Lactobacillus fermentum and its potential immunomodulatory properties

Phenotypic characterization and genomic analysis of Limosilactobacillus fermentum phage

Limosilactobacillus (L.) fermentum is widely utilized for its beneficial properties, but lysogenic phages can integrate into its genome and can be induced to enter the lysis cycle under certain conditions, thus accomplishing lysis of host cells, resulting in severe economic losses. In this study, a lysogenic phage, LFP03, was induced from L. fermentum IMAU 32510 by UV irradiation for 70 s. The electron microscopy showed that this phage belonged to Caudoviricetes class. Its genome size was 39,556 bp with a GC content of 46.08%, which includes 20 functional proteins. Compared with other L. fermentum phages, the genome of phage LFP03 exhibited deletions, inversions and translocations. Biological analysis showed that its optimal multiplicity of infection was 0.1, with a burst size of 133.5 ± 4.9 PFU/infective cell. Phage LFP03 was sensitive to temperature and pH value, with a survival rate of 48.98% at 50 °C. It could be completely inactivated under pH 2. The adsorption ability of this phage was minimally affected by temperature and pH value, with adsorption rates reaching 80% under all treated conditions. Divalent cations could accelerate phage adsorption, while chloramphenicol expressed little influence. This study might expand the related knowledge of L. fermentum phages, and provide some theoretical basis for improving the stability of related products and establishing phage control measures.

Bioprotective potential of lactic acid bacteria for Salmonella biocontrol in vitro

Lactic acid bacteria (LAB) are an important option for Salmonella control in animal production, resulting in lower antibiotic use. The objective of this research was to isolate LAB from meat products and from commercial probiotics sold as nutritional supplements for in vitro verification of their bioprotective potential. Eleven bacteria were identified as Pediococcus acidilactici, two as Lacticaseibacillus rhamnosus, one as Lacticaseibacillus paracasei paracasei, one as Limosilactobacillus fermentum, and one as a consortium of Lactobacillus delbrueckii bulgaricus and L. fermentum. All bacteria showed inhibitory activity against Salmonella, with emphasis on the inhibition of P. acidilactici PUCPR 011 against Salmonella Enteritidis 33SUSUP, S. Enteritidis 9SUSP, S. Enteritidis 56301, S. Enteritidis CRIFS 1016, Salmonella Typhimurium ATCC™ 14,028®, and Salmonella Gallinarum AL 1138, with inhibition halos of 7.3 ± 0.5 mm, 7.7 ± 1.0 mm, 9.0 ± 1.8 mm, 7.3 ± 0.5 mm, 7.7 ± 1.0 mm, and 7.3 ± 0.5, respectively. The isolates P. acidilactici PUCPR 011, P. acidilactici PUCPR 012, P. acidilactici PUCPR 014, L. fermentum PUCPR 005, L. paracasei paracasei PUCPR 013, and L. rhamnosus PUCPR 010 showed inhibition greater than 2 mm against at least 3 Salmonella and were used for encapsulation and in vitro digestion. The encapsulation efficiency ranged from 76.89 ± 1.54 to 116.48 ± 2.23%, and the population after 12 months of storage was from 5.31 ± 0.17 to 9.46 ± 0.09 log CFU/g. When simulating swine and chicken digestion, there was a large reduction in bacterial viability, stabilizing at concentrations close to 2.5 log CFU/mL after the analyses. The analyzed bacteria showed strong in vitro bioprotective potential; further analyses are required to determine in vivo effectiveness.

