice on Blood Circulation and Intestine Flora: Randomized, Double-Blinded, Placebo-Controlled Clinical Trial.

Epidemiological evidence suggests that fruit and vegetable intake significantly positively affects cardiovascular health. Since vegetable juice is more accessible than raw vegetables, it attracts attention as a health functional food for circulatory diseases. Therefore, this study measured blood lipids, antioxidants, blood circulation indicators, and changes in the microbiome to confirm the effect of organic vegetable mixed juice (OVJ) on improving blood circulation. This 4-week, randomized, double-blinded, placebo-controlled study involved adult men and women with borderline total cholesterol (TC) and low-density lipoprotein (LDL) levels. As a result, blood lipid profile indicators, such as TC, triglycerides, LDL cholesterol, and apolipoprotein B, decreased (p < 0.05) in the OVJ group compared with those in the placebo group. Additionally, the antioxidant biomarker superoxide dismutase increased (p < 0.05). In contrast, systolic and diastolic blood viscosities, as blood circulation-related biomarkers, decreased (p < 0.05) in the OVJ group compared with those in the placebo group. After the intervention, a fecal microbiome analysis confirmed differences due to changes in the intestinal microbiome composition between the OVJ and placebo groups. In conclusion, our research results confirmed that consuming OVJ improves blood circulation by affecting the blood lipid profile, antioxidant enzymes, and microbiome changes.

Lacticaseibacillus rhamnosus KY16 Improves Depression by Promoting Intestinal Secretion of 5-HTP and Altering the Gut Microbiota.

Increasing research suggests a connection between gut microbiota and depressive disorders. Targeted changes to the intestinal flora may contribute to alleviating anxiety and depression. This study aimed to identify probiotics that could attenuate stress-induced abnormal behavior and explore potential mechanisms. The administration of LR.KY16 significantly reduced stress-induced abnormal behaviors and physiological dysfunction. The mechanism may be via regulating the structure of the intestinal microbiota in mice, increasing the abundance of Akkermansia muciniphila, prompting enterochromaffin cells to secrete 5-HTP in the gut, which enters the brain through the bloodstream and promotes the synthesis of 5-HT in the brain, and then activates brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) through the 5-HT1A receptor. In addition, LR.KY16 also increased the expression of claudin-7, occludin, and zonula occludens-1 (ZO-1) in the colon, inhibited microglial M1 polarization, and inhibited systemic inflammation.

A New Strategy for Dietary Nutrition to Improve Intestinal Homeostasis in Diarrheal Irritable Bowel Syndrome: A Perspective on Intestinal Flora and Intestinal Epithelial Interaction.

Although a reasonable diet is essential for promoting human health, precise nutritional regulation presents a challenge for different physiological conditions. Irritable Bowel Syndrome (IBS) is characterized by recurrent abdominal pain and abnormal bowel habits, and diarrheal IBS (IBS-D) is the most common, seriously affecting patients' quality of life. Therefore, the implementation of precise nutritional interventions for IBS-D has become an urgent challenge in the fields of nutrition and food science. IBS-D intestinal homeostatic imbalance involves intestinal flora disorganization and impaired intestinal epithelial barrier function. A familiar interaction is evident between intestinal flora and intestinal epithelial cells (IECs), which together maintain intestinal homeostasis and health. Dietary patterns, such as the Mediterranean diet, have been shown to regulate gut flora, which in turn improves the body's health by influencing the immune system, the hormonal system, and other metabolic pathways. This review summarized the relationship between intestinal flora, IECs, and IBS-D. It analyzed the mechanism behind IBS-D intestinal homeostatic imbalance by examining the interactions between intestinal flora and IECs, and proposed a precise dietary nutrient intervention strategy. This increases the understanding of the IBS-D-targeted regulation pathways and provides guidance for designing related nutritional intervention strategies.

