In Situ Electron Microscopy of Lactomicroselenium Particles in Probiotic Bacteria

Exploring the Anti-Inflammatory and Antioxidative Potential of Selenium Nanoparticles Biosynthesized by Lactobacillus casei 393 on an Inflamed Caco-2 Cell Line

Selenium (Se) plays a crucial role in modulating inflammation and oxidative stress within the human system. Biogenic selenium nanoparticles (SeNPs) synthesized by Lactobacillus casei (L. casei) exhibit anti-inflammatory and anti-oxidative properties, positioning them as a promising alternative to traditional supplements characterized by limited bioavailability. With this context in mind, this study investigates the impact of selenium and L. casei in ameliorating inflammation and oxidative stress using a cell line model. The study is centered on the biosynthesis of selenium nanoparticles (SeNPs) by L. casei 393 under anaerobic conditions using a solution of sodium selenite (Na2SeO3) in the bacterial culture medium. The generation of SeNPs ensued from the interaction of L. casei bacteria with selenium ions, a process characterized via transmission electron microscopy (TEM) to confirm the synthesis of SeNPs. To induce inflammation, the human colonic adenocarcinoma cell line, Caco-2 was subjected to interleukin-1 beta (IL-1β) at concentrations of 0.5 and 25 ng/ml. Subsequent analyses encompass the evaluation of SeNPs derived from L. casei, its supernatant, commercial selenium, and L. casei probiotic on Caco2 cell line. Finally, we assessed the inflammatory and oxidative stress markers. The assessment of inflammation involved the quantification of NF-κB and TGF-β gene expression levels, while oxidative stress was evaluated through the measurement of Nrf2, Keap1, NOX1, and SOD2 gene levels. L. casei successfully produced SeNPs, as confirmed by the color change in the culture medium and TEM analysis showing their uniform distribution within the bacteria. In the inflamed Caco-2 cell line, the NF-κB gene was upregulated, but treatment with L. casei-SeNPs and selenium increased TGF-β expression. Moreover, L. casei-SeNPs upregulated SOD2 and Nrf2 genes, while downregulating NOX1, Keap1, and NF-κB genes. These results demonstrated the potential of L. casei-SeNPs for reducing inflammation and managing oxidative stress in the Caco-2 cell line. The study underscores the ability of L. casei-SeNPs to reduce oxidative stress and inflammation in inflamed Caco-2 cell lines, emphasizing the effectiveness of L. casei as a source of selenium. These insights hold significant promise for the development of SeNPs derived from L. casei as potent anti-inflammatory and anti-cancer agents, paving the way for novel therapeutic applications in the field.

CD44-targeting hyaluronic acid-selenium nanoparticles boost functional recovery following spinal cord injury

BACKGROUND

Therapeutic strategies based on scavenging reactive oxygen species (ROS) and suppressing inflammatory cascades are effective in improving functional recovery after spinal cord injury (SCI). However, the lack of targeting nanoparticles (NPs) with powerful antioxidant and anti-inflammatory properties hampers the clinical translation of these strategies. Here, CD44-targeting hyaluronic acid-selenium (HA-Se) NPs were designed and prepared for scavenging ROS and suppressing inflammatory responses in the injured spinal cord, enhancing functional recovery.

RESULTS

The HA-Se NPs were easily prepared through direct reduction of seleninic acid in the presence of HA. The obtained HA-Se NPs exhibited a remarkable capacity to eliminate free radicals and CD44 receptor-facilitated internalization by astrocytes. Moreover, the HA-Se NPs effectively mitigated the secretion of proinflammatory cytokines (such as IL-1β, TNF-α, and IL-6) by microglia cells (BV2) upon lipopolysaccharide-induced inflammation. In vivo experiments confirmed that HA-Se NPs could effectively accumulate within the lesion site through CD44 targeting. As a result, HA-Se NPs demonstrated superior protection of axons and neurons within the injury site, leading to enhanced functional recovery in a rat model of SCI.

CONCLUSIONS

These results highlight the potential of CD44-targeting HA-Se NPs for SCI treatment.

