Supplementation of Bacillus sp. DU-106 Alleviates Antibiotic-Associated Diarrhea in Association with the Regulation of Intestinal Microbiota in Mice

Recovery of intestinal microbial community in Penaeus vannamei after florfenicol perturbation

The concept and application of probiotic intervention for restoring intestinal microbial dysbiosis induced by antibiotics in aquaculture are still in early stages. This study aimed to investigate potential responses of various recovery strategies, including natural recovery and probiotic intervention, in restoring the growth and intestinal microbial community of Penaeus vannamei following florfenicol perturbation. The basal diet (control, CN) was supplemented with florfenicol (FC) or Lactobacillus plantarum W2 (LM) throughout the entire feeding trial. Meanwhile, the basal diet was supplemented with florfenicol for 7 days, followed by a period without florfenicol (natural recovery, FB), or with live strain W2 (probiotic recovery, FM), for a duration of 35 days. Results indicated that dietary supplementation of strain W2, whether continuous or following florfenicol perturbation, along with continuous florfenicol supplementation, significantly enhanced the growth performance of shrimp. Early natural recovery and probiotic intervention did not induce significant alterations in microbial diversity and community structure. Florfenicol perturbation resulted in a decrease in the abundance of potentially beneficial bacteria in intestinal microbial community of shrimp. However, both probiotic intervention and natural recovery strategies gradually reduced the abundance of potentially pathogenic bacteria while increasing the abundance of potentially beneficial ones. The robustness of microbial network decreased during florfenicol perturbation, showed gradual improvement during probiotic recovery, and remained relatively low during natural recovery and continuous florfenicol supplementation. Moreover, the microbial community composition in intestinal habitat significantly differed under various recovery strategies compared to the control. Notably, the microbial community composition of intestinal habitat following probiotic recovery exhibited greater similarity to that of continuous strain W2 supplementation without florfenicol perturbation. In summary, dietary supplementation of florfenicol perturbed intestinal microbial community stability of shrimp, whereas probiotic intervention and natural recovery facilitated the attainment of new stable states by altering keystone taxa. Considering intestinal microbial community stability of shrimp, the recovery of microbial community through probiotic intervention appears to be more effective than natural recovery.

Lactiplantibacillus plantarum ELF051 Alleviates Antibiotic-Associated Diarrhea by Regulating Intestinal Inflammation and Gut Microbiota

Probiotics are widely recognized for their ability to prevent and therapy antibiotic-associated diarrhea (AAD). This study was designed to evaluate Lactiplantibacillus plantarum ELF051 ability to prevent colon inflammation and its effect on gut microbial composition in a mouse model of AAD. The mice were intragastrically administered triple antibiotics for 7 days and then subjected to L. plantarum ELF051 for 14 days. The administration of L. plantarum ELF051 ameliorated the pathological changes in the colon tissue, downregulated interleukin (IL)-1β and tumor necrosis factor (TNF)-α, and upregulated IL-10, and increased the intestinal short-chain fatty acids (SCFAs) level. Lactiplantibacillus plantarum ELF051 also regulated the Toll-like receptor/myeloid differentiation primary response 88/nuclear factor kappa light chain enhancer of activated B cells (TLR4/MyD88/NF-κB) and the phosphatidylinositol 3-kinase/protein kinase B/ NF-κB (PI3K/AKT/ NF-κB) inflammatory signaling pathways. 16S rRNA analyses showed that L. plantarum ELF051 increased the abundance and diversity of gut bacteria, restoring gut microbiota imbalance. A Spearman's rank correlation analysis showed that lactobacilli are closely associated with inflammatory markers and SCFAs. This work demonstrated that L. plantarum ELF051 can attenuate antibiotic-induced intestinal inflammation in a mouse AAD model by suppressing the pro-inflammatory response and modulating the gut microbiota.

Polysaccharides of natural products alleviate antibiotic-associated diarrhea by regulating gut microbiota: a review

Antibiotic-associated diarrhea (AAD) is diarrhea caused by disturbances in intestinal microbiota and metabolism following inappropriate use of antibiotics. With the over-reliance on antibiotics, the incidence of AAD is increasing worldwide. Recently, the role of probiotics and prebiotic preparations in the prevention and treatment of AAD has received increasing attention. Various prebiotics can not only reduce the incidence of AAD, but also effectively shorten the course of the disease and alleviate the symptoms. Notably, many polysaccharides derived from plants and fungi are a class of biologically active and rich prebiotics with great potential to alleviate AAD. Therefore, this review aims to summarize the latest research on natural product polysaccharides to alleviate antibiotic-associated diarrhea by modulating the gut microbiota. It provides a theoretical basis for exploring the mechanism of natural product modulation of gut microbiota to alleviate AAD, and provides a reference for further development of active prebiotics.

