Probiotics: properties, examples, and specific applications

Mucosal adjuvanticity and mucosal booster effect of colibactin-depleted probiotic Escherichia coli membrane vesicles

There is a growing interest in development of novel vaccines against respiratory tract infections, due to COVID-19 pandemic. Here, we examined mucosal adjuvanticity and the mucosal booster effect of membrane vesicles (MVs) of a novel probiotic E. coli derivative lacking both flagella and potentially carcinogenic colibactin (ΔflhDΔclbP). ΔflhDΔclbP-derived MVs showed rather strong mucosal adjuvanticity as compared to those of a single flagellar mutant strain (ΔflhD-MVs). In addition, glycoengineered ΔflhDΔclbP-MVs displaying serotype-14 pneumococcal capsular polysaccharide (CPS14+MVs) were well-characterized based on biological and physicochemical parameters. Subcutaneous (SC) and intranasal (IN) booster effects of CPS14+MVs on systemic and mucosal immunity were evaluated in mice that have already been subcutaneously prime-immunized with the same MVs. With a two-dose regimen, an IN boost (SC-IN) elicited stronger IgA responses than homologous prime-boost immunization (SC-SC). With a three-dose regimen, serum IgG levels were comparable among all tested regimens. Homologous immunization (SC-SC-SC) elicited the highest IgM responses among all regimens tested, whereas SC-SC-SC failed to elicit IgA responses in blood and saliva. Furthermore, serum IgA and salivary SIgA levels were increased with an increased number of IN doses administrated. Notably, SC-IN-IN induced not only robust IgG response, but also the highest IgA response in both serum and saliva among the groups. The present findings suggest the potential of a heterologous three-dose administration for building both systemic and mucosal immunity, e.g. an SC-IN-IN vaccine regimen could be beneficial. Another important observation was abundant packaging of colibactin in MVs, suggesting increased applicability of ΔflhDΔclbP-MVs in the context of vaccine safety.

Construction and characterization of a hypervesiculation strain of Escherichia coli Nissle 1917

Outer membrane vesicles (OMVs) are produced by Gram-negative bacteria and deliver microbial molecules to distant target cells in a host. OMVs secreted by probiotic probiotic strain Escherichia coli Nissle 1917 (EcN) have been reported to induce an immune response. In this study, we aimed to increase the OMV production of EcN. The double gene knockout of mlaE and nlpI was conducted in EcN because the ΔmlaEΔnlpI of experimental strain E. coli K12 showed the highest OMV production in our previous report. The ΔmlaEΔnlpI of EcN showed approximately 8 times higher OMV production compared with the parental (wild-type) strain. Quick-freeze, deep-etch replica electron microscopy revealed that plasmolysis occurred in the elongated ΔmlaEΔnlpI cells and the peptidoglycan (PG) had numerous holes. While these phenomena are similar to the findings for the ΔmlaEΔnlpI of K12, there were more PG holes in the ΔmlaEΔnlpI of EcN than the K12 strain, which were observed not only at the tip of the long axis but also in the whole PG structure. Further analysis clarified that the viability of ΔmlaEΔnlpI of EcN decreased compared with that of the wild-type. Although the amount of PG in ΔmlaEΔnlpI cells was about half of that in wild-type, the components of amino acids in PG did not change in ΔmlaEΔnlpI. Although the viability decreased compared to the wild-type, the ΔmlaEΔnlpI grew in normal culture conditions. The hypervesiculation strain constructed here is expected to be used as an enhanced probiotic strain.

The live biotherapeutic SYNB1353 decreases plasma methionine via directed degradation in animal models and healthy volunteers

Methionine is an essential proteinogenic amino acid, but its excess can lead to deleterious effects. Inborn errors of methionine metabolism resulting from loss of function in cystathionine β-synthase (CBS) cause classic homocystinuria (HCU), which is managed by a methionine-restricted diet. Synthetic biotics are gastrointestinal tract-targeted live biotherapeutics that can be engineered to replicate the benefits of dietary restriction. In this study, we assess whether SYNB1353, an E. coli Nissle 1917 derivative, impacts circulating methionine and homocysteine levels in animals and healthy volunteers. In both mice and nonhuman primates (NHPs), SYNB1353 blunts the appearance of plasma methionine and plasma homocysteine in response to an oral methionine load. A phase 1 clinical study conducted in healthy volunteers subjected to an oral methionine challenge demonstrates that SYNB1353 is well tolerated and blunts plasma methionine by 26%. Overall, SYNB1353 represents a promising approach for methionine reduction with potential utility for the treatment of HCU.