Activation of GABABR Attenuates Intestinal Inflammation by Reducing Oxidative Stress through Modulating the TLR4/MyD88/NLRP3 Pathway and Gut Microbiota Abundance.

Oxidative stress emerges as a prominent factor in the onset and progression of intestinal inflammation, primarily due to its critical role in damaging cells and tissues. GABAergic signaling is important in the occurrence and development of various intestinal disorders, yet its effect on oxidative stress remains unclear. We attempted to assess whether GABAergic signaling participated in the regulation of oxidative stress during enteritis. The results showed that lipopolysaccharide (LPS) significantly decreased γ-aminobutyric acid (GABA) levels in the ileal tissues of mice. Interestingly, the application of GABA significantly repressed the shedding of intestinal mucosal epithelial cells and inflammatory cell infiltration, inhibited the expressions of proinflammatory factors, including granulocyte colony-stimulating factor and granulocyte-macrophage colony stimulating factor, and enhanced the levels of anti-inflammatory cytokines interleukin (IL)-4 and IL-10, indicating that GABA could alleviate enteritis in mice. This observation was further supported by transcriptome sequencing, revealing a total of 271 differentially expressed genes, which exhibited a marked enrichment of inflammatory and immune-related pathways, alongside a prominent enhancement of GABA B receptor (GABABR) signaling following GABA administration. Effectively, Baclofen pretreatment alleviated intestinal mucosal damage in LPS-induced mice, suppressed proinflammatory cytokines IL-1β, IL-6, and tumor necrosis factor alpha expressions, and boosted total antioxidant capacity, superoxide dismutase (SOD), and glutathione (GSH) levels. Moreover, Baclofen notably enhanced the viability of LPS-stimulated IPEC-J2 cells, contracted the proinflammatory secretion factors, and reinforced SOD, GSH, and catalase levels, emphasizing the anti-inflammatory and antioxidant effects associated with GABABR activation. Mechanistically, Baclofen restrained the mRNA and protein levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3), and inducible nitric oxide synthase, while elevating nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 in both mice and IPEC-J2 cells, indicating that activating GABABR strengthened antioxidant abilities by interrupting the TLR4/MyD88/NLRP3 pathway. Furthermore, 16S rDNA analysis demonstrated that Baclofen increased the relative abundance of probiotic, particularly Lactobacillus, renowned for its antioxidant properties, while reducing the relative richness of harmful bacteria, predominantly Enterobacteriaceae, suggesting that GABABR signaling may have contributed to reversing intestinal flora imbalances to relieve oxidative stress in LPS-induced mice. Our study identified previously unappreciated roles for GABABR signaling in constricting oxidative stress to attenuate enteritis, thus offering novel insights for the treatment of intestinal inflammation.

