Sclerotinia sclerotiorum is a major crop pathogen commonly managed using fungicides. Efficient biological alternatives are needed but it is essential to determine whether a biocontrol agent persists in soil and affects non-target microbiota. Here, we assessed the environmental fate and the impact of a novel Bacillus sp. strain (SCL1) on soil microbial communities from three contrasted agricultural soils. The fate and effects of SCL1 applied at an agronomical (LD) or elevated (HD) dose were compared with a commercial biocontrol product, tebuconazole, and an untreated control. SCL1 persistence was monitored by selective plate counts and strain-specific quantitative polymerase chain reaction (qPCR) analysis. After inoculation, SCL1 declined rapidly but remained detectable up to day 168; at late time points the SCL1 population stabilized at low levels [~103 colony-forming units (CFU) g-1 in the high-dose treatment], supporting its long-term persistence. Treatment effects on microbial community composition were limited: differentially abundant operational taxonomic units (OTUs) represented up to 9.9% of bacterial and 3.8% of fungal communities. Fungal taxa associated with soil functioning increased under SCL1 treatment in some soils; e.g., Mortierellomycetes in Trugny soil (5.7% in control versus 10.7% under low-dose SCL1 at day 56). SCL1 persisted for at least 6 months in soil microcosms and induced small shifts in bacterial and fungal communities, comparable with reference products. These findings support further field studies to evaluate the efficacy of SCL1 against S. sclerotiorum in rapeseed crops, as well as its persistence and potential non-target effects on soil microbiota. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Synthetic bacterial community based on microbial interactions for bioremediation of petroleum contaminated sites.

Temperate seagrass meadows are foundation habitats, but their communities are hard to census. Here, I provide a first COI environmental DNA (eDNA) metabarcoding snapshot from seawater at a Zostera marina meadow in the Vostok Bay marine reserve (Peter the Great Bay, Sea of Japan). In September 2021, eDNA from two 900 mL replicates of water were filtered, isolated, amplified for the 313 bp COI fragment with dual-index PCR (multiple replicates), and sequenced on Illumina NovaSeq. I obtained 53,666 reads for 176 operational taxonomic units (OTUs). Eukaryota dominated (154 OTUs; 93.7% of reads), while 22 bacterial OTUs comprised 6.3%. The assemblage was largely photosynthetic microeukaryotes, especially diatoms (61 OTUs; 49% of reads), consistent with late-summer productivity. Metazoan detections included a strong signal of the phoronid Phoronopsis harmeri (7511 reads; 14%), diverse invertebrates, and few vertebrate reads (0.5%), indicating limited fish sensitivity of universal COI assays. One abundant OTU was initially assigned to the giant kelp Macrocystis pyrifera but was rejected after additional BLAST and phylogenetic checks, illustrating database-driven misassignments. COI eDNA offers rapid, low-impact screening for marine protected area monitoring, but robust use requires seasonal replication, multi-marker assays, and a curated regional reference library.

Phytoplankton-derived dissolved organic matter (DOM) sustains complex marine microbial communities, yet the role of marine fungi—particularly yeasts—remains understudied regarding their substrate preferences, enzymatic strategies, and ecological relevance. We developed a novel protocol to investigate substrate-specific growth of marine fungal isolates under defined conditions and high temporal resolution. Using the β-1,3-glucan laminarin—a major marine storage polysaccharide of phytoplankton—and its oligomeric and monomeric breakdown products, we characterized growth and substrate utilization profiles of eleven marine yeast isolates from the epipelagic zone at Helgoland Roads, North Sea. Statistical analyses of growth kinetics distinguished four ecotypes with distinct substrate utilization patterns, quantified via phenol–sulfuric acid assays. Fluorophore-assisted carbohydrate electrophoresis (FACE) revealed the lack of endo-laminarinase activity, suggesting laminarin degradation depends on exo-acting enzymes. FACE also revealed a high diversity of short-chained laminarin-based intermediates accumulating over time, demonstrating that yeasts enhance chemical complexity during laminarin degradation and may fuel other microbes within the microbial loop. Representatives of each yeast ecotype were found to match abundant operational taxonomic units (OTU) in sequence similarity analyses of epipelagic mycoplankton datasets. This supports their ecological success and diverse substrate strategies. Rather than acting solely as opportunists, these yeasts may actively shape DOM turnover and carbon cycling within the microbial loop. Our study highlights a robust experimental approach for resolving functional diversity among marine yeasts and underpins their potential role in maintaining chemical diversity and substrate cross-feeding in the microbial loop.