The effects of synbiotic supplementation on blood pressure and other maternal outcomes in pregnant mothers with mild preeclampsia: a triple-blinded randomized controlled trial

INTRODUCTION

Preeclampsia affects a significant percentage of pregnancies which is a leading cause of premature birth. Probiotics have the potential to affect inflammatory factors, and oxidative stress, which are linked to the development of preeclampsia. The study aimed to compare the effect of synbiotic and placebo on blood pressure and pregnancy duration as primary outcomes, and other pregnancy outcomes.

METHODS

This study comprised 128 pregnant women with mild preeclampsia and gestational ages exceeding 24 weeks who were referred to the high-risk pregnancy clinic. It was a randomized, controlled, phase III, triple-blinded clinical experiment. The intervention and control groups were distributed to the participants at random. Intervention group received one oral synbiotic capsule, and control group received placebo daily until delivery. Based on gestational age at the time of diagnosis, preeclampsia was stratificated as early (< 34 weeks) or late (≥ 34 weeks). Data obtained from questionnaires, and biochemical serum factors were analyzed using SPSS software version 23 software.

RESULTS

With the exception of the history of taking vitamin D3, there were no statistically significant variations in socio-demographic variables between the research groups. After the intervention, the means of systolic blood pressure (adjusted mean difference: -13.54, 95% CI: -5.01 to -22.07), and diastolic blood pressure (adjusted mean difference: -10.30, 95% CI: -4.70 to -15.90) were significantly lower in the synbiotic-supplemented group than in the placebo group. Compared to the placebo group, the incidence of severe PE (p < 0.001), proteinuria (p = 0.044), and mean serum creatinine level (p = 0.005) significantly declined in the synbiotic-supplemented group after the intervention. However, our analysis found no significant association for other outcomes.

CONCLUSION

Based on our results, synbiotic had beneficial effects on some pregnancy outcomes. Further studies with larger samples are needed to verify the advantages of synbiotic supplementation for high-risk pregnancies, particularly with regards to higher doses, and longer intervention periods.

TRIAL REGISTRATION

IRCT20110606006709N20.

Intratumoural microbiota: a new frontier in cancer development and therapy

Human microorganisms, including bacteria, fungi, and viruses, play key roles in several physiological and pathological processes. Some studies discovered that tumour tissues once considered sterile actually host a variety of microorganisms, which have been confirmed to be closely related to oncogenesis. The concept of intratumoural microbiota was subsequently proposed. Microbiota could colonise tumour tissues through mucosal destruction, adjacent tissue migration, and hematogenic invasion and affect the biological behaviour of tumours as an important part of the tumour microenvironment. Mechanistic studies have demonstrated that intratumoural microbiota potentially promote the initiation and progression of tumours by inducing genomic instability and mutations, affecting epigenetic modifications, promoting inflammation response, avoiding immune destruction, regulating metabolism, and activating invasion and metastasis. Since more comprehensive and profound insights about intratumoral microbiota are continuously emerging, new methods for the early diagnosis and prognostic assessment of cancer patients have been under examination. In addition, interventions based on intratumoural microbiota show great potential to open a new chapter in antitumour therapy, especially immunotherapy, although there are some inevitable challenges. Here, we aim to provide an extensive review of the concept, development history, potential sources, heterogeneity, and carcinogenic mechanisms of intratumoural microorganisms, explore the potential role of microorganisms in tumour prognosis, and discuss current antitumour treatment regimens that target intratumoural microorganisms and the research prospects and limitations in this field.

Research Progress for Probiotics Regulating Intestinal Flora to Improve Functional Dyspepsia: A Review

Functional dyspepsia (FD) is a common functional gastrointestinal disorder. The pathophysiology remains poorly understood; however, alterations in the small intestinal microbiome have been observed. Current treatments for FD with drugs are limited, and there are certain safety problems. A class of active probiotic bacteria can control gastrointestinal homeostasis, nutritional digestion and absorption, and the energy balance when taken in certain dosages. Probiotics play many roles in maintaining intestinal microecological balance, improving the intestinal barrier function, and regulating the immune response. The presence and composition of intestinal microorganisms play a vital role in the onset and progression of FD and serve as a critical factor for both regulation and potential intervention regarding the management of this condition. Thus, there are potential advantages to alleviating FD by regulating the intestinal flora using probiotics, targeting intestinal microorganisms. This review summarizes the research progress of probiotics regarding improving FD by regulating intestinal flora and provides a reference basis for probiotics to improve FD.

