Abstract Enteric glial cells (EGCs) are pivotal regulators of intestinal homeostasis, and their dysfunction is implicated in cathartic colon. This study investigated the efficacy and mechanism of Lacticaseibacillus paracasei CCFM1321 in alleviating this condition. A senna leaf extract-induced mouse model was employed, and constipation-related indices were evaluated following intervention with various L. paracasei strains. Among the tested strains, CCFM1321 most effectively improved gut motility and repaired the intestinal barrier. Mechanistically, CCFM1321 modulated the gut microbiota, increased propionic acid production, and subsequently enhanced 5-HT and acetylcholine levels. This neuroendocrine shift activated the GDNF-RET signaling pathway in EGCs, promoting enteric neuron function and epithelial integrity. Our findings elucidate a novel microbial-driven, EGC-mediated pathway for alleviating cathartic colon, highlighting CCFM1321 as a promising probiotic candidate for functional constipation.

A field study was performed in the semi-arid Loess Plateau, China, to explore how different tillage methods improve drought tolerance in wheat by examining plant growth, fungal communities, and soil properties. Four tillage methods were applied for wheat cultivation: (1) T (conventional tillage with no straw), (2) NT (no-tillage with no straw cover), (3) TS (conventional tillage with straw incorporated), and (4) NTS (no-till with straw cover) and data were collected in 2020 and 2021. The results showed that NTS treatment remarkably improved soil physicochemical properties during 2020 and 2021, increasing soil water content by 13.7-62.1 % compared to T at 0-50 cm soil depth. The NTS treatment had the lowest soil bulk density and pH and the highest total N, NO3- -N, and available P. Compared to T, NTS treatment significantly increased endophytic fungal Sobs index and genera like Alternaria, Peyronellaea, Sarocladium, and Schizothecium. The NTS and TS treatments significantly increased antioxidant enzymes, including CAT, POD, and soluble protein by 1.26-25.52 % compared to T. NTS treatment significantly increased yield by 23.64 and 24.28 % and water use efficiency by 16.06-19.97 % compared to T in 2020 and 2021, respectively. The endophytic fungal abundance (Sobs and Chao indices), diversity, and composition (Alternaria, Peyronellaea, Sarocladium, and Schizothecium) in wheat roots were positively correlated with the drought tolerance index, with soil water content, total N, and NO3- -N, being considered as key influencing factors. Collectively, NTS treatment showed the highest drought tolerance in wheat crop by improving soil physicochemical properties and utilizing the microbiome potential, ultimately enhanced water use efficiency and crop yields. Our study findings suggest that the NTS treatment is a promising practice for the semi-arid Loess Plateau area and may further guide future research on harnessing the emergent functions of microbial communities to enhance drought tolerance in wheat cultivated in drylands.

Soil quality is a foundational determinant of grain yield, yet the mechanisms through which tillage and straw management practices influence soil quality and crop productivity remain inadequately characterized in semiarid agroecosystems. This study investigated the microbial mechanisms linking grain yield and soil quality index (SQI) across four practices-conventional tillage with straw removal (T), no-till with straw removal (NT), conventional tillage with straw mulching (TS), and no-till with straw mulching (NTS)-using a 23-year field trial in northwest China. Results showed that TS and NTS significantly enhanced SQI by 60.1%-79.4%, and increased grain yield by 20.5%-31.8% compared to T. In contrast, NT had no significant effect on SQI, or yield. Random forest and structural equation model analyses revealed that long-term straw mulching significantly improved soil quality through restructuring soil microbial community by elevated stoichiometric homeostasis, as reflected in the changes in SIMC:P and SIMC:N ratios. These physicochemical trait shifts alleviated microbial resource limitations, triggering a strategic transition from resource acquisition (A) to growth (Y) strategies. Consequently, the bacterial r/K-strategy ratio increases, while fungal communities become dominated by K-selected taxa. This ecological reconfiguration enhances microbial diversity and network complexity, which in turn amplifies extracellular enzyme activity, particularly for P-acquisition, ultimately elevating SQI, and improving grain yield. NTS exhibited the greatest potential for yield enhancement due to its superior capacity to co-activate microbial and soil quality improvements. This study provides a theoretical basis for understanding the microbial mechanisms underlying long-term conservation tillage impacts on crop yield and soil quality in semiarid regions.