Limosilactobacillus fermentum modulates the gut-airway axis by improving the immune response through FOXP3 activation on combined allergic rhinitis and asthma syndrome (CARAS)

Combined allergic rhinitis and asthma syndrome (CARAS) is an allergic airway inflammatory disorder orchestrated by the type 2 immune response. The close gut-lung relationship has been described, however, the effect of gut-modulating agents such as probiotics in allergic airway disorder is unclear. Thus, the goal of this study was to evaluate theLimosilactobacillus fermentumsupplementation in animals with CARAS. Therefore, BALB/c mice were ovalbumin (OVA) -sensitized and -challenged after being supplemented withL. fermentum. Animals, previously probiotic supplemented, showed a decrease (p < 0.05) of inflammatory cell migration, mainly eosinophil, into the nasal (NALF) and the bronchoalveolar (BALF) fluids as well as reduction of the allergic signs such as sneezing, nasal rubbings, and nasal hyperreactivity induced by histamine as compared with non-supplemented animals. In the systemic context,L. fermentumreduced eosinophilia and the serum levels of OVA-specific IgE. The altered histological aspects of nasal and lung tissues of animals with CARAS were effectively ameliorated byL. fermentum. In the BALF, the immunomodulatory effect was due to the decreasing of type 2 and 3 cytokines (IL-4, IL-13, IL-5 and IL-17A) dependent on type 1 (IFN-γ) and Treg (IL-10) cytokine increasing. Indeed,L. fermentumimproved the FOXP3 activation. Additionally, these effects correlate with the amplification of the gut response as increasing short-chain fatty acids (SCFAs) levels, gut epithelium barrier (ZO-1) maintenance, and colon tissue integrity. These data pointed out that animals' probiotic supplemented presented immunomodulatory responses in CARAS experimental model by activating the intracellular transduction signal underlying the IL-10 gene transcription.

An Overview of the Use and Applications of Limosilactobacillus fermentum in Broiler Chickens

The implementation of government regulations on antibiotic use, along with the public's concern for drug resistance, has strengthened interest in developing alternatives not only aimed at preserving animal production but also at reducing the effects of pathogenic infections. Probiotics, in particular, are considered microorganisms that induce health benefits in the host after consumption of adequate amounts; they have been established as a potential strategy for improving growth, especially by stimulating intestinal homeostasis. Probiotics are commonly associated with lactic acid bacteria, and Limosilactobacillus fermentum is a well-studied species recognized for its favorable characteristics, including adhesion to epithelial cells, production of antimicrobial compounds, and activation of receptors that prompt the transcription of immune-associated genes. Recently, this species has been used in animal production. Different studies have shown that the application of L. fermentum strains not only improves the intestinal ecosystem but also reduces the effects caused by potentially pathogenic microorganisms. These studies have also revealed key insights into the mechanisms behind the actions exerted by this probiotic. In this manuscript, we aim to provide a concise overview of the effects of L. fermentum administration on broiler chicken health and performance.

Strain-specific effect of Limosilactobacillus fermentum with distinct genetic lineages on loperamide-induced constipation in mice: attributing effects to certain genes

In 2013, Limosilactobacillus fermentum was regarded as a "generally recognized as safe" organism by the US Food and Drug Administration, and emerging evidence showed that it can exert beneficial health effects on humans. In this study, five L. fermentum strains from different phylogroups of a phylogenetic tree containing 224 L. fermentum strains were chosen, and their protective effects against loperamide-induced constipation in mice were studied. Animal experiments showed that L. fermentum YN54 significantly alleviated weight loss, increased fecal moisture, accelerated intestinal peristalsis, and increased the small intestinal transit rate in mice with constipation by regulating gastrointestinal peptides and increasing the amount of intestinal short-chain fatty acids. However, the other four L. fermentum strains (XJ61, CECT5716, WX115, and GD121) did not relieve constipation in mice treated with loperamide. A comparative genomic analysis of these strains was conducted and "L. fermentum YN54 only" genes were functionally annotated and validated with the other three L. fermentum strains (FJ12, GX51, and ZH1010) that had different functional genes. Finally, the genes involved in the synthesis of fatty acid hydrase, polysaccharides, and cell membranes were identified to be associated with the probiotic effect of L. fermentum on mice with constipation through preliminary experiments in this study.

