Gut microbiota Turicibacter strains differentially modify bile acids and host lipids

Guizhi Shaoyao Zhimu Decoction ameliorates gouty arthritis in rats via altering gut microbiota and improving metabolic profile

BACKGROUND

The incidence of gouty arthritis (GA) has gradually increased, and modern drug therapies have obvious side effects. Guizhi Shaoyao Zhimu Decoction (GSZD), a classic prescription in Traditional Chinese Medicine for treating various osteoarthritis, has shown significant advantages in curing GA.

PURPOSE

To verify the therapeutic effect of GSZD on GA and investigate its potential pharmacological mechanism via integrated analysis of the gut microbiota and serum metabolites for the first time.

METHODS

The chemical composition of GSZD was determined using UPLC-MS. The GA rat model was established by the induction of a high-purine diet combined with local injection. We examined the effects and mechanisms of GSZD after 21 d using enzyme-linked immunosorbent assays, 16S rRNA, and non-targeted metabolomics. Finally, correlation analysis and validation experiment were performed to explore the association among the gut microbiota, serum metabolites, and GA-related clinical indices.

RESULTS

In total, 19 compounds were identified as GSZD. High-purine feedstuff with local injection-induced arthroceles were significantly attenuated after GSZD treatment. GSZD improved bone erosion and reduced the serum levels of inflammatory factors (lipopolysaccharide, tumor cell necrosis factor-α, and interleukin) and key indicators of GA (uric acid). 16S rRNA analysis indicated that GSZD-treated GA rats exhibited differences in the composition of the gut microbiota. The abundance of flora involved in uric acid transport, including Lactobacillus, Ruminococcaceae, and Turicibacter, was elevated to various degrees, whereas the abundance of bacteria involved in inflammatory responses, such as Blautia, was markedly reduced after treatment. Moreover, serum metabolite profiles revealed 27 different metabolites associated with the amelioration of GA, which primarily included fatty acids, glycerophospholipids, purine metabolism, amino acids, and bile acids, as well as primary metabolic pathways, such as glycerophospholipid metabolism and alanine. Finally, correlation analysis of the heat maps and validation experiment demonstrated a close relationship among inflammatory cytokines, gut microbial phylotypes, and metabolic parameters.

CONCLUSION

This study demonstrated that GSZD could modulate the gut microbiota and serum metabolic homeostasis to treat GA. In addition, the application of gut microbiota and serum metabolomics correlation analyses sheds light on the mechanism of Traditional Chinese Medicine compounds in the treatment of bone diseases.

Anti-obesogenic effect of lupin-derived protein hydrolysate through modulation of adiposopathy, insulin resistance and gut dysbiosis in a diet-induced obese mouse

The prevalence of obesity is increasingly widespread, resembling a global epidemic. Lifestyle changes, such as consumption of high-energy-dense diets and physical inactivity, are major contributors to obesity. Common features of this metabolic pathology involve an imbalance in lipid and glucose homeostasis including dyslipidemia, insulin resistance and adipose tissue dysfunction. Moreover, the importance of the gut microbiota in the development and susceptibility to obesity has recently been highlighted. In recent years, new strategies based on the use of functional foods, in particular bioactive peptides, have been proposed to counteract obesity outcomes. In this context, the present study examines the effects of a lupin protein hydrolysate (LPH) on obesity, dyslipidemia and gut dysbiosis in mice fed a high-fat diet (HFD). After 12 weeks of LPH treatment, mice gained less weight and showed decreased adipose dysfunction compared to the HFD-fed group. HFD-induced dyslipidemia (increased triglycerides, cholesterol and LDL concentration) and insulin resistance were both counteracted by LPH consumption. Discriminant analysis differentially distributed LPH-treated mice compared to non-treated mice. HFD reduced gut ecological parameters, promoted the blooming of deleterious taxa and reduced the abundance of commensal members. Some of these changes were corrected in the LPH group. Finally, correlation analysis suggested that changes in this microbial population could be responsible for the improvement in obesity outcomes. In conclusion, this is the first study to show the effect of LPH on improving weight gain, adiposopathy and gut dysbiosis in the context of diet-induced obesity, pointing to the therapeutic potential of bioactive peptides in metabolic diseases.

Exploratory application of a cannulation model in recently weaned pigs to monitor longitudinal changes in the enteric microbiome across varied porcine reproductive and respiratory syndrome virus (PRRSV) infection statuses

Introduction

The enteric microbiome and its possible modulation to improve feed conversion or vaccine efficacy is gaining more attention in pigs. Weaning pigs from their dam, along with many routine procedures, is stressful. A better understanding of the impact of this process on the microbiome may be important for improving pig production. The objective of this study was to develop a weaner pig cannulation model, thus allowing ileum content collection from the same pig over time for 16S rRNA sequencing under different porcine reproductive and respiratory syndrome virus (PRRSV) infection statuses.

Methods

A total of 15 3-week-old pigs underwent abdominal surgery and were fitted with an ileum cannula, with ileum contents collected over time. In this pilot study, treatment groups included a NEG-CONTROL group (no vaccination, no PRRSV challenge), a POS-CONTROL group (no vaccination, challenged with PRRSV), a VAC-PRRSV group (vaccinated, challenged with PRRSV), a VAC-PRO-PRRSV group (vaccinated, supplemented with a probiotic, challenged with PRRSV), and a VAC-ANTI-PRRSV group (vaccinated, administered an antibiotic, challenged with PRRSV). We assessed the microbiome over time and measured anti-PRRSV serum antibodies, PRRSV load in serum and nasal samples, and the severity of lung lesions.

Results

Vaccination was protective against PRRSV challenge, irrespective of other treatments. All vaccinated pigs mounted an immune response to PRRSV within 1 week after vaccination. A discernible impact of treatment on the diversity, structure, and taxonomic abundance of the enteric microbiome among the groups was not observed. Instead, significant influences on the ileum microbiome were observed in relation to time and treatment.

Discussion

The cannulation model described in this pilot study has the potential to be useful in studying the impact of weaning, vaccination, disease challenge, and antimicrobial administration on the enteric microbiome and its impact on pig health and production. Remarkably, despite the cannulation procedures, all vaccinated pigs exhibited robust immune responses and remained protected against PRRSV challenge, as evidenced by the development of anti-PRRSV serum antibodies and viral shedding data.

Endoscopic duodenal mucosa ablation techniques for diabetes and nonalcoholic fatty liver disease: A systematic review

BACKGROUND

Type 2 diabetes mellitus (T2DM) is increasing at an alarming rate, and only 50% of patients with T2DM achieve or maintain adequate glycemic control with pharmacological therapies. Metabolic surgery demonstrated superior efficacy compared to medical therapy but is unfeasible for most patients with T2DM. Duodenal mucosal resurfacing (DMR) by hydrothermal mucosal ablation, recellularization via electroporation therapy (ReCET), and photodynamic therapy are novel endoscopic procedures that use thermal, electrical, and photochemical energy, respectively, to ablate and reset dysfunctional duodenal mucosa. We assessed the data on the effects of these techniques on glycemic control and nonalcoholic fatty liver disease (NAFLD).

METHODS

We systematically searched independently and in duplicate English and non-English language publications through January 31st, 2024. Outcomes assessed were an improvement in different metabolic health parameters and the safety of duodenal mucosal ablation (DMA) procedures. Outcomes were presented descriptively.

