Screening probiotics from Lactobacillus strains according to their abilities to inhibit pathogen adhesion and induction of pro-inflammatory cytokine IL-8

Taxonomic and phenotypic analysis of bifidobacteria isolated from IBD patients as potential probiotic strains

BACKGROUND

Inflammatory Bowel Diseases (IBD) are a major public health issue with unclear aetiology. Changes in the composition and functionality of the intestinal microbiota are associated with these pathologies, including the depletion of strict anaerobes such as Feacalibacterium prausnitzii. Less evidence is observed for depletion in other anaerobes, among which bifidobacteria. This study characterized the taxonomic and functional diversity of bifidobacteria isolated from the human intestinal microbiota in active and non-active IBD patients by a culturomics approach and evaluated if these bifidobacteria might be used as probiotics for gut health.

RESULTS

A total of 341 bifidobacteria were isolated from the intestinal microbiota of IBD patients (52 Crohn's disease and 26 ulcerative colitis patients), with a high proportion of Bifidobacterium dentium strains (28% of isolated bifidobacteria). In ulcerative colitis, the major species identified was B. dentium (39% of isolated bifidobacteria), in active and non-active ulcerative colitis. In Crohn's disease, B. adolescentis was the major species isolated from non-active patients (40%), while similar amounts of B. dentium and B. adolescentis were found in active Crohn's disease patients. The relative abundance of B. dentium was increased with age, both in Crohn's disease and ulcerative colitis and active and non-active IBD patients. Antibacterial capacities of bifidobacteria isolated from non-active ulcerative colitis against Escherichia coli LF82 and Salmonella enterica ATCC 14028 were observed more often compared to strains isolated from active ulcerative colitis. Finally, B. longum were retained as strains with the highest probiotic potential as they were the major strains presenting exopolysaccharide synthesis, antibacterial activity, and anti-inflammatory capacities. Antimicrobial activity and EPS synthesis were further correlated to the presence of antimicrobial and EPS gene clusters by in silico analysis.

CONCLUSIONS

Different bifidobacterial taxonomic profiles were identified in the microbiota of IBD patients. The most abundant species were B. dentium, mainly associated to the microbiota of ulcerative colitis patients and B. adolescentis, in the intestinal microbiota of Crohn's disease patients. Additionally, the relative abundance of B. dentium significantly increased with age. Furthermore, this study evidenced that bifidobacteria with probiotic potential (antipathogenic activity, exopolysaccharide production and anti-inflammatory activity), especially B. longum strains, can be isolated from the intestinal microbiota of both active and non-active Crohn's disease and ulcerative colitis patients.

Genomic Insights Into Enterococcus mundtii 203: A Promising Probiotic Candidate Isolated From Camel Feces

Enterococcus, a common commensal organism in the human gut, exhibits a dual nature with certain strains offering probiotic benefits, while others are associated with nosocomial infections. In this study, we conducted a comprehensive examination of the genome of Enterococcus mundtii strain 203 to assess its probiotic potential and safety profile. The complete genome sequencing, assembly, and annotation were performed, followed by bioinformatics analysis. Our investigation reveals a detailed characterization of the Enterococcus mundtii 203 genome, originally isolated from camel feces, with a size of 3,053,234 bases and a GC content of 38.4%. Importantly, our analysis suggests that this strain poses no risk as a human pathogen due to the absence of antibiotic resistance determinants and virulence factors. The genome harbors a multitude of genes responsible for lactic acid production, bioactive peptide synthesis, adhesion molecule expression, resistance to harsh gut conditions, and enhancement of host metabolism. These findings underline the potential probiotic functionality of Enterococcus mundtii 203, positioning it as a promising candidate. Notably, our study did not identify any sequences related to insertion elements or CRISPR-Cas fragments.

Probiotic capacity of commensal lactic acid bacteria from the intestine of Guinea pigs (Cavia porcellus)

The intricate balance of intestinal microbiota is significantly influenced by the pivotal role of indigenous lactic acid bacteria (LAB). These LAB not only contribute to antimicrobial activity and enhance animal health and productivity but also serve as defense against intestinal infections. In the present study, the probiotic potential of LAB strains isolated from various intestinal sections of adult and young guinea pigs (Cavia porcellus) was comprehensively assessed. Strains belonging to the genera Ligilactobacillus, Weissella, Enterococcus, and Limosilactobacillus were also identified. The antibacterial activities of the LAB strains against Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus were quantified. Exopolysaccharide production, adherence capacity, antibiotic resistance, and bile salt tolerance (0.15 %, 0.30 %, and 0.45 %) of LAB were quantified. Further analyses focused on the effects of pH (2.9, 5.0, 6.4, and 7.4), temperature (40, 50, and 60 °C) and NaCl concentrations (3.5 % and 6.5 % w/v) on LAB growth. Strains GCI9 and GDE10 (Ligilactobacillus salivarius), isolated from the cecum and intestine of guinea pigs, exhibited significant antimicrobial activity against S. typhimurium, E. coli and S. aureus. Remarkable adherence capacity to porcine gastric mucin was demonstrated by L. salivarius strains, specifically ACI1, GCI9, and GDE10, with the highest exopolysaccharide levels produced by ACI1 and GCI9 (1.71 and 1.76 mg/mL, respectively). The probiotic potential was further underscored by remarkable bile salt tolerance, especially in strain GDE10, and substantial exopolysaccharide production. These strains displayed notable adaptability to varying environmental conditions, including NaCl concentrations at 3.5 % and 6.5 %, temperatures ranging from 40 to 60 °C, and pH levels of 2.9, 5.0, 6.4, and 7.4. This comprehensive assessment of the probiotic properties of L. salivarius strains, particularly ACI1, GCI9, and GDE10, shows promise for the development of probiotic formulations aimed at enhancing the intestinal health of guinea pigs.

Exopolysaccharide production by Lactobacillus plantarum T10 is responsible for the probiotic activity in enhancing intestinal barrier function in vitro and in vivo

Lactobacillus probiotics exert their effects in a strain-specific and metabolite-specific manner. This study aims to identify lactobacilli that can effectively enhance the intestinal barrier function both in vitro and in vivo and to investigate the underlying metabolite and molecular mechanisms involved. Nine Lactobacillus isolates were evaluated for their ability to enhance the IPEC-J2 cellular barrier function and for their anti-inflammatory and anti-apoptotic effects in IPEC-J2 cells after an enterotoxigenic Escherichia coli challenge. Of the nine isolates, L. plantarum T10 demonstrated significant advantages in enhancing the cellular barrier function and displayed anti-inflammatory and anti-apoptotic activities in vitro. The bioactivities of L. plantarum T10 were primarily attributed to the production of exopolysaccharides, which exerted their effects through the TLR-mediated p38 MAPK pathway in ETEC-challenged IPEC-J2 cells. Furthermore, the production of EPS by L. plantarum T10 led to the alleviation of dextran sulfate sodium-induced colitis by reducing intestinal damage and enhancing the intestinal barrier function in mice. The EPS is classified as a heteropolysaccharide with an average molecular weight of 23.0 kDa. It is primarily composed of mannose, glucose, and ribose. These findings have practical implications for the targeted screening of lactobacilli used in the production of probiotics and postbiotics with strain-specific features of exopolysaccharides.