The metabolic efficiency of biotransforming dietary glycans into health-promoting short-chain fatty acids (SCFAs) is strongly influenced by the microbial glycoside hydrolase (GH) repertoire, yet the strain-level correlation between GH genomic diversity and neuroprotective functionality remains elusive. In this study, a large-scale genomic landscape of 464 Bifidobacterium strains (175 B. bifidum, 178 B. breve, and 111 B. longum) was constructed to characterize their GH repertoire diversity. We evaluated the biotransformation capacity of GH-diverse versus GH-limited strains through multi-stage fermentation systems and representative strains were evaluated for their in vivo SCFAs-producing efficiency. Genomic analysis revealed that B. longum possesses a significantly more versatile GH repertoire for degrading complex plant-derived glycans compared to B. bifidum. Strains with high GH diversity exhibited superior fermentation efficiency, yielding significantly higher acetate and butyrate levels. In vivo, these GH-diverse strains remarkably ameliorated repetitive behaviors and social deficits by restoring intestinal SCFAs homeostasis, elevating systemic and central serotonin levels, and suppressing neuroinflammation. These findings provide a mechanistic basis for the genome-guided selection of precision probiotics and highlight the critical role of microbial GH diversity in enhancing the biofunctionality of dietary fibers.

Background & aims Chronic constipation is prevalent among middle-aged and older adults, with current interventions often limited by modest efficacy and adverse effects. Probiotics have emerged as a safe, promising modality; we aimed to evaluate a 28-day multi-strain probiotic in this population using clinical and mechanistic endpoints. Methods We conducted a randomized, double-blind, placebo-controlled trial in adults with chronic constipation: 132 were randomized (probiotics n=66; placebo n=66), and 100 completed per protocol (50/50).The primary endpoint was weekly complete spontaneous bowel movements (CSBMs) at day 28; secondary endpoints included Bristol Stool Form Scale (BSFS), Patient Assessment of Constipation Symptoms (PAC-SYM), bloating scores, and multi-omics profiling (gut microbiota and fecal metabolites at days 0/14/28), with targeted fecal short-chain fatty acids (SCFAs). A pre-specified responder was defined as week-4 CSBMs ≥3 and increases ≥1 from baseline. Results At day 28, probiotics yielded higher CSBMs than placebo (4.53±1.17 vs 2.40±1.01, P<0.0001), improved stool form (higher BSFS), reduced PAC-SYM, and markedly alleviated bloating (0.70±0.46 vs 2.60±0.93, P<0.0001). Microbiologically, α-diversity increased and β-diversity separated between groups at days 14 and 28 (PERMANOVA P=0.003 and 0.001); Faecalibacterium, Lactobacillus, and Bifidobacterium increased, whereas Enterobacter, Collinsella, and Oscillibacter declined. Untargeted metabolomics indicated enrichment of SCFA biosynthetic pathways (butanoate/propanoate), and targeted assays confirmed higher fecal acetate and butyrate at day 28 (P<0.01 and P<0.05), with no significant change in propionate or valerate (both P>0.05). Responder rates were 88% (44/50) with probiotics versus 26% (13/50) with placebo; within the probiotic arm, ΔFaecalibacterium and Δbutyrate correlated positively with ΔCSBM, while ΔEnterobacter correlated negatively. Conclusions In middle-aged and older adults with chronic constipation, a 28-day multi-strain probiotic significantly increases bowel movement frequency, improves symptoms—especially bloating—and favorably remodels gut microbiota and SCFA-related pathways, supporting its use as a nutritional intervention. Trial registration ChiCTR2200065905.