Quorum-Sensing Inhibitors from Probiotics as a Strategy to Combat Bacterial Cell-to-Cell Communication Involved in Food Spoilage and Food Safety

Experience-based knowledge has shown that bacteria can communicate with each other through a cell-density-dependent mechanism called quorum sensing (QS). QS controls specific bacterial phenotypes, such as sporulation, virulence and pathogenesis, the production of degrading enzymes, bioluminescence, swarming motility, and biofilm formation. The expression of these phenotypes in food spoiling and pathogenic bacteria, which may occur in food, can have dramatic consequences on food production, the economy, and health. Due to the many reports showing that the use of conventional methods (i.e., antibiotics and sanitizers) to inhibit bacterial growth leads to the emergence of antibiotic resistance, it is necessary to research and exploit new strategies. Several studies have already demonstrated positive results in this direction by inhibiting autoinducers (low-molecular-weight signaling compounds controlling QS) and by other means, leading to QS inhibition via a mechanism called quorum quenching (QQ). Thus far, several QS inhibitors (QSIs) have been isolated from various sources, such as plants, some animals from aqueous ecosystems, fungi, and bacteria. The present study aims to discuss the involvement of QS in food spoilage and to review the potential role of probiotics as QSIs.

New insights into immunomodulatory properties of lactic acid bacteria fermented herbal medicines

The COVID-19 pandemic has brought more attention to the immune system, the body’s defense against infectious diseases. The immunomodulatory ability of traditional herbal medicine has been confirmed through clinical trial research, and has obvious advantages over prescription drugs due to its high number of potential targets and low toxicity. The active compounds of herbal drugs primarily include polysaccharides, saponins, flavonoids, and phenolics and can be modified to produce new active compounds after lactic acid bacteria (LAB) fermentation. LAB, primary source of probiotics, can produce additional immunomodulatory metabolites such as exopolysaccharides, short-chain fatty acids, and bacteriocins. Moreover, several compounds from herbal medicines can promote the growth and production of LAB-based immune active metabolites. Thus, LAB-mediated fermentation of herbal medicines has become a novel strategy for regulating human immune responses. The current review discusses the immunomodulatory properties and active compounds of LAB fermented herbal drugs, the interaction between LAB and herbal medicines, and changes in immunoregulatory components that occur during fermentation. This study also discusses the mechanisms by which LAB-fermented herbal medicines regulate the immune response, including activation of the innate or adaptive immune system and the maintenance of intestinal immune homeostasis.

Functional genomics of the lactic acid bacterium Limosilactobacillus fermentum LAB-1: metabolic, probiotic and biotechnological perspectives

A genome-based systematic analysis was conducted to characterize the metabolic, probiotic, fitness, and safety properties of Limosilactobacillus fermentum LAB-1, a lactic acid bacterium demonstrating strong antimicrobial effects against clinical pathogens. Gene functional characterization revealed a large number of genes for carbohydrate metabolism and a heterofermentative system for carbon dissimilation. Genes for intact pyruvate oxidation, pentose phosphate, and PRPP biosynthetic pathways were identified. Substantial carbohydrate-active enzymes and transporters were also predicted. Metabolic reconstruction revealed complete sets of enzymes for arginine, lysine, methionine, threonine, proline, and ornithine biosynthesis. The bacterium harbors a diverse range of peptidases, and a large variety of peptide and amino acid uptake systems. It encodes restriction-modification and CRISPR-Cas systems for protection against phage infections and carries a wide spectrum of stress proteins for adaptation in the gut and industrial conditions. Genes related to the biosynthesis of B-group and K vitamins were identified allowing its application for novel bio-enriched food production. Other beneficial traits of probiotic and industrial importance such as production of flavor compounds, exopolysaccharide, acetoin, and butanediol were identified. Three antimicrobial peptides were predicted which showed >98% sequence-identity to experimentally validated bacteriocins. Negative traits such as transmissible antibiotic resistance, pathogenicity or virulence appeared to be absent suggesting the strain to be considered safe. The genome analysis will allow precisely targeted laboratory research and full exploitation of the probiotic potentials towards functional-food, biotechnology and health-related applications.

Limosilactobacillus fermentum-fermented ginseng improved antibiotic-induced diarrhoea and the gut microbiota profiles of rats

AIMS

This study investigated the efficacy of Limosilactobacillus fermentum-fermented ginseng for improving colitis and the gut microbiota profiles in rats and explored the benefits of the L. fermentum fermentation process to ginseng.