Harnessing the power of probiotics to enhance neuroplasticity for neurodevelopment and cognitive function in stunting: a comprehensive review

BACKGROUND

Stunting become a global concern because it's not only affecting physical stature, but also affecting on neurodevelopment and cognitive function. These impacts are resulting in long-term consequences especially for human resources, such as poor-quality labor, decreased productivity due to decreasing of health quality, including immunity and cognitive aspect.

DISCUSSION

This comprehensive review found that based on many studies, there is an altered gut microbiota, or dysbiosis, in stunted children, causing the impairment of brain development through Microbiota-Gut Brain Axis (MGB Axis) mechanism. The administration of probiotics has been known affect MGBA by improving the physical and chemical gut barrier integrity, producing antimicrobial substance to inhibit pathogen, and recovering the healthy gut microbiota. Probiotics, along with healthy gut microbiota, produce SCFAs which have various positive impact on CNS, such as increase neurogenesis, support the development and function of microglia, reduce inflammatory signaling, improve the Blood Brain Barrier's (BBB's) integrity, produce neurotropic factors (e.g. BDNF, GDNF), and promote the formation of new synapse. Probiotics also could induce the production of IGF-1 by intestinal epithelial cells, which functioned as growth factor of multiple body tissues and resulted in improvement of linear growth as well as brain development.

CONCLUSION

These properties of probiotics made it become the promising and feasible new treatment approach for stunting. But since most of the studies in this field are conducted in animal models, it is necessary to translate animal data into human models and do additional study to identify the numerous components in the MGB axis and the effect of probiotics on human.

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

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

Bifidobacterium and the intestinal mucus layer

Bifidobacterium species are integral members of the human gut microbiota and these microbes have significant interactions with the intestinal mucus layer. This review delves into Bifidobacterium-mucus dynamics, shedding light on the multifaceted nature of this relationship. We cover conserved features of Bifidobacterium-mucus interactions, such as mucus adhesion and positive regulation of goblet cell and mucus production, as well as species and strain-specific attributes of mucus degradation. For each interface, we explore the molecular mechanisms underlying these interactions and their potential implications for human health. Notably, we emphasize the ability of Bifidobacterium species to positively influence the mucus layer, shedding light on its potential as a mucin-builder and a therapeutic agent for diseases associated with disrupted mucus barriers. By elucidating the complex interplay between Bifidobacterium and intestinal mucus, we aim to contribute to a deeper understanding of the gut microbiota-host interface and pave the way for novel therapeutic strategies.

Changes in Intracellular and Extracellular Metabolites of Mixed Lactobacillus Strains Enhance Inhibition of Pathogenic Bacterial Growth and Lipopolysaccharide-Induced Alleviation of RAW264.7 Cellular Inflammation

It is important to explore whether there are antagonistic and synergistic effects between different strains of Lactobacillus when developing mixed Lactobacillus strain products. In this study, we investigated the antagonistic and symbiotic effects of co-cultured Lactobacillus strains, as well as their amelioratory effects on lipopolysaccharide (LPS)-induced inflammation and oxidative stress in RAW264.7 cells. The Lactobacillus strains tested in this paper showed no antagonism. Co-culture of Lactiplantibacillus plantarum Y44 and L. plantarum AKS-WS9 was found to show inhibiting effects on the growth of Escherichia coli and Staphylococcus aureus. Additionally, the co-cultured Lactiplantibacillus plantarum Y44 and L. plantarum AKS-WS9 relieved inflammation in RAW264.7 cells induced by LPS by inhibiting the activation of NF-κB and P38 signaling pathways and down-regulating the expression of pro-inflammatory cytokines NO, ROS, iNOs and TNF-α. And the co-cultured Lactobacillus strains activated the Nrf2 signaling pathway in the LPS-induced RAW264.7 cells to promote the expression of antioxidant enzymes in response to oxidative stress. There was a difference in intracellular and extracellular metabolites between single or co-cultured Lactobacillus strains, and the co-cultured Lactobacillus strains significantly increased extracellular metabolites 4-chlorobenzaldehyde, psoromic acid, and 2-dodecylbenzenesulfonic acid and intracellular metabolites 9(S)-HODE, pyocyanin, and LysoPA. We inferred that the better antibacterial and anti-inflammatory ability of the co-cultured Lactobacillus strains were related to the changes in the metabolites of the co-cultured Lactobacillus strains. The co-cultured L. plantarum Y44 and L. plantarum AKS-WS9 strains exhibited better anti-inflammatory abilities and had the potential to alleviate the symptoms of inflammatory diseases as mixed probiotics.

Microbiota perturbation by anti-microbiota vaccine reduces the colonization of Borrelia afzelii in Ixodes ricinus

BACKGROUND

Ticks can transmit a broad variety of pathogens of medical importance, including Borrelia afzelii, the causative agent of Lyme borreliosis in Europe. Tick microbiota is an important factor modulating, not only vector physiology, but also the vector competence. Anti-microbiota vaccines targeting keystone taxa of tick microbiota can alter tick feeding and modulate the taxonomic and functional profiles of bacterial communities in the vector. However, the impact of anti-microbiota vaccine on tick-borne pathogen development within the vector has not been tested.

RESULTS

Here, we characterized the Ixodes ricinus microbiota modulation in response to B. afzelii infection and found that the pathogen induces changes in the microbiota composition, its beta diversity and structure of bacterial community assembly. Tick microbiota perturbation by anti-microbiota antibodies or addition of novel commensal bacteria into tick midguts causes departures from the B. afzelii-induced modulation of tick microbiota which resulted in a lower load of the pathogen in I. ricinus. Co-occurrence networks allowed the identification of emergent properties of the bacterial communities which better defined the Borrelia infection-refractory states of the tick microbiota.

CONCLUSIONS

These findings suggest that Borrelia is highly sensitive to tick microbiota perturbations and that departure from the modulation induced by the pathogen in the vector microbiota pose a high cost to the spirochete. Network analysis emerges as a suitable tool to identify emergent properties of the vector microbiota associated with infection-refractory states. Anti-microbiota vaccines can be used as a tool for microbiota perturbation and control of important vector-borne pathogens. Video Abstract.