Microbial dynamics in a swine wastewater treatment plant and prediction of potential hosts of antibiotic resistance genes.

Insights into polyolefin oligomer stress regulation of microbial communities and degradation mechanisms of polyethylene.

Abstract This study aimed to investigate the rumen microbiome of Charolais bulls with divergent RFI-EPD values to identify microbial taxa associated with feed efficiency. Forty Charolais bulls (443 ± 64 kg body weight) were evaluated for feed intake and growth performance over 60 days, and RFI values were determined. Vytelle (Vytelle Insight Beef Genetics) conducted genetic evaluation of the bulls for residual feed intake-expected progeny difference (RFI-EPD). The 10 most feed-efficient (NegRFI) and 10 least feed-efficient (PosRFI) bulls were selected and ranked based off their RFI-EPD coefficients for microbiome analysis. Rumen fluid samples were collected using an orally administered stomach tube and analyzed via 16S rRNA gene sequencing. Growth performance data showed that NegRFI bulls consumed less dry matter (9.39 kg/d, p = 0.006) compared to PosRFI bulls (10.55 kg/d), with no significant difference in average daily gain (p = 0.073). Microbial analysis revealed no significant differences in alpha (p = 0.92) or beta diversity (p = 0.397) between groups, but differential abundance analysis identified 20 operational taxonomic unit (OTU) as more prevalent in NegRFI bulls, including Clostridiales OTU 133719, Ruminococcus OTU 823658, and S24-7 OTU 4479793. Fifteen OTUs, such as Oscillospira OTU 290253 and F16 OTU 277519, were more abundant in PosRFI bulls. Two OTUs from key genus Prevotella showed different relative abundance in the two RFI-EPD groups. NegRFI bulls had higher relative abundance of Prevotella OTU 109358, while PosRFI bulls had more Prevotella OTU 626329. Additionally, OTUs from Ruminococcus, a genus involved in fiber degradation and volatile fatty acid (VFA) production, were more abundant in NegRFI bulls, suggesting a rumen community optimized for fiber degradation and energy utilization. In contrast, PosRFI bulls had a higher abundance of OTUs from Oscillospira and F16, both linked to butyrate production. These findings highlight the potential of targeting the rumen microbiome to improve feed efficiency in cattle breeding programs. Further research is needed to clarify the functional roles of these microbial taxa.

Abstract Synchronization protocols with progesterone (P4) implants for 7 days contribute to shifts in vaginal microbial populations. However, these alterations have yet to be characterized when utilizing extended implant time protocols. The objective of this study was to determine the diversity and composition of vaginal bacteria and characterize circulating cytokines in pregnant (P) vs. open (OP) beef cows submitted to a 14-day implant (7&7) synchronization protocol. Beef cows (n=133) were enrolled across two farms. Cows were swabbed with a double-guarded culture swab (Jorgensen Laboratories, CO) by spinning on the cranial vagina on days (d) 0, and 14 of the protocol. Additionally, blood samples were collected on d0, d14, and at artificial insemination (AI). On d14, cows received an estrus detection patch (Estrotect™, Rockway INC, WI) and detection was performed every 6h during the daytime, starting 24h after implant pull. Cows underwent artificial AI 12-18h after patch activation. Cows that expressed heat at 54h and up after implant removal were bred at the fixed time (66 ± 2h) and received a concomitant GnRH injection. Pregnancy diagnosis was performed by ultrasonography at d32 post-AI. Cows were grouped post-hoc based on pregnancy status, and then 12 P and 12 OP cows were randomly selected for microbiome and cytokine analysis. Cytokines were analyzed using RayBiotech Quantibody Bovine Cytokine Array Q1 and MyBioSource high-sensitivity ELISA kits for IL6 and TGFβ per the manufacturer’s instructions. Microbiome data were generated from Illumina MiSeq (2x300) sequencing of PCR amplicons targeting the V1-V3 region of the 16 rRNA gene. Sequences were analyzed using custom Perl scripts and software (Mothur v.1.40, RDP classifier, and NCBI Blast). Analysis of species-level operational taxonomic units (OTUs) was performed on the samples. Statistical analysis of microbial abundances used Kruskal-Wallis’s and Pairwise Wilcox’s test. Cytokines data was analyzed with Proc Mixed in Sas 9.4. The topmost abundant OTU, RP1-00038, closely related to Citrobacter gillenii (99.43%), decreased in abundance by d14 (OP:d0=68.6%, OP:d14=9.9%, P:d0=71.6%, P:d14=5.5%; P≤0.00003). OTU RP4-08239, closely related to Helcococcus ovis (99.60%), had abundance increased from d0 to d14 according to status (OP:d0=0.6%, OP:d14=18.4%, P:d0=0.5%, P:d14=24.1%; P< 0.0001). The OTUs RP1-00038 and RP4-08239 were similar between statuses on the same day (P >0.05). Cytokines IFNαA (d0 418.29±109.44, d14 564.34±110.24, AI 561.08±124.19 pg/ml), IL13 (d0 2589.24±404.25, d14 3869.99±601.42, AI 3692.72±402.75 pg/ml), and IL21 (d0 1540.35±227.05, d14 2180.29±318.93, AI 2123.44±208.401 pg/ml) increased from d0 to d14 (P< 0.05) but not from d14 to AI (P >0.05). In conclusion, these results indicate a significant shift in the microbiome population associated with the 14 days of intravaginal implant. In addition, cytokines concentrations were altered in the blood, indicating a potential immune response reaction linked to the presence of the implant for 14 days.