FINDINGS

We selected 12 reports reporting results from 3 randomized and 6 uncontrolled trials (seven evaluating DMR, two evaluating ReCET, all with a low risk of bias) for a total of 317 patients enrolled. DMA reduced HbA1c, fasting plasma glucose, and liver fat. When combined with newer antidiabetic drugs, it allowed insulin discontinuation in up to 86% patients. No major safety signal emerged.

CONCLUSIONS

All DMA techniques improve glucose homeostasis; DMR and ReCET appear to be safe in patients with T2DM. If confirmed by future randomized trials and by trials with histological endpoints in NAFLD, then DMA appears to be a promising alternative or complement option to medications for T2DM and NAFLD treatment.

FUNDING

This study received no funding.

Differences in the Ability of Lactic Acid Bacteria To Prevent Acute Alcohol-Induced Liver Injury via the Gut Microbiota-Bile Acid-Liver Axis

Probiotics can regulate gut microbiota and protect against acute alcohol-induced liver injury through the gut-liver axis. However, efficacy is strain-dependent, and their mechanism remains unclear. This study investigated the effect of lactic acid bacteria (LAB), including Lacticaseibacillus paracasei E10 (E10), Lactiplantibacillus plantarum M (M), Lacticaseibacillus rhamnosus LGG (LGG), Lacticaseibacillus paracasei JN-1 (JN-1), and Lacticaseibacillus paracasei JN-8 (JN-8), on the prevention of acute alcoholic liver injury in mice. We found that LAB pretreatment reduced serum alanine transaminase (ALT) and aspartate transaminase (AST) and reduced hepatic total cholesterol (TC) and triglyceride (TG). JN-8 pretreatment exhibited superior efficacy in improving hepatic antioxidation. LGG and JN-8 pretreatment significantly attenuated hepatic and colonic inflammation by decreasing the expression of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) and increasing the expression of interleukin 10 (IL-10). JN-1 and JN-8 pretreatments have better preventive effects than other LAB pretreatment on intestinal barrier dysfunction. In addition, the LAB pretreatment improved gut microbial dysbiosis and bile acid (BA) metabolic abnormality. All of the strains were confirmed to have bile salt deconjugation capacities in vitro, where M and JN-8 displayed higher activities. This study provides new insights into the prevention and mechanism of LAB strains in preventing acute alcoholic liver injury.

Draft Turicibacter sp. genome isolated from a spore-forming community in mice

Turicibacter is a common mammalian gut commensal; however, very few genomes have been sequenced, and little is understood regarding its importance for host health. Here, we add a complete Turicibacter sp. genome isolated from a spore-forming community in mice.

The changing metabolic landscape of bile acids - keys to metabolism and immune regulation

Bile acids regulate nutrient absorption and mitochondrial function, they establish and maintain gut microbial community composition and mediate inflammation, and they serve as signalling molecules that regulate appetite and energy homeostasis. The observation that there are hundreds of bile acids, especially many amidated bile acids, necessitates a revision of many of the classical descriptions of bile acids and bile acid enzyme functions. For example, bile salt hydrolases also have transferase activity. There are now hundreds of known modifications to bile acids and thousands of bile acid-associated genes, especially when including the microbiome, distributed throughout the human body (for example, there are >2,400 bile salt hydrolases alone). The fact that so much of our genetic and small-molecule repertoire, in both amount and diversity, is dedicated to bile acid function highlights the centrality of bile acids as key regulators of metabolism and immune homeostasis, which is, in large part, communicated via the gut microbiome.

Role of Nonalcoholic Fatty Liver Disease in Periodontitis: A Bidirectional Relationship

Nonalcoholic fatty liver disease (NAFLD) and periodontitis share common risk factors such as obesity, insulin resistance (IR), and dyslipidemia, which contribute to systemic inflammation. It has been suggested that a bidirectional relationship exists between NAFLD and periodontitis, indicating that one condition may exacerbate the other. NAFLD is characterized by excessive fat deposition in the liver and is associated with low-grade chronic inflammation. There are several risk factors for the development of NAFLD, including gender, geriatric community, race, ethnicity, poor sleep quality and sleep deprivation, physical activity, nutritional status, dysbiosis gut microbiota, increased oxidative stress, overweight, obesity, higher body mass index (BMI), IR, type 2 diabetes mellitus (T2DM), metabolic syndrome (MetS), dyslipidemia (hypercholesterolemia), and sarcopenia (decreased skeletal muscle mass). This systemic inflammation can contribute to the progression of periodontitis by impairing immune responses and exacerbating the inflammatory processes in the periodontal tissues. Furthermore, individuals with NAFLD often exhibit altered lipid metabolism, which may affect oral microbiota composition, leading to dysbiosis and increased susceptibility to periodontal disease. Conversely, periodontitis has been linked to the progression of NAFLD through mechanisms involving systemic inflammation and oxidative stress. Chronic periodontal inflammation can release pro-inflammatory cytokines and bacterial toxins into the bloodstream, contributing to liver inflammation and exacerbating hepatic steatosis. Moreover, periodontitis-induced oxidative stress may promote hepatic lipid accumulation and IR, further aggravating NAFLD. The interplay between NAFLD and periodontitis underscores the importance of comprehensive management strategies targeting both conditions. Lifestyle modifications such as regular exercise, a healthy diet, and proper oral hygiene practices are crucial for preventing and managing these interconnected diseases. Additionally, interdisciplinary collaboration between hepatologists and periodontists is essential for optimizing patient care and improving outcomes in individuals with NAFLD and periodontitis.

Gut Microbial Adaptation to Varied Altitudes and Temperatures in Tibetan Plateau Yaks

The yak (Bos grunniens) exhibits exceptional regional adaptability, enabling it to thrive in the distinctive ecological niches of the Qinghai-Tibet Plateau. Its survival relies on the intricate balance of its intestinal microbiome, essential for adapting to harsh environmental conditions. Despite the documented significance of bacteria and fungi in maintaining intestinal homeostasis and supporting immune functions, there is still a substantial gap in understanding how the composition and functionality of yak gut microbiota vary along altitude-temperature gradients. This study aims to fill this gap by employing 16S rRNA and ITS amplicon sequencing techniques to analyze and compare the intestinal microbiome of yaks residing at different elevations and exposed to varying temperatures. The findings demonstrate subtle variations in the diversity of intestinal bacteria and fungi, accompanied by significant changes in taxonomic composition across various altitudes and temperature gradients. Notably, Firmicutes, Actinobacteriota, and Bacteroidota emerged as the dominant phyla across all groups, with Actinobacteriota exhibiting the highest proportion (35.77%) in the LZF group. Functional prediction analysis revealed significant associations between the LZF group and metabolic pathways related to amino acid metabolism and biosynthesis. This suggests a potential role for actinomycetes in enhancing nutrient absorption and metabolism in yaks. Furthermore, our findings suggest that the microbiota of yaks may enhance energy metabolism and catabolism by modulating the Firmicutes-to-Bacteroidota ratio, potentially mitigating the effects of temperature variations. Variations in gut bacterial and fungal communities among three distinct groups were analyzed using metagenomic techniques. Our findings indicate that microbial genera exhibiting significant increases in yaks at lower altitudes are largely beneficial. To sum up, our research investigated the changes in gut bacterial and fungal populations of yaks residing across diverse altitude and temperature ranges. Moreover, these results enhance comprehension of gut microbial makeup and variability, offering perspectives on the environmental resilience of dry lot feeding yaks from a microbial angle.