Influence of dietary supplementation with new Lactobacillus strains on hematology, serum biochemistry, nutritional status, digestibility, enzyme activities, and immunity in dogs

Background and Aim

The use of antibiotics is associated with many side effects, with the development of bacterial resistance being particularly important. It has been found that dogs and their owners host similar resistant bacteria. This contributes to increased concurrent bacterial resistance and a possible trend of increased bacterial resistance in humans. Thus, using probiotics in dogs is an alternative option for preventing and reducing the transmission of bacterial resistance from dogs to humans. Probiotics are characterized by their potential to endure low pH levels and high concentrations of bile acids in the gastrointestinal tract. Lactobacilli are more acid-tolerant and resistant to bile acid, so they are ideal probiotics to be added to the canine diet. According to the previous studies, the benefits of Lactobacillus are a stable nutritional status and greater digestibility, along with improved fecal scores and reduced ammonia in dogs. However, no studies have been conducted with Lactobacillus plantarum CM20-8 (TISTR 2676), Lactobacillus acidophilus Im10 (TISTR 2734), Lactobacillus rhamnosus L12-2 (TISTR 2716), Lactobacillus paracasei KT-5 (TISTR 2688), and Lactobacillus fermentum CM14-8 (TISTR 2720), or their use in combination. Hence, the aim of this study was to examine the possible effects of the aforementioned Lactobacillus on hematological indices, nutritional status, digestibility, enzyme activities, and immunity in dogs. From the results, a new and safe strain of Lactobacillus may emerge for use as a probiotic in the future.

Materials and Methods

In this study, 35 dogs were allocated equally into seven groups: Group 1 received a basal diet (control), while Groups 2-7 received the same diet further supplemented with L. plantarum CM20-8 (TISTR 2676), L. acidophilus Im10 (TISTR 2734), L. rhamnosus L12-2 (TISTR 2716), L. paracasei KT-5 (TISTR 2688), L. fermentum CM14-8 (TISTR 2720), or a mixture of probiotics (L. plantarum, L. acidophilus, L. rhamnosus, L. paracasei, and L. fermentum), respectively. All probiotics were administered at a dose of 10⁹ colony-forming unit/dog for 28 days. Nutritional status, hematology, serum biochemistry, digestibility, enzyme activities, and immunity parameters were assessed.

Results

There were no differences among the groups in body weight, feed intake, body condition score, fecal score, and fecal dry matter on the different sampling days. The hematology and serum biochemical analyses showed a difference only in creatinine activity (p < 0.001), with higher values in group L. fermentum CM14-8 (TISTR 2720) and lower values in group L. paracasei KT-5 (TISTR 2688) than in controls. However, all measurements were within the normal laboratory reference ranges. Fecal characteristics (fecal ammonia and fecal pH), fecal digestive enzyme activities, serum immunoglobulin (IgG), and fecal IgA did not differ significantly among the groups (p > 0.05).

Conclusion

Lactobacillus plantarum CM20-8 (TISTR 2676), L. acidophilus Im10 (TISTR 2734), L. rhamnosus L12-2 (TISTR 2716), L. paracasei KT-5 (TISTR 2688), and L. fermentum CM14-8 (TISTR 2720), along with their mixture are safe and non-pathogenic additives for use as new probiotic strains of Lactobacillus in dogs. Although the new Lactobacillus strains had no effect on hematology, serum biochemistry, nutritional status, digestive enzyme activities, immunity, body weight, feed intake, or body condition scores in dogs, further studies should investigate the intestinal microbiota and the development of clinical treatments.

In vitro characterization of lactic acid bacterial strains isolated from fermented foods with anti-inflammatory and dipeptidyl peptidase-IV inhibition potential

Probiotics are known to stimulate, modulate, and regulate host immune response by regulating specific sets of genes and improve glucose homeostasis through regulating dipeptidyl peptidase (DPP-IV) activity, but the mechanism behind their protective role is not clearly understood. Therefore, the present study was designed to isolate indigenous lactic acid bacterial (LAB) strains from different fermented food samples, vegetables, and human infant feces exhibiting anti-inflammatory, antioxidant, and DPP-IV inhibitory activity. A total of thirty-six Gram-positive, catalase-negative, and rod-shaped bacteria were isolated and screened for their anti-inflammatory activity using lipopolysaccharide (LPS)-induced inflammation on the murine (RAW264.7) macrophages. Among all, sixteen strains exhibited more than 90% reduction in nitric oxide (NO) production by the LPS-treated RAW264.7 cells. Prioritized strains were characterized for their probiotic attributes as per the DBT-ICMR guidelines and showed desirable probiotic attributes in a species and strain-dependent manner. Accordingly, Lacticaseibacillus rhamnosus LAB3, Levilactobacillus brevis LAB20, Lactiplantibacillus plantarum LAB31, Pediococcus acidilactici LAB8, and Lactiplantibacillus plantarum LAB39 were prioritized. Furthermore, these strains when co-supplemented with LPS and treated on RAW264.7 cells inhibited the mitogen-activated protein kinases (MAPKs), i.e., p38 MAPK, ERK1/2, and SAPK/JNK, cyclooxygenase-2 (COX-2), relative to the LPS-alone-treated macrophages. LAB31 and LAB39 also showed 64 and 95% of DPP-IV inhibitory activity relative to the Lacticaseibacillus rhamnosus GG ATCC 53103, which was used as a reference strain in all the studies. Five prioritized strains ameliorated the LPS-induced inflammation by downregulating the JNK/MAPK pathway and could be employed as an alternative bio-therapeutic strategy in mitigating gut-associated inflammatory conditions. The potential mechanism of action of prioritized LAB strains in preventing the LPS-induced inflammation in RAW 264.7 macrophage cells.

Genetic and phenotypic assessment of the antimicrobial activity of three potential probiotic lactobacilli against human enteropathogenic bacteria

Introduction

Lactobacilli are avid producers of antimicrobial compounds responsible for their adaptation and survival in microbe-rich matrices. The bactericidal or bacteriostatic ability of lactic acid bacteria (LAB) can be exploited for the identification of novel antimicrobial compounds to be incorporated in functional foodstuffs or pharmaceutical supplements. In this study, the antimicrobial and antibiofilm properties of Lactiplantibacillus pentosus L33, Lactiplantibacillus plantarum L125 and Lacticaseibacillus paracasei SP5, previously isolated form fermented products, were examined, against clinical isolates of Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Enteritidis and Escherichia coli.