The pea root rot complex is caused by various soil-borne pathogens that likely reinforce each other, influencing the composition of the root microbiome and leading to significant yield reductions. Previous studies have shown variations in the abundance of key microbial taxa and differences in disease susceptibility among plant genotypes. To better understand this relationship between plant genetics and microbiome dynamics, we conducted genetic analyses focusing on plant health and frequency of microbial taxa. Two hundred fifty-two diverse pea lines were grown in naturally infested soil under controlled conditions, genotyped, assessed for their disease symptoms at the seedling stage, and analyzed the associated root microbial communities using amplicon sequencing. Genome-wide association studies (GWAS) revealed genomic loci that influence the abundance of various fungal and bacterial operational taxonomic units (OTUs). We identified 54 independent quantitative trait loci (QTLs) significantly linked to the abundance of 98 out of 1227 detected OTUs, while an additional 20 QTLs were associated with more than one OTU. The most significant region was found on chromosome 6, influencing 50 OTUs across 10 distinct QTLs. When comparing genomic markers and microbial OTUs as predictors in a genomic prediction model for root rot resistance and seedling emergence, we found that the abundance of specific microbial groups provided a significantly better predictive ability than QTLs. The abundance of Fusarium species was correlated with increased infection levels, while others, such as those linked to Dactylonectria and Chaetomiaceae, positively correlated with resistance to root rot. These findings were validated by specific QTLs and high genetic heritability for OTU abundance. The results highlight two key points: (1) the presence and abundance of certain microbial groups in the pea root are influenced by distinct QTLs and, thus, determined by the plant genotype, and (2) these microbial communities show heritable correlations with the plant resistance to root rot. By combining plant and microbiome genetic markers—using a “holobiont” approach—we can improve predictions of root rot resistance compared to predictions based on plant genetics alone. These findings set a foundation for practical applications in breeding programs aimed at enhancing disease resistance through microbiome-assisted approaches.

The rumen microbiome impacts beef cattle feed efficiency, a key economic factor in production systems. This study investigated the rumen microbiome of Charolais bulls with divergent residual feed intake-expected progeny difference (RFI-EPD) values to identify microbial taxa associated with feed efficiency. Forty Charolais bulls were evaluated for feed intake and growth over 60 days, and RFI values were determined. The 10 most efficient (NegRFI) and 10 least efficient (PosRFI) bulls were selected for microbiome analysis. Rumen fluid samples were collected and analyzed via 16S rRNA gene sequencing. Microbial analysis revealed no significant differences in alpha or beta diversity between groups, but differential abundance analysis identified 20 operational taxonomic units (OTUs) as more prevalent in NegRFI bulls, while 15 OTUs were more abundant in PosRFI bulls. Two OTUs from the key genus Prevotella showed different relative abundances in the two RFI-EPD groups. NegRFI bulls had a higher relative abundance of Prevotella OTU 109358, while PosRFI bulls had more Prevotella OTU 626329. Additionally, OTUs from Ruminococcus, a genus involved in fiber degradation and volatile fatty acid (VFA) production, were more abundant in NegRFI bulls. In contrast, PosRFI bulls had a higher abundance of OTUs from Oscillospira and F16, both linked to butyrate production. The results of this study support the need for further exploration into the role of microbial taxa associated with feed efficiency. A deeper understanding of the functional profile of the microbiota could aid in the development of microbiome-informed strategies to enhance nutrient utilization and performance in beef cattle.