Revisiting the Intestinal Microbiome and Its Role in Diarrhea and Constipation

The gut microbiota represents a community of microorganisms (bacteria, fungi, archaea, viruses, and protozoa) that colonize the gut and are responsible for gut mucosal structural integrity and immune and metabolic homeostasis. The relationship between the gut microbiome and human health has been intensively researched in the past years. It is now widely recognized that gut microbial composition is highly responsible for the general health of the host. Among the diseases that have been linked to an altered gut microbial population are diarrheal illnesses and functional constipation. The capacity of probiotics to modulate the gut microbiome population, strengthen the intestinal barrier, and modulate the immune system together with their antioxidant properties have encouraged the research of probiotic therapy in many gastrointestinal afflictions. Dietary and lifestyle changes and the use of probiotics seem to play an important role in easing constipation and effectively alleviating diarrhea by suppressing the germs involved. This review aims to describe how probiotic bacteria and the use of specific strains could interfere and bring benefits as an associated treatment for diarrhea and constipation.

Probing the functional and therapeutic properties of postbiotics in relation to their industrial application

Functional foods are gaining significant research attention of researchers due to their health-endorsing properties due to their bioactive components either living cells (probiotics) or nonviable cells (prebiotics). The term "postbiotic" specifies the soluble substances, such as enzymes, peptides, teichoic acids, muropeptides derived from peptidoglycans, polysaccharides, cell surface proteins, and organic acids, that are secreted by living bacteria or released after bacterial lysis. Due to various signaling molecules which may have antioxidant, immunomodulatory, antiinflammatory, antihypertensive, and antiproliferative activities, postbiotics offer great potential to be used in pharmaceutical, food, and nutraceutical industries, to promote health and ailment prevention. This recent review is a landmark of information relevant to the production of postbiotics along with salient features to use in various fields ranging from food to immunomodulation and selective and effective therapy. It also puts forward the concept that postbiotics are way more effective than probiotics in the veterinary, food as well as medical field which ultimately helps in reducing the disease burden along with human health.

Effect of Lactobacillus sakei OK67 in Reducing Body and Visceral Fat in Lifestyle-Modified Overweight Individuals: A 12-Week, Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Obesity is a global health problem that affects the quality of life. It is a multidimensional chronic risk factor for major medical conditions, such as cardiovascular diseases, diabetes, and cancer. This clinical trial evaluated the efficacy of Lactobacillus sakei OK67 (DW2010), a lactic acid bacterium, in reducing body and visceral fat in overweight individuals (body mass index ≥25 kg/m² and <30 kg/m²), aged 20-60 years. A total of 100 subjects placed in a lifestyle modification program were randomly assigned to receive either DW2010 (2.0 g/day, 1.0 × 10¹⁰ CFU) or a placebo for 12 weeks. The efficacy of DW2010 was evaluated by measuring body fat mass using dual-energy X-ray absorptiometry and visceral fat area using computed tomography. After 12 weeks, the change in body fat in the DW2010 group was not markedly different from that in the placebo group. However, visceral fat area decreased more in the DW2010 group than in the placebo group (p = 0.035). During the clinical trial, no major adverse events were reported. Moreover, no statistical differences were observed in the biochemical parameters of the DW2010 and placebo groups. Overall, we concluded that the intake of DW2010 for 12 weeks is safe and potentially reduces visceral fat in lifestyle-modified overweight subjects.

Gut microbiome homeostasis and the future of probiotics in cancer immunotherapy

The gut microbiome has an impact on cancer immune surveillance and immunotherapy, with recent studies showing categorical differences between immunotherapy-sensitive and immunotherapy-resistant cancer patient cohorts. Although probiotics are traditionally being supplemented to promote treatments or sustain therapeutic benefits; the FDA has not approved any for use with immunotherapy. The first step in developing probiotics for immunotherapy is identifying helpful or harmful bacteria down to the strain level. The gut microbiome's heterogeneity before and during treatment is also being investigated to determine microbial strains that are important for immunotherapy. Moreover, Dietary fiber intake, prebiotic supplementation and fecal microbiota transplantation (FMT) were found to enhance intratumoral CD8+ T cell to T-reg ratio in the clinics. The possibility of probiotic immunotherapy as a "living adjuvant" to CAR treatment and checkpoint blockade resistance is actively being investigated.

The Combined Effect of Potential Probiotic Bacillus licheniformis MCC 2514 and Bifidobacterium breve NCIM 5671 Towards Anti-inflammatory Activity on HT-29 Cell Lines