Multiomics Analysis Reveals Leucine Deprivation Promotes Bile Acid Synthesis by Upregulating Hepatic CYP7A1 and Intestinal Turicibacter sanguinis in Mice

BACKGROUND

Leucine, a branched-chain amino acid, participates in the regulation of lipid metabolism and the composition of the intestinal microbiota. However, the related mechanism remains unclear.

OBJECTIVES

Here, we aimed to reveal the potential mechanisms by which hepatic CYP7A1 (a rate-limiting enzyme for bile acid [BA] synthesis) and gut microbiota coregulate BA synthesis under leucine deprivation.

METHODS

To this end, 8-wk-old C57BL/6J mice were fed with either regular diets or leucine-free diets for 1 wk. Then, we investigated whether secondary BAs were synthesized by Turicibacter sanguinis in 7-wk-old C57BL/6J germ-free mice gavaged with T. sanguinis for 2 wk by determining BA concentrations in the plasma, liver, and cecum contents using liquid chromatography-tandem mass spectrometry.

RESULTS

The results showed that leucine deprivation resulted in a significant increase in total BA concentration in the plasma and an increase in the liver, but no difference in total BA was observed in the cecum contents before and after leucine deprivation. Furthermore, leucine deprivation significantly altered BA profiles such as taurocholic acid and ω-muricholic acid in the plasma, liver, and cecum contents. CYP7A1 expression was significantly upregulated in the liver under leucine deprivation. Leucine deprivation also regulated the composition of the gut microbiota; specifically, it significantly upregulated the relative abundance of T. sanguinis, thus enhancing the conversion of primary BAs into secondary BAs by intestinal T. sanguinis in mice.

CONCLUSIONS

Overall, leucine deprivation regulated BA profiles in enterohepatic circulation by upregulating hepatic CYP7A1 expression and increasing intestinal T. sanguinis abundance. Our findings reveal the contribution of gut microbiota to BA metabolism under dietary leucine deprivation.

Association of Methyl Donor Nutrients' Dietary Intake and Cognitive Impairment in the Elderly Based on the Intestinal Microbiome

Globally, cognitive impairment (CI) is the leading cause of disability and dependency among the elderly, presenting a significant public health concern. However, there is currently a deficiency in pharmacological interventions that can effectively cure or significantly reverse the progression of cognitive impairment. Methyl donor nutrients (MDNs), including folic acid, choline, and vitamin B12, have been identified as potential enhancers of cognitive function. Nevertheless, there remains a dearth of comprehensive research investigating the connection between the dietary intake of MDNs and CI. In our study, we comprehensively assessed the relationship between MDNs' dietary intake and CI in older adults, utilizing 16S rRNA gene sequencing to investigate the potential underlying mechanisms. The results showed an obvious difference in the methyl-donor nutritional quality index (MNQI) between the dementia (D) group and the dementia-free (DF) group. Specifically, there was a lower MNQI in the D group than that in the DF group. For the gut microbiome, the beta diversity of gut flora exhibited higher levels in the high methyl-donor nutritional quality (HQ) group as opposed to the low methyl-donor nutritional quality (LQ) group, and lower levels in the D group in comparison to the DF group. Subsequently, we performed a correlation analysis to examine the relationship between the relative abundance of microbiota, the intake of MDNs, and Montreal Cognitive Assessment (MoCA) scores, ultimately identifying ten genera with potential regulatory functions. Additionally, KEGG pathway analyses suggested that the one-carbon metabolism, chronic inflammation, and DNA synthesis potentially serve as pathways through which MDNs may be promising for influencing cognitive function. These results implied that MDNs might have the potential to enhance cognitive function through the regulation of microbiota homeostasis. This study offers dietary recommendations for the prevention and management of CI in the elderly.

Gut microbiota and immune profiling of microbiota-humanised versus wildtype mouse models of hepatointestinal schistosomiasis

Mounting evidence of the occurrence of direct and indirect interactions between the human blood fluke, Schistosoma mansoni, and the gut microbiota of rodent models raises questions on the potential role(s) of the latter in the pathophysiology of hepatointestinal schistosomiasis. However, substantial differences in both the composition and function between the gut microbiota of laboratory rodents and that of humans hinders an in-depth understanding of the significance of such interactions for human schistosomiasis. Taking advantage of the availability of a human microbiota-associated mouse model (HMA), we have previously highlighted differences in infection-associated changes in gut microbiota composition between HMA and wildtype (WT) mice. To further explore the dynamics of schistosome-microbiota relationships in HMA mice, in this study we (i) characterize qualitative and quantitative changes in gut microbiota composition of a distinct line of HMA mice (D2 HMA) infected with S. mansoni prior to and following the onset of parasite egg production; (ii) profile local and systemic immune responses against the parasite in HMA as well as WT mice and (iii) assess levels of faecal inflammatory markers and occult blood as indirect measures of gut tissue damage. We show that patent S. mansoni infection is associated with reduced bacterial alpha diversity in the gut of D2 HMA mice, alongside expansion of hydrogen sulphide-producing bacteria. Similar systemic humoral responses against S. mansoni in WT and D2 HMA mice, as well as levels of faecal lipocalin and markers of alternatively activated macrophages, suggest that these are independent of baseline gut microbiota composition. Qualitative comparative analyses between faecal microbial profiles of S. mansoni-infected WT and distinct lines of HMA mice reveal that, while infection-induced alterations of the gut microbiota composition are highly dependent on the baseline flora, bile acid composition and metabolism may represent key elements of schistosome-microbiota interactions through the gut-liver axis.

Citrus depressa peel extract acts as a prebiotic to reduce lipid accumulation and modulate gut microbiota in obese mice

Citrus peels contain abundant polyphenols, particularly flavonoids, and have been shown to exert lipid accumulation decreasing ability. In this study, Citrus depressa peel applied to oven drying and extracted with ethanol extract as CDEE to analyze its flavonoids compositions and investigated its effects on a high-fat diet (HFD)-induced obese mice model. CDEE contained several flavonoids such as hesperidin, sinesentin, nobiletin, tangeretin, 5-demethylnobiletin, and 5-demethyltangeretin. The mice fed an HFD, and administration of 2% CDEE to could decrease weight gain, abdominal fat weight, inguinal fat weight, and the adipocyte size, and CDEE also reduced serum total cholesterol (TCHO), triacylglycerol (TG) compared with mice fed only on HFD. CDEE hindered lipid accumulation through a decreased fatty acid synthase (FAS) protein expression via upregulation of the protein expression of AMP-activated protein kinase α (AMPKα). Moreover, CDEE modulated gut microbiota that altered by HFD through an increased abundance of Lactobacillus reuteri compared with the HFD group. The results demonstrated that CDEE helps decrease lipid accumulation through the AMPK pathway, which also indicates a prebiotic-like effect on gut microbiota.