Novel mechanisms of intestinal flora regulation in high-altitude hypoxia

BackgroundThis study investigates the molecular mechanisms behind firmicutes-mediated macrophage (Mψ) polarization and glycolytic metabolic reprogramming through HIF-1α in response to intrinsic mucosal barrier injury induced by high-altitude hypoxia. MethodsEstablishing a hypoxia mouse model of high altitude, we utilized single-cell transcriptome sequencing to identify key cell types involved in regulating intestinal mucosal barrier damage caused by high-altitude hypoxia. Through proteomic analysis of colonic tissue Mψ and metabolomic analysis of Mψ metabolites, we determined crucial proteins and metabolic pathways influencing intestinal mucosal barrier damage induced by high-altitude hypoxia. Mechanistic validation was conducted using RAW264.7 Mψ in vitro by assessing cell viability with CCK-8 assay following treatment with different metabolites. The hypoxia mouse model was further validated in vivo by transplanting gut microbiota of Firmicutes. Histological examinations through H&E staining assessed colonic cell morphology and structure, while the FITC-dextran assay evaluated intestinal tissue permeability. Hypoxia probe signal intensity in mouse colonic tissue was assessed via metronidazole staining. Various experimental techniques, including flow cytometry, immunofluorescence, ELISA, Western blot, and RT-qPCR, were employed to study the impact of HIF-1α/glycolysis pathway and different gut microbiota metabolites on Mψ polarization. ResultsBioinformatics analysis revealed that single-cell transcriptomics identified Mψ as a key cell type, with their polarization pattern playing a crucial role in the intestinal mucosal barrier damage induced by high-altitude hypoxia. Proteomics combined with metabolomics analysis indicated that HIF-1α and the glycolytic pathway are pivotal proteins and signaling pathways in the intestinal mucosal barrier damage caused by high-altitude hypoxia. In vitro cell experiments demonstrated that activation of the glycolytic pathway by HIF-1α led to a significant upregulation of mRNA levels of IL-1β, IL-6, and TNFα while downregulating mRNA levels of IL-10 and TGFβ, thereby promoting M1 Mψ activation and inhibiting M2 Mψ polarization. Further mechanistic validation experiments revealed that the metabolite butyric acid from Firmicutes bacteria significantly downregulated the protein expression of HIF-1α, GCK, PFK, PKM, and LDH, thus inhibiting the HIF-1α/glycolytic pathway that suppresses M1 Mψ and activates M2 Mψ, consequently alleviating the hypoxic symptoms in RAW264.7 cells. Subsequent animal experiments confirmed that Firmicutes bacteria inhibited the HIF-1α/glycolytic pathway to modulate Mψ polarization, thereby mitigating intestinal mucosal barrier damage in high-altitude hypoxic mice. ConclusionThe study reveals that firmicutes, through the inhibition of the HIF-1α/glycolysis pathway, mitigate Mψ polarization, thereby alleviating intrinsic mucosal barrier injury in high-altitude hypoxia.

Study on the metabolism of Xiao-Jian-Zhong-Tang in rats with chronic atrophic gastritis coupled with bioinformatics.

Xiao-Jian-Zhong-Tang (XJZT) has the effect of warming the middle and tonifying the deficiency, easing the urgency and relieving pain according to the theory of traditional Chinese medicine (TCM), and is able to treat spleen deficiency type chronic atrophic gastritis (CAG). Metabolites of TCM in cecum contents are common metabolites of intestinal bacteria and hosts, which can reflect the metabolic status in disease states. The present work was performed to study the effect of XJZT against CAG coupled with the cecal metabolites analysis and bioinformatics. A total of nine prototypical components and 144 metabolites were firstly identified in the cecum metabolites of XJZT using ultra-high performance liquid chromatography added to the quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF/MS), which underwent the metabolism of oxidation, reduction, methylation, and glucuronic acid reaction Furthermore, different prototypical compounds might metabolize into identical metabolites in the presence of intestinal flora. Bioinformatics was further used to correlate these metabolites with the disease and intestinal flora. Components and targets were screened by Cytoscape, and molecular docking of key targets and core components showed good binding ability. This study provided important information for exploring the mechanism of TCM formulae.

Effect of Morchella esculenta polysaccharides on the rectal microbiota of mice challenged with lipopolysaccharides.