METHODS AND RESULTS

Ginseng polysaccharide and ginsenoside from fermented ginseng were analysed by UV and HPLC. Antibiotic-fed rats were treated with fermented ginseng and a L. fermentum-ginseng mixture. Histopathology- and immune-related factors (TNF-α, IL-1β, IL-6 and IL-10) of the colon were assayed by using pathological sections and ELISA. After treatment, fermented ginseng relieved the symptoms of antibiotic-induced diarrhoea and colon inflammation, and the expression of colon immune factors returned to normal. The gut microbial communities were identified by 16S rRNA gene sequencing. The results showed that the alterations in the gut microbiota returned to normal. In addition, the gut microbiota changes were correlated with immune factor expression after treatment. The fermented ginseng had better biological functions than a L. fermentum-ginseng mixture.

CONCLUSIONS

Fermented ginseng can relieve diarrhoea and colon inflammation and restore the gut microbiota to its original state. The process of L. fermentum fermentation can expand the therapeutic use of ginseng.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research suggested the potential function of fermented ginseng to relieve diarrhoea and recover the gut microbiota to a normal level and explored the benefits of the Limosilactobacillus fermentum fermentation process to ginseng.

Anti-Inflammatory Effects of Limosilactobacillus fermentum KGC1601 Isolated from Panax ginseng and Its Probiotic Characteristics

We investigated the potential probiotic properties of Limosilactobacillus fermentum KGC1601 isolated from Panax ginseng. Ginseng cultivated in an experimental field of the Korea Ginseng Research Institute was fermented, followed by single colony selection from MRS agar. We performed 16s-rRNA sequencing and whole-genome analysis to identify L. fermentum and evaluate the biosafety parameters of this strain, respectively. We confirmed this strain was susceptible to six antibiotics, as proposed by the European Food Safety Authority, did not produce biogenic amines, and did not exhibit any hemolytic activity. Acid resistance and bile salt tolerance, which are essential properties of a probiotic agent, were investigated. Notably, distinguishing properties of this strain were that it exhibited excellent bile salt tolerance and anti-inflammatory effects. The excellent bile salt tolerance was confirmed by scanning electron microscopy. Through qRT-PCR and ELISA studies, it was revealed that L. fermentum KGC1601 pre-treatment up-regulates anti-inflammatory cytokines and down-regulates pro-inflammatory cytokines in RAW 264.7 cells. Consequently, we suggested that L. fermentum KGC1601 can be safely used as a potential anti-inflammatory functional probiotic agent.

Differences in the gut microbiota composition of rats fed with soybean protein and their derived peptides

Current studies regarding the effect of different nitrogen sources on gut microbiota have thus far disregarded the ability of probiotics and coliforms to compete for protein. This study aimed to investigate the differences in the utilization of soybean protein (SPro) and its derived peptides (SPep) by the gut microbiota of Sprague Dawley (SD) rats. The SPro and SPep prepared in this study showed extensive SPro molecular weight distribution, while that of SPep was minimal, ranging between 150 and 1000 Da and primarily consisting of two to five amino acids. The cecum microflora composition of the rats was determined via 16S rDNA amplicon sequencing, showing that the SPro and SPep significantly increased the abundance and uniformity of the gut microbiota after 35 days of feeding. The Firmicutes/Bacteroidetes (F/B) ratios of the SPep, SPro, and casein groups were 2.49 ± 0.60, 2.98 ± 1.12, and 2.59 ± 0.74, respectively. Although the rats fed with SPro and SPep displayed similar gut microbiome structures, SPep significantly promoted Lactobacillus and Phascolarctobacterium growth. The results showed that SPep significantly increased the diversity of the gut microbiota and elevated the probiotic proportion. PRACTICAL APPLICATION: SPro and SPep are two nutritious and high-quality nitrogen sources. The results showed that SPro and SPep regulated the structure of gut microbiota in rats, and the effect of SPep was better. This study provides a theoretical basis for developing SPep functional foods able to regulate gut microbiota and maintain health.