Methods

The ability of viable cells to inhibit pathogen colonization on HT-29 cell monolayers, as well as their co-aggregation capacity, were examined utilizing the competitive exclusion assay. The antimicrobial activity of cell-free culture supernatants (CFCS) was determined against planktonic cells and biofilms, using microbiological assays, confocal microscopy, and gene expression analysis of biofilm formation-related genes. Furthermore, in vitro analysis was supplemented with in silico prediction of bacteriocin clusters and of other loci involved in antimicrobial activity.

Results

The three lactobacilli were able to limit the viability of planktonic cells of S. aureus and E. coli in suspension. Greater inhibition of biofilm formation was recorded after co-incubation of S. enterica with the CFCS of Lc. paracasei SP5. Predictions based on sequence revealed the ability of strains to produce single or two-peptide Class II bacteriocins, presenting sequence and structural conservation with functional bacteriocins.

Discussion

The efficiency of the potentially probiotic bacteria to elicit antimicrobial effects presented a strain- and pathogen-specific pattern. Future studies, utilizing multi-omic approaches, will focus on the structural and functional characterization of molecules involved in the recorded phenotypes.

An accidental discovery of mannan-oligosaccharide's protection effect against air exposure and its potential mechanism in hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀)

The original objective was to explore the potential benefiting effects of three prebiotics in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). Therefore, three experimental diets (basal diet + 1% fructooligosaccharide, Diet F; basal diet + 1% inulin, Diet I; basal diet + 0.3% mannan-oligosaccharide, Diet M) and one basal diet (Diet C) were prepared and a feeding trial was conducted. However, at the end of the fourth week into the feeding experiment, a water-leaking accident occurred and fishes of all groups went through an unexpected air exposure event. Surprisingly, different prebiotic-supplemented groups showed significantly different air exposure tolerance: the mortality of M group was significantly lower (P ≤ 0.05) than all the other groups. Examination of antioxidant, non-specific immunity, and stress parameters revealed that comparing to control group, M group showed significantly increased catalase (CAT), acid phosphatase (ACP), and alkaline phosphatase (AKP) activities, decreased superoxide dismutase (SOD) activity, and similar cortisol level (P ≤ 0.05). Real-time PCR experiment revealed that M group significantly increased the expression of CAT, glutathione peroxidase (GPx), and manganese superoxide dismutase (MnSOD) genes in head kidney (P ≤ 0.05). Overall, M exhibited the best anti-air exposure/antioxidative stress effects among the three prebiotics and could be considered a promising feed additive to relieve air exposure/oxidative stress in hybrid grouper culture.

Probiotics, Their Extracellular Vesicles and Infectious Diseases

Probiotics have been shown to be effective against infectious diseases in clinical trials, with either intestinal or extraintestinal health benefits. Even though probiotic effects are strain-specific, some "widespread effects" include: pathogen inhibition, enhancement of barrier integrity and regulation of immune responses. The mechanisms involved in the health benefits of probiotics are not completely understood, but these effects can be mediated, at least in part, by probiotic-derived extracellular vesicles (EVs). However, to date, there are no clinical trials examining probiotic-derived EVs health benefits against infectious diseases. There is still a long way to go to bridge the gap between basic research and clinical practice. This review attempts to summarize the current knowledge about EVs released by probiotic bacteria to understand their possible role in the prevention and/or treatment of infectious diseases. A better understanding of the mechanisms whereby EVs package their cargo and the process involved in communication with host cells (inter-kingdom communication), would allow further advances in this field. In addition, we comment on the potential use and missing knowledge of EVs as therapeutic agents (postbiotics) against infectious diseases. Future research on probiotic-derived EVs is needed to open new avenues for the encapsulation of bioactives inside EVs from GRAS (Generally Regarded as Safe) bacteria. This could be a scientific novelty with applications in functional foods and pharmaceutical industries.

Probiotics as Potential Biological Immunomodulators in the Management of Oral Lichen Planus: What's New?

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory disorder with multifactorial aetiology and malignant transformation potential. Despite the treatments so far identified, new tailored and safe specific measures are needed. Recently, human microbiota imbalance has been linked to several immune-mediated diseases, opening new therapeutic perspectives for probiotics; besides their ability to directly interact with the host microbiota, they also display a strain-specific immune-modulatory effect. Thus, this non-systematic review aims to elucidate the molecular pathways underlying probiotic activity, mainly those of Lactobacilli and Bifidobacteria and their metabolites in OLP pathogenesis and malignant transformation, focusing on the most recent in vitro and in vivo research evidence. Findings related to their activity in other immune-mediated diseases are here included, suggesting a probiotic translational use in OLP. Probiotics show immune-modulatory and microbiota-balancing activities; they protect the host from pathogens, hamper an excessive effector T cell response, reduce nuclear factor-kappa B (NF-kB) signalling and basal keratinocytes abnormal apoptosis, shifting the mucosal response towards the production of anti-inflammatory cytokines, thus preventing uncontrolled damage. Therefore, probiotics could be a highly encouraging prevention and immunotherapeutic approach for a safer and more sustainable OLP management.

Effect of a synbiotic supplement as an antibiotic alternative on broiler skeletal, physiological, and oxidative parameters under heat stress

The aim of this study was to examine if synbiotics can function as alternatives to antibiotics in broiler production under heat stress (HS). Day-old broiler chicks (528 birds) were randomly placed in floor pens within 2 identical temperature-controlled rooms (11 birds/pen and 24 pens/room). The pens of each room were evenly divided among 3 treatments (n = 8): basal diet (CON), the basal diet mixed with 50 ppm of bacitracin methylene disalicylate (BMD) or a synbiotic (50 ppm of PoultryStar me^US, SYN). From d 15, room 2 was under thermoneutral (TN) conditions (TN-CON, TN-BMD, and TN-SYN), while HS was applied to room 1 at 32^oC for 9 hrs/d (0800 to 1700) (HS-CON, HS-BMD, and HS-SYN). Treatment effects on footpad dermatitis and gait score were measured on 5 birds/pen, and latency to lie (LTL) test was measured on 2 birds/pen at d 27 and d 41; and 1 broiler/pen was sampled on d 28 and d 42, respectively. Body, liver, and spleen weight were determined. Plasma levels of interleukins (IL), heat shock protein 70, immunoglobulin (Ig)Y, liver superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were examined. Heat stress suppressed BW and IgY concentrations on both d 28 and d 42, while suppressed plasma IL-6 concentrations, SOD activities, and LTL duration on d 28 only (P < 0.05). Among all treatments, SYN birds had the best foot and skeletal health scores on both d 27 and d 41 (P < 0.05). On d 42, SYN increased BW, and TN-SYN birds had higher relative spleen weight than both TN-BMD and TN-CON birds (P < 0.05). Antibiotic BMD increased BW (P < 0.05) but decreased SOD activities (P < 0.05) on d 42. These results indicate that the SYN supplementation decreases HS negative effect on broilers by improving BW, foot, and skeletal health, while BMD improves BW but also increases oxidative stress in broilers. The data suggest that synbiotic supplement may function as an alternative to antibiotics in broiler production during summer seasons, especially in the tropical and subtropical regions.