Natural plant compounds can be used to supplement livestock diets, improving feed efficiency, production, and health, while also reducing environmental impact. In the present study, a Yucca schidigera (Mohave Yucca) extract was added at four rates of inclusion (ROI) of 0, 5, 15, or 30 g/day to a ryegrass and maize silage-based diet and fed to dairy cows in a 4 × 4 Latin square experimental design. Each period was 28 days in duration, with sampling undertaken during the final week of each period. Solid phase digesta (SPD) and liquid phase digesta (LPD) samples were collected via a rumen cannula and analyzed for volatile fatty acids (VFAs), ammonia N, and microbiome using 16S rRNA gene sequencing. Total fecal and urine collection was undertaken over a 3-day period. Rumen microbial diversity was not affected by ROI (LPD: P = 0.180; SPD: P = 0.059). However, discriminant analysis found a decrease in Methanobrevibacter millerae (linear discriminant analysis, LDA = 2.15) and an increase in an unclassified species of Proteobacteria (LDA = 2.10) associated with ROI. Univariate analysis also revealed differential abundance of operational taxonomic units classified as Prevotellaceae and Fibrobacteraceae by ROI (P < 0.05). Maximum rumen ammonia N concentration decreased linearly from 228 to 109 mg/L with ROI (P = 0.044). Rumen VFA concentration was unaffected with the exception of propionate, which showed a linear increase with ROI (P = 0.010). The diurnal rumen pH range (maximum-minimum) also decreased with ROI (P = 0.004). Dry matter intake and milk yield were not affected (P > 0.05) by ROI; however, there was a linear increase in milk fat content from 38.9 to 42.0 g/kg with ROI (P < 0.05).IMPORTANCEDomestic livestock such as dairy cows are inefficient utilizers of dietary nitrogen. This increases feed costs and reduces animal production efficiency. Excreted nitrogenous compounds are also an environmental hazard, such as when they enter water courses as nitrate or are lost to the atmosphere as ammonia or nitrous oxide. Dietary protein is degraded in the rumen via the activity of the microbial population, mainly into ammonia, which may then be utilized by the microbial population to synthesize microbial protein or absorbed into the blood and potentially excreted. Manipulation of the diet or altering the microbial population may increase the utilization of dietary protein, increasing animal performance, decreasing feed costs, and reducing the environmental impact of milk production. This study examines the effect of Yucca schidigera extract on the rumen microbiome and nitrogen utilization in dairy cows.

Pinus tabuliformis is a well-recognized woody mycorrhizae host plant growing in North China. EM fungi contribute to the host health and the stability of the forest ecosystem. However, ectomycorrhiae (EM) fungal community associated with this species is less documented. In this study, we examined EM fungal diversity and composition of P. tabuliformis from three sites in Inner Mongolia, China by using Illumina MiSeq sequencing on the rDNA ITS2 region. Our results showed that a total of 105 EM fungal operational taxonomic units (OTUs) were identified from 15 composite root samples, and the dominant lineages were /suillus-rhizopogon, /tomentella-thelephora, /tricholoma, /amphinema-tylospora, /wilcoxina, /inocybe, and /Sebacina. A high proportion of unique EM fungal OTUs (33, 31.4% of total OTUs) were detected, and some abundant OTUs preferred to exist in specific sites. The composition of EM fungal communities was significantly different among the sites, with soil, climatic, and spatial variables being related to the community variations. The EM fungal community assembly was mainly driven by environmental factors in deterministic processes. These findings suggest that this endemic Pinaceae species in China also harbored a rich and distinctive EM fungal community and deterministic processes played more important roles than stochastic in shaping the symbiotic fungal community. Our study improves our understanding of EM fungal diversity and community structure from the perspective of a single host plant that has not been investigated exclusively before.

Building plumbing influences the microdiversity and community assembly of the drinking water microbiome.

