Oscillospira: a Central, Enigmatic Component of the Human Gut Microbiota

Targeted modulation of intestinal barrier and mucosal immune-related microbiota attenuates IgA nephropathy progression

IgA nephropathy (IgAN) is related to the balance of gut microbiota. However, it is unclear whether changes in the gut microbiota can cause IgAN or attenuate its progression. This study employed IgAN and human microbiota-associated (HMA)-IgAN models to investigate the impact of IgAN on gut microbiota alteration and the mechanisms by which gut microbiota might trigger IgAN. Furthermore, this study examined the effects of chitooligosaccharides (COS) and COS formulation (COSF) with microbiota-targeting function on enhancing intestinal barrier and renal functions. These results revealed that IgAN led to a reduction in α-diversity and structural alterations in the gut microbiota, characterized by an increase in Shigella sonnei, Streptococcus danieliae, Desulfovibrio fairfieldensis, and a decrease in Bifidobacterium pseudolongum and Clostridium leptum. There was also an imbalance in intestinal B-cell immunity and a decrease in the level of tight junction proteins (ZO-1 and Occludin). Intestinal barrier and mucosal immune-related microbiota (Clostridium leptum, unclassified Lachnospiraceae NK4Al36 group, unclassified Clostridia vadinBB60 group, unclassified Oscillospiraceae, and unclassified Roseburia) were enriched through targeted modulation with COS/COSF, enhancing intestinal ZO-1 expression and reducing APRIL/BAFF overexpression, thereby reducing renal damage in IgAN. In conclusion, this study clarified the kidney-gut crosstalk between gut microbiota and IgAN, providing scientific evidence for developing microbiota-targeted food interventions to improve IgAN outcomes.

Faecalibacterium prausnitzii regulates carbohydrate metabolic functions of the gut microbiome in C57BL/6 mice

The probiotic impact of microbes on host metabolism and health depends on both host genetics and bacterial genomic variation. Faecalibacterium prausnitzii is the predominant human gut commensal emerging as a next-generation probiotic. Although this bacterium exhibits substantial intraspecies diversity, it is unclear whether genetically distinct F. prausnitzii strains might lead to functional differences in the gut microbiome. Here, we isolated and characterized a novel F. prausnitzii strain (UT1) that belongs to the most prevalent but underappreciated phylogenetic clade in the global human population. Genome analysis showed that this butyrate-producing isolate carries multiple putative mobile genetic elements, a clade-specific defense system, and a range of carbohydrate catabolic enzymes. Multiomic approaches were used to profile the impact of UT1 on the gut microbiome and associated metabolic activity of C57BL/6 mice at homeostasis. Both 16S rRNA and metagenomic sequencing demonstrated that oral administration of UT1 resulted in profound microbial compositional changes including a significant enrichment of Lactobacillus, Bifidobacterium, and Turicibacter. Functional profiling of the fecal metagenomes revealed a markedly higher abundance of carbohydrate-active enzymes (CAZymes) in UT1-gavaged mice. Accordingly, UT1-conditioned microbiota possessed the elevated capability of utilizing starch in vitro and exhibited a lower availability of microbiota-accessible carbohydrates in the gut. Further analysis uncovered a functional network wherein UT1 reduced the abundance of mucin-degrading CAZymes and microbes, which correlated with a concomitant reduction of fecal mucin glycans. Collectively, our results reveal a crucial role of UT1 in facilitating the carbohydrate metabolism of the gut microbiome and expand our understanding of the genetic and phenotypic diversity of F. prausnitzii.

Gut microbiome composition and metabolic activity in metabolic-associated fatty liver disease

Metabolic Associated Fatty Liver Disease (MAFLD) impacts approximately 25% of the global population. Between April 2023 and July 2023, 60 patients with MAFLD, along with 60 age, ethnicity, and sex-matched healthy controls (HCs), were enrolled from the Inner Mongolia Autonomous Region, China. Analysis of gut microbiota composition and plasma metabolic profiles was conducted using metagenome sequencing and LC-MS. LEfSe analysis identified five pivotal species: Eubacterium rectale, Dialister invisus, Pseudoruminococcus massiliensis, GGB3278 SGB4328, and Ruminococcaceae bacteria. In subgroup analysis, Eubacterium rectale tended to increase by more than 2 times and more than double in the non-obese MAFLD group, and MAFLD with moderate hepatic steatosis (HS), respectively. Plasma samples identified 172 metabolites mainly composed of fatty acid metabolites such as propionic acid and butyric acid analogues. Ruminococcaceae bacteria have a strong positive correlation with β-alanine, uric acid, and L-valine. Pseudoruminococcus massiliensis has a strong positive correlation with β-alanine. Combinations of phenomics and metabolomics yielded the highest accuracy (AUC = 0.97) in the MAFLD diagnosis. Combinations of phenomics and metagenomics yielded the highest accuracy (AUC = 0.94) in the prediction of the MAFLD HS progress. Increases in Eubacterium rectale and decreases in Dialister invisus seem to be indicative of MAFLD patients. Eubacterium rectale may predict HS degree of MAFLD and play an important role in the development of non-obese MAFLD. Eubacterium rectale can generate more propionic acid and butyric acid analogues to absorb energy and increase lipid synthesis and ultimately cause MAFLD.

The Role of Gut Microbiota in Modulating Brain Structure and Psychiatric Disorders: A Mendelian Randomization Study

The influence of the gut microbiome on the human brain, especially its associations with psychiatric disorders, has emerged as a focal area in contemporary neuroscience and psychiatry research. In this study, we employed a mediation Mendelian randomization approach to delve into the potential causal relationships between gut microbiota and psychiatric disorders, with a focus on the mediating role of brain structural changes. We harnessed genetic data from large - scale genome - wide association studies to analyze how 196 gut microbiota taxa affect ten psychiatric disorders via alterations in 3,143 brain structures. Our key findings revealed significant bidirectional causal relationships. In the gut microbiota - brain structure relationship, certain gut microbiota taxa, such as Bacteroides and Marvinbryantia, were associated with changes in brain activity and white matter integrity respectively. Conversely, brain structures like the right hippocampus and left superior cerebellar peduncle influenced gut microbiota composition. Regarding gut microbiota and psychiatric disorders, we identified numerous associations. For example, the genus Prevotellaceae was significantly associated with an increased risk of Autism Spectrum Disorder, while Ruminococcaceae UCG005 showed a protective effect. In Panic Disorder, Alistipes was positively associated, and for Schizophrenia, both protective (Barnesiella) and risk - associated (Phascolarctobacterium) genera were found. Moreover, through mediation analysis, we found that brain structures mediated the effects of gut microbiota on five psychiatric disorders, including bipolar disorder and anorexia nervosa. In these cases, the influence of gut microbiota on the disorders was fully transmitted through changes in brain structure. Overall, our research clarifies the role of the microbiota - gut - brain axis in mental health. It offers a new perspective on how intestinal microbes impact brain physiology and psychiatric pathology. These findings not only deepen our understanding of the biological interactions between the gut and brain but also suggest that targeted gut microbiota modifications could be novel therapeutic strategies for mental health disorders.

The effect of anthocyanin extract from Lycium ruthenicum Murray on intestinal barrier function in Bamei ternary pigs

The intestinal barrier is a critical defense against external pathogens and plays a central role in immune regulation and nutrient absorption. Oxidative stress and chronic inflammation in high-altitude environments can exacerbate the damage to the intestinal barrier in Baimei ternary pigs. Anthocyanin extract of Lycium ruthenicum Murray (AEL), has garnered widespread attention due to its rich anthocyanin flavonoid content, which exhibits antioxidant and anti-inflammatory properties. These properties help alleviate inflammation and oxidative stress, thereby enhancing gut function in animals. Based on this, the study employed Bamei ternary pigs and supplemented their basic diet with varying concentrations of AEL to investigate its impact on gut barrier function. The results demonstrated that AEL inhibited key factors of the intestinal Toll-like receptor pathway, including Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-associated protein 6 (TRAF6), and nuclear factor kappa B (NF-κB), affecting gene transcription and protein expression levels. This led to a reduction in pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), an increase in anti-inflammatory IL-10 production, and improved antioxidant capacity by enhancing total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity, while decreasing malondialdehyde (MDA) production. Additionally, AEL improved intestinal morphology and facilitated the transcription and expression of tight junction proteins, including zonula occludens-1 (ZO-1), claudin-1 (CLDN-1), and occludin (OCLN). AEL also elevated the transcription levels of mucin 1 (MUC1) and mucin 2 (MUC2), as well as the secretion levels of polymeric immunoglobulin receptor (pIgR) and secretory immunoglobulin A (SIgA), while increased the number of intestinal goblet cells. Furthermore, dietary supplementation with AEL altered the structure of the intestinal microbiota, enhancing the abundance of beneficial bacterial genera such as Verrucomicrobiaceae, Rikenellaceae, Butyricicoccaceae, UCG-005、Rikenellaceae_RC9_gut_group、norank_f_Ruminococcaceae、Eubacterium_oxidoreducens_group, thereby promoting the production of intestinal short-chain fatty acids (SCFAs). In conclusion, AEL inhibits the Toll-like receptor pathway, reduces the production of inflammatory factors, enhances antioxidant levels, improves intestinal morphology and microbiota structure,, thereby reinforcing intestinal barrier function.

Preparation of Sphingan Oligosaccharides by SpnR Hydrolysis and Their Prebiotic Effects on Intestinal Flora

Oligosaccharides have the potential to act as prebiotics and can be obtained by enzymatic hydrolysis of polysaccharides. Sphingans are exopolysaccharides, including gellan, welan, and diutan, which are synthesized by the genus Sphingomonas. Sphingan lyase (SpnR) has attracted a great deal of interest due to its ability to produce oligosaccharides through the degradation of sphingans. However, there are few reports on the catalytic mechanism and hydrolysate analysis of SpnR. Here, SpnR from Sphingomonas sp. HT-1 was heterologously expressed in Escherichia coli. The optimal temperature and pH of the purified SpnR were 35 °C and pH 7.2, respectively. SpnR has good alkali resistance and a relatively mild optimum temperature. Na+ and Fe3+ increased SpnR activities, in contrast to Zn2+ and EDTA. SpnR could degrade sphingans, and the most suitable substrate was welan. Analysis of the cleavage pattern revealed that SpnR acts specifically on the β-1,4-glycosidic bond to obtain minimum trisaccharide sphingan oligosaccharides (SpnOS). The gut microbiota in vitro showed that SpnOS caused a substantial modification in the intestinal microbiota, characterized by an augmented proliferation of beneficial bacterial populations, notably Bacteroides and Lactobacillus.

