Antimicrobial effects of cannabidiol on select agriculturally important Clostridia.

Amino acid-fermenting Clostridia have undesirable effects in agricultural systems, which can be mitigated by antibiotics, but resistance necessitates alternatives. Here, we demonstrate the efficacy of cannabidiol on growth and ammonia inhibition of five agriculturally relevant Clostridia: Clostridium sporogenes, Peptostreptococcus spp., Clostridioides difficile, Acetoanaerobium sticklandii, and Clostridium aminophilum.

Emulsified and Nanoemulsified Essential Oils in the Control of Clostridium botulinum and Clostridium sporogenes in Mortadella.

Clostridium botulinum is a foodborne pathogen responsible for severe neuroparalytic disease associated with the ingestion of pre-formed toxin in food, with processed meats and canned foods being the most affected. Control of this pathogen in meat products is carried out using the preservative sodium nitrite (NaNO2), which in food, under certain conditions, such as thermal processing and storage, can form carcinogenic compounds. Therefore, the objective was to use nanoemulsified essential oils (EOs) as natural antimicrobial agents, with the aim of reducing the dose of NaNO2 applied in mortadella. The antimicrobial activity of nanoemulsions prepared with mixtures of EOs of garlic, clove, pink pepper, and black pepper was evaluated on endospores and vegetative cells of C. botulinum and Clostridium sporogenes (surrogate model) inoculated in mortadella prepared with 50 parts per million NaNO2. The effects on the technological (pH, water activity, and color) and sensory characteristics of the product were also evaluated. The combinations of EOs and their nanoemulsions showed sporicidal effects on the endospores of both tested microorganisms, with no counts observed from the 10th day of analysis. Furthermore, bacteriostatic effects on the studied microorganisms were observed. Regarding the technological and sensorial characteristics of the product, the addition of the combined EOs had a negative impact on the color of the mortadella and on the flavor/aroma. Despite the strong commercial appeal of adding natural preservatives to foods, the effects on flavor and color must be considered. Given the importance of controlling C. botulinum in this type of product, as well as the reduction in the amount of NaNO2 used, this combination of EOs represents a promising antimicrobial alternative to this preservative, encouraging further research in this direction.

Genome-encoded ABCF factors implicated in intrinsic antibiotic resistance in Gram-positive bacteria: VmlR2, Ard1 and CplR.

Genome-encoded antibiotic resistance (ARE) ATP-binding cassette (ABC) proteins of the F subfamily (ARE-ABCFs) mediate intrinsic resistance in diverse Gram-positive bacteria. The diversity of chromosomally-encoded ARE-ABCFs is far from being fully experimentally explored. Here we characterise phylogenetically diverse genome-encoded ABCFs from Actinomycetia (Ard1 from Streptomyces capreolus, producer of the nucleoside antibiotic A201A), Bacilli (VmlR2 from soil bacterium Neobacillus vireti) and Clostridia (CplR from Clostridium perfringens, Clostridium sporogenes and Clostridioides difficile). We demonstrate that Ard1 is a narrow spectrum ARE-ABCF that specifically mediates self-resistance against nucleoside antibiotics. The single-particle cryo-EM structure of a VmlR2-ribosome complex allows us to rationalise the resistance spectrum of this ARE-ABCF that is equipped with an unusually long antibiotic resistance determinant (ARD) subdomain. We show that CplR contributes to intrinsic pleuromutilin, lincosamide and streptogramin A resistance in Clostridioides, and demonstrate that C. difficile CplR (CDIF630_02847) synergises with the transposon-encoded 23S ribosomal RNA methyltransferase Erm to grant high levels of antibiotic resistance to the C. difficile 630 clinical isolate. Finally, assisted by uORF4u, our novel tool for detection of upstream open reading frames, we dissect the translational attenuation mechanism that controls the induction of cplR expression upon an antibiotic challenge.