Objective This study aimed to investigate the regulatory mechanisms of partial substitution of chemical fertilizer with organic fertilizer and plastic film mulching on yield and water use efficiency (WUE) of spring wheat in dryland, and to provide a theoretical basis for high-yield and efficient production of spring wheat in the rainfed farming areas of the Loess Plateau. Method A field experiment was conducted in Dingxi city, Gansu province, from 2023 to 2025, with four treatments established: chemical fertilizer only (NP, supplying 105 kgu00B7N hm-2 and 105 kg P2O5u00B7hm-2), partial substitution of chemical fertilizer with organic fertilizer(MNP, supplying 80 kg Nu00B7hm-2 and 88 kg P2O5u00B7hm-2, plus 8500 kgu00B7hm-2 of composted sheep manure, corresponding to approximately 23.8% and 16.2% substitution of chemical N and P2O5, respectively), chemical fertilizer combined with plastic film mulching (FNP), and the combined application of organic substitution and film mulching (FMNP). The effects of these treatments on root traits, stage-specific water use, dry matter accumulation, yield, and water use efficiency (WUE) of spring wheat were investigated. Result Film mulching treatments (FNP and FMNP) significantly enhanced soil water storage at sowing compared to non-mulched treatments (NP and MNP), with an average increase of 23.7 mm. In contrast, organic substitution without film mulching (MNP) did not exert a significant effect on soil water storage. Relative to NP treatment, FNP and FMNP significantly increased root length density in the 0-20 cm soil layer at maturity by 25.7% and 22.0%, and in the 60-140 cm layer by 33.7% and 45.9%, respectively. Water consumption during the jointing-flowering stage was significantly increased by 16.8% and 24.5%, and the stage-specific water use efficiency was correspondingly enhanced by 34.3% and 35.0% for FNP and FMNP compared to NP. Leaf area index (LAI) was significantly elevated by 12.5%, 30.2%, and 38.7% for MNP, FNP, and FMNP, respectively, compared with NP. Moreover, aboveground dry matter accumulation at maturity was significantly increased by 35.1% and 40.5% for FNP and FMNP, respectively, averaged over the two-year period. Compared with the NP treatment, the FNP and FMNP treatments significantly increased grain yield by 47.0% and 58.7%, respectively, and water use efficiency for grain yield (WUEg) by 31.3% and 41.7% on average, respectively. In contrast, the MNP treatment did not significantly improve grain yield or WUEg relative to NP. Random forest and structural equation modeling analyses indicated that the combined application of organic substitution and film mulching affected root traits, which in turn regulated stage-specific water use and dry matter partitioning, thereby significantly influencing yield and WUEg. Conclusion These results demonstrate that the integration of partial organic fertilizer substitution with plastic film mulching optimizes root architecture, enhances water use during the jointing-flowering stage, increases biomass accumulation, reduces the root-to-shoot ratio, and promotes the allocation of photosynthetic assimilates to grains, ultimately improving both grain yield and water use efficiency of spring wheat in dryland.

Obesity is a global health issue characterized by gut microbiota dysbiosis and lipid accumulation. Probiotics have garnered considerable attention due to their health benefits. This study aims to evaluate the effects of 5 species of probiotics (6 strains) on modulating gut microbiota composition to alleviate obesity in long-term high-fat diet (HFD)-induced obese mice. To establish the obese mouse model, HFD was administered for 10 weeks, followed by 19 weeks of probiotic treatment to assess the anti-obesity effects. The 29 weeks of HFD treatment induced weight gain, disrupted serum factors, and altered cecal and colonic microbiota and colonic short-chain fatty acids (SCFAs). Notably, strain Bifidobacterium adolescentis CCFM1173 demonstrated significant anti-obesity effects, reducing final weight gain and modulating serum factors such as AST, ALT, and TC. Probiotic treatments induced distinct changes in cecal microbiota composition and structure, with similar alterations observed at the phylum level in colonic microorganisms but not at the genus level. Furthermore, B. adolescentis CCFM1173 uniquely promoted anti-obesity effects by increasing the abundance of Akkermansia in the colon by 160-fold, which subsequently stimulated butyric acid production from 7.17 to 11.95 mmol/kg. Genomic analysis of probiotics for carbohydrate-active enzymes (CAZymes) indicated that the content of colonic SCFAs increased with the upregulation of CAZymes in the genera Lactobacillus and Bifidobacterium. In conclusion, this study suggests that B. adolescentis CCFM1173 treatment could be a potential strategy to alleviate obesity. It also implies that administering CAZymes-rich probiotics might be more effective in improving colonic SCFAs levels to alleviate associated diseases.