ABSTRACT Nowadays there is evidence that animals are exposed to microplastics (MPs) via food, however there is not much known about their effect on tissue of gastrointestinal tract and on gut microbiome. In this study, adult male rats were fed with polyethylene MPs, mixed with standard pellet food for 24 days at different concentrations ranging from 0 to 1000 μg/day. At the end of experiment, rats were euthanized and histopathological investigation using light and electron microscopy and the gut microbiome was analyzed using MiSeq 16S rRNA amplicon sequencing. Microscopic analysis revealed significant impact of MPs on the intestine, including visible changes to the crypt area as well as reduction in mucus secretion. Autophagic vacuoles were observed in the livers of the rats fed with MPs at 100 µg/day. Oxidative stress was evident in rats fed with 1000 µg/day of MPs, as indicated by the presence of myeloid bodies in both intestinal and hepatic cells. The gut microbiome was also affected by MPs. Although, no distinct clusters were formed when the bacterial communities in the different treatments were ordinated by multidimensional scaling (NMDS), the diversity indices including operational taxonomic unit (OTU) richness and Chao1 exhibited an increasing trend with increasing MPs concentration. Pearson correlations revealed a linear increase in the relative sequence abundance of Clostridia (R=0.036, P=0.003) with increasing MPs concentration, but not in the case of other bacterial groups,. Lactobacillus faecis was the most abundant OTU in the entire dataset, and its relative abundance decreased significantly with increasing MPs concentration. We conclude that exposure to MPs can disrupt cellular function and disturb microbiome balance, and in the event of prolonged exposure, organisms might experience unpredictable effects.

Vermicomposting has been recognized as a sustainable solution for the managing of organic waste, primarily because of the bacterial communities that drive microbial decomposition. However, while the roles of abundant bacteria in composting processes are well-documented, the contributions of rare bacteria remain underexplored. In this study, we investigated the diversity and composition of abundant and rare bacterial communities in gut of Eudrilus eugeniae and resulting vermicompost, comparing okara as a single substrate compared to a combination of more substrates, such as kitchen waste or okara and kitchen waste. Amplicon sequencing revealed a total of 3085 operational taxonomic units (OTUs), comprising 188 abundant OTUs and 2127 rare OTUs. Significant differences in bacterial community composition were observed between vermicompost and the earthworm gut, particularly in the rare bacterial communities, with distinct abundances of Gemmatimonadota, Desulfobacteria, Myxococcota, Acidobacteria, and Firmicutes. Interestingly, no significant differences were found between treatments in the abundant bacterial communities, suggesting that okara alone can sustain a bacterial community comparable to mixed substrates. However, rare bacterial communities were more sensitive to substrate variation, with okara fostering distinct rare microbial populations in the vermicompost and earthworm gut. Our results indicate okara can support both abundant and rare bacteria, producing compost with similar physico-chemical properties to those derived from mixed substrates. The study highlights the importance of rare bacterial communities in vermicomposting and demonstrates the potential of okara as a valuable resource for sustainable waste management and soil improvement.

Bile acids alleviate intestinal inflammation by modulating gut microbiota composition in LPS-challenged broilers.

BackgroundArbuscular mycorrhizal fungi (AMF) are beneficial root symbionts contributing to improved plant growth and development and resistance to abiotic and biotic stresses. Commercial bioinoculants containing AMF are widely considered as an alternative to agrochemicals in vineyards. However, their effects on grapevine plants grown in soil containing native communities of AMF are still poorly understood. In a greenhouse experiment, we evaluated the influence of five different bioinoculants on the composition of native AMF communities of young Cabernet Sauvignon vines grown in a non-sterile soil. Root colonization, leaf nitrogen concentration, plant biomass and root morphology were assessed, and AMF communities of inoculated and non-inoculated grapevine roots were profiled using high-throughput sequencing.ResultsContrary to our predictions, no differences in the microbiome of plants exposed to native AMF communities versus commercial AMF bioinoculants + native AMF communities were detected in roots. However, inoculation induced positive changes in root traits as well as increased AMF colonization, plant biomass, and leaf nitrogen. Most of these desirable functional traits were positively correlated with the relative abundance of operational taxonomic units identified as Glomus, Rhizophagus and Claroideoglomus genera.ConclusionThese results suggest synergistic interactions between commercial AMF bioinoculants and native AMF communities of roots to promote grapevine growth. Long-term studies with further genomics, metabolomics and physiological research are needed to provide a deeper understanding of the symbiotic interaction among grapevine roots, bioinoculants and natural AMF communities and their role to promote plant adaptation to current environmental concerns.