Probiotics are considered a natural source for treating many intestinal disorders, which deliver health benefits in different ways. The study aims to evaluate the immunomodulatory gene expression on HT-29 cell line using Bacillus licheniformis MCC 2514 and Bifidobacterium breve NCIM 5671 as a single culture and in combination. Upon inflammation induced by LPS, the combination of bacteria downregulated the pro-inflammatory cytokines IL-1α (13.4), IL-12 (14.6), IL-8 (2.6), and IL-6 (1.9), and in contrast, TNF-α (21.2) folds has upregulated. However, anti-inflammatory genes such as IL-4 (0.6), IL-10 (2.9), TGF-2 (92.2), and TGF-3 (85.8) folds were upregulated. The combination of bacteria against oxidative stress downregulated the pro-inflammatory cytokines such as IL-1α & β, IL-6, IL-8, IL-12, and IL-18, and upregulated the anti-inflammatory cytokines IL-10, IL-4, TGF-2, and TGF-3. On the introduction of Kocuria rhizophila, the pro-inflammatory cytokines were upregulated. On supplementation of B. licheniformis and B. breve, the upregulated pro-inflammatory cytokines were decreased, and anti-inflammatory cytokines such as IL-4 (6.2), IL-10 (23.5), TGF-2 (166), and TGF-3(28.4) folds were increased. However, gene expression of toll-like receptor-2 was found high (26 folds) upon introducing probiotic bacteria. ELISA results of Interferon-γ found that the expression was higher (7.19 ng/mL) on the introduction of both the bacteria in combination. The higher anti-inflammatory activity was observed when potential probiotic bacteria were used in combination compared to a single culture. Overall study indicates that the combination of aerobic B. licheniformis and anaerobic B. breve has an anti-inflammatory activity that can sustain an excellent gastrointestinal environment during pathogen invasion and inflammation.

Comprehensive Analysis of the Physiological Characterization of Escherichia coli Nissle 1917

Escherichia coli Nissle 1917 (EcN) is one of the probiotics that has drawn more attention from researchers in recent days as it extends many host beneficial effects. EcN is being used as a treatment regimen especially for gastrointestinal disorders for more than 100 years. Apart from its clinical applications in its original form, EcN is being genetically engineered to meet the therapeutic requirements which ultimately led to the gradual transformation of EcN from being a mere food supplement to a complex therapeutic agent. However, comprehensive analysis of physiological characterization of EcN is inadequate. In this study, we have systematically studied various physiological parameters and found that EcN grows very well at the normal as well as at stressful conditions such as temperature (30, 37 and 42 °C), nutritional (minimal and LB), pH (ranging from 3 to 7) and osmotic stress (0.4 M NaCl, 0.4 M KCl, 0.4 M Sucrose and salt conditions). However, EcN shows nearly onefold reduction in viability at extreme acidic conditions (pH 3 and 4). It produces biofilm and curlin very efficiently compared to the laboratory strain MG1655. Through genetic analysis we have also shown that EcN exhibits high level of transformation efficiency and greater ability to retain heterogenous plasmid. Very interestingly, we have found that EcN is highly resistant to P1 phage infection. Since, EcN is being exploited largely for its clinical and therapeutic applications, the results that we have reported here would add more value and further expand its scope in clinical and biotechnological research.

Microbiome-Induced Autoimmunity and Novel Therapeutic Intervention

Microorganisms' flora, which colonize in many parts of our body, stand out as one of the most important components for a healthy life. This microbial organization called microbiome lives in integration with the body as a single and whole organ/system. Perhaps, the human first encounters the microbial activity it carries through the immune system. This encounter and interaction are vital for the development of immune system cells that protect the body against pathogenic organisms and infections throughout life. In recent years, it has been determined that some disruptions in the host-microbiome interaction play an important role in the physiopathology of autoimmune diseases. Although the details of this interaction have not been clarified yet, the focus is on leaky gut syndrome, dysbiosis, toll-like receptor ligands, and B cell dysfunction. Nutritional regulations, prebiotics, probiotics, fecal microbiota transplantation, bacterial engineering, and vaccination are being investigated as new therapeutic approaches in the treatment of problems in these areas. This article reviews recent research in this area.

Probiotics' effect on visceral and subcutaneous adipose tissue: a systematic review of randomized controlled trials

Probiotics are shown to alter the microbiota, leading to a favorable environment, in which weight loss and metabolic parameters are improve. However, the results on probiotics' effect on specific types of central adipose tissues, mainly visceral (VAT) and subcutaneous adipose tissue (SAT), are conflicting. Therefore, we conducted a systematic review, aimed to evaluate the effects of probiotics on VAT and SAT. PubMed, SCOPUS, EBSCO, and LILACS databases were searched for studies that investigated the effect of probiotics on VAT and SAT. Fixed effects were used to calculate the pooled difference in means (DM) and 95% confidence intervals (95%CI). Fourteen publications met the inclusion criteria, which consisted of 1523 participants. For VAT, overall, there was a significant decrease (DM = -3.63 cm2, 95% CI: -5.08 to -2.17, p < 0.001). When stratified by type of probiotic, single Bifidobacterium (DM = -4.49 cm2, 95% CI:-7.37 to -1.61, p = 0.002) and single Lactobacillus probiotics (DM = -3.84 cm2, 95% CI:-5.74 to -1.93, p < 0.001) resulted in significant reductions. Mixed probiotics had no effect. For SAT, overall, there was a significant decrease (DM = -2.91 cm2, 95% CI:-4.82 to -1.01, p = 0.003), and when stratified by type of probiotic, single Lactobacillus (DM = -3.39 cm2, 95% CI:-5.90 to -0.88, p = 0.008) and mixed probiotics (DM = -5.97 cm2, 95% CI:-10.32 to -1.62, p = 0.007) resulted in a significant decrease. Single Bifidobacterium probiotics had no effect. Using meta-regression, no association was observed between the total daily probiotic dose and VAT or SAT reduction. This study shows that probiotics have a beneficial effect on central adiposity. Single Lactobacillus-based probiotics reduced VAT and SAT, whereas Bifidobacterium-based probiotics reduce VAT.