Characteristics of Lactobacillus casei probiotic microparticles in L-type methacrylic acid copolymer matrix

Lactobacillus casei (LC) is a type of lactic acid bacterium that is known for its beneficial probiotic properties. However, it is not typically found in the human intestine because it lacks acid resistance. LC thrives in an optimal pH environment of 6.8 and can be initiated in a more acidic environment at a pH of 3.5. This study purposed to compare the effect of L-type methacrylic acid copolymer (MAC) as a matrix (0.50%, 0.75%, and 1.00%) on the physical characteristics of LC probiotic microparticles made by the spray drying process. Probiotic microparticles were also made from a dry suspension of LC FNCC 0090 bacteria and dispersed in a solution of L-type MAC. The results showed that a rise in matrix content by 1.00% increased particle size (4.47 ± 0.19 µm) and reduced moisture content (7.45 ± 0.11%). The analysis of microparticle morphology also indicated a positive correlation between the level of L-type MAC and the production of smooth, nonporous, and almost spherical shapes. In addition, it was observed that encapsulation efficiency (92.46 ± 0.17%) and protection against stomach acid (98.17% ±1.17%) increased with the level of the matrix.

Mitigation of Imidacloprid Toxicity in Poultry Chicken by Selenium Nanoparticles: Growth Performance, Lipid Peroxidation, and Blood Traits

Imidacloprid is an insecticide that protects against insects in the agriculture, animal, and poultry production sectors. Since the accumulation of imidacloprid induces adverse impacts on general health status and quality of the food chain, this study tested the impacts on broilers. Besides, selenium nanoparticles were fed to birds to relieve the negative impacts on growth performance and health status. Birds (1-day age, initial weight 46.05 ± 1.0 g) divided into four groups (triplicates) where 15 chicks of each replicate (45 for each group). The first group (control) was fed the basal diet without either selenium or imidacloprid toxicity. The second group was fed selenium nano form at 3 mg/kg. The third group was fed selenium and exposed to imidacloprid at 1/10 LT50 (3 mg/kg body weight). The fourth group was fed selenium nano form (3 mg/kg) and exposed to imidacloprid at 1/10 LT50 (3 mg/kg body weight). All groups were kept under the same conditions for 35 days. The final weight and weight gain of birds fed selenium nano form showed marked improvement compared to the imidacloprid-exposed group, while the feed intake and feed conversion ratio markedly reduced. The red blood cells showed higher values in birds fed selenium nano than the control and those exposed to imidacloprid. Interestingly, the hemoglobulin and hematocrit increased in birds fed selenium nano form with or without imidacloprid exposure. Furthermore, the white blood cells increased in birds fed selenium nano form with or without imidacloprid exposure. The total protein, albumin, and globulin were higher in birds fed selenium nanoparticles than those exposed to imidacloprid with or without selenium feeding. Birds in the control and imidacloprid groups had higher aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde levels than the remaining groups. Accordingly, dietary selenium nanoparticles are suggested in broiler feed to cope with the adverse effects of imidacloprid toxicity.

Biological Selenite Reduction, Characterization and Bioactivities of Selenium Nanoparticles Biosynthesised by Pediococcus acidilactici DSM20284

Selenium (Se) is in great demand as a health supplement due to its superior reactivity and excellent bioavailability, despite selenium nanoparticles (SeNPs) having signs of minor toxicity. At present, the efficiency of preparing SeNPs using lactic acid bacteria is unsatisfactory. Therefore, a probiotic bacterial strain that is highly efficient at converting selenite to elemental selenium is needed. In our work, four selenite-reducing bacteria were isolated from soil samples. Strain LAB-Se2, identified as Pediococcus acidilactici DSM20284, had a reduction rate of up to 98% at ambient temperature. This strain could reduce 100 mg L^-1 of selenite to elemental Se within 48 h at pH 4.5-6.0, a temperature of 30-40 °C, and a salinity of 1.0-6.5%. The produced SeNPs were purified, freeze-dried, and subsequently systematically characterised using FTIR, DSL, SEM-EDS, and TEM techniques. SEM-EDS analysis proved the presence of selenium as the foremost constituent of SeNPs. The strain was able to form spherical SeNPs, as determined by TEM. In addition, DLS analysis confirmed that SeNPs were negatively charged (-26.9 mV) with an average particle size of 239.6 nm. FTIR analysis of the SeNPs indicated proteins and polysaccharides as capping agents on the SeNPs. The SeNPs synthesised by P. acidilactici showed remarkable antibacterial activity against E. coli, B. subtilis, S. aureus, and K. pneumoniae with inhibition zones of 17.5 mm, 13.4 mm, 27.9 mm, and 16.2 mm, respectively; they also showed varied MIC values in the range of 15-120 μg mL^-1. The DPPH, ABTS, and hydroxyl, and superoxide scavenging activities of the SeNPs were 70.3%, 72.8%, 95.2%, and 85.7%, respectively. The SeNPs synthesised by the probiotic Lactococcus lactis have the potential for safe use in biomedical and nutritional applications.