Genomic Analysis of Limosilactobacillus fermentum ATCC 23271, a Potential Probiotic Strain with Anti-Candida Activity

Limosilactobacillus fermentum (ATCC 23271) was originally isolated from the human intestine and has displayed antimicrobial activity, primarily against Candida species. Complete genome sequencing and comparative analyses were performed to elucidate the genetic basis underlying its probiotic potential. The ATCC 23271 genome was found to contain 2,193,335 bp, with 2123 protein-coding sequences. Phylogenetic analysis revealed that the ATCC 23271 strain shares 941 gene clusters with six other probiotic strains of L. fermentum. Putative genes known to confer probiotic properties have been identified in the genome, including genes related to adhesion, tolerance to acidic pH and bile salts, tolerance to oxidative stress, and metabolism and transport of sugars and other compounds. A search for bacteriocin genes revealed a sequence 48% similar to that of enterolysin A, a protein from Enterococcus faecalis. However, in vitro assays confirmed that the strain has inhibitory activity on the growth of Candida species and also interferes with their adhesion to HeLa cells. In silico analyses demonstrated a high probability of the protein with antimicrobial activity. Our data reveal the genome features of L. fermentum ATCC 23271, which may provide insight into its future use given the functional benefits, especially against Candida infections.

Optimization of Fermentation Conditions for Cell Envelope Proteinase Produced by Lactobacillus Plantarum LP69

Cell-envelope proteinases (CEPs) can hydrolyze casein into functional peptides, which is beneficial to the health of the host. The single factor experiment screened out that the optimal conditions for CEP production by Lactobacillus plantarum LP69 were 37°C, 20h, initial pH of 7, and optimal inoculation amount of 5%. The best conditions for this experiment were obtained by orthogonal experiment: time 22h, temperature 39°C, initial pH value of 6, and inoculation amount of 5%. Under this culture condition, the target protease activity of Lactobacillus plantarum LP69 reached 22.31±0.82U/mL, the protein content was 19.07±0.36mg/mL, and the specific activity was 1.17±0.06U/mg. The specific activity significantly increased by 15.8% compared with the control (p<0.05).

Suitability Analysis of 17 Probiotic Type Strains of Lactic Acid Bacteria as Starter for Kimchi Fermentation

The use of probiotic starters can improve the sensory and health-promoting properties of fermented foods. This study aimed to evaluate the suitability of probiotic lactic acid bacteria (LAB) as a starter for kimchi fermentation. Seventeen probiotic type strains were tested for their growth rates, volatile aroma compounds, metabolites, and sensory characteristics of kimchi, and their characteristics were compared to those of Leuconostoc (Le.) mesenteroides DRC 1506, a commercial kimchi starter. Among the tested strains, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Lacticaseibacillus paracasei, and Ligilactobacillus salivarius exhibited high or moderate growth rates in simulated kimchi juice (SKJ) at 37 °C and 15 °C. When these five strains were inoculated in kimchi and metabolite profiles were analyzed during fermentation using GC/MS and ¹H-NMR, data from the principal component analysis (PCA) showed that L. fermentum and L. reuteri were highly correlated with Le. mesenteroides in concentrations of sugar, mannitol, lactate, acetate, and total volatile compounds. Sensory test results also indicated that these three strains showed similar sensory preferences. In conclusion, L. fermentum and L. reuteri can be considered potential candidates as probiotic starters or cocultures to develop health-promoting kimchi products.

An optimized culture medium to isolate Lactobacillus fermentum strains from the human intestinal tract