Novel Lytic Enzyme of Prophage Origin from Clostridium botulinum E3 Strain Alaska E43 with Bactericidal Activity against Clostridial Cells.

Clostridium botulinum is a Gram-positive, anaerobic, spore-forming bacterium capable of producing botulinum toxin and responsible for botulism of humans and animals. Phage-encoded enzymes called endolysins, which can lyse bacteria when exposed externally, have potential as agents to combat bacteria of the genus Clostridium. Bioinformatics analysis revealed in the genomes of several Clostridium species genes encoding putative N-acetylmuramoyl-l-alanine amidases with anti-clostridial potential. One such enzyme, designated as LysB (224-aa), from the prophage of C. botulinum E3 strain Alaska E43 was chosen for further analysis. The recombinant 27,726 Da protein was expressed and purified from E. coli Tuner(DE3) with a yield of 37.5 mg per 1 L of cell culture. Size-exclusion chromatography and analytical ultracentrifugation experiments showed that the protein is dimeric in solution. Bioinformatics analysis and results of site-directed mutagenesis studies imply that five residues, namely H25, Y54, H126, S132, and C134, form the catalytic center of the enzyme. Twelve other residues, namely M13, H43, N47, G48, W49, A50, L73, A75, H76, Q78, N81, and Y182, were predicted to be involved in anchoring the protein to the lipoteichoic acid, a significant component of the Gram-positive bacterial cell wall. The LysB enzyme demonstrated lytic activity against bacteria belonging to the genera Clostridium, Bacillus, Staphylococcus, and Deinococcus, but did not lyse Gram-negative bacteria. Optimal lytic activity of LysB occurred between pH 4.0 and 7.5 in the absence of NaCl. This work presents the first characterization of an endolysin derived from a C. botulinum Group II prophage, which can potentially be used to control this important pathogen.

The synergic interaction between environmental factors (pH and NaCl) and the physiological state (vegetative cells and spores) provides new possibilities for optimizing processes to manage risk of C. sporogenes spoilage.

Clostridium sporogenes has been widely used as a surrogate for proteolytic C. botulinum for validating thermal processes in low-acid cans. To limit the intensity of heat treatments, industrials must use other ways of control as an association of acidic and saline environment after a low heat treatment. The probability of growth of pH (7-4.4), sodium chloride concentration (0-11%) and heat treatment (80°C-10 min; 100°C-1.5 min and 5.2 min) were studied on C. sporogenes PA 3679 spores and vegetative cells. Vegetative cells or heat-treated spores were inoculated in PYGm broth at 30 °C for 48 days in anaerobic conditions. Vegetative cells growth (pH 4.6-pH 4.5; 7%-8% NaCl) range is larger than the spore one (pH 5.2-pH 5.0; 6%-7% NaCl). Spores germination and outgrowth rage is decreased if the spores are heat-treated at 100 °C for 1.5 min (pH 5.5-5.3; 4%-5% NaCl) and 5.2 min (pH 5.7-5.3; 4%-5% NaCl). The C. sporogenes PA 3679 spores germination and outgrowth is impacted by their physiological state. The synergic interaction between environmental factors (pH and NaCl) and the physiological state (vegetative cells and spores) opening new possibilities for optimizing food formulation processes to manage the risks of C. sporogenes spoilage.

Evaluation of the therapeutic effect of propolis on Fasciola gigantica and Clostridium novyi type B infections in sheep.