Intestinal dysfunction poses a severe problem by preventing the digestion and absorption of nutrients. The gut, being the most vital organ for these processes, plays a crucial role in ensuring our body receives the nutrients it needs. We explored the mitigating effect of Morchella esculenta polysaccharides (MEP) on intestinal injury induced by lipopolysaccharides (LPS) through the modulation of intestinal flora. For this purpose, Kunming mice (KM) were divided into three groups, namely, PC, PM, and PY. Group PY was treated with MEP, while groups PM and PY were induced with LPS. The results showed that weight loss in the PM group was significantly greater than that in the PY group (P < 0.05), and the organ indexes of the lung and spleen in the PM group were significantly higher than those in the PC (P < 0.01) and PY (P < 0.05) groups. LPS caused severe injuries in KM mice in the PM group, characterized by broken villi. However, MEP treatment could alleviate this damage in the PY group, resulting in relatively intact villi. The serum analysis showed that tumor necrosis factor alpha (TNF-ɑ) (P < 0.01), interleukin 6 (IL-6) (P < 0.01), and 3,4-methylenedioxyamphetamine (MDA) (P < 0.05) levels were significantly higher in the PM group, while IL-10 (P < 0.001), superoxide dismutase (SOD) (P < 0.01) and glutathione peroxidase (GSH-Px) (P < 0.01) were significantly lower in that group. Interestingly, supplementation with MEP could lower the levels of TNF-ɑ, IL-10, IL-6, MDA while increasing the levels of superoxide dismutase (SOD) (P < 0.01) and GSH-Px. The gut microbiota analysis yielded 630,323 raw reads and 554,062 clean reads, identifying 3,390 amplicon sequencing variants (ASVs). One phylum and five genera were notably different among animal groups, including Escherichia_Shigella, Limosilactobacillus, unclassified_Geminicoccaceae, unclassified_Rhodobacteraceae, and Parabacteroides (P. distasonis). In conclusion, we found that MEP could mitigate the intestinal damage caused by LPS by modulating the inflammatory response, oxidative resistance, and intestinal flora of KM mice. Our results may provide insights into novel treatment options for intestine-related diseases.

Overlap of gallbladder dysfunction and irritable bowel syndrome: clinical and microbiological features and therapeutic possibilities

Objective — to analyse the clinical and microbiological features in patients with an overlap between gallbladder dysfunction (GBD) and irritable bowel syndrome (IBS) and a complex assessment of the effectiveness and safety of using ursodeoxycholic acid (Ursis) in these patients. Materials and methods. Under our observation were 115 patients with the overlap of GBD and IBS aged from 19 to 52. The majority of them were women (62.6%). All patients complained of abdominal pain, mostly without clear localization or in the right hypochondrium and along the course of the large intestine. Constipation was diagnosed in 83 (72.2%) patients, and meteorism in 89 (77.4%) patients. Therefore, 62 patients with the overlap of GBD and IBS, who had abdominal pain, constipation and meteorism, were selected for further study. During the study, all patients kept a diary in which the frequency and nature of bowel movements, the severity of abdominal pain, and the degree of meteorism were recorded. All patients before and after treatment underwent an ultrasound examination of the abdominal cavity, which included the study of the contractile function of the gallbladder, the emptying coefficient of the gallbladder, the thickness and density of its wall, and the density of bile. Changes in the main bacterial enterotypes were analyzed by qRT‑PCR using primers targeting 16S rRNA. We studied Bacteroidetes, Firmicutes, Actinobacteria, as well as the content of butyrate‑producing bacteria (Faecalibacterium prausnitzii and Akkermansia muciniphila) and methanogens (Methanobrevibacter smithii and Methanosphaera stadmanae). Results. Before treatment, all patients had abdominal pain of moderate intensity (6.9±0.7 points), mostly without clear localization, constipation, with a frequency of defecation (1.4±0.5) times a week, and meteorism. Before treatment, patients with an overlap of GBD and IBS had changes in the contractile function of the gallbladder with a decrease in the emptying ratio, a thickening of the gallbladder wall and an increase in its density and bile density, as well as a disturbance of the intestinal microbiome (an increase in the number of Firmicutes, Actinobacteria and methanogenic archaea and a decrease in Bacteroidetes and butyrate‑producing bacteria). Conclusions. The use of Ursis® medication in the complex therapy of patients with a GBD and IBS overlap is effective and safe. The aplication of Ursis® led to a more pronounced positive clinical dynamics (a decrease in the intensity of abdominal pain, normalization of the frequency of bowel movements, a decrease in meteorism and an improvement in general well‑being) than in the patients of the comparison group. After treatment with Ursis® the coefficient of emptying of the gallbladder increased, the thickness and density of its wall decreased. The use of the drug Ursis® in the complex therapy of patients with the overlap of GBD and IBS contributed to the improvement of intestinal flora: an increase in the number of Bacteroidetes and butyrate‑producing bacteria (Faecalibacterium prausnitzii and Akkermansia muciniphila), and a decrease in the content of methanogens (Methanobrevibacter smithii and Methanosphaera stadmanae).