Probiotic effects of Pseudoalteromonas ruthenica: Antibacterial, immune stimulation and modulation of gut microbiota composition

This study aimed to characterise and evaluate the probiotic properties of a newly isolated marine bacterium, strain S6031. The isolated strain was identified as Pseudoalteromonas ruthenica. In vivo experiments were conducted with P. ruthenica-immersed larvae and P. ruthenica-enriched Artemia fed to adult zebrafish. Disease tolerance of larval zebrafish against Edwardsiella piscicida was demonstrated by 66.34% cumulative per cent survival (CPS) in the P. ruthenica-exposed group, which was higher than the CPS of the control (46.67%) at 72 h post challenge (hpc). Heat-stressed larvae had 55% CPS in the P. ruthenica-immersed group, while the control had 30% CPS at 60 hpc. Immune-stress response gene transcripts (muc5.1, muc5.2, muc5.3, alpi2, alpi3, hsp70, and hsp90a) were induced, while pro-inflammatory genes (tnfα, il1b, and il6) were downregulated in P. ruthenica-immersed larvae compared to the control. This trend was confirmed by low pro-inflammatory and high stress-responsive protein expression levels in P. ruthenica-exposed larvae. Adult zebrafish had higher CPS (27.2%) in the P. ruthenica-fed group than the control (9.52%) upon E. piscicida challenge, suggesting increased disease tolerance. Histological analysis demonstrated modulation of goblet cell density and average villus height in the P. ruthenica-supplemented group. Metagenomics analysis clearly indicated modulation of alpha diversity indices and the relative abundance of Proteobacteria in the P. ruthenica-supplemented zebrafish gut. Furthermore, increased Firmicutes colonisation and reduced Bacteroidetes abundance in the gut were observed upon P. ruthenica supplementation. Additionally, this study confirmed the concentration-dependent increase of colony dispersion and macrophage uptake upon mucin treatment. In summary, P. ruthenica possesses remarkable functional properties as a probiotic that enhances host defence against diseases and thermal stress.

Chinese patent medicine shouhui tongbian capsule attenuated loperamide-induced constipation through modulating the gut microbiota in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Shouhui tongbian capsule (SHTC) is a commercial Chinese patent medicine used in the treatment of constipation. However, its mechanism of action remains unclear.

AIM OF THE STUDY

The present study was undertaken to assess SHTC relieved effects on the clinical symptoms of loperamide (LOP) induced constipation in Sprague Dawley (SD) rat model and to clarify the relationship between the protective effect of SHTC on constipation and the gut microbiota.

MATERIALS AND METHODS

Constipation male SD rats models were induced with solution of LOP (1.5 mg/kg bw), and rats were treated with an oral dose of SHTC (35, 70 mg/kg bw) three times a day after successful modeling. All rats were assessed weekly by change in body weight, gastric emptying rate, fecal moisture content and wet/dry weight. Hematoxylin and eosin (H&E) were used to observe parts of the rats small intestine. The gut microbiota in colonic contents was analyzed using 16SrRNA gene sequencing. Contents of short-chain fatty acids (SCFAs) were analyzed by gas chromatography-mass spectrometer (GCMS).

RESULTS

The results confirmed the therapeutic effects of SHTC on constipation. Specifically, SHTC could alleviate the decrease in body weight, gastric emptying rate and fecal moisture content caused by LOP-induced constipation. The pathological damage of small intestine was significantly improved by H&E staining. Notably, SHTC increased the relative abundances of Lactobacillus and the ratio of Firmicutes to Bacteroides (F/B). In addition, the content of acetic acid and propionic acid was significantly increased in constipated rats fed with SHTC.

CONCLUSION

SHTC could ameliorate the development of LOP-induced constipation in rats by remodeling the structure of gut microbial community and regulating production of intestinal metabolites.