Background: Functional constipation (FC) represents a highly prevalent gastrointestinal disorder, affecting approximately 8.5% of the population in China. It is frequently associated with anxiety and depression, significantly impairing patients' quality of life. Conventional microecological therapeutic approaches predominantly rely on empirical probiotic-prebiotic combinations. However, these pairings are seldom selected based on strain-specific metabolic characteristics, ultimately leading to suboptimal therapeutic synergy. Methods: The generation time (GT) of four constipation-relief strains was measured across eight oligosaccharides to identify optimal substrates for synbiotic formulation. The GT-optimized synbiotic was verified in a loperamide-induced mouse model vs. single probiotics/prebiotics. The related mechanisms of were assessed through 16S rDNA sequencing, targeted metabolomics, and qPCR. Results: The GT-optimized synbiotic significantly outperformed all single components. Specifically, the synbiotic significantly decreased the time to first black stool and increased fecal water content. Mechanistically, it restored colonic neurotransmitter balance, suppressed aquaporin expression, enriched butyrate-producing bacteria, and repaired barrier integrity. Overall, these effects work together, increasing the moisture content of the feces and accelerating intestinal peristalsis, ultimately alleviating constipation. Conclusions: We propose a GT-guided precision-pairing strategy that identifies optimal prebiotics based on strain-specific generation times, demonstrating synergistic enhancement of short-chain fatty acid (SCFA) production, enteric neurotransmitter signaling, and aquaporin-mediated water transport. This GT guided synbiotic approach shows promise in preclinical models and warrants validation in human trials.

Correction for 'Bifidobacterium bifidum CCFM1359 alleviates intestinal motility disorders through the BDNF-TrkB pathway' by Linlin Wang et al., Food Funct., 2025, 16, 437-451, https://doi.org/10.1039/D4FO03710C.

BACKGROUND:Chitosan (CTS) and chitosan oligosaccharides (COS) are widely used in the food industry due to their bioactive properties. However, their cationic nature enables interaction with whey protein isolate (WPI), affecting protein digestibility. Fucoidan (FUC), a naturally occurring anionic sulfated polysaccharide from brown algae, can form electrostatic complexes with CTS and COS to partially alleviate this effect; however, this process requires optimization. RESULTS:Chitosan-fucoidan (CTS-FUC) and chitosan oligosaccharide-fucoidan (COS-FUC) complexes were successfully prepared and characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, and other analytical instruments, confirming that complexation occurred via electrostatic interactions between amino groups of CTS and COS and the sulfate groups of FUC. Subsequently, the impact of these carbohydrates on WPI's digestibility was assessed during simulated gastrointestinal digestion. The CTS-FUC and COS-FUC complexes mitigated the inhibition of protein digestion caused by CTS and by COS alone. Specifically, the addition of the CTS-FUC complex increased the degree of hydrolysis of WPI by 24.6% compared with the corresponding mixed group, whereas the COS-FUC complex increased it by 22.6% compared with its corresponding mixed group. Furthermore, compared with the group containing CTS + FUC or COS + FUC, both preformed complexes increased protein concentration to 1.08-fold. The free trypsin concentration in the CTS-FUC + WPI group was 1.11 times that in the CTS + FUC + WPI group, whereas the concentration in the COS-FUC + WPI group was 1.06 times that in the COS + FUC + WPI group. Spectroscopic and chemical methods further revealed that the complexes reduced the binding of CTS and COS to protein and trypsin. CONCLUSION:Overall, this study demonstrates that CTS-FUC and COS-FUC complexes effectively alleviated the negative impact of CTS and COS on protein digestion, offering new insights into mitigating their adverse nutritional effects in food systems. © 2026 Society of Chemical Industry.

