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Exosomes are nanosized cell-derived vesicles that have recently gained attention for their use as a biomarker since the biomolecules encountered in these vesicles are directly linked to specific diseases including immuno-inflammatory, cardiovascular, and hepatic disorders. Furthermore, due to their nano size and safe travel in extracellular fluids, exosomes have been investigated as natural drug delivery systems, delivering cargo to destined cells with excellent specificity and efficiency, and crossing the blood–brain barrier. This necessitates the isolation and detection of exosomes. However, numerous exosome isolation techniques are available, including ultracentrifugation, size-based chromatography, polymer precipitation, microfluidics, and immunoaffinity-based isolation, with the downfalls of non-specificity and lower cost-effectiveness. This article introduces an immunoaffinity-based detection of exosomes using targeted anti-exosome antibodies raised in chickens due to its economic and commercial viability. The current study is unique in that it identified a specific antigenic region on exosomal surface tetraspanins (CD9, CD63, CD81) and constructed a multiple antigenic peptide dendrimer for making a small peptide as an immunogen without the use of a carrier protein. The antigenic region selection is critical to the study because it determines the efficiency of antibodies for exosome capture. This technique was validated using enzyme-linked immunosorbent assay in various biological fluids such as serum, urine, milk, plasma, and blood due to its numerous advantages including high sensitivity, specificity, handling multiple samples at once, requiring a small sample amount, and no purification as an antigen. In light of this technique, it is a useful tool for clinical monitoring of the patient’s biological conditions.

AimsProbiotics are known to maintain intestinal homeostasis through the regulation of the immune response of the host. Hence, the role of histone modifications as epigenetic agents on immune modulations by potential probiotic bacteria has been investigated.Methods and ResultsHuman colonic epithelial cells (Caco-2) pre-treated with class I histone deacetylase (HDAC) specific inhibitor, MS-275, were incubated either with potential probiotic bacteria (Limosilactobacillus fermentum MTCC 5898 and Lacticaseibacillus rhamnosus MTCC 5897) or Escherichia coli (ATCC 14948) as an inflammatory agent. Initially, transcriptional expression of potential immune-related genes (IL-6, IL-8, and hBD-2) was analyzed using RT-qPCR, and later H3 histone acetylation (H3Ac) at the promoter region of these genes was confirmed with a chromatin immunoprecipitation (ChIP) assay respectively. Potential probiotic L. fermentum (MTCC 5898) significantly suppressed (P ConclusionsPotential probiotics used in the study were found to regulate the immune response of host cells through histone acetylation in a strain-specific manner.Significance and Impact of StudyOccurrence of probiotic-mediated regulation of immune genes by H3 acetylation in a strain-specific manner.

This study investigated the physicochemical characteristics and antioxidative role of novel acidic cell-bound exopolysaccharide (EPS-b) from probiotic Limosilactobacillus fermentum (MTCC 5898) and gained an insight into the structure-function relationship. The physicochemical analysis of EPS-b isolated by ultrasonication method revealed a heteropolysaccharide molecule with an average MW of 96.97 kDa composed of glucose and galactose subunits present in random-coiled conformation. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses further supported the observation and indicated the presence of α-(1 → 6) linkages. The analyses implicated the significant influence of structural features on the antioxidative activity of EPS-b by showing remarkable ABTS scavenging, reducing, and metal chelating potential with increasing concentration. Besides, the EPS-b by its scavenging potential also maintained the oxidative balance in the Caco-2 cells under oxidative stress and preserved the cellular antioxidative defense system (CAT, GPx, SOD, HO1, and GCLC) at the basal level.

The epigenome of an organism is as important as the genome for the normal development and functioning of an individual. The human epigenome can be affected by various environmental factors including nutrients, microbiota and probiotics through epigenetic modifiers and mediates various health-promoting effects. The present study was aimed to explore the temporal changes in DNA and histone modifiers (DNMT1, TET2, p300, HDAC1, KMT2A, KDM5B, EzH2 and JMJD3) in intestinal epithelial cells (Caco-2) by probiotic lactobacilli (Limosilactobacillus fermentum MTCC 5898 and Lacticaseibacillus rhamnosus MTCC 5897) in comparison to opportunistic commensal pathogen Escherichia coli (ATCC 14849). Cells were treated separately with probiotic strains and E. coli for different durations and temporal changes in gene expression among DNA and histone modifiers were measured. Time-dependent studies showed that L. fermentum enhanced the transcription of epigenetic modifiers at 12 h of treatment (P 0.05) contrary to E. coli which reduced the expression of these genes during the same duration of treatment. On the other hand, probiotic L. rhamnosus was not able to induce any significant changes in gene expression of these modifiers. Furthermore, during the exclusion of E. coli by L. fermentum, the probiotic was found to resist the changes made by E. coli in the transcription of some of the epigenetic modifiers. Thus, it is concluded that the probiotics modulated the mRNA expression of DNA and histone modifiers contrarily to E. coli in a strain-specific manner.

The epigenome is an overall epigenetic state of an organism, which is as important as that of the genome for normal development and functioning of an individual. Epigenetics involves heritable but reversible changes in gene expression through alterations in DNA methylation, histone modifications and regulation of non-coding RNAs in cells, without any change in the DNA sequence. Epigenetic changes are owned by various environmental factors including pollution, microbiota and diet, which have profound effects on epigenetic modifiers. The bioactive compounds present in the diet mainly include curcumin, resveratrol, catechins, quercetin, genistein, sulforaphane, epigallocatechin-3-gallate, alkaloids, vitamins, and peptides. Bioactive compounds released during fermentation by the action of microbes also have a significant effect on the host epigenome. Besides, recent studies have explored the new insights in vitamin's functions through epigenetic regulation. These bioactive compounds exert synergistic, preventive and therapeutic effects when combined as well as when used with chemotherapeutic agents. Therefore, these compounds have potential of therapeutic agents that could be used as "Epidrug" to treat many inflammatory diseases and various cancers where chemotherapy results have many side effects. In this review, the effect of diet derived bioactive compounds through epigenetic modulations on in vitro and in vivo models is discussed.

The probiotic extracellular matrix components (ECM) have been considered as an important factor in eliciting the beneficial roles of the bacteria. The study involved the growth phase-dependent extraction of the surface layer protein (SLP) and cell-bound exopolysaccharide (EPS-b) from novel Limosilactobacillus fermentum (MTCC 5898). Both SLP and EPS-b were optimally extracted at the late logarithmic phase of the bacteria upon 8 h of incubation. Furthermore, the adhesive, immunomodulatory, and anti-oxidative potential of the extracted components were evaluated using in vitro models. The major role of SLP was evidenced on bacterial adhesion to mucin and was related to its hydrophobic character. Under in vitro conditions, no effect of SLP and EPS-b was observed on the proliferation of murine splenocytes; however, both the components stimulated the phagocytosis of murine peritoneal macrophages at varying concentrations. Furthermore, all the components exhibited strong radical scavenging, chelating, and reducing potential with increasing concentration. Therefore, the ECM components of L. fermentum exhibited a variable biofunctional effect, providing crucial information to enable its further use as functional foods and overcome the challenges posed by probiotics.

This study investigated the physicochemical characteristics and antioxidative role of novel acidic cell-bound exopolysaccharide (EPS-b) from probiotic