Whole-Genome Sequencing, Phylogenetic and Genomic Analysis of Lactiplantibacillus pentosus L33, a Potential Probiotic Strain Isolated From Fermented Sausages

Lactobacillus is a diverse genus that includes species of industrial and biomedical interest. Lactiplantibacillus pentosus, formerly known as Lactobacillus pentosus, is a recently reclassified species, that contains strains isolated from diverse environmental niches, ranging from fermented products to mammalian gut microbiota. Importantly, several L. pentosus strains present health-promoting properties, such as immunomodulatory and antiproliferative activities, and are regarded as potential probiotic strains. In this study, we present the draft genome sequence of the potential probiotic strain L. pentosus L33, originally isolated from fermented sausages. Comprehensive bioinformatic analysis and whole-genome annotation were performed to highlight the genetic loci involved in host-microbe interactions and the probiotic phenotype. Consequently, we found that this strain codes for bile salt hydrolases, adhesins and moonlighting proteins, and for Class IIb bacteriocin peptides lacking the GxxxG and GxxxG-like motifs, crucial for their inhibitory activity. Its adhesion ability was also validated in vitro, on human cancer cells. Furthermore, L. pentosus L33 contains an exopolysaccharide (EPS) biosynthesis cluster, and it does not carry transferable antibiotic resistance genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and CAZymes analyses showed that L. pentosus L33 possesses biosynthetic pathways for seven amino acids, while it can degrade a wide array of carbohydrates. In parallel, Clusters of Orthologous Groups (COGs) and KEGG profiles of L. pentosus L33 are similar to those of 26 L. pentosus strains, as well as of two well documented L. plantarum probiotic strains. Conclusively, L. pentosus L33 exhibits good probiotic potential, although further studies are needed to elucidate the extent of its biological properties.

Probiotics Regulate Gut Microbiota: An Effective Method to Improve Immunity

Probiotics are beneficial active microorganisms that colonize the human intestines and change the composition of the flora in particular parts of the host. Recently, the use of probiotics to regulate intestinal flora to improve host immunity has received widespread attention. Recent evidence has shown that probiotics play significant roles in gut microbiota composition, which can inhibit the colonization of pathogenic bacteria in the intestine, help the host build a healthy intestinal mucosa protective layer, and enhance the host immune system. Based on the close relationship between the gut microbiota and human immunity, it has become an extremely effective way to improve human immunity by regulating the gut microbiome with probiotics. In this review, we discussed the influence of probiotics on the gut microbiota and human immunity, and the relationship between immunity, probiotics, gut microbiota, and life quality. We further emphasized the regulation of gut microflora through probiotics, thereby enhancing human immunity and improving people’s lives.

Milk fat globule membrane phospholipids modify adhesion of Lactobacillus to mucus-producing Caco-2/Goblet cells by altering the cell envelope

The importance of various Lactobacillus strains and milk components, such as the milk fat globule membrane, has been studied from various perspectives and proven to have a positive role in human health. On one end, lactic acid bacteria produce metabolites with direct effect in the immune system, changes of pH in the gut, and antagonistic substances for pathogenic bacteria as well as competition. On the other end, the milk fat globule membrane improves gastrointestinal status by promoting cell proliferation, epithelial tight junction patterns, and development of intestinal epithelial cells. Interaction between beneficial bacteria and milk fat is a natural occurring phenomenon in dairy products; however, it has not been fully characterized. In this work, we studied the effect of milk phospholipids in the adhesion of Lactobacillus to mucus-producing Caco-2/Goblet cell co-cultures and found that treatment with phospholipids produced bacterial cells with increased surface electronegativity, which was correlated with increased bacterial cells adhered to the intestinal model. Moreover, we utilized an original means of characterizing the adhesion using quartz crystal microbalance. All strains studied, experienced modification of adhesion either physicochemical or kinetic parameters studied. Furthermore, by imaging bacterial cells by electron microscopy, we identified that some strains, such as L. acidophillus and L. casei, metabolized MPL, which improved their adhesion to hydrophilic surfaces such as gold. We identified another group of bacteria, such as L. delbrueckii and L. plantarum, that, instead of metabolizing MPL, kept the phospholipids bound irreversibly to the surface of the cell envelope thus decreasing their adherence to gold surfaces. One of the most important aspects of probiotic lactic acid bacteria -besides survival in the stomach-is the colonization and extended resident time in the intestine to effectively change the gut microbiome. We found that bacterial treatment with milk phospholipids enhances adhesion to intestinal models and will in turn, increase the residence time with the concomitant benefits to the consumer.

Evaluation of Probiotic Characteristics of Newly Isolated Lactic Acid Bacteria from Dry-Aged Hanwoo Beef

Dry aging is a traditional method that improves meat quality, and diverse microbial communities are changed during the process. Lactic acid bacteria (LAB) are widely present in fermented foods and has many beneficial effects, such as immune enhancement and maintenance of intestinal homeostasis. In this study, we conducted metagenomic analysis to evaluate the changes in the microbial composition of dry-aged beef. We found that lactic acid bacterial strains were abundant in dry-aged beef including Lactobacillus sakei and Enterococcus faecalis. We investigated their abilities in acid and bile tolerance, adhesion to the host, antibiotic resistance, and antimicrobial activity as potential probiotics, confirming that L. sakei and E. faecalis strains had remarkable capability as probiotics. The isolates from dry-aged beef showed at least 70% survival under acidic conditions in addition to an increase in the survival level under bile conditions. Antibiotic susceptibility and antibacterial activity assays further verified their effectiveness in inhibiting all pathogenic bacteria tested, and most of them had low resistance to antibiotics. Finally, we used the Caenorhabditis elegans model to confirm their life extension and influence on host resistance. In the model system, 12D26 and 20D48 strains had great abilities to extend the nematode lifespan and to improve host resistance, respectively. These results suggest the potential use of newly isolated LAB strains from dry-aged beef as probiotic candidates for production of fermented meat.