Research studies have shown that Lactobacillus fermentum generally exists in the human gut and has potential health benefits on host health due to its antimicrobial and antioxidant properties. However, the lack of an effective culture medium for the isolation of L. fermentum has presented a significant obstacle on the path to screen L. fermentum strains from the human intestinal tract with a large diversity of commensal microbes. In this study, a total of 51 Lactobacillus species are detected in 200 human fecal samples and we aim to distinguish L. fermentum from these common existing Lactobacillus species and design a more efficient culture medium for isolating L. fermentum strains from the human gut. Based on antibiotic susceptibility and sugar utilization tests, a new optimized medium called LFMATA containing arabinose as the carbon source and 20 mg L-1 vancomycin, 64 mg L-1 gentamicin and 256 mg L-1 streptomycin was developed. Genotype and phenotype analysis for antibiotic resistance and carbohydrate metabolism showed that though glycometabolism-related genes (araA, xylA, manX, bglX, treP and rbsK) correlated with the carbon utilization of Lactobacillus, the genes conferring resistance to streptomycin (gidB and rpsL) and gentamicin (tlyA) were not directly associated with the antibiotic resistance of Lactobacillus strains. This new selective medium greatly increased the efficiency of screening L. fermentum strains from human fecal samples, with the rate of L. fermentum isolation on LFMATA being 10-fold higher than that on LAMVAB.

Quantitative changes in selected bacteria in the stool during the treatment of Crohn's disease

PURPOSE

The aim of this study was to determine quantitative changes in selected species of bacteria (Bacteroides fragilis, Lactobacillus fermentum, Lactobacillus rhamnosus, Serratia marcescens) in the stool of patients with Crohn's disease (CD) in the course of induction treatment with exclusive enteral nutrition (EEN) or anti-tumor necrosis factor alpha (Infliximab, IFX) vs. healthy controls (HC).

MATERIALS/METHODS

DNA was isolated from stool samples of CD (n = 122) and HC (n = 17), and quantitative real-time Polymerase Chain Reaction (qPCR) was applied. In both treatment groups, the first stool sample was taken before the start of treatment, and the second 4 weeks after its end: in EEN (n = 48; age (mean; SD) 13.35 ± 3.09 years) and IFX groups (n = 13; age (mean; SD) 13.09 ± 3.76 years).

RESULTS

The only species that showed a statistically significant difference between the two groups of patients before any therapeutic intervention was L. fermentum. Moreover, its number increased after completion of EEN and differed significantly when compared with the HC. In the IFX group the number of L. fermentum decreased during the therapy but was significantly higher than in the HC. The number of S. marcescens in the EEN group was significantly lower than in the controls both before and after EEN.

CONCLUSION

The implemented treatment (EEN or IFX) modifies the microbiome in CD patients, but does not make it become the same as in HC.

Protective effects of Lactobacillus fermentum U-21 against paraquat-induced oxidative stress in Caenorhabditis elegans and mouse models

The aims of this work were to identify in vivo manifestations of antioxidant activity of Lactobacillus strains isolated from healthy human biotopes and to show the possibility of protective action of the selected strain on the model of oxidative stress induced by paraquat in the model of early Parkinson's disease (PD) in mice. We studied the protective effects of 14 Lactobacillus strains belonging to five species on the lifespan of the soil nematode Caenorhabditis elegans experiencing oxidative stress induced by paraquat. The Lactobacillus strains used in this study were selected previously based on their ability to reduce oxidative stress in vitro. One of the strains that showed promising results on C. elegans was tested in a mouse model of PD in which C57/BL6 mice were injected regularly with paraquat. We assessed the state of their internal organs, the preservation of dopaminergic neurons in the substantia nigra as well as their motor coordination. The positive impact of Lactobacillus fermentum U-21 strain supplementation on paraquat treated animals was observed. L. fermentum U-21 strain reduced the toxicity of paraquat in C. elegans model: the lifespan of the soil nematode C. elegans was extended by 25%. L. fermentum U-21 protected the mice against anatomical and behavioral changes typical of PD: there were no changes in the coordination of movement and the preservation of dopaminergic neurons in the brain. Life span of the nematode C. elegans pre-grown on a lawn of E. coli OP50 + Lactobacillus under oxidative stress conditions; the concentration of the oxidizing agent paraquat in the S medium was 50 mmol l^-1.