The use of natural products for disease control is a promising approach to solving the problem of drug resistance. The aim of the research reported here was to evaluate the fasciolicidal and anti-Clostridium novyi type B activities of propolis administered orally to sheep infected with Fasciola gigantica and C. novyi type B. Sheep infected with both pathogens were divided into two groups: an infected treated group and an infected non-treated group. The treatment was oral administration of 50 mg propolis extract/kg daily for 15 days. The body weight of the sheep, fecal egg counts of F. gigantica, serum levels of F. gigantica IgG, concentrations of cytokines (IL-2, IL-10, and IL-17), and bacterial counts of C. novyi were evaluated. Following treatment, the sheep had increased body weight and a significant decrease in the egg count, which was reduced by 54.54% at 15 days post treatment. The level of anti- Fasciola IgG increased, whereas levels of IL-2, IL-10, and IL-17 decreased in propolistreated sheep. Treatment of sheep with propolis produced a significant reduction in fecal count of C. novyi, from 8 × 109 to 3 × 103 colony units per gram at 15 days post treatment. This research highlights the therapeutic potential of Egyptian propolis extract as a treatment against F. gigantica and C. novyi type B infections, and investigated its mode of action through its effect on some cellular and humoral responses in sheep with both infections.

S-Nitroso-N-acetylcysteine (NAC-SNO) vs. nitrite as an anti-clostridial additive for meat products.

Nitrite is added to meat products as a preservative and it acts as a bacteriostatic compound against Clostridium botulinum growth. Nitric-oxide (˙NO), myoglobin and S-nitroso-compounds seem to be the main molecules generated from nitrite in meat products, which by decomposition to ˙NO, form the main anti-clostridial factor. The growth of C. sporogenes from activated spores in the presence of 0.5-2.5 mM NAC-SNO was compared to nitrite, both at 37 °C for 5 days and at room temperature for 28 days. The present study demonstrates that NAC-SNO under the same conditions and concentrations, in meat products, acts as an anti-clostridial compound similar to nitrite. In contrast to nitrite which must be activated in meat by heating, NAC-SNO generates the anti-clostridial factor directly, without heating, as was evaluated in an unheated bacteriological medium. The toxic effect of NAC-SNO and nitrite in methaemoglobinaemia and generation of N-nitrosamines in vivo, in mice, were also determined. Mice were gavage fed milk containing 45 mg per kg per bw of nitrite or an equimolar equivalent of NAC-SNO in the presence of 50 mg per kg per bw of N-methylaniline. Nitrite generated methaemoglobinaemia and carcinogenic N-nitrosoamines (N-nitrosomethylaniline); however, NAC-SNO under the same conditions and concentrations generates much less methaemoglobin and no detectable N-nitrosoamines in the blood, in vivo.

Antibiotic susceptibility screening of primate-associated Clostridium ventriculi.

Clostridium ventriculi (syn. Sarcina ventriculi) is a Gram-positive opportunistic pathogen with sarcina morphology. In the case of gastrointestinal disorders, the treatment is often empirical. Due to the common occurrence in primates and the potential risk of dysbiosis; the antibiotic susceptibility screening of C. ventriculi strains isolated from guenon monkeys and crested gibbons to 58 antibiotics was performed to reduce potentially ineffective antibiotic use in case of disease. Isolates were found to be susceptible to the majority of the tested antibiotics, mainly to (fluoro)quinolones, macrolides, penicillins, and tetracyclines. The susceptibility profiles were similar despite the hosts. Tested strains showed also natural resistance to a few antibiotics on the genus level. Detected in vitro antibiotic efficiency is consistent with documented human treatment cases.

A rare case of Clostridium paraputrificum bacteremia in a 78-year-old Caucasian man diagnosed with an intestinal neoplasm.

Clostridium like species, particularly Clostridium perfrigens, are the second most common causes of human anaerobic infections, including myonecrosis and bacteremia. Clostridium paraputrificum is an infrequent isolate, which has been identified in only 1% of reported cases of clostridial infections. We herein report a rare case of C. paraputrificum bacteremia in a 78-year-old Caucasian man diagnosed with an intestinal carcinoma and liver neoplastic lesions. The isolate was susceptible to chloramphenicol, meropenem, metronidazole, vancomycin, and resistant to clindamycin and penicillin, and the patient was successfully treated with metronidazole. Malignancy and inflammatory bowel diseases are often associated with clostridial bacteremia, which cannot be neglected.