Co-applications of organic fertilizer and biochar have been demonstrated to have the advantages of improving soil fertility and food production while maintaining environmental benefits. However, the underground microbiological mechanism of the co-application-mediated crop production gain described above were still insufficiently explored. Therein, an over decade-long field study was conducted to compare the effects of chemical-only fertilization and organic amendment on the microbial communities and functions of rhizosphere and non-rhizosphere soils as well as their production consequence. Findings indicated that long-term chemical-only fertilization notably reduced soil microbial diversity, whereas the loss of such diversity was mitigated by biochar and manure inputs. Additionally, biochar and manure inputs could enhance the complexity and stability of soil microbial community compared to no fertilizer or chemical-only fertilization. Interestingly, biochar and manure inputs replenished the certain microbiota involved in nutrient cycles that have disappeared as a result of long-term chemical-only fertilization, and meanwhile, reduced microbial pathogenic potential in rhizosphere and non-rhizosphere soils. These positive shifts in microbial communities and functions were closely associated with the changed soil physicochemical properties induced by organic amendment, which partly supported better crop growth and nutrient uptake. Overall, this study highlights the importance of incorporating biochar and manure into agricultural production to mitigate chemical-fertilizer-induce negative impacts on soil biology, which will further solidify food production and security.

Low-molecular-weight carrageenan has attracted great attention in the food and medical industries due to its excellent solubility and diverse biological activities. However, the development of environmentally friendly methods for low-molecular-weight carrageenan production is still in great need. In the present study, a photocatalysis-freeze-thaw circle degradation method of x-carrageenan was developed based on its two-phase properties after freezing and thawing. Interestingly, the addition of KCl with the ability to enhance the gel strength could lead to the molecular weight decrease of the prepared low-molecular-weight carrageenan whose relative molecular weight could reduce to <= 2.8 kDa. Moreover, FT-IR, ESI-MSn, NMR, and TEM analysis results showed that the photocatalysis-freeze-thaw circle method could separate the degraded low-molecular-weight carrageenan in time to avoid overreaction during the reaction process, which could fully protect the sulfate groups of low-molecular-weight carrageenan from destruction and produce less by-products. In addition, the digestion and distribution of low-molecular-weight carrageenan in vivo were tracked after fluorescent labeling, and the results demonstrated that low-molecular-weight carrageenan could enter the liver and kidney after oral administration. Thus, the present study demonstrated a novel method to prepare low-molecular-weight carrageenan and revealed in vivo distribution after oral administration.

Bifidobacterium species are known for their efficacy in alleviating constipation. This study aimed to compare the constipation-relieving effects of different Bifidobacterium species (Bifidobacterium longum subsp. longum, Bifidobacterium bifidum, Bifidobacterium animalis, Bifidobacterium breve, Bifidobacterium longum subsp. infantis, and Bifidobacterium adolescentis) and to explore the underlying mechanisms from both the bacterial and host perspectives. We evaluated six Bifidobacterium species for their physiological properties, including growth rate, oligosaccharide utilization, osmotic pressure resistance, cell adhesion, and bile acid dissociation capability. Mice with severe constipation induced by loperamide hydrochloride were treated with these bacteria at a density of 109 CFU per mL for 17 days. Gastrointestinal indices such as fecal water content, time to first black stool defecation, and small intestine propulsion rate were measured to assess constipation relief. Microbiome and metabolome (bile acid and tryptophan) analyses were conducted to elucidate the differences in constipation relief among the species. Our results demonstrated that Bifidobacterium longum subsp. longum exhibited superior physiological traits, including rapid growth, extensive oligosaccharide utilization, and high bile salt dissociation capacity. Notably, only Bifidobacterium longum subsp. longum significantly ameliorated constipation symptoms in the mouse model. Furthermore, this strain markedly restored bile acid and short-chain fatty acid levels in the intestines of constipated mice and altered the composition of the intestinal microbiota. These findings suggest that the enhanced efficacy of Bifidobacterium longum subsp. longum in relieving constipation is associated with its ability to modulate intestinal physiology and microbiota structure and metabolism.