Engineering a Dual-Function Starch-Cellulose Composite for Colon-Targeted Probiotic Delivery and Synergistic Gut Microbiota Regulation in Type 2 Diabetes Therapeutics

Objectives: This study engineered a colon-targeted drug delivery system (CTDS) using the dual pharmaceutical and edible properties of Pueraria lobata to encapsulate Lactobacillus paracasei for Type 2 diabetes mellitus (T2DM) therapy. Methods: The CTDS was designed as a core-shell composite through microwave-hydrothermal engineering, comprising the following: (1) a retrograded starch shell with acid/enzyme-resistant crystallinity to protect probiotics from gastric degradation; (2) a porous cellulose core derived from Pueraria lobata's natural microstructure, serving as a colonization scaffold for probiotics. Results: Structural characterization confirmed the shell's resistance to acidic/pancreatic conditions and the core's hierarchical porosity for bacterial encapsulation. pH/enzyme-responsive release kinetics were validated via fluorescence imaging, demonstrating targeted probiotic delivery to the colon with minimal gastric leakage. In diabetic models, the CTDS significantly reduced fasting blood glucose and improved dyslipidemia, while histopathological analysis revealed restored hepatic and pancreatic tissue architecture. Pharmacologically, the system acted as both a probiotic delivery vehicle and a microbiota modulator, selectively enriching Allobaculum and other short-chain fatty acid (SCFA)-producing bacteria to enhance SCFA biosynthesis and metabolic homeostasis. The CTDS further exhibited direct compression compatibility, enabling its translation into scalable oral dosage forms (e.g., tablets). Conclusions: By integrating natural material engineering, microbiota-targeted delivery, and tissue repair, this platform bridges the gap between pharmaceutical-grade probiotic protection and metabolic intervention in T2DM.

Modified Pulsatilla decoction ameliorates ulcerative colitis by affecting gut microbiota and metabolite profiles

To investigate the therapeutic effects of a specific modified Pulsatilla decoction (MPD) on ulcerative colitis (UC) in mice, 32 male Balb/c mice were randomly assigned to four groups: Control, Model, High-dose (H-dose), and Low-dose (L-dose), with eight mice per group. All groups except the Control group were administered 3% dextran sulfate sodium (DSS) in their drinking water for 7 days to induce acute UC. The H-dose group and L-dose group mice were gavaged, respectively, with different concentrations of MPD, while the Control group and Model group received the same amount of steriled water by gavage. Clinical symptoms of the mice were observed and recorded throughout the study. Subsequently, pathological sections of the colon tissues were prepared, and 16S rRNA high-throughput sequencing and metabolomics analysis were conducted on the intestinal contents. The results indicated that MPD improved the structure and morphology of colon tissue, significantly reducing inflammatory damage in DSS-treated mice. Furthermore, MPD alleviated DSS-induced intestinal injury by enhancing the abundance of beneficial intestinal probiotics, such as Actinobacteriota and Oscillospirates. Metabolomic analysis revealed significant changes in the MPD group compared to the Model group, with 53 metabolites upregulated and 22 downregulated. Key upregulated metabolites included Esculetin, Glutarate semialdehyde, and Licoricone, while downregulated metabolites included Ectoine and Trans-Piceid. KEGG enrichment analysis indicated that MPD primarily targets pathways such as linoleic acid metabolism, VEGF signaling, and glutamatergic synapse, highlighting its potential regulatory effects. In conclusion, we revealed that this MPD has the potential to alleviate DSS-induced colitis by reducing inflammation, regulating intestinal microbiota and intestinal metabolism.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Type 3 resistant starch prepared from jackfruit alleviated the hyperlipidemia via gut microbiota regulation

Although resistant starch (RS) isolated from raw starch exhibits established regulatory effects on the mouse gut microbiota and associated hyperlipidemia, critical questions persist regarding RS in heated foods - the predominant form in the human diets, namely, the role of RS from heated food in the regulation of hyperlipidemia through gut microbiota is still unclear. This study evaluated the effects of a RS (jackfruit heated resistant starch, JFRS3) from heat-treated jackfruit native starch (JFNS) on hyperlipidemia in golden hamster gut microbes. Compared with JFNS, JFRS3 developed an irregular block-like shape with numerous grooves, exhibited more ordered structures (R1047/1022: 2.952 and R1022/995: 0.964) and greater crystallinity (relative crystallinity (RC): 21.96 %), and transformed into a C-type crystalline structure. Additionally, JFRS3 demonstrated significant antihyperlipidemic effects, which included an increase in high-density lipoprotein cholesterol (HDLC) levels (4.36 mmol/L) and reductions in triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels (14.39, 4.55, and 4.61 mmol/L, respectively), thereby alleviating liver fatty lesions, reducing fat accumulation, and inhibiting adipocyte enlargement. These effects were closely linked to intestinal microbial changes, such as specific microbial enrichment and enhanced gut microbial diversity, potentially influenced by the structural properties of JFRS3. Furthermore, the consumption of JFRS3 was more effective in slowing weight gain and improving blood lipid profiles compared with raw RS present in JFNS. These findings prove that JFRS3 modulates hyperlipidemia induced by a high-fat diet and contributes to the development of alternative strategies for managing high-fat-diet-associated hyperlipidemia.

Prenatal Intake of High Multivitamins or Folic Acid With or Without Choline Contributes to Gut Microbiota-Associated Dysregulation of Serotonin in Offspring

The gut microbiota is amenable to early nutrition including micronutrients but intake above and below the recommendations commonly occur with unknown consequences. Serotonin (5-hydroxytryptamine [5-HT]) is a monoamine found centrally and peripherally with diverse functions such as food intake regulation via the hypothalamic 5-HT receptor 2C (5-HTR2C). This study determined the impact of prenatal micronutrients on the gut microbiota and serotonergic system in offspring. Pregnant Wistar rats were fed either recommended vitamins (RV), high vitamins (HV), high folic acid with recommended choline (HFRC), or high folic acid with no choline (HFNC). Offspring were fed a high-fat diet for 12 weeks postweaning. HV, HFRC, and HFNC males and females had lower hypothalamic 5-HTR2C protein expression compared to RV. Brain 5-HT concentrations were lower but colon 5-HT concentrations were higher in HV and HFNC males and females and HFRC males compared to RV. Refeeding response after 5-HTR2C agonist was negatively correlated with hypothalamic 5-HTR2C protein expression in males and with brain 5-HT concentrations in females. Random forest revealed top bacterial taxa, which Lactococcus, Ruminococcus, Bacteroides, and Oscillospira showed significant correlations with refeeding response and concentrations of brain and colon 5-HT. In conclusion, excess or imbalanced prenatal consumption of micronutrients leads to gut microbiota-associated disturbances in the serotonergic system in offspring.

Long-term soy dietary fiber diet modifies the intestinal internal environment: Focus on chronic ulcerative colitis

Okara is a major by-product of soybean processing, which not only has negative impacts on the environment but also leads to resource waste. Soybean residue is rich in insoluble dietary fiber, which is known to have a positive effect on ulcerative colitis. This study aimed to investigate whether long-term consumption of high-purity soy isolate dietary fiber (HPSIDF) promotes the proliferation of beneficial intestinal substances, thereby alleviating intestinal damage caused by chronic ulcerative colitis (CUC). This study induced CUC using 2 % dextran sulfate sodium (DSS) and conducted a three-phase (9-week) intervention experiment. The study showed that long-term consumption of HPSIDF can regulate the level of inflammatory factors in mice and relieve damage to intestinal tissue. In addition, long-term intake of HPSIDF inhibited the degradation of Lactobacillus intestinalis and promoted the proliferation of Oscillospira and the production of beneficial substances such as Agmatine and Betaine, which played an important role in the maintenance of intestinal bacterial flora and the improvement of the internal environment. This study clarified that long-term intake of HPSIDF not only changes the intestinal self-properties but also promotes the proliferation of beneficial flora and metabolites, providing a solution strategy for the high-value utilization of okara.

The Role of Beneficial Microbiota in COVID-19: Insights from Key Bacterial Genera

The COVID-19 pandemic has highlighted the need for a comprehensive understanding of the factors influencing disease severity and progression. Emerging research indicates that the human microbiota, particularly beneficial bacteria, significantly impacts immune responses and health outcomes in COVID-19 patients. While existing studies provide general insights into the relationship between the microbiota and probiotics with COVID-19, they often lack a detailed exploration of how specific bacterial taxa might be used as adjunctive treatments. This review aims to address this gap by focusing on ten key genera of beneficial bacteria, discussing their roles in COVID-19 and evaluating their potential as probiotics for prevention and treatment. The review covers the impact of these microbes on human health, their population alterations in COVID-19 patients, and their interactions with other viral infections. Among these microbes, several exhibit distinct patterns of abundance in COVID-19 patients, influencing disease outcomes and highlighting their potential roles in infection dynamics. In COVID-19 patients, populations of Akkermansia, Ruminococcus, and Roseburia are consistently reduced, while those of Faecalibacterium show a significant decline in more severe cases. Bacteroides presents varying effects depending on the species involved. Alterations in the abundance of Blautia and Lachnospiraceae are associated with increased inflammation and disease severity. Likewise, the depletion of Lachnospira and Coprococcus populations, both linked to anti-inflammatory effects, may exacerbate symptom severity. Oscillospira, though less studied, is connected to overall health and could have implications for viral infections. This review synthesizes the current understanding of these beneficial microbes to highlight the importance of maintaining a healthy microbiota to alleviate the impact of COVID-19 and contribute to the development of novel therapeutic strategies involving microbiota modulation.