Dietary Fermented Soy Extract and Oligo-Lactic Acid Alleviate Chronic Kidney Disease in Mice via Inhibition of Inflammation and Modulation of Gut Microbiota.

Chronic kidney disease (CKD) is a global epidemic with an increasing prevalence worldwide. Effective preventive strategies are urgently needed. This study aimed to investigate the effect of nutraceutical components, a fermented soybean product (ImmuBalance, IMB) and an oligo-lactic acid product (LAP), on the prevention of adenine-induced CKD in mice. Female C57BL/6 mice were randomly assigned into following experimental groups: negative control; model control; and models treated with IMB at 250 or 1000 mg/kg body weight (BW), LAP at 1000 or 2000 mg/kg BW, and IMB/LAP combinations. The CKD model was established by intraperitoneal injection of adenine daily for 4 weeks, and treatments started 2 weeks before adenine injection and ended after 10 weeks. Compared with the model control, the treatments did not significantly alter the body weight or food intake. Both IMB and LAP, especially their combination, significantly inhibited tubular dilation, tubulointerstitial degeneration or atrophy, interstitial chronic inflammation and acute inflammation in the kidneys of CKD mice, and significantly decreased serum cystatin C levels. IMB or LAP significantly reversed CKD-associated increases of circulating and kidney levels of inflammatory cytokines, circulating levels of kidney injury biomarkers, and kidney levels of stem cell biomarkers, and significantly reversed CKD-associated reduction of cecum Clostridium leptum group. Our results suggest that dietary supplementation of IMB or LAP may significantly delay the development and/or progression of CKD.

Ficus carica polysaccharide attenuates DSS-induced ulcerative colitis in C57BL/6 mice.

The Ficus carica polysaccharide (FCPS) components of the common fig fruit have been demonstrated to exhibit antioxidant and immunity-enhancing activities. However, it is unclear whether it could prevent the ulcerative colitis development. Here, we reported that 5 week orally administered FCPS (150-300 mg per kg bw) significantly prevented DSS-induced colitis in C57BL/6J mice by improving the colon length and suppressing the infiltration of inflammatory cells in the gut. FCPS treatment protected the goblet cells, elevated the expression of tight junction protein claudin-1, and suppressed the formation of cytokines including TNF-α and IL-1ß. FCPS supplementation significantly reformed the gut microbiome by enhancing the abundance of S24-7, Bacteroides, and Coprococus, and suppressing the abundance of Escherichia and Clostridium at the genus level. Consistently, the formation of beneficial microbial metabolites, short chain fatty acids, especially acetate and butyrate, were improved in FCPS-treated colitis mice. The correlation analysis indicated that the protective effects of FCPS on ulcerative colitis might be highly correlated with the microbiota composition changes and the formation of SCFAs. In conclusion, these results indicated that FCPS supplementation could be a promising nutritional strategy for reducing inflammatory bowel disease and the gut microbes play essential roles in providing these beneficial effects.

Selective Enrichment of Clostridium Spp. by Nutrition Control from Sihe Coal Geological Microbial Communities.

In the coal biogasification, butyric acid is an important intermediate product. The enrichment of butyric acid-producing bacteria in coal geological methanogens is critical to confirm this assertion. Therefore, to study a method for enrichment of butyric acid-producing bacteria and to explore characteristic factors for evaluating the enrichment effect would be the basis for further strain isolation and metabolomics research. In this study, the nutrition control method was used for the butyric acid-producing bacteria enrichment from concentrated bacteria solution in Sihe coal seam. The characteristic factors' changes in gas production, gas composition, butyric acid concentration, and pH were observed and analyzed in the experiment. High-throughput sequencing was used as a verification method to validate the medium and genera enrichment effect that can be used for the butyric acid-producing bacteria. Through experimental research and analysis, it was identified that the glucose-sucrose-maltose medium was the beneficial medium to the enrichment of butyric acid-producing bacteria, and the high-throughput sequencing determined that the enriched genera were Clostridium spp. Glucose-sucrose-maltose medium experimental data confirmed that the decrease of CO2 and H2 daily yield, the increase of butyric acid concentration, and the decrease of pH value had a significant positive correlation with the enrichment of Clostridium spp.