Multiomics Reveals the Microbiota and Metabolites Associated with Sperm Quality in Rongchang Boars

In this study, we investigated the correlation between the composition and function of the gut microbiota and the semen quality of Rongchang boars. Significant differences in gut microbial composition between boars with high (group H) and low (group L) semen utilization rates were identified through 16S rRNA gene sequencing, with 18 differential microbes observed at the genus level. Boars with lower semen utilization rates exhibited a higher relative abundance of Treponema, suggesting its potential role in reducing semen quality. Conversely, boars with higher semen utilization rates showed increased relative abundances of Terrisporobacter, Turicibacter, Stenotrophomonas, Clostridium sensu stricto 3, and Bifidobacterium, with Stenotrophomonas and Clostridium sensu stricto 3 showing a significant positive correlation with semen utilization rates. The metabolomic analyses revealed higher levels of gluconolactone, D-ribose, and 4-pyridoxic acid in the H group, with 4 pyridoxic acid and D-ribose showing a significant positive correlation with Terrisporobacter and Clostridium sensu stricto 3, respectively. In contrast, the L group showed elevated levels of D-erythrose-4-phosphate, which correlated negatively with Bifidobacterium and Clostridium sensu stricto 3. These differential metabolites were enriched in the pentose phosphate pathway, vitamin B6 metabolism, and antifolate resistance, potentially influencing semen quality. These findings provide new insights into the complex interplay between the gut microbiota and boar reproductive health and may offer important information for the discovery of disease biomarkers and reproductive health management.

Influence of Varied Environment Conditions on the Gut Microbiota of Yaks

Despite the crucial role of the gut microbiota in different physiological processes occurring in the animal body, reports regarding the gut microbiota of animals residing in different environmental conditions like high altitude and different climate settings are limited. The Qinghai-Tibetan Plateau is renowned for its extreme climatic conditions that provide an ideal environment for exploring the effects of high altitude and temperature on the microbiota of animals. Yaks have unique oxygen delivery systems and genes related to hypoxic response. Damxung, Nyêmo, and Linzhou counties in Tibet have variable altitudes and temperatures that offer distinct settings for studying yak adaptation to elevated terrains. The results of our study suggest that amplicon sequencing of V3-V4 and internal transcribed spacer 2 (ITS2) regions yielded 13,683 bacterial and 1912 fungal amplicon sequence variants (ASVs). Alpha and beta diversity indicated distinct microbial structures. Dominant bacterial phyla were Firmicutes, Bacteroidota, and Actinobacteriota. Genera UCG-005, Christensenellaceae_R-7_group, and Rikenellaceae_RC9_gut_group were dominant in confined yaks living in Damxung county (DXS) and yaks living in Linzhou county (LZS), whereas UCG-005 prevailed in confined yaks living in Nyêmo county (NMS). The linear discriminant analysis effect size (LEfSe) analysis highlighted genus-level differences. Meta-stat analysis revealed significant shifts in bacterial and fungal community composition in yaks at different high altitudes and temperatures. Bacterial taxonomic analysis revealed that two phyla and 32 genera differed significantly (p < 0.05). Fungal taxonomic analysis revealed that three phyla and four genera differed significantly (p < 0.05). Functional predictions indicated altered metabolic functions, especially in the digestive system of yaks living in NMS. This study reveals significant shifts in yak gut microbiota in response to varying environmental factors, such as altitude and temperature, shedding light on previously unexplored aspects of yak physiology in extreme environments.

Banxia Xiexin decoction modulates gut microbiota and gut microbiota metabolism to alleviate DSS-induced ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia Xiexin decoction (BXD) is a classic traditional Chinese medicine prescription for treating ulcerative colitis (UC). However, its potential mechanism of action is still unclear.

AIM OF THE STUDY

Reveal the correlation between the beneficial impacts of BXD on UC and the composition of the gut microbiota.

MATERIALS AND METHODS

The major constituents of BXD were identified using the HPLC-DAD technique. An experimental model of UC was induced in male C57BL/6 mice by administering dextran sodium sulfate (DSS). A total of 48 mice were divided into different groups, including control, model, high-dose BXD treatment, medium-dose BXD treatment, low-dose BXD treatment, and a group treated with 5-amino acid salicylic acid (5-ASA). Body weight changes and disease activity index (DAI) scores were documented; colon length, colon index, spleen index, and thymus index scores were determined; myeloperoxidase (MPO) and tumor necrosis factor-α (TNF-α) activities were assessed; and histological staining with hematoxylin-eosin and alcian blue/phosphate Schiff was performed. The immunofluorescence technique was employed to examine the presence of ZO-1 and occludin in the colon tissue. 16S rRNA sequencing was employed to assess the gut microbiota's diversity and metabolomics was utilized to examine alterations in metabolites within the gut microbiota. The impact of BXD on the gut microbiota was confirmed through fecal microbiota transplantation (FMT).

RESULTS

BXD exhibited a positive impact on UC mice, particularly in the high-dose BXD treatment group. The BXD group experienced weight recovery, decreased DAI scores, improved colon length, and restored of spleen and thymus index scores compared to the DSS group. Additionally, BXD alleviated colon damage and the inflammatory response while restoring intestinal barrier function. FMT in BXD-treated mice also showed therapeutic effects in UC mice. At the phylum level, the relative abundance of Desulfobacterota, Deferribacterota and Actinobacteriota increased; at the genus level, g__norank__f__Muribaculaceae, Dubosiella, Akkermansia, and Lactobacillus increased, whereas Faecalibaculum, Alloprevotella, Turicibacter, and g_Paraprevotella decreased. g__norank_f__Muribaculaceae was positively correlated with body weight and colon length and negatively with colon index scores, splenic index scores, and MPO levels; Alloprevotella was positively correlated with splenic index scores, histological scores, and TNF-α levels and negatively with thymus index scores and thymus index scores. Faecalibaculum was positively correlated with colon index scores and MPO levels. Metabolic investigations revealed 58 potential indicators, primarily associated with the metabolism of amino acids, purines, and lipids. Alloprevotella, g_Paraprevotella, and Bifidobacterium were strongly associated with metabolic pathways.

CONCLUSION

BXD showed beneficial therapeutic effects in UC mice. The mechanism may be by promoting the balance and variety of gut microbiota, as well as regulating the metabolism of amino acids, purines, and lipids.

Modulation of the rat intestinal microbiota in the course of Anisakis pegreffii infection

Background

Anisakis are globally distributed, marine parasitic nematodes that can cause human health problems, including symptoms such as vomiting, acute diarrhea, and allergic reactions. As parasitic nematodes that primarily affect the patient's digestive tract, intestinal helminths can interact directly with the host microbiota through physical contact, chemicals, or nutrient competition. It is widely accepted that the host microbiota plays a crucial role in the regulation of immunity.

Materials and methods

Nematodes collected from the abdominal cavity of marine fish were identified by molecular biology and live worms were artificially infected in rats. Infection was determined by indirect ELISA based on rat serum and worm extraction. Feces were collected for 16S rDNA-based analysis of microbiota diversity.

Results

Molecular biology identification based on ITS sequences identified the collected nematodes as A. pegreffii. The success of the artificial infection was determined by indirect ELISA based on serum and worm extraction from artificially infected rats. Microbiota diversity analysis showed that a total of 773 ASVs were generated, and PCoA showed that the infected group was differentiated from the control group. The control group contained five characterized genera (Prevotellaceae NK3B31 group, Turicibacter, Clostridium sensu stricto 1, Candidatus Stoquefichus, Lachnospira) and the infected group contained nine characterized genera (Rodentibacter, Christensenella, Dubosiella, Streptococcus, Anaeroplasma, Lactococcus, Papillibacter, Desulfovibrio, Roseburia). Based on the Wilcoxon test, four processes were found to be significant: bacterial secretion system, bacterial invasion of epithelial cells, bacterial chemotaxis, and ABC transporters.