Dietary Supplementation with Complex Enzymes and Tea Residue Improved the Production Efficiency of Xiangling Pigs

This study evaluated the effects of tea residue combined with complex enzymes on the growth performance, serum biochemistry, meat quality, and intestinal microbiota of Xiangling fattening pigs. A total of 120 healthy Xiangling fattening pigs, with an average weight of 47.93 kg (±15.28 kg), were randomly assigned to five treatment groups, each comprising four replicates of six pigs. The control group (CON) received a basal diet; the experimental groups received a diet containing 5.8% fermented tea residue as an alternative energy and protein source (dry matter basis) and mixed additional 0 (CZ), 200 (M200), 400 (M400), and 800 (M800) complex enzymes. The trial lasted for 83 days. The results showed that tea residue and complex enzymes failed to affect growth performance (p > 0.05). Tea residue reduced the serum aspartate aminotransferase and alkaline phosphatase activities (p < 0.01), and complex enzyme supplementation lowered the total cholesterol levels and reduced the alanine aminotransferase activity (p < 0.05). Additionally, tea residue decreased the pH24h and b*1h values (p < 0.05), and complex enzyme supplementation increased the L*24h value and pork shear force (p < 0.05). In terms of amino acid content, tea residue significantly elevated aspartic acid and inosine monophosphate (p < 0.05), and complex enzyme addition increased the glutamic acid, lysine, alanine, valine, tyrosine, isoleucine, leucine, and phenylalanine levels (p < 0.05). The 800 mg/kg complex enzyme group exhibited a reduction in the C10:0, C15:0, and C17:0 contents (p < 0.05). Microbial analysis showed that tea residue promoted the abundance of Oribacterium and Butyricicoccus, while enzyme supplementation enriched Eggerthellaceae, Oscillospirales, and Peptococcaceae. Overall, the combination of tea residue and complex enzymes improved the pork quality, enhanced metabolic health markers, and modulated the gut microbiota composition, with the 400 mg/kg enzyme dose (M400) achieving the most pronounced benefits. These findings suggest a potential feeding strategy for improving pork quality without compromising growth performance.

Milk Exosomes From Gestational Diabetes Mellitus Parturients Demonstrate Weaker Ability to Promote Intestinal Development in Offspring

This study aims to investigate whether human milk exosomes from gestational diabetes mellitus (GDM-EXO) and healthy (HEA-EXO) parturients differ in regulating intestinal development in offspring. The differential miRNAs associated with intestinal development in GDM-EXO and HEA-EXO were verified by using qPCR and their relationships with gut microbiota (GM) in infants were analyzed. C57BL/6J mice were gavaged with 50 mg/kg·BW HEA-EXO or GDM-EXO. The intestinal morphology, gut barriers, ZO-1 and Occludin, and GM were determined by histological staining, Western blotting, and 16S rDNA amplicon sequencing, respectively. Hsa-miR-19b-3p, hsa-miR-148a-3p, and hsa-miR-320a-3p were upregulated, and hsa-miR-429 was decreased in GDM-EXO compared to HEA-EXO. The GDM parturients' infants had increased intestinal Coriobacteriaceae, Clostridiaceae, Erysipelotrichaceae, Erysipelatoclostridiaceae, and fewer Lactobacillaceae than the healthy parturient's infants. The four differential miRNAs in GDM-EXO all correlated with the infants' GM. GDM-EXO- and HEA-EXO-fed mice had greater villus lengths, villus length-to-crypt depth ratios, goblet cell numbers, elevated ZO-1 and Occludin, and lower crypt depths than control mice. HEA-EXO-fed mice had better intestinal morphology and gut barrier integrity than GDM-EXO-fed mice. GDM-EXO-fed mice had significantly decreased Lachnospiraceae and Oscillospiraceae than HEA-EXO-fed mice. GDM-EXO demonstrate weaker ability to promote intestinal development in offspring than HEA-EXO.

Dynamic changes in the gut microbiota play a critical role in age-associated cognitive dysfunction via SCFAs and LPS synthesis metabolic pathways during brain aging

BACKGROUND

Gut microbiota plays an essential role in cognitive dysfunction during aging. The aim of this study was to investigate the dynamic alterations in the gut microbiota and screen for key gut bacterial taxa correlated with age-associated cognitive dysfunction during natural aging.

METHODS

16S rRNA gene sequencing was performed to determine the composition of the gut microbiota in faecal samples from SAMR1 and SAMP8 mice, cognitively normal controls (NC), and patients with amnestic mild cognitive impairment (aMCI). Faecal microbiota transplantation (FMT) and GMrepo database were used to screen key gut microbiota associated with cognitive decline in aging mice and humans.

RESULTS

The composition of the gut microbiota dynamically changed during natural aging in SAMR1 and SAMP8 mice, as well as in healthy subjects of different ages extracted from the GMrepo database. FMT from SAMR1 to SAMP8 mice altered the gut microbiota composition and improved the cognitive impairment in SAMP8 mice. Key gut bacterial taxa, including Lactobacillus, Akkermansia, Clostridium, Oscillospira and Dorea, were screened and validated to correlate with aging-associated cognitive decline. The function of the key gut bacterial taxa predicted by PICRUSt2 indicated that the metabolic pathways related to short-chain fatty acids (SCFAs) and lipopolysaccharide (LPS) synthesis were involved in age-associated cognitive dysfunction during natural aging.

CONCLUSION

These results demonstrate that the composition of the gut microbiota changes dynamically during brain aging, with some key gut bacterial taxa playing critical roles in age-associated cognitive dysfunction through SCFAs and LPS synthesis metabolic pathways.

Survey of gut microbial biogeography and their functional niche in the grow-finishing swine of ordinary feeding

Background

Swine represent one of the most economically significant livestock worldwide, and their intestinal microbial communities are crucial for maintaining physiological development and regulating host metabolism. While extensive research has focused on the fecal microbiota of swine, investigations into microbial communities across different intestinal segments remain limited.

Objective

This study aims to elucidate the intestinal microbiota of swine by analyzing luminal contents from different intestinal segments, including the duodenum, jejunum, ileum, cecum, and colon.

Methods

We employed 16S rRNA sequencing to explore the diversity and structure of gut microbial biogeography, microbial functional niches, and their associated pathways.

Results

Our findings reveal significantly lower microbial richness and diversity in the small intestine (duodenum, jejunum, and ileum) compared to the large intestine (cecum and colon) (p < 0.05). At the phylum level, Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes were the dominant phyla, collectively accounting for over 90% of the total sequences. In the small intestine, Proteobacteria (4.76-34.2%), Actinobacteria, and Fusobacteriota were more abundant, whereas in the large intestine, Firmicutes (89.8-90.4%) was predominated. At the genus level, Fusobacterium, Corynebacterium, Rothia, Bradyrhizobium, and Brevundimonas were predominant in duodenum. Romboutsia, Clostridium_sensu_stricto_1, Terrisporobacter, and Jeotgalicoccus demonstrated greater abundances in the jejunum and ileum. Oscillospiraceae_UCG-005 in the cecum and Christensenellaceae_R-7_group in the colon were more abundant with 16.4 and 20.2% relative abundances, respectively. The specialists detected from the duodenum to the colon were all the predominant genera in each intestinal segment with relatively higher relative abundance. For instance, Romboutsia (3.06-36.1%), Clostridium_sensu_stricto_1 (5.31-18.6%), and Terrisporobacter (0.849-5.72%) were dominant genera and specialists in the small intestine, associated with enriched pathways of Amino acid metabolism and Lipid metabolism. Conversely, Oscillospiraceae_UCG-005 (16.4%, 4.06%) and Christensenellaceae_R-7_group (5.44%, 20.2%) are predominant genera and specialists within the large intestine, linked to pathways involved in Glycan biosynthesis and metabolism pathway, as well as the Biosynthesis of other secondary metabolites.

Conclusion

These highlight the importance of genus specialists compared to genus generalists. The findings provide essential data for assessing the role of the intestinal microbiome in maintaining and enhancing swine health and productivity, offering fundamental guidance for further exploration of host-microbe interaction mechanisms and regulatory pathways.

Multi-Omics Analysis Revealed the Molecular Mechanisms Affecting Average Daily Gain in Cattle

The average daily gain (ADG) is a critical index for evaluating growth rates in cattle and is closely linked to the economic benefits of the cattle industry. Heredity is one of the factors affecting the daily gain of cattle. However, the molecular mechanisms regulating ADG remain incompletely understood. This study aimed to systematically unravel the molecular mechanisms underlying the divergence in ADG between high average daily gain (HADG) and low average daily gain (LADG) Angus cattle through integrated multi-omics analyses (microbiome, metabolome, and transcriptome), hypothesizing that the gut microbiota-host gene-metabolism axis is a key regulatory network driving ADG divergence. Thirty Angus cattle were classified according to their HADG and LADG. Fecal and serum samples were collected for 16S, fecal metabolome, and blood transcriptome analysis. The results showed that compared with the LADG group, the abundance of Firmicutes increased in the HADG group, while the abundance of Bacteroidetes and Proteobacteria decreased. Metabolomics and transcriptomic analysis revealed that KEGG pathways associated with differentially expressed genes (DEGs) and differentially abundant metabolites (DAMs) were enriched in bile acid metabolism. Spearman correlation analysis showed that Oscillospira was positively correlated with ZBTB20 and negatively correlated with RADIL. ZBTB20 was negatively correlated with dgA-11_gut_group. This study analyzed the regulatory mechanism of average daily gain of beef cattle from genetic, metabolic, and microbial levels, providing a theoretical basis for analyzing the mechanism of differential daily gain of beef cattle, and has important significance for improving the production performance of beef cattle. The multi-omics network provides biomarker foundations for machine learning-based ADG prediction models, offering potential applications in precision breeding. While these biomarkers show promise for precision breeding, their causal roles require further validation. The conclusions are derived from a single breed (Angus) and gender (castrated males). Future studies should include females and diverse breeds to assess generalizability.