Clinical relevance of Clostridium bacteremia: An 8-year retrospective study.

Clostridium spp. are recovered from 25% of the blood culture positive with anaerobes. However, the clinical relevance of Clostridium bacteremia has been controverted in the literature, particularly for C. perfringens. We aimed to evaluate the clinical relevance of Clostridium bacteremia, either due to C. perfringens or other Clostridium species, and to identify the risk factors of mortality in these patients. A retrospective cohort study was conducted from January 2010 to April 2018. All the patients with at least one blood culture positive with any Clostridium species were included. Eighty-one patients with a least one blood culture positive with any Clostridium species were included. Seventy patients (86.4%) fulfilled the criteria for clinically relevant bacteremia. Bacteremia due to C. perfringens tended to be less clinically relevant than other Clostridium species but this was not statistically significant (76% vs 91.2%, P = 0.09). In case of clinically relevant bacteremia, the 30-day mortality rate was 31.4%. In multivariate analysis, adequate empiric antimicrobial therapy was significantly associated with survival (P = 0.03). In conclusion, bacteremia due to C. perfringens or other Clostridium species is usually clinically relevant. This finding was also supported by an improved survival at 30 days when adequate empiric antimicrobial therapy was administered.

Antimicrobial Resistance in Clostridium and Brachyspira spp. and Other Anaerobes.

This article describes the antimicrobial resistance to date of the most frequently encountered anaerobic bacterial pathogens of animals. The different sections show that antimicrobial resistance can vary depending on the antimicrobial, the anaerobe, and the resistance mechanism. The variability in antimicrobial resistance patterns is also associated with other factors such as geographic region and local antimicrobial usage. On occasion, the same resistance gene was observed in many anaerobes, whereas some were limited to certain anaerobes. This article focuses on antimicrobial resistance data of veterinary origin.

Antibiotics in early life associate with specific gut microbiota signatures in a prospective longitudinal infant cohort.

BACKGROUND: The effects of antibiotics on infant gut microbiota are unclear. We hypothesized that the use of common antibiotics results in long-term aberration in gut microbiota. METHODS: Antibiotic-naive infants were prospectively recruited when hospitalized because of a respiratory syncytial virus infection. Composition of fecal microbiota was compared between those receiving antibiotics during follow-up (prescribed at clinicians' discretion because of complications such as otitis media) and those with no antibiotic exposure. Fecal sampling started on day 1, then continued at 2-day intervals during the hospital stay, and at 1, 3 and 6 months at home. RESULTS: One hundred and sixty-three fecal samples from 40 patients (median age 2.3 months at baseline; 22 exposed to antibiotics) were available for microbiota analyses. A single course of amoxicillin or macrolide resulted in aberration of infant microbiota characterized by variation in the abundance of bifidobacteria, enterobacteria and clostridia, lasting for several months. Recovery from the antibiotics was associated with an increase in clostridia. Occasionally, antibiotic use resulted in microbiota profiles associated with inflammatory conditions. CONCLUSIONS: Antibiotic use in infants modifies especially bifidobacterial levels. Further studies are warranted whether administration of bifidobacteria will provide health benefits by normalizing the microbiota in infants receiving antibiotics.

Impact of Simulated Martian Conditions on (Facultatively) Anaerobic Bacterial Strains from Different Mars Analogue Sites.