Intestinal motility disorder is characterised by abnormal intestinal motility function, often resulting in symptoms such as diarrhoea and constipation. Probiotics are increasingly recognised as an effective treatment for gastrointestinal disorders, including intestinal motility disorders. In this study, we used senna extract to induce an animal model of intestinal dysfunction characterised by BDNF downregulation. By assessing relevant indicators of intestinal dyskinesia, we found that Bifidobacterium bifidum CCFM1359 effectively alleviated the dyskinesia. However, this alleviating effect was nullified when a TrkB receptor inhibitor was introduced, suggesting that Bifidobacterium bifidum CCFM1359 operates through the BDNF-TrkB pathway. Further analysis revealed that Bifidobacterium bifidum CCFM1359 likely exerts its beneficial effects by regulating intestinal microecology (increasing the relative abundance of Bifidobacterium bifidum and valeric acid content while decreasing Faecalibacterium and butyric acid content), reducing intestinal inflammation (upregulating the anti-inflammatory factor IL-10 and downregulating pro-inflammatory factors TNF-alpha and IL-1 beta), and remodelling intestinal nerves (upregulating S100 beta and the excitatory neurotransmitter ACh, while downregulating the inhibitory neurotransmitter nNOS). This study provides a theoretical basis for using probiotics to alleviate intestinal motility disorders.

AIMS:Fertilizers can significantly influence leaf senescence and hormonal regulation, which in turn impacts crop yield. Despite significant advancements in understanding fertilizer effects on plant growth, the specific molecular mechanisms through which fertilizers influence hormonal regulation and leaf senescence, and subsequent impact on yield, remain underexplored. This study addresses this critical gap by examining transcriptional, physiological, and molecular mechanisms in the semiarid regions of rainfed spring maize under long-term fertilizers. METHODS:Fertilizer treatments include no amendment (NA), inorganic fertilizer (CF), combined inorganic and organic fertilizer (SC), organic fertilizer (SM), and maize straw (MS) replicated three times. RESULTS:The highest number of differentially expressed genes (DEGs) were observed under CF (3972) followed by SC (1949) in comparison to NA, showing a strong effect of inorganic fertilizer on gene expressions. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that numerous genes involved in the biosynthesis of secondary metabolites, plant hormone signaling, photosynthesis pathways, and metabolic pathways showed varied expressions of up- and downregulation. Genes involved in the ethylene, abscisic acid, jasmonic acid, salicylic acid, and brassinosteroid pathways indicated their interaction and promoted leaf senescence, whereas those related to auxin and gibberellin pathways had minimal impact. In the ethylene pathway known to influence senescence, two ethylene receptor (ETR) genes (Zm00001d013486 and Zm00001d021687) were downregulated, whereas, two ethylene-insensitive proteins 3 (EIN2) genes (Zm00001d053594 and Zm00001d033625) showed upregulation in the CF, SC and SM treatments. Furthermore, 86 highly up-regulated genes involved in the photosynthesis pathway encompassing components such as photosynthesis antenna, photosynthesis complexes II, cytochrome complexes, photosynthesis electron transport, and ATP complex in SC and CF compared to SM and MS. CONCLUSION:In summary, the study finds that DEGs showed stronger responses to inorganic fertilizers, likely due to organic fertilizers decomposing at a slower rate. Nevertheless, transcriptional and physiological analyses indicate that the SC treatment sustainably enhances maize productivity without causing adverse environmental effects, outperforming the other treatments (NA, CF, SM, MS). These results provide new perspectives on genetic regulation and pathway discovery in rainfed maize cultivation in semiarid areas.