Abstract Background The lung microbiota of healthy individuals tends to remain stable, but dysbiosis disrupts pulmonary homeostasis, impacting respiratory illness severity and mortality rates. Understanding lung microbiome alterations and their impact on clinical outcomes in ICU-admitted patients has been proposed as a crucial point to improve clinical outcomes, yet this area still needs to be explored. Therefore, this study aims to investigate microbial composition in the lower respiratory tract and assess whether microbial diversity in mechanically ventilated ICU patients is linked to mortality.Figure 1. Beta Diversity Comparisons in the Respiratory Microbiomes of BAL Samples from ICU Admitted Patients Stratified by Hospital Mortality.The beta diversity of bronchoalveolar lavage (BAL) samples from ICU-admitted patients is illustrated through a PCoA scatter plot utilizing Bray-Curtis distances, showing a significant albeit modest differentiation between groups (p = 0.029). The variance explained by each principal coordinate is delineated in the axis titles (p = 0.51 for PC1 and p = 0.01 for PC2). Methods Conducted at Clinica Universidad de La Sabana in Colombia from January 2020 to July 2022, this prospective cohort study enrolled ventilated patients within 12 hours of ICU admission. Bronchoalveolar lavage samples were collected on the day of intubation. The operational taxonomic units (OTUs) were identified using 16S ribosomal RNA (rRNA) gene sequencing. Statistical analyses were performed using RStudio.Figure 2. Comparison of Relative Abundance of OTUs Stratified by Hospital Mortality in ICU Admitted Patients.Percent of relative abundance of the top 20 most abundant microbes in the lungs. Student's t-test was used to calculate the p-value. Asterisks denote the level of significance ​observed: * = p ≤ 0.05; ** = p ≤ 0.01; *** = p ≤ 0.001.​ Results The analysis of 141 intubated patients revealed a predominantly male population (65% [91/139]) with a median (IQR) age of 50.0 years (30.5-67.0). Sequencing generated 20808915 reads and identified 18477 OTUs, with an average of 130873 reads and 13 OTUs per bronchoalveolar lavage sample. Subsequent refinement significantly reduced OTUs to 2096. Comparative analysis, employing Bray-Curtis distances, indicated a statistically significant differentiation (p = 0.02) between patients who died during hospitalization and survivors (Fig. 1). The primary components explained 73.2% of the data variance (R^2=0.73). Prevotella, Acinetobacter, Streptococcus, Staphylococcus, and Veillonella were the predominant OTUs identified in terms of relative abundance, although no significant differences were observed between groups (Fig. 2). Conclusion Dysbiosis of the lung microbiome, characterized by a reduction in the beta diversity and increased concentration of Acinetobacter, was associated with increased mortality in patients requiring invasive mechanical ventilation at ICU admission. These findings highlight the importance of comprehending lung microbial alterations in ICU settings and their potential implications for intubated patients. Disclosures All Authors: No reported disclosures