Combination of Lactiplantibacillus Plantarum ELF051 and Astragalus Polysaccharides Improves Intestinal Barrier Function and Gut Microbiota Profiles in Mice with Antibiotic-Associated Diarrhea

The purpose of this study was to investigate the improvement of the intestinal barrier and gut microbiota in mice with antibiotic-associated diarrhea (AAD) using Lactiplantibacillus plantarum ELF051 combined with Astragalus polysaccharides. The amoxicillin, clindamycin, and streptomycin triple-mixed antibiotic-induced AAD models were administered with L. plantarum ELF051 or Astragalus polysaccharides or L. plantarum ELF051 + Astragalus polysaccharides for 14 days. Our findings revealed that the combination of L. plantarum ELF051 and Astragalus polysaccharides elevated the number of goblet cells and enhanced the proportion of mucous within the colon tissue. Furthermore, the expression of sIgA and IgG were upregulated, while the levels of IL-17A, IL-4, DAO, D-LA, LPS, and TGF-β1 were downregulated. L. plantarum ELF051 combined with Astragalus polysaccharides elevated the expression of tight junction (TJ) proteins, facilitating intestinal mucosal repair via Smad signaling nodes. Furthermore, their combination effectively increased the relative abundance of lactic acid bacteria (LAB) and Allobaculum, and decreased the relative abundance of Bacteroides and Blautia. Spearman rank correlation analysis demonstrated that LAB were closely related to permeability factors, immune factors, and indicators of intestinal barrier function. In summary, the effect of combining L. plantarum ELF051 and Astragalus polysaccharides on AAD mice was achieved by enhancing intestinal barrier function and regulating the composition of the gut microbiota.

Oral delivery of sodium alginate/chitosan bilayer microgels loaded with Lactobacillus rhamnosus GG for targeted therapy of ulcerative colitis

Probiotics regulate intestinal flora balance and enhance the intestinal barrier, which is useful in preventing and treating colitis. However, they have strict storage requirements. In addition, they degrade in a strongly acidic environment, resulting in a significant decrease in their activity when used as microbial agents. Lactobacillus rhamnosus GG (LGG) was loaded into acid-resistant and colon-targeting double-layer microgels. The inner layer consists of guar gum (GG) and low methoxyl pectin (LMP), which can achieve retention and degradation in the colon. To achieve colon localization, the outer layer was composed of chitosan (CS) and sodium alginate (SA). The formulation demonstrated favorable bio-responses across various pH conditions in vitro and sustained release of LGG in the colon lesions. Bare LGG survival decreased by 52.2 % in simulated gastric juice (pH 1.2) for 2 h, whereas that of encapsulated LGG decreased by 18.5 %. In the DSS-induced inflammatory model, LGG-loaded microgel significantly alleviated UC symptoms in mice and reduced inflammatory factor levels in the colon. Encapsulation of LGG improved its stability in acidic conditions, thus increasing its content at the colon lesions and reducing pathogenic bacteria. These findings provide an experimental basis and a technical reference for developing and applying probiotic microgel preparations.

Potential Probiotic Weizmannia coagulans WC10 Improved Antibiotic-Associated Diarrhea in Mice by Regulating the Gut Microbiota and Metabolic Homeostasis

Antibiotic-associated diarrhea (AAD) is a common side effect of long-term and heavy antibiotic therapy. Weizmannia coagulans (W. coagulans) is an ideal probiotic because of its high viability, stability, and numerous health benefits to the host. In this study, the strains were first screened for W. coagulans WC10 (WC10) with a high combined ability based on their biological properties of gastrointestinal tolerance, adhesion, and short-chain fatty acid production ability. The effect of WC10 on mice with AAD was further evaluated. The results showed that WC10 was effective in improving the symptoms of AAD, effectively restoring antibiotic-induced weight loss, and reducing diarrhea status score and fecal water content. In addition, WC10 decreased the expression of pro-inflammatory cytokines and increased the expression of anti-inflammatory cytokines, alleviated intestinal tissue damage and inflammation, and improved intestinal epithelial barrier function by decreasing serum levels of enterotoxin, DAO, and D-lactic acid, and by increasing the expression of the intestinal mucosal immune factors sIgA and occludin. Importantly, the composition and function of the gut microbiota gradually recovered after WC10 treatment, increasing the number of SCFAs-producing Bifidobacterium and Roseburia. Subsequently, the short-chain fatty acid (SCFA) content was examined and WC10 significantly increased acetate, propionate, and butyrate production. Additionally, metabolomic analysis also showed that WC10 reversed the antibiotic interference with major metabolic pathways. These findings provide a solid scientific basis for the future application of W. coagulans WC10 in the treatment of AAD.