Effect of Probiotic E. coli Nissle 1917 Supplementation on the Growth Performance, Immune Responses, Intestinal Morphology, and Gut Microbes of Campylobacter jejuni Infected Chickens

Campylobacter jejuni is the most common cause of bacterial foodborne gastroenteritis and holds significant public health importance. The continuing increase of antibiotic-resistant Campylobacter necessitates the development of antibiotic-alternative approaches to control infections in poultry and in humans. Here, we assessed the ability of E. coli Nissle 1917 (EcN; free and chitosan-alginate microencapsulated) to reduce C. jejuni colonization in chickens and measured the effect of EcN on the immune responses, intestinal morphology, and gut microbes of chickens. Our results showed that the supplementation of 3-week-old chickens daily with free EcN in drinking water resulted in a 2.0 log reduction of C. jejuni colonization in the cecum, whereas supplementing EcN orally three times a week, either free or microencapsulated, resulted in 2.0 and 2.5 log reductions of C. jejuni colonization, respectively. Gavaged free and microencapsulated EcN did not have an impact on the evenness or the richness of the cecal microbiota, but it did increase the villous height (VH), crypt depth (CD), and VH:CD ratio in the jejunum and ileum of chickens. Further, the supplementation of EcN (all types) increased C. jejuni-specific and total IgA and IgY antibodies in chicken’s serum. Microencapsulated EcN induced the expression of several cytokines and chemokines (1.6 to 4.3-fold), which activate the Th1, Th2, and Th17 pathways. Overall, microencapsulated EcN displayed promising effects as a potential nonantibiotic strategy to control C. jejuni colonization in chickens. Future studies on testing microencapsulated EcN in the feed and water of chickens raised on built-up floor litter would facilitate the development of EcN for industrial applications to control Campylobacter infections in poultry.

The effect of Escherichia coli ŽP strain with a conjugation-based colicin E7 delivery on growth performance, hematological, biochemical, and histological parameters, gut microbiota, and nonspecific immunity of broilers

The Escherichia coli ŽP strain (ŽP) was constructed based on the known probiotic E. coli strain Nissle 1917. It was genetically modified to carry the colicin E7 synthesis gene encoding DNase on a conjugative plasmid and the colicin E7 immunity gene in the chromosome. The aim of this study was to evaluate the effects of the daily ŽP per oral administration (5 × 10⁸ or 5 × 10¹⁰ CFU per bird) on the growth performance, hematological, biochemical, histological parameters, gut microbiota, and nonspecific immunity of the 4-24 days old broilers. The ŽP administration increased the abundance of genera Bacillus, Butyrivibrio, and Clostridium and did not influence the weight gain of 4-16 days old broilers. The biochemical parameters were within normal ranges for poultry in experimental and control groups. The ŽP administration had no effect on the erythrocyte numbers, hemoglobin and immunoglobulin Y concentrations, but significantly increased the serum lysozyme concentration, leukocyte numbers, and reactive oxygen species production by phagocytes compared with the control group. It did not cause inflammatory changes in intestinal mucosa, Peyer's patches, and spleen. Thus, the ŽP had no detrimental effects on broiler health and could be an efficient probiotic for the broiler colibacillosis prophylaxis.

Evaluation of Enterococcus faecalis, Lactobacillus acidophilus, and Lactobacillus plantarum in Biopsy Samples of Colorectal Cancer and Polyp Patients Compared to Healthy People

Background: Colorectal cancer (CRC) is one of the leading causes of death in both men and women worldwide. According to different studies, infectious agents or microbiota dysbiosis can play a role in CRC progression. Objective: This study aimed to evaluate the prevalence of Enterococcus faecalis, Lactobacillus acidophilus, and Lactobacillus plantarum in people with polyps or CRC compared to healthy individuals. Methods: In this study, 60 biopsy samples were collected from three groups, including patients with CRC, polyps, and healthy people. The genomic DNA was extracted from the collected samples and amplified by polymerase chain reaction (PCR) to detect E. faecalis, L. acidophilus, and L. plantarum. In the next step, quantitative Real-Time PCR was used to evaluate the copy number of the bacteria in the studied groups. Results: There was no statistically significant difference between the studied groups regarding age and gender (P > 0.05). The mean number of E. faecalis was higher in patients with CRC than in patients with polyps and healthy individuals (P < 0.05). Also, the mean numbers of L. acidophilus and L. plantarum were higher in healthy individuals than in patients with polyps and CRC (P < 0.05). Conclusions: Our findings indicate that L. acidophilus and L. plantarum in people with a family history of CRC and patients with polyps may effectively prevent or reduce CRC progression.