Lactobacillus fermentum JX306 Restrain D-galactose-induced Oxidative Stress of Mice through its Antioxidant Activity

Oxidative stress-induced series of related degenerative diseases have received widespread attention. To screen new lactic acid bacteria (LAB) strains to resist oxidative stress, traditional Chinese fermented vegetables were used as a resource library to screen of LAB. The Lactobacillus fermentum JX306 strain, which showed high scavenging activity of DPPH free radical and hydrogen radical, and a strong lipid peroxidation inhibition rate in vitro was selected. L. fermentum JX306 was also examined for its antioxidant capacity in D-galactose-induced aging mice. The results showed that L. fermentum JX306 could significantly decrease malondialdehyde (MDA) levels and improve the activity of glutathione peroxidase (GSH-Px), and total antioxygenic capacity (TOC) in the serum, kidney, and liver. Meanwhile, the strain could remarkably upregulate the transcriptional level of the antioxidant-related enzyme genes, such as peroxiredoxin1 (Prdx1), glutathione reductase (Gsr), glutathione peroxidase (Gpx1), and thioredoxin reductase (TR3) encoding genes in the liver. Besides, histopathological observation proves that this probiotic strain could effectively inhibit oxidative damage to the liver and kidney in aging mice. Therefore, this unique antioxidant strain may have a high application value in the functional food industry and medicine industry.

Anticancer and immunomodulatory activity of egg proteins and peptides: a review

Eggs are widely recognized as a highly nutritious food source that offer specific health benefits for humans. Eggs contain all of the proteins, lipids, vitamins, minerals, and growth factors necessary for embryonic development. In particular, egg white and yolk proteins are considered functional food substances because they possess biological activities such as antimicrobial, antioxidant, metal-chelating, antihypertensive, anticancer, and immunomodulatory activities. Peptides produced via processes such as enzymatic hydrolysis, fermentation by microorganisms, and some chemical and physical treatments of egg proteins have been shown to enhance the functional properties and solubility of these peptides. Peptide activity is strongly related to amino acid sequence, composition, and length. At present, cancer remains among the leading causes of mortality worldwide, and therefore research aimed at developing new treatments for cancer immunotherapy is of great interest. The present review focuses primarily on the anticancer and immunomodulatory activities of egg proteins and their peptides and provides some insight into their underlying mechanisms of action. A number of egg proteins and peptides have been reported to induce apoptosis in cancer cells, protect against DNA damage, decrease the invasion ability of cancer cells, and exhibit cytotoxic and antimutagenic activity in various cancer cell lines. Furthermore, egg proteins and peptides can stimulate or suppress pro- or anti-inflammatory cytokines, as well as affect the production of inflammatory mediators in a variety of cell lines. In addition, the composition of eggs and the processes of egg proteins and peptides production will be discussed.

Lactobacillus fermentum Administration Modulates Cytokine Expression and Lymphocyte Subpopulation Levels in Broiler Chickens Challenged with Campylobacter coli

This investigation was performed to assess the supplementation of probiotics on cytokine expression and lymphocyte subpopulation in Campylobacter coli challenged chickens. Thirty-six individuals were equally separated into four experimental treatments: C = untreated chickens, LB = probiotic control (Lactobacillus fermentum), Cc = Campylobacter-challenged control, LBCc = probiotic + Cc. All chicks were slaughtered and cecum samples were collected on day 4 postinfection. Gene expression analysis, using reverse transcription quantitative PCR (RT-qPCR), revealed significant differences in cytokine transcript expression between untreated and probiotic-treated chickens. In addition, flow cytometry was used to quantitate the levels of lymphocyte subpopulations. Principal component analysis showed that probiotic administration induced an overall downregulation of cytokine expression. C. coli exposure provoked a similar response to that of L. fermentum but to a lesser extent. Colonization of C. coli in the presence of the probiotic evoked a complex response with an upregulation of some type II cytokines, including interleukin IL-4 and IL-13, which could explain the increased presence of antibodies in both lamina propria and epithelium. Moreover, despite that the percentage of CD8 intraepithelial lymphocytes (IELs) was found to be higher, downregulation of proinflammatory cytokines IL-15, IL-16, and interferon γ was observed. This suggests that the detected CD8 are not effector cells but induced IELs, which release antimicrobial peptides, and are ready to be primed upon encountering antigen. These outcomes demonstrate that probiotic administration promotes a humoral response to a C. coli infection while dampening any potential inflammation mediated by effector T cells in 1-week-old chicks.