Five bacterial (facultatively) anaerobic strains, namely Buttiauxella sp. MASE-IM-9, Clostridium sp. MASE-IM-4, Halanaerobium sp. MASE-BB-1, Trichococcus sp. MASE-IM-5, and Yersinia intermedia MASE-LG-1 isolated from different extreme natural environments were subjected to Mars relevant environmental stress factors in the laboratory under controlled conditions. These stress factors encompassed low water activity, oxidizing compounds, and ionizing radiation. Stress tests were performed under permanently anoxic conditions. The survival rate after addition of sodium perchlorate (Na-perchlorate) was found to be species-specific. The inter-comparison of the five microorganisms revealed that Clostridium sp. MASE-IM-4 was the most sensitive strain (D10-value (15 min, NaClO4) = 0.6 M). The most tolerant microorganism was Trichococcus sp. MASE-IM-5 with a calculated D10-value (15 min, NaClO4) of 1.9 M. Cultivation in the presence of Na-perchlorate in Martian relevant concentrations up to 1 wt% led to the observation of chains of cells in all strains. Exposure to Na-perchlorate led to a lowering of the survival rate after desiccation. Consecutive exposure to desiccating conditions and ionizing radiation led to additive effects. Moreover, in a desiccated state, an enhanced radiation tolerance could be observed for the strains Clostridium sp. MASE-IM-4 and Trichococcus sp. MASE-IM-5. These data show that anaerobic microorganisms from Mars analogue environments can resist a variety of Martian-simulated stresses either individually or in combination. However, responses were species-specific and some Mars-simulated extremes killed certain organisms. Thus, although Martian stresses would be expected to act differentially on microorganisms, none of the expected extremes tested here and found on Mars prevent the growth of anaerobic microorganisms.

The antibiotic susceptibility pattern of gas gangrene-forming Clostridium spp. clinical isolates from South-Eastern Hungary.

Introduction:Clostridium perfringens and other gas gangrene-forming clostridia are commensals of the human gut and vaginal microbiota, but can cause serious or even fatal infections. As there are relatively few published studies on antibiotic susceptibility of these bacteria, we decided to perform a 10-year retrospective study in a South-Eastern Hungarian clinical centre.Methods: A total of 372 gas gangrene-forming Clostridium spp. were isolated from clinically relevant samples and identified with rapid ID 32A (bioMérieux, France) and MALDI-TOF MS (Bruker Daltinics, Germany) methods. Antibiotic susceptibility was determined with E-tests.Results: We identified 313 C. perfringens, 20 C. septicum, 10 C. sordellii, 10 C. sporogenes, 9 C. tertium, 6 C. bifermentans, 4 C. histolyticum isolates. In C. perfringens isolates, the rate of penicillin resistance was 2.6% and the rate of clindamycin resistance 3.8%. Penicillin resistance was found in 6.8% and clindamycin resistance in 8.5% of the non-perfringens Clostridium spp. isolates.Conclusion: The antibiotic susceptibility of C. perfringens isolates was in good agreement with previous publications. The rates of resistance to penicillin and clindamycin were very low. The resistance rates of non-perfringens Clostridium spp. isolates were higher than those of C. perfringens strains, but lower than those published in the literature.

High pressure sensitization of heat-resistant and pathogenic foodborne spores to nisin.

Today, there is no effective non-thermal method to inactivate unwanted bacterial spores in foods. High-Pressure (HP) process has been shown to act synergistically with moderate heating and the bacteriocin nisin to inactivate spores but the mechanisms have not been elucidated. The purpose of the present work was to investigate in depth the synergy of HP and nisin on various foodborne spore species and to bring new elements of understandings. For this purpose, spores of Bacillus pumilus, B. sporothermodurans, B. licheniformis, B. weihenstephanensis, and Clostridium sp. were suspended in MES buffer, in skim milk or in a liquid medium simulating cooked ham brine and treated by HP at 500 MPa for 10 min at 50 °C or 20 °C. Nisin (20 or 50 IU/mL) was added at three different points during treatment: during HP, during and or in the plating medium of enumeration. In the latter two cases, a high synergy was observed with the inhibition of the spores of Bacillus spp. The evaluation of the germinated fraction of Bacillus spp. spores after HP revealed that this synergy was likely due to the action of nisin on HP-sensitized spores, rather than on HP-germinated spores. Thus, the combination of nisin and HP can lead to Bacillus spp. spore inhibition at 20 °C. And Nisin can act on HP-treated spores, even if they are not germinated. This paper provides new information about the inhibition of spores by the combination of HP and nisin. The high synergy observed at low temperature has not been reported yet and could allow food preservation without the use of any thermal process.