Effect and Mechanism of Apple Polyphenols in Regulating Intestinal Flora and Inhibiting the TLR4/NF-κB/TGF-β Signaling Pathway to Alleviate Alcoholic Liver Fibrosis

Effect and Mechanism of Apple Polyphenols in Regulating Intestinal Flora and Inhibiting the TLR4/NF-κB/TGF-β Signaling Pathway to Alleviate Alcoholic Liver Fibrosis

The key to intestinal health: a review and perspective on food additives.

In this review, we explore the effects of food additives on intestinal health. Food additives, such as preservatives, antioxidants and colorants, are widely used to improve food quality and extend shelf life. However, their effects on intestinal microecology May pose health risks. Starting from the basic functions of food additives and the importance of intestinal microecology, we analyze in detail how additives affect the diversity of intestinal flora, oxidative stress and immune responses. Additionally, we examine the association between food additives and intestinal disorders, including inflammatory bowel disease and irritable bowel syndrome, and how the timing, dosage, and individual differences affect the body's response to additives. We also assess the safety and regulatory policies of food additives and explore the potential of natural additives. Finally, we propose future research directions, emphasizing the refinement of risk assessment methods and the creation of safer, innovative additives.

Rosa roxburghii fermented juice mitigates LPS-induced acute lung injury by modulation of intestinal flora and metabolites.

Acute lung injury (ALI) is a severe pulmonary condition with high mortality and morbidity, lacking effective pharmacotherapeutic options. Rosa roxburghii Tratt, a unique fruit from southwestern China, is valued for its rich nutritional content and functional properties. Fermentation is known to enhance the nutritional value, flavor, and shelf life of foods. In this study, we investigated the effects of fermented Rosa roxburghii juice (RRFJ) on gut microbiota, metabolites, and the levels of short-chain fatty acids in the intestines, as well as its impact on lung tissue and intestine tissue injury, inflammation, and oxidative stress in murine models. The results showed that RRFJ modulated gut microbiota and metabolites, increased short-chain fatty acid levels, and consequently reduced lung tissue injury, inflammation, and oxidative stress in mice with ALI. These findings suggest that RRFJ has the potential to serve as a functional dietary adjunct in the management of acute lung injury, providing a scientific basis for its therapeutic role.

Metagenomic and Metabolomic Analyses Reveal the Role of Gut Microbiome-Associated Metabolites in the Muscle Elasticity of the Large Yellow Croaker (Larimichthys crocea).

The large yellow croaker (LYC, Larimichthys crocea) is highly regarded for its delicious taste and unique flavor. The gut microbiota has the ability to affect the host muscle performance and elasticity by regulating nutrient metabolism. The purpose of this study is to establish the relationship between muscle quality and intestinal flora in order to provide reference for the improvement of the muscle elasticity of LYC. In this study, the intestinal contents of high muscle elasticity males (IEHM), females (IEHF), and low muscle elasticity males (IELM) and females (IELF) were collected and subjected to metagenomic and metabolomic analyses. Metagenomic sequencing results showed that the intestinal flora structures of LYCs with different muscle elasticities were significantly different. The abundance of Streptophyta in the IELM (24.63%) and IELF (29.68%) groups was significantly higher than that in the IEHM and IEHF groups. The abundance of Vibrio scophthalmi (66.66%) in the IEHF group was the highest. Based on metabolomic analysis by liquid chromatograph-mass spectrometry, 107 differentially abundant metabolites were identified between the IEHM and IELM groups, and 100 differentially abundant metabolites were identified between the IEHF and IELF groups. Based on these metabolites, a large number of enriched metabolic pathways related to muscle elasticity were identified. Significant differences in the intestinal metabolism between groups with different muscle elasticities were identified. Moreover, the model of the relationship between the intestinal flora and metabolites was constructed, and the molecular mechanism of intestinal flora regulation of the nutrient metabolism was further revealed. The results help to understand the molecular mechanism of different muscle elasticities of LYC and provide an important reference for the study of the mechanism of the effects of LYC intestinal symbiotic bacteria on muscle development, and the development and application of probiotics in LYC.