Selenium-Enriched Probiotic Alleviates Western Diet-Induced Non-alcoholic Fatty Liver Disease in Rats via Modulation of Autophagy Through AMPK/SIRT-1 Pathway

Current study was aimed to investigate the ability of L.acidophilus SNZ 86 to biotransform inorganic selenium to a more active organic form, resulting in trace element enrichment. Selenium-enriched L. acidophilus SNZ 86 has been shown to be effective in the treatment of a variety of gastrointestinal illnesses, indicating the need for additional research to determine the full potential of this therapeutic strategy in the treatment of metabolic disorders. Herein, we employed the western style diet-induced model of non-alcoholic fatty liver disease (NAFLD) to explore the therapeutic effect of selenium-enriched probiotic (SP). Male Sprague Dawley rats (160-180 g) were fed a high-fat (58% Kcal of fat) and high-fructose (30% w/v) diet for 12 weeks to develop an animal model mimicking NAFLD. High-fat and High-fructose diet-fed rats exhibited hyperglycemia, hyperlipidemia, insulin resistance, abnormal liver function test, increased hepatic oxidative stress, and steatosis. SP was then administered orally (L acidophilus 1 × 10⁹ CFU/ml containing 0.4 g Se/day; p.o.) for 8 weeks. The selenium enrichment within L. acidophilus SNZ 86 was validated by TEM, which allowed for visualisation of the selenium deposition and size distribution in the probiotic. In NAFLD control rats, the expression of autophagy proteins (LC-3 A/B and Beclin), AMPK, and SIRT-1 was significantly reduced indicating downregulation of autophagy. However, supplementation of SP ameliorates hepatic steatosis as evidenced by improved biochemical markers and autophagic activation via upregulation of the AMPK and SIRT-1 pathway showing the relevance of autophagy in the disease aetiology. Collectively, these findings provide us with a better understanding of the role of SP in the treatment of hepatic steatosis and establish a therapeutic basis for potential clinical application of SP in the prevention of NAFLD and associated pathological conditions.

Evaluation of Different Surface Coating Agents for Selenium Nanoparticles: Enhanced Anti-Inflammatory Activity and Drug Loading Capacity

Background

Inflammation is the keystone in the disease’s pathological process in response to any damaging stimuli. Therefore, any agent that inhibits the inflammatory response is under focus, either a drug or a bioactive compound. Selenium nanoparticles have drawn attention in various biomedical applications, including the anti-inflammatory activity.

Purpose

In the current study, we aimed to evaluate the capacity of different surface coating materials (soybean lecithin, PEG 6000, and β-cyclodextrin) to enhance the anti-inflammatory activity of the synthesized selenium nanoparticles (SeNPs). The capability of the coated SeNPs to adsorb indomethacin (IND) on their surfaces compared to the uncoated SeNPs was also evaluated.

Methods

SeNPs were synthesized, coated with different materials, and characterized in vitro using X-ray diffraction, UV-Vis spectrophotometer, FTIR, SEM, TEM, and particle size and zeta potential measurements. The in vivo anti-inflammatory activity of the uncoated/coated SeNPs loaded into hydrogel was evaluated using a carrageenan-induced paw edema rat model. The effect of SeNPs surface coatings was further evaluated for IND loading capacity.

Results

Our findings proved the superior anti-inflammatory activity of all coated SeNPs compared to the uncoated SeNPs, especially with β-cyclodextrin surface coating. Regarding the IND loading capacity of the prepared uncoated/coated SeNPs, the amount of drug loaded was 0.12, 1.12, 0.3, and 0.14 µg IND/µg SeNPs for the uncoated, lecithin-, PEG- and β-CD-coated SeNPs, respectively.

Conclusion

Surface functionalization of SeNPs can provide a synergistic therapeutic activity. Our results are promising for further investigation of the in vivo anti-inflammatory synergistic activity of the IND-loaded surface-coated SeNPs.