Characterization of Choerospondias axillaris polysaccharide‑iron (III) complex and its effect on iron deficiency anemia mice

Iron deficiency anemia (IDA) is a prevalent nutritional deficiency problem. This study aimed to investigate the characteristics of Choerospondias axillaris polysaccharide-Fe (III) complex and its effect on IDA mice. CAP-Fe (III) complex was synthesized by co-thermal synthesis method with an iron content of 27.31 ± 0.97 %. The chelation of Fe3+ reduced the crystallinity, increased the thermal stability and changed the morphological features of CAP, which was evidenced by XRD, TG, and SEM analysis. The probable existence of the β-FeOOH structure was supported by the characteristic absorption peaks in the FT-IR, XRD, and Mössbauer spectra. The CAP-Fe (III) complex showed a therapeutic effect on IDA mice, confirmed by improved erythroid parameters, iron levels, and oxidative stress. The results of gene expression levels determined by RT-qPCR demonstrated that the CAP-Fe (III) complex could regulate iron metabolism homeostasis, alleviate liver inflammation, and enhance intestinal barrier function. Furthermore, the dysbiosis of intestinal microbiota induced by IDA was effectively restored by CAP-Fe (III) complex, through enriching beneficial bacteria (Firmicutes, Blautia, Oscillibacter, Colidextribacter) and depleting harmful bacteria (Actinobacteria, Proteobacteria, Parasutterella, Faecalibaculum, Escherichia-Shigella). These findings suggested that CAP-Fe (III) may serve as a novel iron supplement for treating IDA.

Gut Dysbiosis Exacerbates Intestinal Absorption of Cadmium and Arsenic from Cocontaminated Rice in Mice Due to Impaired Intestinal Barrier Functions

Globally, humans face gut microbiota dysbiosis; however, its impact on the bioavailability of cadmium (Cd) and arsenic (As) from rice consumption─a major source of human exposure to these metals─remains unclear. In this study, we compared Cd and As accumulation in the liver and kidneys of mice with disrupted gut microbiota (administered cefoperazone sodium), restored microbiota (administered probiotics and prebiotics following antibiotic exposure), and normal microbiota, all after consuming cocontaminated rice. Compared to normal mice, microbiota-disrupted mice exhibited 30.9-119% and 30.0-100% (p < 0.05) higher Cd and As levels in tissues after a 3 week exposure period. The increased Cd and As bioavailability was not due to changes in the duodenal expression of Cd-related transporters or As speciation biotransformation in the intestine. Instead, it was primarily attributed to a damaged mucus layer and depleted tight junctions associated with gut dysbiosis, which increased intestinal permeability. These mechanisms were confirmed by observing 34.3-74.3% and 25.0-75.0% (p < 0.05) lower Cd and As levels in the tissues of microbiota-restored mice with rebuilt intestinal barrier functions. This study enhances our understanding of the increased risk of dietary metal(loid) exposure in individuals with gut microbiota dysbiosis due to impaired intestinal barrier functions.

Exploring the causal associations of the gut microbiota and plasma metabolites with ovarian cancer: an approach of mendelian randomization analysis combined with network pharmacology and molecular docking

BACKGROUND

While increasing evidence suggests that alterations in the gut microbiota and metabolites are associated with ovarian cancer (OC) risk, whether these associations imply causation remains to be identified.

METHODS

We conducted a two-sample Mendelian randomization (MR) study utilizing a large-scale genome-wide association study (GWAS) to explore the causal effects of the gut microbiota of 196/220 individuals and 1,400 plasma metabolites on OC and epithelial ovarian cancer (EOC) subtypes. Data on the gut microbiota were obtained from the MiBioGen consortium of 18,340 subjects and the Dutch Microbiome Project of 7,738 volunteers. Data on plasma metabolites were derived from a GWAS of plasma metabolites in 8,299 participants. Ovarian cancer (n = 25,509) and EOC subtypes were obtained from the Ovarian Cancer Association Consortium (OCAC). Metabolites and associated targets were analyzed via network pharmacology and molecular docking.

RESULTS

At the genus and species levels, we identified seven risk factors for the gut microbiota: the genus Dialister (P = 0.024), genus Ruminiclostridium5 (P = 0.0004), genus Phascolarctobacterium (P = 0.0217), species Bacteroides massiliensis (P = 0.011), species Phascolarctobacterium succinatutens (P = 0.0212), species Paraprevotella clara (P = 0.0247) and species Bacteroides dorei (P = 0.0054). In addition, five gut microbes at the genus and species levels were found to be protective: genus Family XIII AD3011 group (P = 0.006), genus Butyrivibrio (P = 0.0095), genus Oscillibacter (P = 0.0206), species Roseburia hominis (P = 0.0241), and species Bifidobacterium bifidum (P = 0.0224). For plasma metabolites, we revealed five positive and four negative correlations with OC. Among these, caffeic acid and caffeine metabolites and sphingomyelin and ceramide metabolites were identified as risk factors, whereas phenylalanine metabolites, butyric acid metabolites, and some lipid metabolites were recognized as protective factors. A series of sensitivity analyses revealed no abnormalities, including pleiotropy and heterogeneity analyses.

CONCLUSION

Our MR analysis demonstrated that the gut microbiota and metabolites are causally associated with OC, which has significant potential for the early detection and diagnosis of OC and EOC subtypes, providing valuable insights into this area of research.

Disruption of Gut Microbiota and Associated Fecal Metabolites in Collagen-Induced Arthritis Mice During the Early Stage

Background

Rheumatoid arthritis (RA) is a chronic autoimmune disease and increasing evidence suggests that disturbances in the composition and function of gut microbiota are potentially implicated in the progression of RA. Further revealing the microbiota and related metabolic disorders in the preclinical stage of RA (pre-RA) is of great significance for exploration of disease mechanisms.

Methods

DBA/1 mice were injected with type II collagen on days 0 and 21 to establish collagen-induced arthritis (CIA) mouse model. Footpad thickness, serum autoantibodies, and joint histopathology were used to assess the progression of RA. A combination of 16S rRNA sequencing, untargeted metabolomics and targeted short-chain fatty acids (SCFAs) analysis were employed to comprehensively investigate the alterations of gut microbiota and fecal metabolites in CIA during the pre-RA stage.

Results

20 days after the initial collagen immunization, CIA mice showed immune responses without joint symptoms, alongside gut microbiota disruption. Alterations were observed in 20 microbial taxa, including Oscillospira, Bifidobacterium, Ruminococcus, Allobaculum, Alistipes, Lactobacillus, and Candidatus_Arthromitus, etc. Untargeted and targeted metabolomics identified 33 altered fecal metabolites, mainly including sugars and their derivatives, amino acids, long-chain fatty acids and SCFAs, etc. Correlation analysis showed significant correlations between specific gut microbial abundances and fecal metabolite levels. Especially, SCFAs were strongly associated with Bifidobacterium, Alistipes, Ruminococcus, Anaerotruncus, and Allobaculum.

Conclusion

These findings suggest that collagen immunization leads to disruption of gut microbiome and induces changes of fecal metabolites in mice, which may play a key role in early development of RA in CIA mice.

Alterations of lung and gut microbiota in sodium butyrate alleviating heat stress-induced lung injury of broilers

Heat-induced stress has a significant impact on the health of broilers. It induces panting behavior and elevates oxygen consumption, leading to considerable strain on the broiler lungs. However, the precise effects of heat stress on lung injury, along with changes in the lung and gut microbiota, are not yet fully understood. In our study, Arbor Acres (AA) broilers were employed as a model to assess the efficacy of sodium butyrate (SB) in mitigating heat stress-induced lung injury, while concurrently exploring the potential role of lung and gut microbiota in this phenomenon. Heat stress negatively affected broilers, particularly leading to lung injury, which was alleviated by dietary supplementation with SB. However, antibiotic-induced dysbiosis of the microbiota diminished the protective effects of SB, highlighting the critical importance of gut microbiota homeostasis. Heat stress resulted in a reduction in lung microbial diversity and altered its composition, primarily due to the depletion of g_Clostridia and the proliferation of g_Staphylococcus. SB supplementation helped restore beneficial microbes and improved their adaptation to heat stress. Heat stress induced comparable effects on the gut microbiota, resulting in a decline in p_Firmicutes and an elevation in p_Bacteroidetes. However, SB supplementation effectively modulated these alterations in the gut microbiota, promoting a more beneficial microbial profile. Our findings highlighted the significant contributions of both lung and gut microbiota in maintaining homeostasis during heat stress. Moreover, SB administration demonstrated its efficacy in mitigating heat stress-induced lung injury in broilers. This study provides critical insights for developing dietary strategies to reduce heat stress and promote broiler health.

Gut Microbiota: An Important Participant in Childhood Obesity

Increasing prevalence of childhood obesity has emerged as a critical global public health concern. Recent studies have challenged the previous belief that obesity was solely a result of excessive caloric intake. Alterations in early-life gut microbiota can contribute to childhood obesity through their influence on nutrient absorption and metabolism, initiation of inflammatory responses, and regulation of gut-brain communication. The gut microbiota is increasingly acknowledged to play a crucial role in human health, as certain beneficial bacteria have been scientifically proven to possess the capacity to reduce body fat content and enhance intestinal barrier function and their metabolic products to exhibit anti-inflammatory effect. Examples of such microbes include bifidobacteria, Akkermansia muciniphila, and Lactobacillus reuteri. In contrast, an increase in Enterobacteriaceae and propionate-producing bacteria (Prevotellaceae and Veillonellaceae) has been implicated in the induction of low-grade systemic inflammation and disturbances in lipid metabolism, which can predispose individuals to obesity. Studies have demonstrated that modulating the gut microbiota through diet, lifestyle changes, prebiotics, probiotics, or fecal microbiota transplantation may contribute to gut homeostasis and the management of obesity and its associated comorbidities. This review aimed to elucidate the impact of alterations in gut microbiota composition during early life on childhood obesity and explores the mechanisms by which gut microbiota contributes to the pathogenesis of obesity and specifically focused on recent advances in using short-chain fatty acids for regulating gut microbiota and ameliorating obesity. Additionally, it aimed to discuss the therapeutic strategies for childhood obesity from the perspective of gut microbiota, aiming to provide a theoretical foundation for interventions targeting pediatric obesity based on gut microbiota.