Low-dose tetracycline exposure alters gut bacterial metabolism and host-immune response: "Personalized" effect?

The human gut microbiome (GM) in healthy people is chronically exposed to tetracycline (TET) via environmental exposure and dietary uptake. However, limited information is available on its effect on the GM metabolome and effect on the host, especially at the dietary exposure level. Here, we investigated how TET at both sub-pharmaceutical and dietary exposure levels affects the metabolome and the secretome-induced host immune response by studying several representative gut bacteria. Interestingly, the metabolome showed a highly species-specific pattern with a distinct dose-response relationship. B. fragilis was highly sensitive to TET and vitamin, nucleotide, and amino acid metabolism pathways were the most vulnerable metabolic pathways at dietary exposure level. For key metabolite short chain fatty acids, TET significantly induced the synthesis of butyrate in B. fragilis, rather than C. sporogenes and E. coli. Furthermore, TET induced the release of lipopolysaccharides (LPS) in E. coli and enhanced the immune response; however, there was no obvious effect on B. fragilis. Interestingly, the overall immune response modulation with TET exposure relied on the ratio between E. coli and B. fragilis, possibly due to the neutralization of active LPS from E. coli by the LPS from B. fragilis. Overall, our results showed that the effect of TET from environmental exposure on the host health would be highly dependent on the GM composition, especially for the gut bacterial metabolome and secretome induced immune response.

The effects of dietary supplementation with porous zinc oxide on growth performance, intestinal microbiota, morphology, and permeability in weaned piglets.

The objective of this experiment was to evaluate the effects of dietary supplementation with porous zinc oxide (HiZox) on growth performance, intestinal microbiota, morphology, and permeability in weaned piglets. A total of 128 weaned piglets [(Landrace × Yorkshire) × Duroc] with an average body weight (BW) of (6.55 ± 0.25 kg; 21 d of age) were randomly assigned to four dietary treatments: (1) a corn-soybean basal diet; (2) basal diet + 3,000 mg/kg conventional ZnO; (3) basal diet + 200 mg/kg HiZox; (4) basal diet + 500 mg/kg HiZox. The experiments lasted for 28 days. Incremental HiZox in the diet increased ADG (linear p = 0.015; quadratic p = 0.043) and ADFI (linear p = 0.027; quadratic p = 0.038), and the diarrhea index decreased linearly and quadratically (p < 0.01) as HiZox supplemented increased. Furthermore, supplementation with HiZox increased the amounts of Lactobacillus spp. (p < 0.05) in the ileum and cecum in comparison with that of control treatment or 3,000 mg/kg ZnO treatment, while decreased the populations of Escherichia coli, Clostridium coccoides, and Clostridium. leptum subgroup (p < 0.05) in the ileum and cecum relative to those in control treatment. The addition of HiZox increased the villus height and villus-to-crypt ratio (VC) of duodenum, jejunum, and ileum (p < 0.05), while decreased the crypt depth of jejunum (p < 0.05) and tended to reduce the crypt depth of duodenum (p < 0.10) compared with the control treatment. Piglets fed with 500 mg/kg HiZox had lower serum D-lactate and diamine oxidase (DAO) than those fed with basal control diet or 3,000 mg/kg ZnO diet (p < 0.01). The results suggested that supplementation with HiZox modulated intestinal microbial composition and improved intestinal morphology, which may exert protective effects on the integrity of the mucosal barrier function of weaned piglets, was as efficacious as pharmaceutical doses of ZnO in enhancing growth performance, indicating that the HiZox may be a promising alternative to pharmaceutical doses of ZnO.