Conclusion

This study is the first to analyze the diversity of the intestinal microbiota of rats infected with A. pegreffii and to determine the damage and regulation of metabolism and immunity caused by the infection in the rat gut. The findings provide a basis for further research on host-helminth-microbe correlationships.

Microbial Signatures in COVID-19: Distinguishing Mild and Severe Disease via Gut Microbiota

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has significantly impacted global healthcare, underscoring the importance of exploring the virus's effects on infected individuals beyond treatments and vaccines. Notably, recent findings suggest that SARS-CoV-2 can infect the gut, thereby altering the gut microbiota. This study aimed to analyze the gut microbiota composition differences between COVID-19 patients experiencing mild and severe symptoms. We conducted 16S rRNA metagenomic sequencing on fecal samples from 49 mild and 43 severe COVID-19 cases upon hospital admission. Our analysis identified a differential abundance of specific bacterial species associated with the severity of the disease. Severely affected patients showed an association with Enterococcus faecium, Akkermansia muciniphila, and others, while milder cases were linked to Faecalibacterium prausnitzii, Alistipes putredinis, Blautia faecis, and additional species. Furthermore, a network analysis using SPIEC-EASI indicated keystone taxa and highlighted structural differences in bacterial connectivity, with a notable disruption in the severe group. Our study highlights the diverse impacts of SARS-CoV-2 on the gut microbiome among both mild and severe COVID-19 patients, showcasing a spectrum of microbial responses to the virus. Importantly, these findings align, to some extent, with observations from other studies on COVID-19 gut microbiomes, despite variations in methodologies. The findings from this study, based on retrospective data, establish a foundation for future prospective research to confirm the role of the gut microbiome as a predictive biomarker for the severity of COVID-19.

Turicibacter faecis sp. nov., isolated from faeces of heart failure mouse model

Strain TC023T, a Gram-positive, long, rod-shaped, spore-forming anaerobe, was isolated from the faeces of a heart failure mouse model. The strain formed greyish-white coloured colonies with a convex elevation on brain-heart infusion medium supplemented with 0.1 % sodium taurocholate, incubated at 37 °C for 2 days. Taxonomic analysis based on the 16S rRNA gene sequence showed that TC023T belonged to the genus Turicibacter, and was closely related to Turicibacter bilis MMM721T (97.6 %) and Turicibacter sanguinis MOL361T (97.4 %). The whole genome of the strain has a G+C content of 37.3 mol%. The average nucleotide identity and genome-to-genome distance between TC023T and Turicibacter bilis MMM721T were 77.6 % and 24.3 %, respectively, and those with Turicibacter sanguinis MOL361T were 75.4 % and 24.3 %, respectively. These genotypic, phenotypic, and biochemical analyses indicated that the isolate represents a novel species in the genus Turicibacter, and the name Turicibacter faecis sp. nov. is proposed. The type strain is TC023T (RIMD 2002001T=TSD 372T).

Multi-trajectories of body mass index, waist circumference, gut microbiota, and incident dyslipidemia: a 27-year prospective study

Background

Evidence is insufficient to establish a longitudinal association between combined trajectories of body mass index (BMI) and waist circumference (WC) and dyslipidemia. Our study aimed to explore the association between multi-trajectories of BMI and WC and incident dyslipidemia and identify microbiota and metabolite signatures of these trajectories.

Methods

Stratified by sex, we used a group-based trajectory modeling approach to identify distinct multi-trajectories of BMI and WC among 10,678 participants from the China Health and Nutrition Survey over a 24-year period. For each sex, we examined the associations between these multi-trajectories (1991-2015) and the onset dyslipidemia (2018) using multivariable logistic regression adjusting for sociodemographic and lifestyles factors. We characterized the gut microbial composition and performed LASSO and logistic regression to identify gut microbial signatures associated with these multi-trajectories in males and females, respectively.

Results

We identified four multi-trajectories of BMI and WC among both males and females: Normal (Group 1), BMI&WC normal increasing (Group 2), BMI&WC overweight increasing (Group 3), and BMI&WC obesity increasing (Group 4). Among males, Group 2 (OR: 2.10, 95% CI: 1.28-3.46), Group 3 (OR: 2.69, 95% CI: 1.56-4.63) and Group 4 (OR: 3.56, 95% CI: 1.85-6.83) had higher odds of developing dyslipidemia. However, among females, only those in Group 2 (OR: 1.54, 95% CI: 1.03-2.30) were more likely to develop dyslipidemia. In males, compared with Group 1, we observed lower alpha-diversity within Groups 2,3, and 4, and significant beta-diversity differences within Groups 3 and 4 (p 0.001). We also identified 3, 8, and 4 characteristic bacterial genera in male Groups 2, 3 and 4, and 2 genera in female Group 2. A total of 23, 25 and 10 differential metabolites were significantly associated with the above genera, except for Group 2 in males.

Conclusions

The ascending combined trajectories of BMI and WC are associated with a higher risk of dyslipidemia, even with normal baseline levels, especially in males. Shared and unique gut microbial and metabolic signatures among these high-risk trajectories could enhance our understanding of the mechanisms connecting obesity to dyslipidemia.

Evaluating the therapeutic potential of moxibustion on polycystic ovary syndrome: a rat model study on gut microbiota and metabolite interaction

Polycystic ovary syndrome (PCOS) is a common systemic disorder related to endocrine disorders, affecting the fertility of women of childbearing age. It is associated with glucose and lipid metabolism disorders, altered gut microbiota, and insulin resistance. Modern treatments like pioglitazone, metformin, and spironolactone target specific symptoms of PCOS, while in Chinese medicine, moxibustion is a common treatment. This study explores moxibustion's impact on PCOS by establishing a dehydroepiandrosterone (DHEA)-induced PCOS rat model. Thirty-six specific pathogen-free female Sprague-Dawley rats were divided into four groups: a normal control group (CTRL), a PCOS model group (PCOS), a moxibustion treatment group (MBT), and a metformin treatment group (MET). The MBT rats received moxibustion, and the MET rats underwent metformin gavage for two weeks. We evaluated ovarian tissue changes, serum testosterone, fasting blood glucose (FBG), and fasting insulin levels. Additionally, we calculated the insulin sensitivity index (ISI) and the homeostasis model assessment of insulin resistance index (HOMA-IR). We used 16S rDNA sequencing for assessing the gut microbiota, 1H NMR spectroscopy for evaluating metabolic changes, and Spearman correlation analysis for investigating the associations between metabolites and gut microbiota composition. The results indicate that moxibustion therapy significantly ameliorated ovarian dysfunction and insulin resistance in DHEA-induced PCOS rats. We observed marked differences in the composition of gut microbiota and the spectrum of fecal metabolic products between CTRL and PCOS rats. Intriguingly, following moxibustion intervention, these differences were largely diminished, demonstrating the regulatory effect of moxibustion on gut microbiota. Specifically, moxibustion altered the gut microbiota by increasing the abundance of UCG-005 and Turicibacter, as well as decreasing the abundance of Desulfovibrio. Concurrently, we also noted that moxibustion promoted an increase in levels of short-chain fatty acids (including acetate, propionate, and butyrate) associated with the gut microbiota of PCOS rats, further emphasizing its positive impact on gut microbes. Additionally, moxibustion also exhibited effects in lowering FBG, testosterone, and fasting insulin levels, which are key biochemical indicators associated with PCOS and insulin resistance. Therefore, these findings suggest that moxibustion could alleviate DHEA-induced PCOS by regulating metabolic levels, restoring balance in gut microbiota, and modulating interactions between gut microbiota and host metabolites.