Gut microbiota, inflammatory cytokines and gastro-esophageal reflux disease: A Mendelian randomization analysis

Gut microbiota has been recognized as an extrahepatic manifestation of gastro-esophageal reflux disease (GERD) in observational studies. However, the directionality and causality of the association and whether cytokines act as a mediator remain unclear. We aim to estimate the casual relationship between gut microbiota, inflammatory cytokines and GERD using a 2-sample Mendelian randomization method. Gut microbiota, cytokines, and GERD were identified using summary data from the genome-wide association studies and the FinnGen consortium. The primary method for causal estimation was the inverse-variance weighted approach, complemented by a range of sensitivity analyses aimed at assessing heterogeneity, horizontal pleiotropy, and the robustness of the findings. Furthermore, mediation analysis was conducted to evaluate the association between gut microbiota and GERD, with 5 cytokines, and to calculate the mediated proportions. We found 3 positive and 3 negative causal associations observed between genetic predisposition in gut microbiota and GERD. Additionally, 2 positive and 3 negative causal associations were identified between cytokines and GERD. Our analysis unveiled that TNF-related apoptosis-inducing ligand levels (TRAIL) mediated the causal relationships between the genera Family XIII UCG001 and Senegalimassilia, and GERD. We identified causal effects between 6 bacterial traits, 5 inflammatory cytokines, and GERD. Notably, we furnished causal evidence linking TRAIL levels to a substantial proportion of the risk attributed to genus Family XIII UCG001 and genus Senegalimassilia, thereby mediating the risk of GERD. These findings offer novel avenues for therapeutic interventions targeting individuals with GERD.

Sesamin Alleviates Allergen-Induced Diarrhea by Restoring Gut Microbiota Composition and Intestinal Barrier Function

Food allergens are the key triggers of allergic diarrhea, causing damage to the immune-rich ileum. This weakens the mucosal barrier and tight junctions, increases intestinal permeability, and exacerbates allergen exposure, thereby worsening the condition. Sesamin, a natural lignan isolated from sesame seed, has shown potential in regulating immune responses, but its effects on intestinal health remain unclear. In this study, we constructed an ovalbumin (OVA)-induced allergic diarrhea mouse model, which demonstrated increased mast cell degranulation, reduced tight junction integrity, and impaired intestinal barrier function. Pro-inflammatory cytokines were significantly increased in the ileum, along with unbalanced cluster of differentiation 4 (CD4+) T-cell immunity, altered gut microbiota composition, and disrupted bacterial metabolism. Sesamin treatment significantly alleviated intestinal damage by modulating gut microbiota abundance, enhancing short-chain fatty acid (SCFA) production, and increasing SCFA receptor expression. This study suggests that sesamin may be a promising therapeutic candidate for allergic diarrhea and intestinal injury.

Structural characteristics and nonvolatile metabolites of theabrownins and their impact on intestinal microbiota in high-fat-diet-fed mice

This study prepared enzymatic theabrownins (TBs-e), alkaline theabrownins (TBs-a), and Pu-erh tea theabrownins (TBs-f), and investigated whether different preparation processes affected the structures, nonvolatile metabolites, and biofunctional activities of TBs. Structural characterization revealed that TBs were polymeric phenolic compounds rich in hydroxyl and carboxyl groups. Nontargeted metabolomics revealed that amino acids were the primary nonvolatile metabolites in TBs-e and TBs-a, accounting for over 70 % of the total nonvolatile content. TBs-f contained more polyphenols, caffeine, and flavonoids, accounting for 14.2 %, 3.9 %, and 0.8 % of total nonvolatile content, respectively. In vivo, at 560 mg/kg body weight, TBs-f were associated with regulation of blood glucose and lipid concentrations in mice. Moreover, 16S rRNA indicated that at 1120 mg/kg body weight, TBs-a were associated with increased numbers of microbiota linked with hypolipidemic activity. This study explores the impacts of different preparation processes on TBs and provides a theoretical foundation for the understanding of TBs.

Comprehensive omics analysis of the fecal microbiome and serum metabolome in Dezhou donkey foals at the end of weaning and after weaning

Weaning is essential for foal growth and development. We determined the intestinal flora structure of donkey foals at the end of weaning (PreW_4d) and three stages after weaning (PostW_4d, PostW_8d, and PostW_15d) to explore the effects of weaning on intestinal development of donkey foals. The results showed that the main microbial flora in the gut of the donkey foal were Firmicutes and Bacteroides, and the proportion of Firmicutes gradually increased with weaning, which was an important reflection of the donkey foal's adaptability to the transition from lactose liquid feed to plant fiber solid feed. We also identified important microorganisms that maintain intestinal stability and boost immune, such as oscillospiraceae, Firmicutes, and lachnospiraceae. The metabolome showed that serum metabolites were mainly enriched in arachidonic acid metabolism and the tricarboxylic acid cycle (TCA cycle), which can influence energy metabolism, growth, and immunity in weaned donkey foals. We also found that the metabolite resveratrol was positively correlated with g_NK4A214_group and lactobacillus, which may have important implications for the prevention of diseases such as colon-inflammation in donkey foals. In summary, we provide a theoretical basis for studying the mechanism of intestinal microbiome and serum metabolite changes in weaning and postweaning donkey foals.

Bifidobacterium longum JBLC-141 alleviates hypobaric hypoxia-induced intestinal barrier damage by attenuating inflammatory responses and oxidative stress

Hypobaric hypoxia exposure occurs at high altitudes, including plateaus, and affects normal intestinal function and microbiota composition. Exposure induces an intestinal inflammatory response and oxidative stress injury, ultimately disrupting intestinal homeostasis and causing barrier damage. Thus, due to its anti-inflammatory, antioxidative, and intestinal microbiota-regulating properties, Bifidobacterium longum is a potentially effective probiotic intervention to protect the intestinal barrier during low-pressure hypoxia on plateaus. However, its mechanism of action is not fully defined. In this study, we investigate the mechanism by which B. longum intervenes in intestinal barrier damage caused by plateau low-pressure hypoxia. To this end, an in vivo model is established by exposing rats to a simulated low-pressure hypoxic plateau environment. The experimental rats were subsequently supplemented with a B. longum strain (JBLC-141) extracted from the feces of healthy adults in Bama, Guangxi. B. longum JBLC-141 mitigates the effects of plateau low-pressure hypoxia on the rat intestinal barrier. This is achieved by activating the intestinal Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway, alleviating plateau hypoxia-induced intestinal oxidative stress injury. B. longum JBLC-141 also attenuates the inflammatory response and upregulates the expression of the tight junction proteins claudin-1, occludin, and zonula occludens-1. Furthermore, it reduces intestinal permeability, effectively ameliorating and repairing the barrier histological damage induced by the plateau low-pressure hypoxic environment. In addition, B. longum JBLC-141 positively regulates the intestinal microbiota, increasing the relative abundance of beneficial bacteria while reducing that of pathogenic bacteria and maintaining intestinal flora homeostasis in rats.

Artemisia annua Residue Regulates Immunity, Antioxidant Ability, Intestinal Barrier Function, and Microbial Structure in Weaned Piglets

Artemisia annua residue (AR), as the byproduct of industrial extraction of artemisinin, contains rich nutrients and active ingredients. This study was conducted to determine the effects of AR as an unconventional feed material on growth performance, immunity, and intestinal health in weaned piglets. Thirty-two piglets weaned at 21 days (7.53 ± 0.31 kg average BW) were fed with a corn-soybean basal diet (BD) and a basal diet with 1% (LAR), 2% (MAR), and 4% (HAR) AR diets for 28 days. AR diets increased the serum IgA and complement component 3 levels, superoxide dismutase activity, and villus height in the duodenum (p < 0.05). The MAR group increased the ADG, serum total protein, and mRNA expression levels of Claudin-1 in the duodenum and zonula occludens-1 (ZO-1) and the mucin 2 (MUC2) in the colon, as well as colonic Romboutsia and Anaerostipes abundances, and decreased the Proteobacteria abundance (p < 0.05). To sum up, dietary AR supplementation may enhance growth performance by improving serum immunoglobulin and antioxidant enzyme activity, intestinal morphology, tight junction protein expression, and gut microbiota of weaned piglets. Regression analysis showed that the optimal AR supplemental level for growth performance, immunity, antioxidant ability, and intestinal health of weaned piglets was 2.08% to 4.24%.

Identification of a PET hydrolytic enzyme from the human gut microbiome unveils potential plastic biodegradation in human digestive tract

Widespread use of polyethylene terephthalate (PET) plastics and their recycling challenges have led to substantial accumulation of PET wastes in global environments, with inevitable consequences for their entry into the food chains. Recent studies have increasingly documented the ingestion of microplastics by humans through food and beverages. However, the fate of these microplastics within the gastrointestinal tract, particularly the role of the human gut microbiota, remains inadequately understood. To address this knowledge gap, we employed a bioinformatics workflow integrated with functional verification to investigate the PET digestion/degradation capabilities of intestinal microorganisms. This approach identified a novel PET hydrolase-HGMP01 from the human gut metagenome, which exhibits the capacity to hydrolyze PET nanoparticles. Moreover, comprehensive exploration for HGMP01 homologues in the human gut metagenome and metatranscriptome unveil their distribution in diverse intestinal microorganisms. This study provides biochemical evidence for an unforeseen role of human gut microbiome in plastic digestion, thus holding substantial implications for human health.