Water footprint (WF) is a water sustainable management indicator that quantifies the virtual water use in crop production. Water productivity (WP) and WF were examined under different tillage practices for wheat (Triti-cumaestivum L.) in the semiarid Loess Plateau of China. Wheat was grown in 2002-2017 with six tillage practices: conventional tillage (T), no-till without straw cover (NT), conventional tillage with straw cover (TS), no-till with straw cover (NTS), conventional tillage with plastic mulching (TP), no-till with plastic mulching (NTP). Tillage practices did not significantly increase crop evapotranspiration, but NTS, TP, and NTP reduced soil evaporationwhile increasing transpiration, root growth and biomass accumulation. Additionally, NTS reduced the water consumption during the early stage but increased the water utilization from heading to harvest, while TP, and NTP exhibited the opposite pattern. Wheat yield under TS, NTS, TP, and NTP was higher by13, 28, 22, and 24 %, respectively, than under T, with corresponding improvements in water productivity of 15, 24, 26, and 24 %, respectively. The change in net economic return was 39, 21, 148,-49, and 18 % for NT, TS, NTS, TP, and NTP, respectively, compared to T; the sustainability yield index was 0.45, 0.41, 0.52, 0.55, 0.48 and 0.47, respectively. Total water consumption was significantly increased by 8.2 and 9.8 % under TS and NTS, respectively, compared to T. WF under NTS, TP and NTP was significantly decreased by 18.6, 18.5 and 22.3 % compared to T, respectively. These results suggests that NTS increased yield, economic benefits and WP with less WF through enhancing root growth and water utilization during the filling period. Therefore, NTS represented a sustainable a sustainable water management strategy for wheat in the semiarid Loess Plateau.

Cathartic colon (CC) is a type of slow-transit constipation caused by a patient's long-term use of irritating laxatives. Probiotics play a crucial role in managing constipation.

Plastic materials, ubiquitous in daily life, degrade into microplastics (MPs) that can accumulate in humans through the food chain, leading to health issues. While some antioxidants have been shown to mitigate the toxicity caused by MPs exposure, they are only effective at high doses, which can be harmful to human health when ingested in excess. Concurrently, Lactobacillus species have demonstrated the ability to adsorb onto microand nano-plastics (MNPs), with certain strains exhibiting high antioxidant activity. In this study, Lactobacillus plantarum strains with varying antioxidant capacities and affinities for polystyrene nanoparticles (PS-NPs) were utilized to investigate their effects on toxicity induced by exposure to PS-MPs. The results indicated that the antioxidant capabilities of Lactobacillus plantarum can reduce oxidative damage caused by PS-MPs exposure, and their ability to bind with PS-MNPs can reduce the body's PS-MPs content and increase fecal PS-MPs content, thereby reducing toxicity. Notably, the strain 89-L1, which possesses low antioxidant activity and low binding affinity for PS-MNPs, also reduced toxicity, potentially through repairing the intestinal barrier and modulating bile acid (BAs) metabolism. Our findings suggest that the mechanisms by which Lactobacillus plantarum reduces PS-MPs-induced toxicity extend beyond antioxidant and binding capabilities; the repair of the intestinal barrier and modulation of BAs metabolism also play significant roles in reducing toxicity caused by PS-MPs exposure and may act partially independently of these capacities. This study provides a theoretical basis for the future development of strategies for Lactobacillus plantarum to reduce toxicity caused by exposure to MPs.