The modulatory role of gut microbiota on host behavior: exploring the interaction between the brain-gut axis and the neuroendocrine system

The brain-gut axis refers to the communication between the central nervous system and the gastrointestinal tract, with the gut microbiome playing a crucial role. While our understanding of the interaction between the gut microbiome and the host's physiology is still in its nascent stage, evidence suggests that the gut microbiota can indeed modulate host behavior. Understanding the specific mechanisms by which the gut microbiota community modulates the host's behavior remains the focus of present and future neuro-gastroenterology studies. This paper reviews several pieces of evidence from the literature on the impact of gut microbiota on host behavior across animal taxa. We explore the different pathways through which this modulation occurs, with the aim of deepening our understanding of the fascinating relationship between the gut microbiome and the central nervous system.

Sulfur dioxide-free wine with polyphenols promotes lipid metabolism via the Nrf2 pathway and gut microbiota modulation

Moderate wine consumption is often associated with preventing obesity, yet concerns arise due to the health risks linked to its constituent antioxidant, SO2. Recent focus has turned to polyphenols as a potential substitute for SO2. This investigation explores the impact and mechanisms of sulfur dioxide-free wine enriched with polyphenols on lipid regulation. Through a comprehensive analysis involving oxidative stress, lipid metabolism, and gut microorganisms in high-fat-diet mouse models, this study reveals that sulfur dioxide-free wine containing the polyphenol resveratrol exhibits a heightened ability to regulate lipids. It modulates oxidative stress by influencing NF-E2-related factor 2, a crucial factor, while enhancing lipid metabolism and fatty acid β-oxidation through key genes such as carnitine palmitoyltransferase I and peroxisome proliferator-activated receptor alpha. Furthermore, oral administration of sulfur dioxide-free wine supplemented with resveratrol demonstrates an increase in the relative abundance of beneficial intestinal microflora, such as Turicibacter, Allobaculum, Bacteroides, and Macellibacteroides, while decreasing the Firmicutes/Bacteroidetes ratio.

Gut microbiota composition is associated with the efficacy of Delta-24-RGDOX in malignant gliomas

Glioblastoma, the most common primary brain tumor, has a 6.8% survival rate 5 years post diagnosis. Our team developed an oncolytic adenovirus with an OX-40L expression cassette named Delta-24-RGDOX. While studies have revealed the interaction between the gut microbiota and immunotherapy agents, there are no studies linking the gut microbiota with viroimmunotherapy efficacy. We hypothesize that gut bacterial signatures will be associated with oncolytic viral therapy efficacy. To test this hypothesis, we evaluated the changes in gut microbiota in two mouse cohorts: (1) GSC-005 glioblastoma-bearing mice treated orally with indoximod, an immunotherapeutic agent, or with Delta-24-RGDOX by intratumoral injection and (2) a mouse cohort harboring GL261-5 tumors used to mechanistically evaluate the importance of CD4+ T cells in relation to viroimmunotherapy efficacy. Microbiota assessment indicated significant differences in the structure of the gut bacterial communities in viroimmunotherapy-treated animals with higher survival compared with control or indoximod-treated animals. Moreover, viroimmunotherapy-treated mice with prolonged survival had a higher abundance of Bifidobacterium. The CD4+ T cell depletion was associated with gut dysbiosis, lower mouse survival, and lower antitumor efficacy of the therapy. These findings suggest that microbiota modulation along the gut-glioma axis contributes to the clinical efficacy and patient survival of viroimmunotherapy treated animals.

Comparative analysis of the gut bacteria and fungi in migratory demoiselle cranes (Grus virgo) and common cranes (Grus grus) in the Yellow River Wetland, China

Introduction

Gut microbiota are closely related to the nutrition, immunity, and metabolism of the host and play important roles in maintaining the normal physiological activities of animals. Cranes are important protected avian species in China, and they are sensitive to changes in the ecological environment and are thus good environmental indicators. There have been no reports examining gut fungi or the correlation between bacteria and fungi in wild Demoiselle cranes (Grus virgo) and Common cranes (Grus grus). Related research can provide a foundation for the protection of rare wild animals.

Methods

16S rRNA and ITS high-throughput sequencing techniques were used to analyze the gut bacterial and fungal diversity of Common and Demoiselle cranes migrating to the Yellow River wetland in Inner Mongolia.

Results

The results revealed that for gut bacteria α diversity, Chao1 index in Demoiselle cranes was remarkably higher than that in Common cranes (411.07 ± 79.54 vs. 294.92 ± 22.38), while other index had no remarkably differences. There was no remarkable difference in fungal diversity. There were marked differences in the gut microbial composition between the two crane species. At the phylum level, the highest abundance of bacteria in the Common crane and Demoiselle crane samples was Firmicutes, accounting for 87.84% and 74.29%, respectively. The highest abundance of fungi in the guts of the Common and Demoiselle cranes was Ascomycota, accounting for 69.42% and 57.63%, respectively. At the genus level, the most abundant bacterial genus in the Common crane sample was Turicibacter (38.60%), and the most abundant bacterial genus in the Demoiselle crane sample was Catelicoccus (39.18%). The most abundant fungi in the Common crane sample was Penicillium (6.97%), and the most abundant fungi in the Demoiselle crane sample was Saccharomyces (8.59%). Correlation analysis indicated that there was a significant correlation between gut bacteria and fungi.

Discussion

This study provided a research basis for the protection of cranes. Indeed, a better understanding of the gut microbiota is very important for the conservation and management of wild birds, as it not only helps us to understand their life history and related mechanisms, but also can hinder the spread of pathogenic microorganisms.

Bisphenol A exposure affects specific gut taxa and drives microbiota dynamics in childhood obesity

Cumulative xenobiotic exposure has an environmental and human health impact which is currently assessed under the One Health approach. Bisphenol A (BPA) exposure and its potential link with childhood obesity that has parallelly increased during the last decades deserve special attention. It stands during prenatal or early life and could trigger comorbidities and non-communicable diseases along life. Accumulation in the nature of synthetic chemicals supports the "environmental obesogen" hypothesis, such as BPA. This estrogen-mimicking xenobiotic has shown endocrine disruptive and obesogenic effects accompanied by gut microbiota misbalance that is not yet well elucidated. This study aimed to investigate specific microbiota taxa isolated and selected by direct BPA exposure and reveal its role on the overall children microbiota community and dynamics, driving toward specific obesity dysbiosis. A total of 333 BPA-resistant isolated species obtained through culturing after several exposure conditions were evaluated for their role and interplay with the global microbial community. The selected BPA-cultured taxa biomarkers showed a significant impact on alpha diversity. Specifically, Clostridium and Romboutsia were positively associated promoting the richness of microbiota communities, while Intestinibacter, Escherichia-Shigella, Bifidobacterium, and Lactobacillus were negatively associated. Microbial community dynamics and networks analyses showed differences according to the study groups. The normal-weight children group exhibited a more enriched, structured, and connected taxa network compared to overweight and obese groups, which could represent a more resilient community to xenobiotic substances. In this sense, subnetwork analysis generated with the BPA-cultured genera showed a correlation between taxa connectivity and more diverse potential enzymatic BPA degradation capacities.IMPORTANCEOur findings indicate how gut microbiota taxa with the capacity to grow in BPA were differentially represented within differential body mass index children study groups and how these taxa affected the overall dynamics toward patterns of diversity generally recognized in dysbiosis. Community network and subnetwork analyses corroborated the better connectedness and stability profiles for normal-weight group compared to the overweight and obese groups.