Protective Effects of Selenium Nanoparticle-Enriched Lactococcus lactis NZ9000 against Enterotoxigenic Escherichia coli K88-Induced Intestinal Barrier Damage in Mice

Composite microecological agents have received widespread attention due to their advantageous properties, including safety, multiple effects, and low cost. This study was conducted to evaluate the protective effects of selenium (Se) nanoparticle (SeNP)-enriched Lactococcus lactis NZ9000 (L. lactis NZ9000-SeNPs) against enterotoxigenic Escherichia coli (ETEC) K88-induced intestinal barrier damage in C57BL/6 mice. The oral administration of L. lactis NZ9000-SeNPs significantly increased the villus height and the number of goblet cells in the ileum; reduced the levels of serum and ileal interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ); and increased the activities of thioredoxin reductase (TrxR) and glutathione peroxidase (GSH-Px) compared with the ETEC K88-infected group not treated with L. lactis NZ9000-SeNPs. In addition, L. lactis NZ9000-SeNPs significantly attenuated the reduction of the expression levels of occludin and claudin-1, dysbiosis of the gut microbiome, and activation of the Toll-like receptor (TLR)/nuclear factor kappa B (NF-κB)-mediated signaling pathway induced by ETEC K88. These findings suggested that L. lactis NZ9000-SeNPs may be a promising and safe Se supplement for food or feed additives. IMPORTANCE The beneficial effects of microecological agents have been widely proven. Se, which is a nutritionally essential trace element for humans and animals, is incorporated into selenoproteins that have a wide range of pleiotropic effects, ranging from antioxidant to anti-inflammatory effects. However, sodium selenite, a common addition form of Se in feed and food, has disadvantages such as strong toxicity and low bioavailability. We investigated the protective effects of L. lactis NZ9000-SeNPs against ETEC K88-induced intestinal barrier injury in C57BL/6 mice. Our results show that L. lactis NZ9000-SeNPs effectively alleviate ETEC K88-induced intestinal barrier dysfunction. This study highlights the importance of developing a promising and safe Se supplement for the substitution of sodium selenite applied in food, feed, and biomedicine.

In Vivo Bioavailability of Selenium in Selenium-Enriched Streptococcus thermophilus and Enterococcus faecium in CD IGS Rats

The selenium (Se) enrichment of yeasts and lactic acid bacteria (LAB) has recently emerged as a novel concept; the individual health effects of these beneficial microorganisms are combined by supplying the essential micronutrient Se in a more bioavailable and less toxic form. This study investigated the bioavailability of Se in the strains Enterococcus faecium CCDM 922A (EF) and Streptococcus thermophilus CCDM 144 (ST) and their respective Se-enriched forms, SeEF and SeST, in a CD (SD-Sprague Dawley) IGS rat model. Se-enriched LAB administration resulted in higher Se concentrations in the liver and kidneys of rats, where selenocystine was the prevalent Se species. The administration of both Se-enriched strains improved the antioxidant status of the animals. The effect of the diet was more pronounced in the heart tissue, where a lower glutathione reductase content was observed, irrespective of the Se fortification in LAB. Interestingly, rats fed diets with EF and SeEF had higher glutathione reductase activity. Reduced concentrations of serum malondialdehyde were noted following Se supplementation. Diets containing Se-enriched strains showed no macroscopic effects on the liver, kidneys, heart, and brain and had no apparent influence on the basic parameters of the lipid metabolism. Both the strains tested herein showed potential for further applications as promising sources of organically bound Se and Se nanoparticles.

Effects of Selenium- and Zinc-Enriched Lactobacillus plantarum SeZi on Antioxidant Capacities and Gut Microbiome in an ICR Mouse Model