Oral supplementation with lactic acid bacteria improve the intestinal epithelial barrier and gut microbiota of broiler chicks to alleviate Salmonella Enteritidis infection

Lactic acid bacteria (LAB) play a key role in regulating the balance of gut microbiota and serve as a suitable alternative to antibiotics. This study aims to evaluate the characteristics of 2 LAB isolates Lactiplantibacillus plantarum Lp71 (L. plantarum Lp71) and Enterococcus faecium Ef72 (E. faecium Ef72), and their roles in alleviating Salmonella Enteritidis infection. Sixty 1-day-old chicks were randomly divided into 4 groups which treated with or without L. plantarum Lp71 and E. faecium Ef72 mixture for 21 d, and then intestinal samples were collected for gut microbiota analysis, pathological and immunohistochemical analysis at 24 h post infection with or without Salmonella Enteritidis on the 22nd d. The results showed that L. plantarum Lp71 and E. faecium Ef72 had the ability to anti-acid and anti-bile salt. Salmonella Enteritidis infection damaged the intestinal epithelial barrier and reduced the expression level of tight junction proteins (ZO-1, Claudin-1, Occludin). Oral supplementation with L. plantarum Lp71 and E. faecium Ef72 mixture could alleviated the damages to intestinal epithelial barrier by Salmonella Enteritidis infection. Salmonella Enteritidis could cause abnormal Akkermansia muciniphila proliferation and decrease the diversity of cecal microbiota in chicks. These conditions could have further led to reduce gut microbiota health index (GMHI), and improve microbial dysbiosis index (MDI). Moreover, oral supplementation with L. plantarum Lp71 and E. faecium Ef72 mixture could effectively prevent the aforementioned infection outcomes and increase the abundance proportions of the several key functions in metabolic pathways metabolic pathways such as transcription and signal transduction mechanisms. In summary, L. plantarum Lp71 and E. faecium Ef72 could be the probiotics candidates that used to prevent the damage from enteric pathogens such as Salmonella Enteritidis in broiler chicks.

Differences in gut microbiota and metabolites between wrestlers with varying precompetition weight control effect

This study intended to analyze the effects of body weight control by the diet, training adaptation, and gut microbiota metabolites of wrestlers in the week leading up to competition. According to the weight difference of wrestlers from the target weight 1 wk before the competition, those whose weight control effectiveness is less than 2 kg were classified as the CW group, whereas more than 2 kg were classified as the CnW group. The body weight, body composition, and diet of wrestlers were recorded; urine samples were taken for standard urine testing, and stool samples were collected for the analysis of gut microbiota and metabolites. The data showed that the relative values of carbohydrate and fat energy in the CnW group were significantly higher than those of the CW group, but the relative values of protein energy were significantly lower. The white blood cells, occult blood, and protein appeared in urine in the CnW group. The microbiota with higher abundance values in the CnW group were positively correlated with the relative value of carbohydrate energy, while the abundance value of Streptococcus was negatively correlated, and the functional prediction of differential bacteria was related to riboflavin and selencompound metabolism. The differential metabolites of CW/CnW group were functionally enriched in the processes of lipid and amino acid metabolism. Overall, the extent of weight control in wrestlers was correlated with sensible dietary patterns, adaptability to training load, and distinct gut microbiota and metabolites.NEW & NOTEWORTHY The purpose of this study is to observe the differences in precompetition diet structure, adaptability to training, gut microbiota, and metabolites of wrestlers with different weight control effects and analyze the correlation between them, aiming to provide scientific guidance and advice on weight control for wrestlers.

In Silico Analysis of Probiotic Bacteria Changes Across COVID-19 Severity Stages

The gut microbiota plays a crucial role in modulating the immune response during COVID-19, with several studies reporting significant alterations in specific bacterial genera, including Akkermansia, Bacteroides, Bifidobacterium, Faecalibacterium, Lactobacillus, Oscillospira, and Ruminococcus. These genera are symbionts of the gut microbiota and contribute to host health. However, comparing results across studies is challenging due to differences in analysis methods and reference databases. We screened 16S rRNA raw datasets available in public databases on COVID-19, focusing on the V3-V4 region of the bacterial genome. In total, seven studies were included. All samples underwent the same bioinformatics pipeline, evaluating the differential abundance of these seven bacterial genera at each level of severity. The reanalysis identified significant changes in differential abundance. Bifidobacterium emerged as a potential biomarker of disease severity and a therapeutic target. Bacteroides presented a complex pattern, possibly related to disease-associated inflammation or opportunistic pathogen growth. Lactobacillus showed significant changes in abundance across the COVID-19 stages. On the other hand, Akkermansia and Faecalibacterium did not show significant differences, while Oscillospira and Ruminococcus produced statistically significant results but with limited relevance to COVID-19 severity. Our findings reveal new insights into the differential abundance of key bacterial genera in COVID-19, particularly Bifidobacterium and Bacteroides.

Impact of high-fructose diet and metformin on histomorphological and molecular parameters of reproductive organs and vaginal microbiota of female rat

There are limited data on the effects of a high-fructose diet on the female reproductive system. Although metformin has some functional effects on female fertility, its reproductive outcome on high fructose diet-induced metabolic syndrome is unclear. The aim of the present study is to evaluate the impact of a high fructose diet on histomorphological and molecular parameters of the reproductive organs and vaginal microbiota as well as the treatment potential of metformin. Wistar albino rats were used in the study. The metabolic syndrome model was induced by a high-fructose diet in rats for 15 weeks. Metformin was orally administered once a day for the last 6 weeks. The high-fructose diet increased blood glucose, triglycerides, insulin, and ovarian testosterone levels; however, it reduced ovarian aromatase levels and follicle numbers and caused uterine inflammation. The high-fructose diet-induced molecular abnormalities on ovarian tissue were demonstrated by the downregulation of ovarian insulin signaling pathway proteins and dysregulation of ovarian mitogenic and apoptotic pathway proteins. A high-fructose diet caused vaginal dysbiosis, metformin increased probiotic bacteria in the vaginal microbiota. Our results revealed that metformin improves ovarian impairments by modulating hormonal balance, insulin level, mapk, and apoptotic signaling molecules, as well as regulating the vaginal microbiota.

Mediterranean Diet and Olive Oil Redox Interactions on Lactate Dehydrogenase Mediated by Gut Oscillibacter in Patients with Long-COVID-19 Syndrome

Chronic viral inflammation is associated with oxidative stress and changes in gut microbiota. The Mediterranean diet (MD), with recognized anti-inflammatory and antioxidant properties, modulates gut microorganisms, specifically on the interaction between extra virgin olive oil, a key component of the MD with well-documented antioxidant effects. This study investigated the influence of adherence to MD and antioxidant-rich foods (extra virgin olive oil) on biochemical, inflammatory, and microbiota profiles in patients with chronic inflammation defined as a prolonged inflammatory response due to immune dysregulation following the acute phase of the viral infection. Participants were classified into low (n = 54) and high (n = 134) MD adherence groups (cut-off of 7 points based on previous studies utilizing the same threshold in the assessment of MD adherence). Gut microbiota was sequenced using the 16S technique, and the adherence to MD was assessed using a validated questionnaire for a Spanish population. High adherence to the MD was linked to significant improvements in inflammatory and oxidative stress markers, including reductions in LDL-cholesterol, glucose, and lactate dehydrogenase (LDH) levels, an indicative of redox balance, as well as a significant higher consumption of antioxidant foods. Moreover, gut microbiota analysis revealed distinct compositional shifts and a lower abundance of the Oscillibacter genus in the high adherence group. Notably, a significant interaction was observed between MD adherence and extra virgin olive oil consumption, with Oscillibacter abundance influencing LDH levels, suggesting that the MD antioxidant properties may modulate inflammation through gut microbiota-mediated mechanisms. These findings provide new evidence that adherence to the Mediterranean diet can reduce inflammatory markers in patients with long-COVID-19, a population that has not been extensively studied, while also highlighting the potential role of the bacterial genus Oscillibacter in modulating this effect.

Bioresponsive and transformable coacervate actuated by intestinal peristalsis for targeted treatment of intestinal bleeding and inflammation

Developing an oral in situ-forming hydrogel that targets the inflamed intestine to suppress bleeding ulcers and alleviate intestinal inflammation is crucial for effectively treating ulcerative colitis (UC). Here, inspired by sandcastle worm adhesives, we proposed a water-immiscible coacervate (EMNs-gel) with a programmed coacervate-to-hydrogel transition at inflammatory sites composed of dopa-rich silk fibroin matrix containing embedded inflammation-responsive core-shell nanoparticles. Driven by intestinal peristalsis, the EMNs-gel can be actuated forward and immediately transform into a hydrogel once contacting with the inflamed intestine to yield strong tissue adhesion, resulting from matrix metalloproteinases (MMPs)-triggered release of Fe3+ from embedded nanoparticles and rearrangement of polymer network of EMNs-gel on inflamed intestine surfaces. Extensive in vitro experiments and in vivo UC models confirmed the preferential hydrogelation behavior of EMNs-gel to inflamed intestine surfaces, achieving highly effective hemostasis, and displaying an extended residence time ( > 48 h). This innovative EMNs-gel provides a non-invasive solution that accurately suppresses severe bleeding and improves intestinal homeostasis in UC, showcasing great potential for clinical applications.

Alginate Oligosaccharides Enhance Gut Microbiota and Intestinal Barrier Function, Alleviating Host Damage Induced by Deoxynivalenol in Mice

BACKGROUND

Alginate oligosaccharides (AOS) exhibits notable effects in terms of anti-inflammatory, antibacterial, and antioxidant properties. Deoxynivalenol (DON) has the potential to trigger intestinal inflammation by upregulating pro-inflammatory cytokines and apoptosis, thereby compromising the integrity of the intestinal barrier function and perturbing the balance of the gut microbiota.

OBJECTIVES

We assessed the impact of AOS on mitigating DON-induced intestinal damage and systemic inflammation in mice.

METHODS

After a 1-wk acclimatization period, the mice were divided into 4 groups. For 3 wk, the AOS and AOS + DON groups were gavaged daily with 200 μL of AOS [200 mg/kg body weight (BW)], whereas the CON and DON groups received an equivalent volume of sterile Phosphate-Buffered Saline (PBS). Subsequently, for 1 wk, the DON and AOS + DON groups received 100 μL of DON (4.8 mg/kg BW) daily, whereas the control (CON) and AOS groups continued receiving PBS.