Effect of municipal sludge-based biochar produced at different pyrolysis temperatures on humification and oxytetracycline degradation of pig manure composting

This study explored the influence of pyrolysis temperatures on the properties of municipal sludge-based biochar (MSB) and evaluated the impact of MSB on humification and oxytetracycline (OTC, a broad-spectrum antibiotic) degradation in pig manure composting. Three types of MSB were produced from sewage sludge pyrolyzed at 300 °C, 500 °C, and 700 °C, respectively. Results indicated that pyrolysis temperature adjusted the formation sequence of the functional groups in MSB, and higher pyrolysis temperatures enriched the aromaticity of the biochar and augmented the concentrations of humic precursor compounds. The MSB addition to pig manure composting enhanced the peak temperature and prolonged the thermophilic phase. Moreover, the MSB addition significantly increased the HI (humic acid/fulvic acid) values (1.6-2.57) compared with the control (1.28), with a more pronounced effect observed at higher biochar pyrolysis temperatures. Furthermore, the MSB reduced the half-life of OTC degradation (1.47-2.44 d) during composting, accelerating its degradation compared with the control (2.66 d). The study demonstrated that the MSB provided a substantial amount of humic precursor materials into the composting process while also expediting the degradation of organic matter, thereby enhancing the humification process. Moreover, the extended duration of the thermophilic phase accelerated the degradation of OTC and shortened its half-life. Notably, the MSB at 700 °C had the best performance compared with other MSBs.

Dietary tangeretin improved antibiotic-associated diarrhea in mice by enhancing the intestinal barrier function, regulating the gut microbiota, and metabolic homeostasis

Antibiotic-associated diarrhea is mediated by antibiotic treatment and is usually caused by the disruption of the intestinal barrier, gut microbiota, and metabolic balance. To identify a dietary strategy that can mitigate the side effects of antibiotics, this study investigated the effect of tangeretin on antibiotic-associated diarrhea in C57BL/6 mice. The results revealed that dietary tangeretin significantly ameliorated symptoms of antibiotic-associated diarrhea, as evidenced by the decreased diarrhea status scores, the reduced fecal water content, the decreased caecum/body weight ratio, and the alleviated colonic tissue damage. Dietary tangeretin also exhibited a protective effect on the intestinal barrier function by upregulating the mRNA and protein expression of claudin-1 and ZO-1. Furthermore, analysis of the gut microbiota using 16S rRNA gene sequencing indicated that dietary tangeretin modulated the gut microbiota of mice with antibiotic-associated diarrhea via increasing the gut microbiota diversity and the abundance of beneficial bacteria, e.g., Lactobacillaceae and Ruminococcaceae, and decreasing the abundance of harmful bacteria, e.g., Enterococcus and Terrisporobacter. Additionally, dietary tangeretin restored the levels of short-chain fatty acids and modulated metabolic pathways by enriching purine metabolism, bile acid metabolism, ABC transporters, and choline metabolism in cancer. Collectively, these findings provide a solid scientific basis for the rational use of tangeretin as a preventive and therapeutic agent for antibiotic-associated diarrhea.