Selenium and zinc are essential trace minerals for humans with various biological functions. In this study, selenium- and zinc-tolerant lactic acid bacteria (LAB) isolates were screened out from human fecal samples. Amongst three hundred LAB isolates, the Lactobacillus plantarum SeZi strain displayed the tolerance against selenium and zinc with the greatest biomass production and bioaccumulation of selenium and zinc. To further assess the characteristics of this strain, the lyophilized L. plantarum SeZi were prepared and administered to Institute of Cancer Research (ICR) mice. The mice were divided into four groups, provided with normal chow (Con), or normal chow supplemented with Na₂SeO₃ and ZnSO₄∙7H₂O (SZ), L. plantarum SeZi (Lp), or selenium- and zinc-enriched L. plantarum SeZi (SZ + Lp), respectively. After 4 weeks of oral administration, the concentrations of selenium and zinc in blood were significantly increased in the SZ + Lp group when compared to the control or SZ group (p < 0.05). The increased selenium level led to an enhanced glutathione peroxidase activity and decreased blood malondialdehyde level in the SZ + Lp group (p < 0.05). Meanwhile, the results of bacterial community and microbial metabolic pathway analysis via 16S rRNA gene amplicon sequencing showed that L. plantarum SeZi significantly promoted the utilization of selenocysteine, seleno-cystathionine and seleno-methionine in the selenocompounds metabolism. Here, the in vivo antioxidant capacities of the selenium- and zinc-enriched lactobacillus strain showed us the utilization of a unique probiotic as a Se/Zn supplement with high availability, low toxicity, and additional probiotic advantages.

Identifying different types of microorganisms with terahertz spectroscopy

Most microbial detection techniques require pretreatment, such as fluorescent labeling and cultivation processes. Here, we propose novel tools for classifying and identifying microorganisms such as molds, yeasts, and bacteria based on their intrinsic dielectric constants in the THz frequency range. We first measured the dielectric constant of films that consisted of a wide range of microbial species, and extracted the values for the individual microbes using the effective medium theory. The dielectric constant of the molds was 1.24-1.85, which was lower than that of bacteria ranging from 2.75-4.11. The yeasts exhibited particularly high dielectric constants reaching 5.63-5.97, which were even higher than that of water. These values were consistent with the results of low-density measurements in an aqueous environment using microfluidic metamaterials. In particular, a blue shift in the metamaterial resonance occurred for molds and bacteria, whereas the molds have higher contrast relative to bacteria in the aqueous environment. By contrast, the deposition of the yeasts induced a red shift because their dielectric constant was higher than that of water. Finally, we measured the dielectric constants of peptidoglycan and polysaccharides such as chitin, α-glucan, and β-glucans (with short and long branches), and confirmed that cell wall composition was the main cause of the observed differences in dielectric constants for different types of microorganisms.

Biosynthesis of Polysaccharides-Capped Selenium Nanoparticles Using Lactococcus lactis NZ9000 and Their Antioxidant and Anti-inflammatory Activities

Lactococcus lactis (L. lactis) NZ9000, which has been genetically modified, is the most commonly used host strain for nisin regulated gene expression. Selenium (Se) is an essential trace element in the diet of humans and animals important for the maintenance of health and growth. Biosynthesized Se nanoparticles (SeNPs) that use microorganisms as a vehicle are uniquely advantages in terms of low costs, low toxicity and high bioavailability. This study was aimed at preparing novel functionalized SeNPs by L. lactis NZ9000 through eco-friendly and economic biotechnology methods. Moreover, its physicochemical characteristics, antioxidant and anti-inflammatory activities were investigated. L. lactis NZ9000 synthesized elemental red SeNPs when co-cultivated with sodium selenite under anaerobic conditions. Biosynthesized SeNPs by L. lactis NZ9000 were mainly capped with polysaccharides and significantly alleviated the increase of malondialdehyde (MDA) concentration, the decrease of glutathione peroxidase (GPx) and total superoxide dismutase (T-SOD) activity in porcine intestinal epithelial cells (IPEC-J2) challenged by hydrogen peroxide (H₂O₂). SeNPs also prevented the H₂O₂-caused reduction of transepithelial electrical resistance (TEER) and the increase of FITC-Dextran fluxes across IPEC-J2. Moreover, SeNPs attenuated the increase of reactive oxygen species (ROS), the reduction of adenosine triphosphate (ATP) and the mitochondrial membrane potential (MMP) and maintained intestinal epithelial permeability in IPEC-J2 cells exposed to H₂O₂. In addition, SeNPs pretreatment alleviated the cytotoxicity of Enterotoxigenic Escherichia coli (ETEC) K88 on IPEC-J2 cells and maintained the intestinal epithelial barrier integrity by up-regulating the expression of Occludin and Claudin-1 and modulating inflammatory cytokines. Biosynthesized SeNPs by L. lactis NZ9000 are a promising selenium supplement with antioxidant and anti-inflammatory activities.