Polysaccharide from Panax japonicus C.A. Mey prevents non-alcoholic fatty liver disease development based on regulating liver metabolism and gut microbiota in mice

In this study, a new polysaccharide (PSPJ) with specific molecular weight and monosaccharide compositions was isolated and purified from the water extract of Panacis Japonici Rhizoma (PJR). 16S rRNA analysis and untargeted metabolomic analysis were used to assess PSPJ's efficacy in averting non-alcoholic fatty liver disease (NAFLD). This study indicated that PSPJ significantly reduced liver fat accumulation, the increase in blood lipids and ALT caused by HFD, indicating that PSPJ can prevent NAFLD. We demonstrated through cell experiments that PSPJ does not directly affect liver cells. The gut microbiota disorder and alterations in short-chain fatty acids (SCFAs) induced by the high-fat diet (HFD) were ameliorated by PSPJ, as evidenced by the analysis of 16S rRNA. In particular, supplementing PSPJ reduced the abundance of Turicibacter, Dubosiella, and Staphylococcus, and increased the abundance of Bacteroides, Blautia, and Lactobacillus. Untargeted metabolomic analysis shows that PSPJ improves liver metabolic disorders by regulating arachidonic acid metabolism, carbohydrate digestion and absorption, fatty acid biosynthesis, fatty acid metabolism and retinol metabolism. The findings of our investigation indicate that PSPJ has the potential to modulate liver metabolism through alterations in the composition of intestinal bacteria, hence preventing NAFLD.

Heat-Killed Saccharomyces boulardii Alleviates Dextran Sulfate Sodium-Induced Ulcerative Colitis by Restoring the Intestinal Barrier, Reducing Inflammation, and Modulating the Gut Microbiota

Ulcerative colitis (UC) is a global intestinal disease, and conventional therapeutic drugs often fail to meet the needs of patients. There is an urgent need to find efficient and affordable novel biological therapies. Saccharomyces boulardii has been widely used in food and pharmaceutical research due to its anti-inflammatory properties and gut health benefits. However, there is still a relatively limited comparison and evaluation of different forms of S. boulardii treatment for UC. This study aimed to compare the therapeutic effects of S. boulardii, heat-killed S. boulardii, and S. boulardii β-glucan on UC, to explore the potential of heat-killed S. boulardii as a new biological therapy. The results demonstrate that all three treatments were able to restore body weight, reduce the disease activity index (DAI), inhibit splenomegaly, shorten colon length, and alleviate histopathological damage to colonic epithelial tissues in DSS-induced colitis mice. The oral administration of S. boulardii, heat-killed S. boulardii, and S. boulardii β-glucan also increased the levels of tight junction proteins (Occludin and ZO-1), decreased the levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in the serum, and suppressed the expressions of TNF-α, IL-1β, and IL-6 mRNA in the colon. In particular, in terms of gut microbiota, S. boulardii, heat-killed S. boulardii, and S. boulardii β-glucan exhibited varying degrees of modulation on DSS-induced dysbiosis. Among them, heat-killed S. boulardii maximally restored the composition, structure, and functionality of the intestinal microbiota to normal levels. In conclusion, heat-killed S. boulardii showed greater advantages over S. boulardii and S. boulardii β-glucan in the treatment of intestinal diseases, and it holds promise as an effective novel biological therapy for UC. This study is of great importance in improving the quality of life for UC patients and reducing the burden of the disease.

Causal relationship between the gut microbiome and basal cell carcinoma, melanoma skin cancer, ease of skin tanning: evidence from three two-sample mendelian randomisation studies

Objectives

The present study used publicly available genome-wide association study (GWAS) summary data to perform three two-sample Mendelian randomization (MR) studies, aiming to examine the causal links between gut microbiome and BCC, melanoma skin cancer, ease of skin tanning.

Methods

SNPs associated with exposures to basal cell carcinoma, melanoma skin cancer and ease of skin tanning from the genome-wide association study data of UK Biobank and MRC-IEU (MRC Integrative Epidemiology Unit), and the meta-analysis data from Biobank and MRC-IEU were used as instrumental variables (IVs). The casual estimates were assessed with a two-sample Mendelian randomisation test using the inverse-variance-weighted (IVW) method, Wald ratio, MR-Egger method, maximum likelihood, weighted median, simple mode, and weighted mode.

Results

After the application of MR analysis, diffirent effects of multiple groups of gut microbiota was observed for BCC, melanoma skin cancer and ease of skin tanning. The relationships between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning were supported by a suite of sensitivity analyses, with no statistical evidence of instrument heterogeneity or horizontal pleiotropy. Further investigation is required to explore the relationship between between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning.

Conclusion

Our study initially identified potential causal roles between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning, and highlighted the role of gut microbiome in the progression of basal cell carcinoma, melanoma skin cancer, ease of skin tanning.

Therapeutic Role of Polyphenol Extract from Prunus cerasifera Ehrhart on Non-Alcoholic Fatty Liver

Prunus cerasifera Ehrhart (P. cerasifera) flourishes uniquely in the arid landscapes of Xinjiang, China. Preliminary studies have revealed the therapeutic potential of its polyphenol extract (PPE) in mitigating liver lipid accumulation in mice fed a high-fat diet. We established a mouse model that was subjected to a continuous high-fat diet for 24 weeks and administered PPE to investigate the effects of PPE on cholesterol and BA metabolism in NAFLD mice. The results showed that PPE administration (200 and 400 mg/kg/day, BW) led to a reduction in liver TC, an increase in liver T-BAs, and normalization of the disrupted fecal BA profile. Concurrently, it decreased levels of lipotoxic BAs and inhibited hepatic cholesterol synthesis (evidenced by reduced HMGCR activity) and intestinal cholesterol absorption (indicated by lower ACAT2 levels) while enhancing intestinal cholesterol efflux (via LXRα, ABCA1, ABCG5, and ABCG8) and stimulating hepatic BA synthesis (CYP7A1, CYP27A1) and secretion (BSEP). PPE thus led to a significant reduction in lipotoxic BAs metabolized by gut microbiota and a downregulation of the BA secretion pathway under its influence. Our findings reveal the therapeutic effect of PPE on NAFLD mice via regulating cholesterol and BA metabolism, providing a theoretical basis for exploring the potential functions of P. cerasifera.

Gut microbiota-mediated polyphenol metabolism is restrained by parasitic whipworm infection and associated with altered immune function in mice

Polyphenols are phytochemicals commonly found in plant-based diets which have demonstrated immunomodulatory and anti-inflammatory properties. However, the interplay between polyphenols and pathogens at mucosal barrier surfaces has not yet been elucidated in detail. Here, we show that proanthocyanidin (PAC) polyphenols interact with gut parasites to influence immune function and gut microbial-derived metabolites in mice. PAC intake inhibited mastocytosis during infection with the small intestinal roundworm Heligmosomoides polygyrus, and altered the host tissue transcriptome at the site of infection with the large intestinal whipworm Trichuris muris, with a notable enhancement of type-1 inflammatory and interferon-driven gene pathways. In the absence of infection, PAC intake promoted the expansion of Turicibacter within the gut microbiota, increased fecal short chain fatty acids, and enriched phenolic metabolites such as phenyl-γ-valerolactones in the cecum. However, these putatively beneficial effects were reduced in PAC-fed mice infected with T. muris, suggesting concomitant parasite infection can attenuate gut microbial-mediated PAC catabolism. Collectively, our results suggest an inter-relationship between a phytonutrient and infection, whereby PAC may augment parasite-induced inflammation (most prominently with the cecum dwelling T. muris), and infection may abrogate the beneficial effects of health-promoting phytochemicals.