RESULTS

After administering DON via gavage to mice, there was a significant decrease (P < 0.05) in body weights compared with the CON group. Interestingly, AOS exhibited a tendency to mitigate this weight loss in the AOS + DON group. In the feces of mice treated with both AOS and DON, the concentration of DON significantly increased (P < 0.05) compared with the DON group alone. Histological analysis revealed that DON exposure caused increased intestinal damage, including shortened villi and eroded epithelial cells, which was ameliorated by presupplementation with AOS, alleviating harm to the intestinal barrier function. In both jejunum and colon tissues, DON exposure significantly reduced (P < 0.05) the expression of tight junction proteins (claudin and occludin in the colon) and the mucin protein mucin 2, compared with the CON group. Prophylactic administration of AOS alleviated these reductions, thereby improving the expression levels of these key proteins. Additionally, AOS supplementation protected DON-exposed mice by increasing the abundance of probiotics such as Bifidobacterium, Faecalibaculum, and Romboutsia. These gut microbes are known to enhance (P < 0.05) anti-inflammatory responses and the production of short-chain fatty acids (SCFAs), including total SCFAs, acetate, and valerate, compared with the DON group.

CONCLUSIONS

This study unveils that AOS not only enhances gut microbiota and intestinal barrier function but also significantly mitigates DON-induced intestinal damage.

Metabolic modelling as a powerful tool to identify critical components of Pneumocystis growth medium

Establishing suitable in vitro culture conditions for microorganisms is crucial for dissecting their biology and empowering potential applications. However, a significant number of bacterial and fungal species, including Pneumocystis jirovecii, remain unculturable, hampering research efforts. P. jirovecii is a deadly pathogen of humans that causes life-threatening pneumonia in immunocompromised individuals and transplant patients. Despite the major impact of Pneumocystis on human health, limited progress has been made in dissecting the pathobiology of this fungus. This is largely due to the fact that its experimental dissection has been constrained by the inability to culture the organism in vitro. We present a comprehensive in silico genome-scale metabolic model of Pneumocystis growth and metabolism, to identify metabolic requirements and imbalances that hinder growth in vitro. We utilise recently published genome data and available information in the literature as well as bioinformatics and software tools to develop and validate the model. In addition, we employ relaxed Flux Balance Analysis and Reinforcement Learning approaches to make predictions regarding metabolic fluxes and to identify critical components of the Pneumocystis growth medium. Our findings offer insights into the biology of Pneumocystis and provide a novel strategy to overcome the longstanding challenge of culturing this pathogen in vitro.

Study on the physicochemical properties and gut microbiota regulation of Poria cocos pachyman treated by ball milling

The effect of ball milling on the physicochemical properties and gut microbiota regulation of Poria cocos pachyman (PAC) was investigated. Ball milling reduced the particle size of PAC from 102 μm to 25.19 μm after 12 h, resulting in increasing particle uniformity. Scanning electron microscopy (SEM) revealed surface roughening and fragmentation of PAC after ball milling. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) indicated reduced crystallinity and increased hydroxyl group exposure in ball-milled PAC (BMP). Thermogravimetric analysis (TGA) showed decreased thermal stability in BMP. The optimal ball milled time was 7 h. Moisture contents in PAC and BMP-7 h were 10.30 ± 0.47 % and 10.72 ± 0.12 %, and carbohydrate contents were 81.02 ± 2.27 % and 74.54 ± 1.46 %. In vivo studies on mice demonstrated that both PAC and BMP-7 h increased diversity and reshaped the composition of gut microbiota, with BMP-7 h showing a more pronounced effect. BMP-7 h reduced the Firmicutes/Bacteroidetes ratio, and raised the abundance of Bacteroides, suggesting enhanced prebiotic potential. These findings highlight the role of ball milling in improving the physicochemical properties and prebiotic potential of water-insoluble polysaccharides and provide a theoretical basis for its broader application in the food and biopharmaceutical industries.

Ternary inulin hydrogel with long-term intestinal retention for simultaneously reversing IBD and its fibrotic complication

Excessive accumulation of reactive oxygen and nitrogen species (RONS) and dysbiosis of intestinal microbiota are pivotal symptoms for inflammatory bowel disease (IBD) and its associated complications, such as intestinal fibrosis. This research introduces a probiotic inulin hydrogel loaded with polypyrrole (PPy) nanozymes and antifibrotic drug pirfenidone (PFD) (PPy/PFD@Inulin gel) designed for the concurrent amelioration of IBD and its fibrotic complication. Upon oral administration, the inulin gel matrix could extend the gastrointestinal residence time of PPy nanozymes and PFD, facilitating the efficient reduction of pro-inflammatory cytokine levels and enhancement of the intestinal epithelial barrier repair as well as the suppression of intestinal fibrosis through sustained RONS scavenging, modulation of gut microbiota and attenuation of the TGF-β/Smad signaling pathway to inhibit fibroblast proliferation. Notably, the PPy/PFD@Inulin gel demonstrated significant prophylactic and therapeutic efficacy in acute and chronic colitis as well as intestinal fibrosis induced by dextran sodium sulfate (DSS) in mouse models. Thus, the engineered ternary PPy/PFD@Inulin gel offered a pioneered paradigm for simultaneous reversal of IBD and its associated complications, such as intestinal fibrosis, in a single therapeutic regimen.

Xiaoer-Feire-Qing granules alleviate pyretic pulmonary syndrome induced by Streptococcus pneumoniae in young rats by affecting the lungs and intestines: An in vivo study based on network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) Xiaoer-Feire-Qing granules (XEFRQ) has been used to treat pyretic pulmonary syndrome (PPS) in children for many years. The function of the lungs is considered to be closely related to the large intestine in TCM.

PURPOSE

We aimed to investigate the effects of XEFRQ on PPS and the underlying mechanisms via network pharmacology and animal experiments.

METHODS

The TCMSP platform was used to identify the ingredients and potential targets of XEFRQ. The GeneCards, OMIM, and TTD databases were used to predict PPS-associated targets. Cytoscape 3.9.1 was employed to construct the protein-protein interaction network, and target prediction was performed by GO and KEGG analyses. For the animal experiment, a PPS model was constructed by three cycles of nasal drip of Streptococcus pneumoniae (STP; 0.5 mL/kg). The animals were randomly divided into the following four groups according to their weight (n = 10 rats per group): the blank group, the model group, the XEFRQ-L (16.3 g/kg) group, and the XEFRQ-H (56.6 g/kg) group. Rats in the blank group and the model group were given 0.5% CMC-Na by gavage. The general conditions of the rats were observed, and their food-intake, body weight, and body temperature were recorded for 14 days. After the intervention of 14 days, serum was collected to detect inflammatory cytokines (TNF-α, IL-1β, and PGE2) and neurotransmitters (5-HT, SP, and VIP). H&E staining was used to observe the pathological morphology of lung and colon tissue. AQP3 expression was detected by Western blot. In addition, the gut microbiota in cecal content samples were analyzed by 16S rDNA high-throughput sequencing.

RESULTS

Our network analysis revealed that XEFRQ may alleviate PPS injury by affecting the levels of inflammatory cytokines and neurotransmitters and mitigating STP-induced PPS.In vivo validation experiments revealed that XEFRQ improved STP-induced PPS and reduced the expression of inflammatory cytokines and neurotransmitters. Notably, XEFRQ significantly decreased the protein expression levels of AQP3, which was associated with dry stool. Our gut microbiota analysis revealed that the relative abundance of [Eubacterium]_ruminantium_group, Colidextribacter, Romboutsia, and Oscillibacter was decreased, which means XEFRQ exerts therapeutic effects against PPS associated with these bacteria.

CONCLUSION

Our results demonstrate that XEFRQ alleviates PPS by affecting the lungs and intestines, further guiding its clinical application.

Effects of bamboo leaf flavonoids on growth performance, antioxidants, immune function, intestinal morphology, and cecal microbiota in broilers

BACKGROUND

Bamboo leaf flavonoids (BLF) are the main bioactive ingredients in bamboo leaves. They have antioxidant, anti-inflammatory, antibacterial, and other effects. In this study, the effects of dietary BLF on growth performance, immune response, antioxidant capacity, and intestinal microbiota of broilers were investigated. A total of 288 broilers were divided into three groups with eight replicates and 12 birds in each replicate. Broilers were fed a basic diet or the basic diet supplemented with 1000 or 2000 mg kg-1 BLF for 56 days.

RESULTS

The results showed that supplementation of BLF increased body weight (BW) and average daily weight gain (ADG), and reduced average daily feed intake (ADFI) (P < 0.05). The serum immunoglobulin A (IgA), immunoglobulin M (IgM), and interleukin 10 (IL-10) content of broilers in the BLF1000 group was increased and the interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α) content was decreased (P < 0.05). The levels of IgM and IL-10 in jejunum mucosa were found to be enhanced by BLF (P < 0.05). The BLF1000 group exhibited a significant reduction in the concentration of TNF-α (P < 0.05). Serum and jejunum mucosa total antioxidant capacity (T-AOC) levels in the BLF1000 group were increased (P < 0.05). The serum catalase (CAT) and glutathione peroxidase (GSH-Px) effects of the BLF1000 group and serum CAT effects of BLF2000 group were increased (P < 0.05). The CON group demonstrated a lower relative abundance of Christensenellaceae_R-7_group and Oscillibacter than the BLF group (P < 0.05).

CONCLUSION

Dietary BLF inclusion enhanced the growth performance, immune, and antioxidant functions, improved the intestinal morphology, and ameliorated the intestinal microflora structure in broiler. Adding 1000 mg kg-1 BLF to the broiler diet can be considered as an effective growth promoter. © 2024 Society of Chemical Industry.

Weight, habitual fibre intake, and microbiome composition predict tolerance to fructan supplementation

Fructans are commonly used as dietary fibre supplements for their ability to promote the growth of beneficial gut microbes. However, fructan consumption has been associated with various dosage-dependent side effects. We characterised side effects in an exploratory analysis of a randomised trial in healthy adults (n = 40) who consumed 18 g/day inulin or placebo. We found that individuals weighing more or habitually consuming higher fibre exhibited the best tolerance. Furthermore, we identified associations between gut microbiome composition and host tolerance. Specifically, higher levels of Christensenellaceae R-7 group were associated with gastrointestinal discomfort, and a machine-learning-based approach successfully predicted high levels of flatulence, with [Ruminococcus] torques group and (Oscillospiraceae) UCG-002 sp. identified as key predictive taxa. These data reveal trends that can help guide personalised recommendations for initial inulin dosage. Our results support prior ecological findings indicating that fibre supplementation has the greatest impact on individuals whose baseline fibre intake is lowest.