Probiotics: If It Does Not Help It Does Not Do Any Harm. Really?

Probiotics per definition should have beneficial effects on human health, and their consumption has tremendously increased in the last decades. In parallel, the amount of published material and claims for their beneficial efficacy soared continuously. Recently, multiple systemic reviews, meta-analyses, and expert opinions expressed criticism on their claimed effects and safety. The present review describes the dark side of the probiotics, in terms of problematic research design, incomplete reporting, lack of transparency, and under-reported safety. Highlighted are the potential virulent factors and the mode of action in the intestinal lumen, risking the physiological microbiome equilibrium. Finally, regulatory topics are discussed to lighten the heterogeneous guidelines applied worldwide. The shift in the scientific world towards a better understanding of the human microbiome, before consumption of the probiotic cargo, is highly endorsed. It is hoped that better knowledge will extend the probiotic repertoire, re-confirm efficacy or safety, establish their efficacy and substantiate their beneficial effects.

Biogenic Synthesis of Novel Functionalized Selenium Nanoparticles by Lactobacillus casei ATCC 393 and Its Protective Effects on Intestinal Barrier Dysfunction Caused by Enterotoxigenic Escherichia coli K88

Selenium (Se) is an essential element for human and animal health. Biogenic selenium nanoparticles (SeNPs) by microorganism possess unique physical and chemical properties and biological activities compared with inorganic Se and organic Se. The study was conducted to investigate the mainly biological activities of SeNPs by Lactobacillus casei ATCC 393 (L. casei 393). The results showed that L. casei 393 transformed sodium selenite to red SeNPs with the size of 50–80 nm, and accumulated them intracellularly. L. casei 393-SeNPs promoted the growth and proliferation of porcine intestinal epithelial cells (IPEC-J2), human colonic epithelial cells (NCM460), and human acute monocytic leukemia cell (THP-1)-derived macrophagocyte. L. casei 393-SeNPs significantly inhibited the growth of human liver tumor cell line-HepG2, and alleviated diquat-induced IPEC-J2 oxidative damage. Moreover, in vivo and in vitro experimental results showed that administration with L. casei 393-SeNPs protected against Enterotoxigenic Escherichia coli K88 (ETEC K88)-caused intestinal barrier dysfunction. ETEC K88 infection-associated oxidative stress (glutathione peroxidase activity, total superoxide dismutase activity, total antioxidant capacity, and malondialdehyde) was ameliorated in L. casei 393-SeNPs-treated mice. These findings suggest that L. casei 393-SeNPs with no cytotoxicity play a key role in maintaining intestinal epithelial integrity and intestinal microflora balance in response to oxidative stress and infection.

Two Lactobacillus Species Inhibit the Growth and α-Toxin Production of Clostridium perfringens and Induced Proinflammatory Factors in Chicken Intestinal Epithelial Cells in Vitro

Clostridium perfringens is the causative pathogen of avian necrotic enteritis. Lactobacillus spp. are well-characterized probiotics with anti-microbial and immune-modulatory activities. In the present study, we investigated the effects of L. acidophilus and L. fermentum on the growth, α-toxin production and inflammatory responses of C. perfringens. In in vitro culture experiments, both lactobacilli inhibited the growth of C. perfringens (P < 0.01), accompanied with a decrease in pH (P < 0.01). Supernatants from lactobacilli cultures also suppressed the growth of C. perfringens during 24 h of incubation (P < 0.01), but this inhibitory effect disappeared after 48 h. Both lactobacilli decreased the α-toxin production of C. perfringens (P < 0.01) without influencing its biomass, and even degraded the established α-toxin (P < 0.01). Lower environmental pH reduced the α-toxin production as well (P < 0.01). Preincubation with L. acidophilus decreased the attachment of C. perfringens to cells (P < 0.01) with the cell cytotoxicity being unaffected. Both lactobacilli pretreatment reduced the up-regulation of proinflammatory factors, peptidoglycan (PGN) receptors and nuclear factor kappa B (NF-κB) p65 in C. perfringens-challenged chicken intestinal epithelial cells (P < 0.05). In conclusion, L. acidophilus and L. fermentum inhibited the pathological effects of C. perfringens in vitro conditions.