Fibroblast growth factor 21 improves insulin sensitivity by modulating the bile acid-gut microbiota axis in type Ⅱ diabetic mice

BackgroundFibroblast growth factor 21 (FGF21) is an important regulator of glycolipid metabolism. However, whether the gut microbiota is related to the anti-diabetic and obesity effects of FGF21 remains unclear. MethodsOur research used KO/KO db/db male mice and streptozotocin (STZ)-induced to simulate the construction of two type II diabetic mellitus (T2DM) models, and detected impaired glucose tolerance in the model by using the ipGTT and ITT assays, and collected feces from the model mice for sequencing of the intestinal flora and the content of short-chain fatty acids. H＆E staining was used to detect changes in intestinal tissue, the serum levels of LPS and GLP-1 were detected by ELISA. ResultsIn this study, we found that FGF21 significantly improved insulin sensitivity, attenuated intestinal lesions, and decreased serum lipopolysaccharide (LPS) concentrations in T2DM mice. Moreover, FGF21 reshaped the gut microbiota and altered their metabolic pathways in T2DM mice, promoting the production of short-chain fatty acids (SCFAs) and the secretion of glucagon-like peptide 1 (GLP-1). Fecal transplantation experiments further confirmed that feces from FGF21-treated diabetic mice demonstrated similar effects as FGF21 in terms of anti-diabetic activity and regulation of gut microbiota dysbiosis. Additionally, the antibiotic depletion of gut microbiota abolished the beneficial effects of FGF21, including increased GLP-1 secretion and fecal SCFA concentration. Additionally, the FGF21 effects of ameliorating intestinal damage and suppressing plasma LPS secretion were suppressed. All these findings suggest that FGF21 prevents intestinal lesions by modifying the gut microbiota composition. Furthermore, FGF21 affected bile acid synthesis by inhibiting CYP7A1, the key enzyme of bile acid synthesis. ConclussionTherefore, FGF21 enriched beneficial bacteria by preventing bile acid synthesis and stimulating the secretion of the intestinal hormone GLP-1 via the increased production of gut microbiota metabolites, thereby exerting its anti-diabetic effects.

&lt;i&gt;KLEBSIELLA PNEUMONIAE&lt;/i&gt; – CAUSATIVE AGENT OF ENTEROCOLITIS.

Gastrointestinal diseases have one of the highest incidence rates worldwide. Klebsiella spp., which is a part of the large family Enterobacterales, isolated from fecal samples is considered as a part of the normal intestinal flora, even when it presents as a monoculture. The transmission of virulent plasmids from E. coli strains to Klebsiella spp., raises the question whether those bacteria can be an etiological factor for severe diarrhoea. By using PCR methods, the lth gene which is coding heat-labile enterotoxin (LT) was presented in the plasmids of Klebsiella spp. strains, and its expression was assessed.by measuring the cytopathic effect induced by the LT toxin.