Probiotic Lactobacillus sp. Strains Inhibit Growth, Adhesion, Biofilm Formation, and Gene Expression of Bacterial Vaginosis-Inducing Gardnerella vaginalis

Gardnerella vaginalis contributes significantly to bacterial vaginosis, which causes an ecological imbalance in vaginal microbiota and presents with the depletion of Lactobacillus sp. Lactobacillus supplementation was reported to be an approach to treat bacterial vaginosis. We investigated the applicability of three Lactobacillus sp. strains (Lactobacillus delbrueckii DM8909, Lactiplantibacillus plantarum ATCC14917, and Lactiplantibacillus plantarum ZX27) based on their probiotic abilities in vitro. The three candidate Lactobacillus sp. strains for bacterial vaginosis therapy showed distinct properties in auto-aggregation ability, hydrophobicity, adhesion to cervical epithelial cells, and survivability in 0.01% hydrogen peroxide. Lpb. plantarum ZX27 showed a higher yield in producing short-chain fatty acids and lactic acid among the three candidate strains, and all three Lactobacillus sp. strains inhibited the growth and adhesion of G. vaginalis. Furthermore, we discovered that the culture supernatant of Lactobacillus sp. exhibited anti-biofilm activity against G. vaginalis. In particular, the Lpb. plantarum ZX27 supernatant treatment decreased the expression of genes related to virulence factors, adhesion, biofilm formation, metabolism, and antimicrobial resistance in biofilm-forming cells and suspended cells. Moreover, Lactobacillus sp. decreased the upregulated expression of interleukin-8 in HeLa cells induced by G. vaginalis or hydrogen peroxide. These results demonstrate the efficacy of Lactobacillus sp. application for treating bacterial vaginosis by limiting the growth, adhesion, biofilm formation, and virulence properties of G. vaginalis.

Differences in the gut microbiota between young and elderly persons in Korea

The gut microbiota differs among countries owing to the prevailing diet composition. For the characterization of the gut microbiota of Koreans at different ages in future studies, e.g., in an in vitro human digestion model, we tried to investigate whether the gut microbiota differs between the young and elderly in Korea. Two hundred fecal samples were collected: 100 from elderly people (over 65 years old) at geriatric nursing hospitals and 100 from young people (university students, 20-25 years old) in Gyeonggi province, Korea. The composition of the gut microbiota in these fecal samples was analyzed by next-generation sequencing methods. There were significant differences in the taxonomic composition of the microbiota (the top 10 most abundant taxa) between the young and elderly people in Korea, especially in terms of relative abundance levels of bacteria in phyla Firmicutes, Proteobacteria, Tenericutes, and Fusobacteria (P < 001). The gut microbiota of young people contained higher relative abundance of Lactobacillus than did the microbiota of elderly people, while the microbiota of elderly people manifested higher relative abundance of Escherichia. Even though the sample size may not be large enough for this study to be representative of the entire population of Korea, the study still provides data that are suggestive of differences in the gut microbiota between young and elderly people in Korea. Furthermore, our findings may be applied to develop an improved age-based in vitro model of digestion of Koreans for future research.

Harnessing the potential of Lactobacillus species for therapeutic delivery at the lumenal-mucosal interface

Lactobacillus species have been studied for over 30 years in their role as commensal organisms in the human gut. Recently there has been a surge of interest in their abilities to natively and recombinantly stimulate immune activities, and studies have identified strains and novel molecules that convey particular advantages for applications as both immune adjuvants and immunomodulators. In this review, we discuss the recent advances in Lactobacillus-related activity at the gut/microbiota interface, the efforts to probe the boundaries of the direct and indirect therapeutic potential of these bacteria, and highlight the continued interest in harnessing the native capacity for the production of biogenic compounds shown to influence nervous system activity. Taken together, these aspects underscore Lactobacillus species as versatile therapeutic delivery vehicles capable of effector production at the lumenal-mucosal interface, and further establish a foundation of efficacy upon which future engineered strains can expand.

Isolation of a Lactobacillus paracasei Strain with Probiotic Attributes from Kefir Grains

Κefir is a rich source of potentially probiotic bacteria. In the present study, firstly, in vitro screening for probiotic characteristics of ten lactic acid bacteria (LAB) isolated from kefir grains was performed. Strain AGR 4 was selected for further studies. Molecular characterization of strain AGR 4, confirmed that AGR 4 belongs to the Lactobacillus paracasei (reclassified to Lacticaseibacillus paracasei subsp. paracasei) species. Further testing revealed that L. paracasei AGR 4 displayed adhesion capacity on human adenocarcinoma cells, HT-29, similar to that of the reference strain, L. casei ATCC 393. In addition, the novel strain exerted significant time- and dose-dependent antiproliferative activity against HT-29 cells and human melanoma cell line, A375, as demonstrated by the sulforhodamine B cytotoxicity assay. Flow cytometry analysis was employed to investigate the mechanism of cellular death; however, it was found that AGR 4 did not act by inducing cell cycle arrest and/or apoptotic cell death. Taken together, these findings promote the probiotic character of the newly isolated strain L. paracasei AGR 4, while further studies are needed for the detailed description of its biological properties.

A Novel Major Pilin Subunit Protein FimM Is Involved in Adhesion of Bifidobacterium longum BBMN68 to Intestinal Epithelial Cells

Adhesion to the gastrointestinal tract is considered to be important for bifidobacteria to colonize the human gut and exert their probiotic effects. Some cell surface proteins of bifidobacteria, known as adhesins, play critical roles in the binding to host cells or the extracellular matrix (ECM). To elucidate the mechanisms associated with the adhesion of Bifidobacterium longum BBMN68, a centenarian originated potential probiotic, PSORTdb was employed to identify putative extracellular localized proteins in the B. longum BBMN68. Of the 560 predicted extracellular proteins, 21 were further identified as putative adhesion proteins using the conserved domain database of NCBI, and four were successfully overexpressed in the heterologous host, Lactococcus lactis NZ9000. Notably, a recombinant strain expressing FimM showed a significantly increased adhesive affinity for both HT-29 and mucus-secreting LS174T goblet cells (2.2- and 5.4-fold higher than that of the control strain, respectively). Amino acid sequence alignment showed that FimM is a major pilin subunit protein containing a Cna-B type domain and a C-terminal LPKTG sequence. However, in silico analysis of the fimM-coding cluster revealed that BBMN68_RS10200, encoding a pilus-specific class C sortase, was a pseudogene, indicating that FimM may function as a surface adhesin that cannot polymerize into a pili-like structure. Immunogold electron microscopy results further confirmed that FimM localized to the surface of L. lactis NZfimM and B. longum BBMN68 but did not assemble into pilus filaments. Moreover, the adhesive affinity of L. lactis NZfimM to fibronectin, fibrinogen, and mucin were 3.8-, 2.1-, and 3.1-fold higher than that of the control. The affinity of FimM for its attachment receptors was further verified through an inhibition assay using anti-FimM antibodies. In addition, homologs of FimM were found in Bifidobacterium bifidum 85B, Bifidobacterium gallinarum CACC 514, and 23 other B. longum strains by sequence similarity analysis using BLASTP. Our results suggested that FimM is a novel surface adhesin that is mainly present in B. longum strains.