CHIKV infection drives shifts in the gastrointestinal microbiome and metabolites in rhesus monkeys

BACKGROUND

Many studies have demonstrated the association between intestinal microbiota and joint diseases. The "gut-joint axis" also has potential roles in chikungunya virus (CHIKV) infection. Pro-inflammatory arthritis after CHIKV infection might disrupt host homeostasis and lead to dysbacteriosis. This study investigated the characteristics of fecal and gut microbiota, intestinal metabolites, and the changes in gene regulation of intestinal tissues after CHIKV infection using multi-omics analysis to explore the involvement of gut microbiota in the pathogenesis of CHIKV infection.

RESULTS

CHIKV infection increases the systemic burden of inflammation in the GI system of infected animals. Moreover, infection-induced alterations in GI microbiota and metabolites may be indirectly involved in the modulation of GI and bone inflammation after CHIKV infection, including the modulation of inflammasomes and interleukin-17 inflammatory cytokine levels.

CONCLUSION

Our results suggest that the GI tract and its microbes are involved in the modulation of CHIKV infection, which could serve as an indicator for the adjuvant treatment of CHIKV infection. Video Abstract.

Mixed Bacillus subtilis and Lactiplantibacillus plantarum-fermented feed improves gut microbiota and immunity of Bamei piglet

Antibiotics are widely used in the breeding production of Bamei pigs, affecting the quality and safety of pork and causing enormous harm to human health, the environment, and public health. The use of probiotic fermented feed to replace antibiotic feed is one of the solutions, which has the potential to improve the intestinal microbiota, promote animal growth, and enhance immunity. The purpose of this study was to evaluate the effect of fermented feed with Lactiplantibacillus (L.) plantarum QP28-1a or Bacillus (B.) subtilis QB8a on feed, growth performance, gut microbiota, and immunity of weaned piglets. A total of 60 freshly weaned piglets from the Tibetan Plateau were randomly divided into five groups and fed basal feed, L. plantarum fermented feed, B. subtilis fermented feed, mixed fermented feed, and antibiotic fermented feed for 60 days, respectively. The results showed fermented feed supplemented with L. plantarum QP28-1a or B. subtilis QB8a significantly lowered the pH of the feed (P < 0.05), produced lactic acid and acetic acid, inhibited the growth of harmful bacteria in the feed, and reduced the feed conversion rate in the group fed mixed fermented feed (P < 0.05). The fermented feed increased the α-diversity and prominently altered the β-diversity of the intestinal microbiota, increasing the relative abundance of beneficial bacteria such as Lactobacillus and Turicibacter and decreasing the relative abundance of conditional pathogens such as Streptococcus and Clostridium, improving the intestinal microbiota of the Bamei piglets. Notably, the mixed fermented feed improved the immunity of Bamei piglets by modulating the production of pro-inflammatory cytokines, anti-inflammatory cytokines, and inflammatory-related signaling pathways. Spearman's correlation analysis revealed that the increased expression of immune-related cytokines may be associated with a significant enrichment of Lactobacillus, Prevotellaceae, Erysipelotrichaceae, and Ruminococcaceae in the gut. In conclusion, the probiotic fermented feed maintained an acidic environment conducive to suppressing pathogens, reduced the feed conversion ratio, optimized the intestinal microbiota, improved immunity, and alleviated intestinal inflammation that may be caused by weaning, demonstrating the excellent application prospects of L. plantarum QP28-1a and B. subtilis QB8a fermented feed in the feeding of Bamei piglets.

Gut microbiome diversity within Clostridia is negatively associated with human obesity

Clostridia are abundant in the human gut and comprise families associated with host health such as Oscillospiraceae, which has been correlated with leanness. However, culturing bacteria within this family is challenging, leading to their detection primarily through 16S rRNA amplicon sequencing, which has a limited ability to unravel diversity at low taxonomic levels, or by shotgun metagenomics, which is hindered by its high costs and complexity. In this cross-sectional study involving 114 Colombian adults, we used an amplicon-based sequencing strategy with alternative markers-gyrase subunit B (gyrB) and DNA K chaperone heat protein 70 (dnaK)-that evolve faster than the 16S rRNA gene. Comparing the diversity and abundance observed with the three markers in our cohort, we found a reduction in the diversity of Clostridia, particularly within Lachnospiraceae and Oscillospiraceae among obese individuals [as measured by the body mass index (BMI)]. Within Lachnospiraceae, the diversity of Ruminococcus_A negatively correlated with BMI. Within Oscillospiraceae, the genera CAG-170 and Vescimonas also exhibited this negative correlation. In addition, the abundance of Vescimonas was negatively correlated with BMI. Leveraging shotgun metagenomic data, we conducted a phylogenetic and genomic characterization of 120 metagenome-assembled genomes from Vescimonas obtained from a larger sample of the same cohort. We identified 17 of the 72 reported species. The functional annotation of these genomes showed the presence of multiple carbohydrate-active enzymes, particularly glycosyl transferases and glycoside hydrolases, suggesting potential beneficial roles in fiber degradation, carbohydrate metabolism, and butyrate production.

IMPORTANCE

The gut microbiota is diverse across various taxonomic levels. At the intra-species level, it comprises multiple strains, some of which may be host-specific. However, our understanding of fine-grained diversity has been hindered by the use of the conserved 16S rRNA gene. While shotgun metagenomics offers higher resolution, it remains costly, may fail to identify specific microbes in complex samples, and requires extensive computational resources and expertise. To address this, we employed a simple and cost-effective analysis of alternative genetic markers to explore diversity within Clostridia, a crucial group within the human gut microbiota whose diversity may be underestimated. We found high intra-species diversity for certain groups and associations with obesity. Notably, we identified Vescimonas, an understudied group. Making use of metagenomic data, we inferred functionality, uncovering potential beneficial roles in dietary fiber and carbohydrate degradation, as well as in short-chain fatty acid production.

Silymarin decreases liver stiffness associated with gut microbiota in patients with metabolic dysfunction-associated steatotic liver disease: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Despite centuries of traditional use of silymarin for hepatoprotection, current randomized controlled trial (RCT) studies on the effectiveness of silymarin in managing metabolic dysfunction-associated steatotic liver disease (MASLD) are limited and inconclusive, particularly when it is administered alone. The low bioavailability of silymarin highlights the possible influence of gut microbiota on the effectiveness of silymarin; however, no human studies have investigated this aspect.

OBJECTIVE

To determine the potential efficacy of silymarin in improving MASLD indicators and to investigate the underlying mechanisms related to gut microbiota.

METHOD

In this 24-week randomized, double-blind, placebo-controlled trial, 83 patients with MASLD were randomized to either placebo (n = 41) or silymarin (103.2 mg/d, n = 42). At 0, 12, and 24 weeks, liver stiffness and hepatic steatosis were assessed using FibroScan, and blood samples were gathered for biochemical detection, while faecal samples were collected at 0 and 24 weeks for 16S rRNA sequencing.

RESULTS

Silymarin supplementation significantly reduced liver stiffness (LSM, -0.21 ± 0.17 vs. 0.41 ± 0.17, P = 0.015) and serum levels of γ-glutamyl transpeptidase (GGT, -8.21 ± 3.01 vs. 1.23 ± 3.16, P = 0.042) and ApoB (-0.02 ± 0.03 vs. 0.07 ± 0.03, P = 0.023) but had no significant effect on the controlled attenuation parameter (CAP), other biochemical indicators (aminotransferases, total bilirubin, glucose and lipid parameters, hsCRP, SOD, and UA), physical measurements (DBP, SBP, BMI, WHR, BF%, and BMR), or APRI and FIB-4 indices. Gut microbiota analysis revealed increased species diversity and enrichment of Oscillospiraceae in the silymarin group.

CONCLUSION

These findings suggest that silymarin supplementation could improve liver stiffness in MASLD patients, possibly by modulating the gut microbiota.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trial Registry (ChiCTR2200059043).

A Critical Review on Akkermansia muciniphila: Functional Mechanisms, Technological Challenges, and Safety Issues

Due to its physiological benefits from in vitro and in vivo points of view, Akkermansia muciniphila, a common colonizer in the human gut mucous layer, has consistently been identified as an option for the next-generation probiotic. A. muciniphila is a significant bacterium that promotes host physiology. However, it also has a great deal of potential to become a probiotic due to its physiological advantages in a variety of therapeutic circumstances. Therefore, it can be established that the abundance of A. muciniphila in the gut environment, which is controlled by many genetic and dietary variables, is related to the biological behaviors of the intestinal microbiota and gut dysbiosis/eubiosis circumstances. Before A. muciniphila is widely utilized as a next-generation probiotic, regulatory obstacles, the necessity for significant clinical trials, and the sustainability of manufacturing must be eliminated. In this review, the outcomes of recent experimental and clinical reports are comprehensively reviewed, and common colonization patterns, main factors involved in the colonization of A. muciniphila in the gut milieu, their functional mechanisms in establishing homeostasis in the metabolic and energy pathways, the promising delivery role of microencapsulation, potential genetic engineering strategies, and eventually safety issues of A. muciniphila have been discussed.

Evaluation of biological activity and prebiotic properties of proanthocyanidins with different degrees of polymerization through simulated digestion and in vitro fermentation by human fecal microbiota

The bioactive activity of proanthocyanidins (PAs) is closely associated with their degree of polymerization (DP), however, the effects of PAs with different DP on digestion and gut microbiota have remained unclear. To investigate this, we conducted in vitro simulated digestion and colonic fermentation studies on samples of PAs with different DP. The results showed that PAs was influenced by both protein precipitation and enzymolysis, resulting in a decrease in functional activity. PAs with a high DP were more sensitive to the gastrointestinal environment. The significant clustering trend in colonic fermentation verified the reliability of multivariate statistical techniques for screening samples with distinct functional differences. The gut microbiota analysis showed that oligomeric PAs had a stronger promoting effect on beneficial bacteria, while high polymeric PAs had a greater inhibitory effect on harmful bacteria. This study offers new insights into the biological activity and microbiological mechanisms of PAs with different DP.