The vaginal microbiome of transgender men receiving gender-affirming hormonal therapy in comparison to that of cisgender women

The vaginal microbiome of trans men and menopausal women is suspected to be similar due to a lack of estrogen leading to the absence of lactobacilli. However, data are scarce. We performed an analysis of the vaginal microbiome of trans men (n = 25) in comparison to that of menopausal (n = 25) and premenopausal women (n = 25). The vaginal microbiome of trans men and menopausal women showed a higher alpha diversity than that of premenopausal women. Various beta diversity indices (e.g., Bray‒Curtis (Un-)Weigthed Unifrac), showed significant differences in community composition between trans men and premenopausal (p < 0.001) and menopausal women (p < 0.001). The vaginal microbiome of trans men is characterized by a loss of Lactobacillus and an increase in bacteria associated with the intestinal flora (e.g., Campylobacter, Anaerococcus, Dialister, Prevotella). The abundance of Dialister and Prevotella decreased with the length of hormonal therapy in trans men. The Nugent score, Pap smear and HPV status did not differ between the study groups. The vaginal microbiome of trans men differs from that of premenopausal women but shows similarities to that of menopausal women. The duration of hormonal therapy in trans men may have important impacts on the vaginal microbiome and thus possibly on the risk for STIs.

Water-soluble garlic polysaccharide (WSGP) improves ulcerative colitis by modulating the intestinal barrier and intestinal flora metabolites

WSGP has demonstrated significant potential for various bioactive effects. However, limited research has explored their anti-ulcerative colitis (UC) effects and mechanism on the colonic system and gut microbial metabolites. We evaluated the ameliorative effects of WSGP on the UC mice model. Using H&E to assess histological injury of colon morphology, AB-PAS staining to detect mucin secretion from goblet cells and the mucous layer, IF to evaluate the expression of intercellular tight junction proteins, ELISA to measure inflammatory factors, WB analysis to measure protein expression of inflammatory signaling pathways, RT-qPCR to quantify gene transcription of inflammatory factors, and LC-MS to analyze metabolites in mouse cecum contents. WSGP supplementation increased food intake, body weight, and colon length while reducing disease activity and histological scores in colitis-afflicted mice. WSGP mitigated colonic tissue damage and restored intestinal barrier integrity by suppressing NF-κB/STAT3 signaling, thereby decreasing gene transcription, protein expression of proinflammatory factors, and nitric oxide production. Additionally, WSGP improved UC by altering the variety of intestinal microbial metabolites. This study demonstrates that WSGP supplementation attenuates UC mice by suppressing the NF-κB/STAT3 signaling pathway, enhancing mucosal barrier function, reducing pro-inflammatory cytokines, and modulating gut microbial metabolites.

Cyanidin‐3‐O‐glucoside magic: Unveiling the power to inhibit cholesterol absorption via the intestinal farnesoid X receptor–bile acids pathway with Lactobacillus Marvel

AbstractCyanidin‐3‐O‐glucoside (C3G), an abundant and widely utilized anthocyanin monomer, has been shown to significantly inhibit cholesterol absorption. Building on our previous research demonstrating the role of Lactobacillus as a specific intestinal microflora associated with C3G‐mediated cholesterol absorption inhibition, the present study aimed to evaluate the inhibitory effects of C3G on high‐fat diet–induced cholesterol absorption. Results indicate that C3G significantly reduced total cholesterol and triglyceride levels while suppressing red grease formation in Caco‐2 cells. In vivo, C3G ameliorated blood lipid levels and mitigated small intestinal damage, as evidenced by restored villus length and basal thickness. Additionally, C3G upregulated intestinal farnesoid X receptor (FXR) mRNA expression and inhibited the expression of key cholesterol absorption proteins, Niemann‐Pick C1‐Like 1 and acetyl‐CoA acetyltransferase 2. Furthermore, C3G increased short‐chain fatty acid content and activated ileal bile acid‐binding protein expression. C3G also inhibited intestinal bile acid (BA) reabsorption, promoted fecal BA excretion, and obstructed cholesterol emulsification. Moreover, C3G modulated gut microbiota abundance and diversity, increasing the abundance of Akkermansia, Bifidobacterium, Coprococcus, Ruminococcus, and Butyricicoccus. In conclusion, our findings suggest that C3G inhibits cholesterol absorption by reshaping intestinal flora composition and regulating the FXR‐BAs axis. This study provides a theoretical foundation for the use of C3G as a raw material for inhibiting cholesterol absorption.