Effects of Lactobacillus plantarum and Weissella viridescens on the Gut Microbiota and Serum Metabolites of Mice with Antibiotic-Associated Diarrhea

Antibiotic-associated diarrhea (AAD) refers to diarrhea caused by gut microbiota disorders after the use of antibiotics, which seriously threatens the health of humans and animals. Therefore, it is necessary to find an effective therapy to treat AAD. This research aimed to explore the effects of Lactobacillus plantarum H-6 (L. plantarum H-6) and Weissella viridescens J-1 (W. viridescens J-1) on alleviating antibiotic-associated diarrhea induced by lincomycin hydrochloride (LH) in mice. The results show that L. plantarum H-6 could significantly reduce the expression of pro-inflammatory factors such as IL-1β and IL-6 in colon tissue. At the same time, L. plantarum H-6 significantly increased the abundance of Lactobacillus and Akkermansia, decreased the abundance of Bacteroides, and increased the contents of L-tryptophan, LysoPC (20:4 (8Z, 11Z, 14Z, 17Z)), reduced riboflavin, threoninyl-methionine, and N-palmitoyl in serum. However, W. viridescens J-1 had little effect on the treatment of AAD. It can be concluded that L. plantarum H-6 can regulate mice's colonic microbial composition, improve their serum metabolic process, and alleviate antibiotic-associated diarrhea. This research may provide a novel therapeutic option for AAD.

Oral delivery of porous starch-loaded bilayer microgels for controlled drug delivery and treatment of ulcerative colitis

We prepared one type of bilayer microgels for oral administration with three effects: pH responsiveness, time lag, and colon enzyme degradation. Combined with the dual biological effects of curcumin (Cur) for reducing inflammation and promoting repair of colonic mucosal injury, targeted colonic localization and release of Cur according to the colonic microenvironment were enhanced. The inner core, derived from guar gum and low-methoxyl pectin, afforded colonic adhesion and degradation behavior; the outer layer, modified by alginate and chitosan via polyelectrolyte interaction, achieved colonic localization. The porous starch (PS)-mediated strong adsorption allowed Cur loading in inner core to achieve a multifunctional delivery system. In vitro, the formulations exhibited good bioresponses at different pH conditions, potentially delaying Cur release in the upper gastrointestinal tract. In vivo, dextran sulfate sodium-induced ulcerative colitis (UC) symptoms were significantly alleviated after oral administration, accompanied by reduced levels of inflammatory factors. The formulations facilitated colonic delivery, allowing Cur accumulation in colonic tissue. Moreover, the formulations could alter gut microbiota composition in mice. During Cur delivery, each formulation increased species richness, decreased pathogenic bacterial content, and afforded synergistic effects against UC. These PS-loaded bilayer microgels, exhibiting excellent biocompatibility, multi-bioresponsiveness, and colon targeting, could be beneficial in UC therapy, allowing development into a novel oral formulation.

Protective effect of bioactive iridium nanozymes on high altitude-related hypoxia-induced kidney injury in mice

Introduction: High altitude-related hypoxia-induced organ damage significantly impacts people who are exposed to acute high-altitude environment. At present, kidney injury still lacks effective treatment strategies. Iridium nanozymes (Ir-NPs) are a nanomaterial with various enzymatic activities and are expected to be used in kidney injury treatment. Methods: In this study, we simulated a high-altitude environment (6000 m) to induce a kidney injury model, and explored the therapeutic effect of Ir-NPs in mice with kidney injury in this environment. Changes in the microbial community and metabolites were analyzed to explore the possible mechanism underlying the improvement of kidney injury during acute altitude hypoxia in mice treated with Ir-NPs. Results: It was discovered that plasma lactate dehydrogenase and urea nitrogen levels were considerably increased in mice exposed to acute altitude hypoxia compared to mice in a normal oxygen environment. Furthermore, there was a substantial increase in IL-6 expression levels in hypoxic mice; contrastingly, Ir-NPs decreased IL-6 expression levels, reduced the levels of succinic acid and indoxyl sulfate in the plasma and kidney pathological changes caused by acute altitude hypoxia. Microbiome analysis showed that bacteria, such as Lachnospiraceae_UCG_006 predominated in mice treated with Ir-NPs. Conclusion: Correlation analysis of the physiological, biochemical, metabolic, and microbiome-related parameters showed that Ir-NPs could reduce the inflammatory response and protect kidney function under acute altitude hypoxia, which may be related to intestinal flora distribution regulation and plasma metabolism in mice. Therefore, this study provides a novel therapeutic strategy for hypoxia-related kidney injury, which could be applied to other hypoxia-related diseases.