Probiotics and prebiotics in non-bovine milk

Probiotics are live microorganisms that, when administered in adequate numbers, confer health benefit/s on the host, while prebiotics are nondigestible food ingredients that are selectively stimulate the growth of beneficial microorganisms in the distal parts of the host digestive tract conferring health benefits. Dairy products manufactured mainly using bovine milk is the major vehicle in delivering probiotics to humans. At present, there is an increasing demand for non-bovine probiotic milk products. Both bovine and non-bovine dairy products contain several ingredients with prebiotic properties such as oligosaccharides that could positively interact with probiotics to alter their functional properties. Furthermore, these bovine and non-bovine products could be fortified with prebiotics from various sources such as inulin and oligofructose in order to provide additional health benefits. In addition, non-bovine milk products are good sources for isolating novel potential probiotics. Non-bovine milk such as goat, sheep, camel and donkey have been used in producing several probiotic products including set-yoghurt, drinking-yoghurt, stirred-yoghurt, ice cream and cheese. Prebiotic inclusions in non-bovine milk at present is mainly associated with goat and sheep milk products. In this context, this chapter focuses on the different types of non-bovine milk products containing probiotics and prebiotics, and product quality and microbiological characteristics with special reference to probiotic viability.

Antibiofilm Activity of Lactobacillus plantarum 12 Exopolysaccharides against Shigella flexneri

In developing countries, Shigella flexneri is the most common enteric pathogen causing bacillary dysentery. Biofilm formation by S. flexneri can cause the emergence of antibiotic-resistant strains, which poses serious threats to food safety and human health. In this study, the effects of Lactobacillus plantarum 12 exopolysaccharides (L-EPSs) and S. flexneri exopolysaccharides (S-EPSs) on S. flexneri CMCC51574 biofilm formation were investigated. The results showed that L-EPS could decrease polysaccharide production in the extracellular polymeric matrix of S. flexneri and inhibit biofilm formation by S. flexneri L-EPS could decrease the minimum biofilm elimination concentration (MBEC) of antibiotics against S. flexneri biofilm and inhibit S. flexneri adhesion to and invasion into HT-29 cell monolayers, which might be ascribed to S. flexneri biofilm disturbance by L-EPS. In contrast, S-EPS exhibited the opposite effects compared to L-EPS. The monosaccharide composition analysis showed that L-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, galactose, and xylose, with the molar ratio of 32.26:0.99:1.79:5.63:0.05:4.07, while S-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, and galactose, with the molar ratio of 25.43:2.28:7.13:5.35. L-EPS was separated into the neutral polysaccharide L-EPS 1-1 and the acidic polysaccharide L-EPS 2-1 by ion-exchange chromatography and gel chromatography. L-EPS 2-1 exerted higher antibiofilm activity than L-EPS 1-1. The antibiofilm activity of L-EPS might be associated with its structure.IMPORTANCES. flexneri is a widespread foodborne pathogen causing food contamination and responsible for food poisoning outbreaks related to various foods in developing countries. Not only has biofilm formation by S. flexneri been difficult to eliminate, but it has also increased the drug resistance of the strain. In the present study, it was demonstrated that L-EPSs secreted by Lactobacillus plantrum 12 could inhibit S. flexneri biofilm formation on, adhesion to, and invasion into HT-29 cells. Also, L-EPSs could decrease the minimum biofilm elimination concentration (MBEC) of the antibiotics used against S. flexneri biofilm. Therefore, L-EPSs were shown to be bioactive macromolecules with the potential ability to act against S. flexneri infections.

In Vitro Antibiofilm and Anti-Inflammatory Properties of Bacteriocins Produced by Pediococcus acidilactici Against Enterococcus faecalis

Although Enterococcus faecalis is known as a commensal microorganism in the gastrointestinal tract, it is linked to various foodborne infections. In addition, biofilm formation in E. faecalis is associated with the infections by exacerbating inflammation. Hence, we demonstrated that bacteriocins produced by Pediococcus acidilactici exhibited antibiofilm and anti-inflammatory activities against E. faecalis. Bacteriocins of P. acidilactici K10 and HW01 strains significantly reduced biofilm formation by E. faecalis on surfaces of polystyrene (p < 0.005 and p < 0.01 at 24 h, respectively) and stainless steel (p < 0.005 and p < 0.01 at 72 h, respectively), while both bacteriocins did not effectively reduce the growth of E. faecalis planktonic cells. Moreover, extracellular polymeric substances (EPSs) produced by E. faecalis were substantially decreased in the presence of P. acidilactici bacteriocin (p < 0.005), suggesting that E. faecalis biofilm formation was reduced by decreasing the production of EPSs, but not by killing bacteria. The bacteriocin of P. acidilactici also reduced the adhesion of E. faecalis to human intestinal epithelial cells (p < 0.005). Furthermore, both bacteriocins significantly inhibited E. faecalis-induced interleukin-8 production in human intestinal epithelial cells (p < 0.01 for K10 bacteriocin and p < 0.005 for HW01 bacteriocin). These results suggest that the bacteriocin of P. acidilactici can eradicate E. faecalis biofilms and inhibit the E. faecalis-induced inflammatory response in intestinal epithelial cells.

Secretome-Mediated Interactions with Intestinal Epithelial Cells: A Role for Secretome Components from Lactobacillus rhamnosus R0011 in the Attenuation of Salmonella enterica Serovar Typhimurium Secretome and TNF-α-Induced Proinflammatory Responses

Recent evidence suggests that lactic acid bacteria communicate with host cells via secretome components to influence immune responses but less is known about gut-pathogen secretomes, impact of lactic acid bacteria secretomes on host-pathogen interactions, and the mechanisms underlying these interactions. Genome-wide microarrays and cytokine profiling were used to interrogate the impact of the Lactobacillus rhamnosus R0011 secretome (LrS) on TNF-α and Salmonella enterica subsp. enterica serovar Typhimurium secretome (STS)-induced outcomes in human intestinal epithelial cells. The LrS attenuated both TNF-α- and STS-induced gene expression involved in NF-κB and MAPK activation, as well as expression of genes involved in other immune-related signaling pathways. Specifically, the LrS induced the expression of dual specificity phosphatase 1 (DUSP1), activating transcription factor 3 (ATF3), and tribbles pseudokinase 3 (TRIB3), negative regulators of innate immune signaling, in HT-29 intestinal epithelial cells challenged with TNF-α or STS. TNF-α- and STS-induced acetylation of H3 and H4 histones was attenuated by the LrS, as was the production of TNF-α- and STS-induced proinflammatory cytokines and chemokines. Interestingly, the LrS induced production of macrophage migration inhibitory factor (MIF), a cytokine involved in host-microbe interactions at the gut interface. We propose that the LrS attenuates proinflammatory mediator expression through increased transcription of negative regulators of innate immune activity and changes in global H3 and H4 histone acetylation. To our knowledge, these findings provide novel insights into the complex multifaceted mechanisms of action behind secretome-mediated interdomain communication at the gut-mucosal interface.