IntroductionFood security faces multiple challenges, and increasing crop yields is an effective way to address this issue. Replacing chemical fertilizers (CFs) with organic fertilizers can affect soil nutrient cycling and hence crop yields, with changes in organic carbon content being an important way in which soil nutrient content affects crop production. However, the dynamics of the effect of organic fertilizer substitution on soil organic carbon and the mechanism by which it further contributes to yield formation are not clear.MethodsTo this end, a 2 - year maize field experiment (2019-2020) was conducted to study the effect of organic substitution on soil properties, organic carbon fractions, and maize yields. Six treatments were applied: no fertilizer (CK), CF, and four different organic substitution rates (50%, 37.5%, 25%, and 12.5%), denoted by (50% OF), (37.5% OF), (25% OF), and (12.5% OF), respectively. Fully film - mulched double ridge-furrow technology was used to optimize water retention and soil temperature.ResultsResults demonstrated that 12.5% OF reduced water consumption by 1.40% during critical maize growth stages compared to CF. It also increased 0-30 cm total phosphorus (TP) by 15.09%, soil porosity by 4.82%, and available phosphorous (AP) by 34.81% at harvest, respectively, compared with CK of 2 years average. Partial substitution of CF with organic fertilizer led to a significant increase in soil organic carbon (SOC) and fractions through improvement in physicochemical properties. The 12.5% OF at 0-30 cm soil layer significantly increased easily oxidizable organic carbon (EOC) by 33.23%, SOC by 2.18%, and particulate organic carbon (POC) by 6.64% compared to CF, respectively. At 10-30 cm, 37.5% OF increased microbial biomass carbon (MBC) by 9.90% and hot water-soluble carbon (HOC) by 6.90% compared to CF. Under 12.5% OF, an EOC increased by 13.20% at 0-5 cm, while dissolved organic carbon (DOC) and light fraction organic carbon (LFOC) rose by 18.65% and 37.13% at 0-10 cm, respectively. Interestingly, the 12.5% OF boosted grain yields by 6.60% and biomass by 4.59% compared to CF, and by 213.02% and 208.13% compared to CK. Water use efficiency (WUE) increased by 11.43% and 153.27% under CK and CF treatment, respectively. Randomized forest analysis highlighted that increases in soil MBC, HOC, and DOC content were critical for maize yield improvement.DiscussionIn summary, 12.5% OF and 37.5% OF can increased MBC, HOC, and DOC content by increasing soil porosity, TP and AP content and decreasing soil water depletion, thereby increasing crop yield. Compared to 37.5% OF, 12.5% OF was more environmentally sustainable, increased crop yields, and increase economic benefits. This provided a theoretical basis for partial substitution of CF with organic fertilizer to improve soil health and crop yield. The present study showed that 12.5% OF (200 kg hm-2 of N) was a suitable cropping pattern in the region and was recommended for wider use in the region.

Various dietary factors in human milk are important nutrients for the formation of the infant gut microbiota (GM). While promoting the growth of the GM, some human milk components that are difficult to absorb and utilize will be broken down by the GM, and converted into nutrients that the baby can use, such as breast milk oligosaccharides-the 'carbon source' for infant GM. This study reveals that nucleotides (NTs), significant non- protein nitrogen sources in human milk, can enhance the abundance of beneficial microbial genera such as g_Bifidobacterium, , g_Bacteroides, , and g_Blautia in in vitro fecal fermentation fluids of infants at low doses (2 mg/ mL). Conversely, high doses of NTs (20 mg/mL) increased the abundance of g_Escherichia-Shigella. . Furthermore, low-dose NTs fermentation broth significantly enhanced the expression of neurodevelopmental marker genes such as Tuj1, Sox2, Dcx, , and NeuN in NE-4C neural stem cells, whereas a single NTs digestion broth did not exhibit significant activity. However, in vivo studies using neonatal rats as a model demonstrated that both low- dose NTs fermentation broth and NTs digestive juices promoted behavioral development in neonatal rats (PND 20) and neuron maturation in the prefrontal cortex and hippocampus. Non-targeted metabolomics results indicate that low-dose dietary NTs promote the production of certain neuroregulatory metabolites in infant fecal fermentation, such as uridine, L-tyrosine, L-glutamic acid, and succinic acid. These findings suggest that NTs may serve as an important "nitrogen source" during GM formation in early life and have a dose effect in driving the development of the microbiota-gut-brain axis in early life.