Synbiotic Effects of Fermented Rice on Human Health and Wellness: A Natural Beverage That Boosts Immunity

Fermented foods have been an important component of the human diet from the time immemorial. It contains a high amount of probiotics that have been associated to a wide range of health benefits, including improved digestion and immunity. This review focuses on the indigenously prepared prebiotic- and probiotic-containing functional fermented rice (named Xaj-pani) by the Ahom Community from Assam, in Northeast India, including all the beneficial and potential effects on human health. Literature was searched from scientific databases such as PubMed, ScienceDirect and Google Scholar. Glutinous rice (commonly known as bora rice of sali variety) is primarily employed to prepare beverages that are recovered through the filtration process. The beer is normally consumed during religious rites, festivals and ritual practices, as well as being used as a refreshing healthy drink. Traditionally, it is prepared by incorporating a variety of medicinal herbs into their starter culture (Xaj-pitha) inoculum which is rich in yeasts, molds and lactic acid bacteria (LAB) and then incorporated in alcoholic beverage fermentation. The Ahom communities routinely consume this traditionally prepared alcoholic drink with no understanding of its quality and shelf life. Additionally, a finally produced dried cake, known as vekur pitha act as a source of Saccharomyces cerevisiae and can be stored for future use. Despite the rampant use in this community, the relationship between Xaj-pani's consumption, immunological response, infectious and inflammatory processes remains unknown in the presence of factors unrelated or indirectly connected to immune function. Overall, this review provides the guidelines to promote the development of prebiotic- and probiotic-containing functional fermented rice that could significantly have an impact on the health of the consumers.

Ruminal bacteria lipopolysaccharides: an immunological and microbial outlook

Lipopolysaccharides (LPS) are outer membrane components of Gram-negative bacteria made of three regions: the O-antigen; the core oligosaccharide; and a glucosamine disaccharide linked to hydroxy fatty acids, which is named lipid A. The number phosphate groups, and hydroxy fatty acid chains is associated with the immunopotency and the immunomodulatory activity of LPS, where six-acyl chain lipid A with two phosphate groups is found in virulent strains and five- or four-acyl chain lipid A with one phosphate group are found in non-virulent bacteria strains. Ruminal bacteria are predominantly Gram-negative and their LPS have not been thoroughly investigated. In the rumen, LPS is comprised of mixed ruminal LPS. Drawing upon a body of theoretical and applied work, this paper aims to critically review the scientific literature regarding single-species and mixed ruminal bacteria LPS, highlighting the importance of ruminal LPS to the host. Lastly, future research directions are suggested in order to further our understanding of the roles of LPS in the rumen. Possible suggestions for further understanding ruminal LPS include (1) in silico evaluation of major bacteria contributing to ruminal LPS, (2) structural characterization of LPS from prominent ruminal bacteria species, such as ruminal selenomonads and Megasphaera elsdenii, and, (3) ruminal epithelial tissue immune response evaluation from single-species and mixed ruminal LPS. In conclusion, this review identifies numerous areas for future research, including setting the basis for future modeling and simulation of host microbiome interactions in ruminants.

Microcins reveal natural mechanisms of bacterial manipulation to inform therapeutic development

Microcins are an understudied and poorly characterized class of antimicrobial peptides. Despite the existence of only 15 examples, all identified from the Enterobacteriaceae, microcins display diversity in sequence, structure, target cell uptake, cytotoxic mechanism of action and target specificity. Collectively, these features describe some of the unique means nature has contrived for molecules to cross the 'impermeable' barrier of the Gram-negative bacterial outer membrane and inflict cytotoxic effects. Microcins appear to be widely dispersed among different species and in different environments, where they function in regulating microbial communities in diverse ways, including through competition. Growing evidence suggests that microcins may be adapted for therapeutic uses such as antimicrobial drugs, microbiome modulators or facilitators of peptide uptake into cells. Advancing our biological, ecological and biochemical understanding of the roles of microcins in bacterial interactions, and learning how to regulate and modify microcin activity, is essential to enable such therapeutic applications.

Precise Thermal Regulation of Engineered Bacteria Secretion for Breast Cancer Treatment In Vivo

For the biomedical application of engineered bacteria, strictly regulating the function of engineered bacteria has always been the goal pursued. However, the existing regulation methods do not meet the needs of the in vivo application of engineered bacteria. Therefore, the exploration of the precise regulation of engineered bacteria is necessary. Herein, heat-sensitive engineered bacteria that can respond to thermal stimuli within 30 min were constructed, and the precise control of functions was verified in the intestines of various model organisms (including C. elegans, bees, and mice). Subsequently, heat-sensitive engineered bacteria were shown to colonize the mouse tumor microenvironment. Finally, thermal stimulation was proven to control engineered bacteria to produce the therapeutic protein tumor necrosis factor α (TNF-α) in the tumor. After three heat stimulation treatments, the growth of the tumor was significantly inhibited, suggesting that heat can be used as a strategy to precisely control engineered bacteria in vivo.