Characterization and probiotic properties of Lactobacilli from human breast milk

Several studies have reported a complex microbial community in human breast milk. This community impacts the shape of the infant gut microbiota and consequently impacts host health. Lactobacillus is an important probiotic and has many applications in the functional food industry. This study isolated and evaluated the potential probiotic bacteria from human milk. Two Lactobacillus species, L. plantarum and L. pentosus, were isolated from the breast milk of Thai women. L. pentosus HM04-22, L. pentosus HM04-3, L. plantarum HM04-80, L. plantarum HM04-88 and L. plantarum HM01-1 showed good adhesion activity (> 55%) and resistance in gastric (pH 2) and bile (pH 8) conditions. Characterization of the probiotic properties indicated that all selected Lactobacillus isolates had anti-adhesion properties against Escherichia coli and Salmonella Typhimurium. Lactobacillus isolates protected Caco-2 cells from pathogen adhesion at 25-40%. In addition, the five selected strains presented anti-inflammatory properties by reducing interleukin (IL)-8 expression at 0.14 ± 0.16 to 0.52 ± 0.117-fold. However, the strains had no effect on the expression of tight junction genes, including zona occludens (ZO)-1, occludin and claudin-1. In conclusion, five selected Lactobacillus isolates from human milk were candidates for use as probiotics to promote health. However, more tests in animal models and clinical trials need to be performed.

Adhesion mechanisms mediated by probiotics and prebiotics and their potential impact on human health

Adhesion ability to the host is a classical selection criterion for potential probiotic bacteria that could result in a transient colonisation that would help to promote immunomodulatory effects, as well as stimulate gut barrier and metabolic functions. In addition, probiotic bacteria have a potential protective role against enteropathogens through different mechanisms including production of antimicrobial compounds, reduction of pathogenic bacterial adhesion and competition for host cell binding sites. The competitive exclusion by probiotic bacteria has a beneficial effect not only on the gut but also in the urogenital tract and oral cavity. On the other hand, prebiotics may also act as barriers to pathogens and toxins by preventing their adhesion to epithelial receptors. In vitro studies with different intestinal cell lines have been widely used along the last decades to assess the adherence ability of probiotic bacteria and pathogen antagonism. However, extrapolation of these results to in vivo conditions still remains unclear, leading to the need of optimisation of more complex in vitro approaches that include interaction with the resident microbiota to address the current limitations. The aim of this mini review is to provide a comprehensive overview on the potential effect of the adhesive properties of probiotics and prebiotics on the host by focusing on the most recent findings related with adhesion and immunomodulatory and antipathogenic effect on human health.

Potential prebiotics and their transmission mechanisms: Recent approaches

Prebiotics are non-digestible carbohydrates which can be used as prime source of energy for gut microflora. These can be naturally occurring in fruit and vegetables or can be made synthetically by enzymatic digestions. New versatile sources of prebiotics had been found nowadays for economic commercialization. This review will decipher on highlighting the importance of prebiotics in immunomodulation and nutrient absorption abilities of gut, as it is important for the anti-effective capacity of the organism especially in the neonatal period. Moreover, new prebiotics transmission strategies with higher penetrating capacity such as microencapsulation and immobilization have been discussed. In addition to this, literature had shown the modulation of gut microflora by the continuous use of prebiotics in many disorders so here, the role of prebiotics in health-related issues such as diabetes and inflammatory bowel disease (IBS) have been explained.

Mechanisms by Which the Gut Microbiota Influences Cytokine Production and Modulates Host Inflammatory Responses

The gastrointestinal tract encounters a wide variety of microorganisms, including beneficial symbionts, pathobionts, and pathogens. Recent evidence has shown that the gut microbiota, directly or indirectly through its components, such as metabolites, actively participates in the host inflammatory response by cytokine-microbiota or microbiota-cytokine modulation interactions, both in the gut and systemically. Therefore, further elucidation of host cytokine molecular pathways and microbiota components will provide a novel and promising therapeutic approach to control or prevent inflammatory disease and to maintain host homeostasis. The purpose of this review is to summarize well-established scientific findings and provide an updated overview regarding the direct and indirect mechanisms by which the gut microbiota can influence the inflammatory response by modulating the host's cytokine pathways that are mostly involved, but not exclusively so, with gut homeostasis. In addition, we will highlight recent results from our group, which suggest that the microbiota promotes cytokine release from inflammatory cells though activation of microbial metabolite sensor receptors that are more highly expressed on inflammatory and intestinal epithelial cells.

The ameliorative effect of a Lactobacillus strain with good adhesion ability against dextran sulfate sodium-induced murine colitis

The objective of this study was to effectively screen out a Lactobacillus strain with excellent adhesion ability and ameliorative effect on the disease symptoms of a murine ulcerative colitis model.

A Surface Protein From Lactobacillus plantarum Increases the Adhesion of Lactobacillus Strains to Human Epithelial Cells

Adhesion to epithelial cells is considered important for Lactobacillus to exert probiotic effects. In this study, we found that trypsin treatment decreased the adhesion ability of Lactobacillus plantarum AR326 and AR269, which exhibit good adhesion ability, and surface proteins extracts increased the adhesion of the strains with poor adhesion ability. By SDS–polyacrylamide gel electrophoresis and mass spectrometry analysis, the main component of the surface proteins was detected and identified as a protein of approximately 37 kDa. It was 100% homologous with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from L. plantarum WCFS1. The adhesion of AR326 and AR269 was decreased significantly by blocking with the anti-GAPDH antibody, and GAPDH restored the adhesion of AR326 and AR269 treated with trypsin. In addition, purified GAPDH significantly increased the adhesion of the strains with poor adhesion ability. These results indicated that GAPDH mediates the adhesion of these highly adhesive lactobacilli to epithelial cells and can be used to improve the adhesion ability of probiotics or other bacteria of interest.