ObjectiveThis study aimed to investigate the impact of electroacupuncture (EA) on blood glucose levels, gut microbiota, short-chain fatty acids (SCFAs), and glucagon-like peptide-1 (GLP-1) in a rat model of type 2 diabetes mellitus (T2DM).MethodsForty Sprague–Dawley (SD) rats were randomly assigned to five groups (n = 8/group) using a random number table: normal control, T2DM model, electroacupuncture (EA), EA + antibiotics (EA + A), and antibiotics (A). The normal rats received a standard diet and saline gavage, while the other groups were fed a high-fat diet and emulsion. The EA + A and A groups received additional antibiotic solution gavage. The normal, model, and A groups were immobilized and restrained for 30 min, six times per week, for 4 weeks. The EA and EA + A groups received EA treatment at specific acupoints for 30 min, six times per week, for 4 weeks. EA parameters were continuous waves at 10 Hz and 1–2 mA. During the intervention, water and food consumption, body weight, fasting blood glucose (FBG), and oral glucose tolerance test (OGTT) were monitored. Pancreatic tissue was examined using hematoxylin and eosin (H&E) staining. Fecal microbial communities were analyzed by 16S rDNA sequencing, and short-chain fatty acids (SCFAs) were measured using gas chromatography–mass spectrometry (GC–MS). Serum levels of fasting insulin (FINS), glycated hemoglobin (HbA1c), and glucagon-like peptide-1 (GLP-1) were determined using enzyme-linked immunosorbent assay (ELISA).ResultsEA significantly improved daily water intake, food consumption, and body weight in T2DM rats (p < 0.01). EA also reduced FBG, the area under the curve of the OGTT, FINS, and homeostasis model assessment of insulin resistance (HOMA-IR) in T2DM rats (p < 0.05). The ELISA results showed a lower concentration of HbA1c in the EA group (p < 0.05). EA improved the overall morphology and area of pancreatic islets, increased the number of β-cell nuclei, and alleviated β-cell hypertrophy. The abundance of operational taxonomic units (OTUs) in the EA group increased than the model group (p < 0.05), and EA upregulated the Shannon, Chao1, and Ace indices (p < 0.05). EA increased the concentrations of acetic acid, butyric acid, and GLP-1 (p < 0.05). Correlation analysis revealed negative associations between Lactobacillaceae (R = −0.81, p = 0.015) and Lactobacillus (R = −0.759, p = 0.029) with FBG. Peptostreptococcaceae and Romboutsia were negatively correlated with HbA1c (R = −0.81, p = 0.015), while Enterobacteriaceae was positively correlated with OGTT (R = 0.762, p = 0.028). GLP-1 was positively correlated with acetic acid (R = 0.487, p = 0.001), butyric acid (R = 0.586, p = 0.000), isovaleric acid (R = 0.374, p = 0.017), valeric acid (R = 0.535, p = 0.000), and caproic acid (R = 0.371, p = 0.018). Antibiotics disrupted the intestinal microbiota structure and weakened the therapeutic effects of EA.ConclusionEA effectively improved glucose metabolism in T2DM rats. The hypoglycemic effects of EA were associated with the regulation of gut microbiota, SCFAs, and GLP-1.

This study examined how insoluble corn-based fibrous coproducts (ICBF) affect gastrointestinal (GI) mucosal microbiota, gene expression, and intestinal morphology in growing pigs compared to fiber deprivation. Fifty-six gilts (26.7 ± 2.5 kg BW) were randomly assigned to one of seven semi-synthetic diets. Treatments included a fiber-deprived control (CTL;<1% insoluble dietary fiber [IDF]), and six diets where an ICBF replaced 30% of corn starch: dehulled degermed corn (DHDG; IDF = 1.7%), ground corn (COR; IDF = 4.7%), corn gluten meal (CGM; IDF = 5.2%), dried distillers grains (DDGS; IDF = 8.6%), high protein dried distillers grains (HP; IDF = 13.5%), and corn bran (BRN; IDF = 17.5%). Pigs were individually housed and limit-fed 2.4 times maintenance. On day 31, duodenum, jejunum, ileum, and colon tissues were collected. Microbial 16S rRNA sequencing of mucosal material, tissue transcriptomics, and histological analyses were conducted in various intestinal regions. Data were analyzed using mixed models with diet as a fixed effect and linear and quadratic contrasts to assess response IDF. A negative binomial model with FDR correction were used for operational taxonomic unit (OTU) analysis, and transcriptomics were evaluated with DESeq2 comparing ICBF sources to CTL (Q ≤ 0.05, |log2FC| ≥ 2). In the ileal mucosa, Shannon and Simpson diversity indices linearly increased with IDF%, while in the colon mucosa Chao1 and Shannon diversity responded quadratically (P < 0.05). Among the top 100 most abundant OTUs, 60 and 86 differed in ileal and colonic mucosa, respectively (Q < 0.05). In the ileum and colon, pigs fed low-ICBF diets (CTL, DHDG) had increased abundance of OTUs containing opportunistic or potentially pathogenic species (e.g., Enterobacteriaceae, Campylobacter, and Streptococcus). However, moderate-to-high ICBF diets, CGM, DDGS, and BRN, enriched mucosal-associated Lactobacillus, Bifidobacterium, and Akkermansia. In the duodenum and ileum, villous height had a positive quadratic relationship to increasing IDF, while the jejunum villous height linearly decreased (P < 0.05). Gene expression profiles revealed that moderate-to-high ICBF (DDGS, HP, and BRN) upregulated genes associated with cell structure and extracellular matrix (ECM) remodeling (TPPP3, MUC5AC, SERPINA1). Fiber-deprivation upregulated genes associated with ECM degradation (MMP9, MMP12) and collagen formation (COL26A1). Thus, both fiber deprivation and excessive ICBF can disrupt mucosal microbial and host homeostasis.