Bacillus-derived probiotics: metabolites and mechanisms involved in bacteria-host interactions

Bacillus probiotics have a sporulation capacity that makes them more suitable for processing and storage and for surviving passage through the gastrointestinal tract. The probiotic functions and regulatory mechanisms of different Bacillus have been exploited in many reports, but little is known about how various Bacillus probiotics perform different functions. This knowledge gap results in a lack of specificity in the selection and application of Bacillus. The probiotic properties are strain-specific and cell-type-specific, and are related to the germination potential and to the diversity of metabolites produced following intestinal germination, as this causes the variation in probiotic function and mechanisms. In this review, we discuss the Bacillus metabolites produced during germination and sporulation in the GI tract, as well as possible processes affecting intestinal homeostasis. We conclude that the oxygen-capturing capability and the production of antimicrobials, exoenzymes, competence and sporulation factors (CSF), exopolysaccharides, lactic acid, and cell components are specifically associated with the functional mechanisms of probiotic Bacillus. The aim of this review is to guide the screening of potential Bacillus strains for probiotics and their application in nutrition research. The information provided will also promote further research on Bacillus-derived functional metabolites in human nutrition.

Bacillus sp. DU-106 ameliorates type 2 diabetes by modulating gut microbiota in high-fat-fed and streptozotocin-induced mice

AIMS

Type 2 diabetes mellitus (T2D) is a chronic disease that manifests as endocrine and metabolic disorders that seriously threatening public health. This study aimed to investigate the effects of Bacillus sp. DU-106 on anti-diabetic effects and gut microbiota in C57BL/6J mice fed a high-fat diet and streptozotocin-induced T2D.

METHODS AND RESULTS

Bacillus sp. DU-106 was administered to model mice for eight consecutive weeks. Oral administration of Bacillus sp. DU-106 decreased food and water intake and alleviated body weight loss. Moreover, Bacillus sp. DU-106 imparted several health benefits to mice, including balanced blood glucose, alleviation of insulin resistance in T2D mice, and an improvement in lipid metabolism. Furthermore, Bacillus sp. DU-106 protected against liver and pancreatic impairment. Additionally, Bacillus sp. DU-106 treatment reshaped intestinal flora by enhancing gut microbial diversity and enriching the abundance of certain functional bacteria.

CONCLUSION

Collectively, these findings suggest that Bacillus sp. DU-106 can ameliorate T2D by regulating the gut microbiota.

SIGNIFICANCE AND IMPACT OF STUDY

Therefore, a novel probiotic, Bacillus sp. DU-106 may be a promising therapeutic agent for improving and alleviating T2D in mice.

Regulatory Effect of Lactiplantibacillus plantarum 2-33 on Intestinal Microbiota of Mice With Antibiotic-Associated Diarrhea

Diarrhea is one of the common adverse reactions in antibiotic treatment, which is usually caused by the imbalance of intestinal flora, and probiotics play an important role in the structure of intestinal flora. Therefore, this experiment studied the regulatory effect of Lactiplantibacillus plantarum 2-33 on antibiotic-associated diarrhea (AAD) mice. First, the AAD mice model was established by the mixed antibiotic solution of gentamicin sulfate and cefradine. Then, the physiological indexes and diarrhea of mice were observed and recorded by gastric perfusion of low dose (1.0 × 10⁷ CFU/ml), medium dose (1.0 × 10⁸CFU/ml), and high dose (1.0 × 10⁹ CFU/ml) strain 2-33. 16S rRNA gene V3-V4 regions were sequenced in colon contents of mice in control group, model group, self-healing group, and experimental group, respectively, and the diversity of intestinal flora and gene function prediction were analyzed. The results showed that the intestinal flora of AAD mice was not significantly regulated by gastric perfusion of strain 2-33 to 7 days, but the relative abundance and diversity of intestinal flora of AAD mice were significantly improved by gastric perfusion to 14 days (p < 0.05). In addition, at the genus level, the relative abundance of Lactobacillus increased significantly, and the relative abundance of Enterococcus and Bacillus decreased significantly (p < 0.05). In addition, the regulation of strain 2-33 on intestinal flora of AAD mice was time- and dose-dependent, short-term gastric perfusion, and low dose had no significant effect (p > 0.05). Strain 2-33 can significantly increase the levels of anti-inflammatory cytokines IL-4 and IL-10, significantly decrease the levels of proinflammatory cytokines TNF-α and IFN-γ (p < 0.05), and can also adjust carbohydrate metabolism, amino acid metabolism, and energy metabolism to normal levels, thus accelerating the recovery of intestinal flora structure of AAD mice. In summary, strain 2-33 can improve the structure and diversity of intestinal flora of AAD mice, balance the level of substance and energy metabolism, and play a positive role in relieving diarrhea, maintaining and improving the intestinal microecological balance.