Tracking the extracellular and intracellular antibiotic resistance genes across whole year in wastewater of intensive dairy farm

Monitoring the annual variation of antibiotic resistance genes (ARGs) in livestock wastewater is important for determining the high-risk period of transfer and spread of animal-derived antibiotic resistance into the environment. However, the knowledge regarding the variation patterns of ARGs, especially intracellular ARGs (iARGs) and extracellular ARGs (eARGs), over time in livestock wastewater is still unclear. Herein, we conducted a year-round study to trace the profiles of ARGs at a Chinese-intensive dairy farm, focusing on the shifts observed in different months. The results showed significant differences in the composition and variation between iARGs and eARGs. Tetracycline, sulfonamide, and macrolide resistance genes were the major types of iARGs, while cfr was the major type of eARG. The environmental adaptations of the host bacteria determine whether ARGs appear as intracellular or extracellular forms. The total abundance of ARGs was higher from April to September, which can be attributed to the favorable climatic conditions for bacterial colonization and increased antibiotic administration during this period. Integron was found to be highly correlated with most iARGs, potentially playing a role in the presence of these genes within cells and their similar transmission patterns in wastewater. The intracellular and extracellular bacterial communities were significantly different, primarily because of variations in bacterial adaptability to the high salt and anaerobic environment. The intracellular co-occurrence network indicated that some dominant genera in wastewater, such as Turicibacter, Clostridium IV, Cloacibacillus, Subdivision5_genera_incertae_sedis, Saccharibacteria_genera_incertae_sedis and Halomonas, were potential hosts for many ARGs. To the best of our knowledge, this study demonstrates, for the first time, the annual variation of ARGs at critical points in the reuse of dairy farm wastewater. It also offers valuable insights into the prevention and control of ARGs derived from animals.

Exposure and resistance to lantibiotics impact microbiota composition and function

The intestinal microbiota is composed of hundreds of distinct microbial species that interact with each other and their mammalian host. Antibiotic exposure dramatically impacts microbiota compositions and leads to acquisition of antibiotic-resistance genes. Lantibiotics are ribosomally synthesized and post-translationally modified peptides produced by some bacterial strains to inhibit the growth of competing bacteria. Nisin A is a lantibiotic produced by Lactococcus lactis that is commonly added to food products to reduce contamination with Gram-positive pathogens. Little is known, however, about lantibiotic-resistance of commensal bacteria inhabiting the human intestine. Herein, we demonstrate that Nisin A administration to mice alters fecal microbiome compositions and the concentration of taurine-conjugated primary bile acids. Lantibiotic Resistance System genes (LRS) are encoded by lantibiotic-producing bacterial strains but, we show, are also prevalent in microbiomes across human cohorts spanning vastly different lifestyles and 5 continents. Bacterial strains encoding LRS have enhanced in vivo fitness upon dietary exposure to Nisin A but reduced fitness in the absence of lantibiotic pressure. Differential binding of host derived, secreted IgA contributes to fitness discordance between bacterial strains encoding or lacking LRS. Although LRS are associated with mobile genetic elements, sequence comparisons of LRS encoded by distinct bacterial species suggest they have been long-term components of their respective genomes. Our study reveals the prevalence, abundance and physiologic significance of an underappreciated subset of antimicrobial resistance genes encoded by commensal bacterial species constituting the human gut microbiome, and provides insights that will guide development of microbiome augmenting strategies.

The Dose-Response Effect of Fluoride Exposure on the Gut Microbiome and Its Functional Pathways in Rats

Metabolic activities within the gut microbiome are intimately linked to human health and disease, especially within the context of environmental exposure and its potential ramifications. Perturbations within this microbiome, termed "gut microbiome perturbations", have emerged as plausible intermediaries in the onset or exacerbation of diseases following environmental chemical exposures, with fluoride being a compound of particular concern. Despite the well-documented adverse impacts of excessive fluoride on various human physiological systems-ranging from skeletal to neurological-the nuanced dynamics between fluoride exposure, the gut microbiome, and the resulting dose-response relationship remains a scientific enigma. Leveraging the precision of 16S rRNA high-throughput sequencing, this study meticulously examines the ramifications of diverse fluoride concentrations on the gut microbiome's composition and functional capabilities within Wistar rats. Our findings indicate a profound shift in the intestinal microbial composition following fluoride exposure, marked by a dose-dependent modulation in the abundance of key genera, including Pelagibacterium, Bilophila, Turicibacter, and Roseburia. Moreover, discernible alterations were observed in critical functional and metabolic pathways of the microbiome, such as D-lyxose ketol-isomerase and DNA polymerase III subunit gamma/tau, underscoring the broad-reaching implications of fluoride exposure. Intriguingly, correlation analyses elucidated strong associations between specific bacterial co-abundance groups (CAGs) and these shifted metabolic pathways. In essence, fluoride exposure not only perturbs the compositional equilibrium of the gut microbiota but also instigates profound shifts in its metabolic landscape. These intricate alterations may provide a mechanistic foundation for understanding fluoride's potential toxicological effects mediated via gut microbiome modulation.

Dissecting the association between gut microbiota and liver cancer in European and East Asian populations using Mendelian randomization analysis

Background

Ample evidence suggests an important role of the gut microbiome in liver cancer, but the causal relationship between gut microbiome and liver cancer is unclear. This study employed Mendelian randomization (MR) analysis to examine the causal relationship between the gut microbiome and liver cancer in European and East Asian populations.

Methods

We sourced genetic variants linked to gut microbiota from the MiBioGen consortium meta-analysis, and procured liver cancer genome-wide association study (GWAS) summary data from the FinnGen consortium and Biobank Japan. We employed the inverse variance weighted method for primary statistical analysis, fortified by several sensitivity analyses such as MR-PRESSO, MR-Egger regression, weighted median, weighted mode, and maximum likelihood methods for rigorous results. We also evaluated heterogeneity and horizontal pleiotropy.

Results

The study examined an extensive set of gut microbiota, including 131 genera, 35 families, 20 orders, 16 classes, and 9 phyla. In Europeans, ten gut microbiota types displayed a suggestive association with liver cancer (p < 0.05). Notably, Oscillospira and Mollicutes RF9 exhibited a statistically significant positive association with liver cancer risk, with odds ratios (OR) of 2.59 (95% CI 1.36-4.95) and 2.03 (95% CI 1.21-3.40), respectively, after adjusting for multiple testing. In East Asians, while six microbial types demonstrated suggestive associations with liver cancer, only Oscillibacter displayed a statistically significant positive association (OR = 1.56, 95% CI 1.11-2.19) with an FDR < 0.05. Sensitivity analyses reinforced these findings despite variations in p-values.

Conclusion

This study provides evidence for a causal relationship between specific gut microbiota and liver cancer, enhancing the understanding of the role of the gut microbiome in liver cancer and may offer new avenues for preventive and therapeutic strategies.