Probiotics and Phytochemicals: Role on Gut Microbiota and Efficacy on Irritable Bowel Syndrome, Functional Dyspepsia, and Functional Constipation

Functional gastrointestinal disorders (FGIDs), such as irritable bowel syndrome, functional constipation, and functional dyspepsia, have had a high prevalence over the past few years. Recent evidence suggests that functional foods and bioactive compounds, such as probiotics and phytochemicals, may have a positive effect in treating the symptoms of the above diseases. In this systematic review study, 32 published studies were selected with the use of comprehensive scientific databases, according to PRISMA guidelines, with emphasis on recent interventional studies that reflect the effect of probiotics and selected phytochemicals on the improvement of FGID symptoms. The bioactive compounds in the selected studies were administered to patients either in capsule form or in enriched food products (yogurt, juice, etc.). According to the results, there is a correlation between the consumption of probiotics and phytochemicals, such as polyphenols, and the relief of symptoms in selected gastrointestinal disorders. Enriching foods that are regularly consumed by the population, such as fruit juices, yogurt, and cheese, with ingredients that may have a positive effect on gastrointestinal disorders, could be a possible novel goal for the management of these diseases. However, further evidence is required for the role of probiotics and phytochemicals in FGIDs to be fully understood.

Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics

Antibiotic resistance, and, in a broader perspective, antimicrobial resistance (AMR), continues to evolve and spread beyond all boundaries. As a result, infectious diseases have become more challenging or even impossible to treat, leading to an increase in morbidity and mortality. Despite the failure of conventional, traditional antimicrobial therapy, in the past two decades, no novel class of antibiotics has been introduced. Consequently, several novel alternative strategies to combat these (multi-) drug-resistant infectious microorganisms have been identified. The purpose of this review is to gather and consider the strategies that are being applied or proposed as potential alternatives to traditional antibiotics. These strategies include combination therapy, techniques that target the enzymes or proteins responsible for antimicrobial resistance, resistant bacteria, drug delivery systems, physicochemical methods, and unconventional techniques, including the CRISPR-Cas system. These alternative strategies may have the potential to change the treatment of multi-drug-resistant pathogens in human clinical settings.

Differential effects of lung inflammation on insulin resistance in humans and mice

BACKGROUND

The rates of obesity, its associated diseases, and allergies are raising at alarming rates in most countries. House dust mites (HDM) are highly allergenic and exposure often associates with an urban sedentary indoor lifestyle, also resulting in obesity. The aim of this study was to investigate the epidemiological association and physiological impact of lung inflammation on obesity and glucose homeostasis.

METHODS

Epidemiological data from 2207 adults of the population-based KORA FF4 cohort were used to test associations between asthma and rhinitis with metrics of body weight and insulin sensitivity. To obtain functional insights, C57BL/6J mice were intranasally sensitized and challenged with HDM and simultaneously fed with either low-fat or high-fat diet for 12 weeks followed by a detailed metabolic and biochemical phenotyping of the lung, liver, and adipose tissues.

RESULTS

We found a direct association of asthma with insulin resistance but not body weight in humans. In mice, co-development of obesity and HDM-induced lung inflammation attenuated inflammation in lung and perigonadal fat, with little impact on body weight, but small shifts in the composition of gut microbiota. Exposure to HDM improved glucose tolerance, reduced hepatosteatosis, and increased energy expenditure and basal metabolic rate. These effects associate with increased activity of thermogenic adipose tissues independent of uncoupling protein 1.

CONCLUSIONS

Asthma associates with insulin resistance in humans, but HDM challenge results in opposing effects on glucose homeostasis in mice due to increased energy expenditure, reduced adipose inflammation, and hepatosteatosis.

A Novel Pseudoalteromonas xiamenensis Marine Isolate as a Potential Probiotic: Anti-Inflammatory and Innate Immune Modulatory Effects against Thermal and Pathogenic Stresses

A marine bacterial strain was isolated from seawater and characterized for it beneficial probiotic effects using zebrafish as a model system. The strain was identified by morphological, physiological, biochemical, and phylogenetic analyses. The strain was most closely related to Pseudoalteromonas xiamenensis Y2, with 99.66% similarity; thus, we named it Pseudoalteromonas xiamenensis S1131. Improvement of host disease tolerance for the P. xiamenensis isolate was adapted in a zebrafish model using Edwardsiella piscicida challenge. The larvae were pre-exposed to P. xiamenensis prior to E. piscicida challenge, resulting in a 73.3% survival rate compared to a 46.6% survival for the control. The treated larvae tolerated elevated temperatures at 38 °C, with 85% survival, compared to 60% survival for the control. Assessment of immunomodulatory responses at the mRNA level demonstrated the suppression of pro-inflammatory markers tnfα and il6, and upregulation of heat shock protein hsp90 and mucin genes. The same effect was corroborated by immunoblot analysis, revealing significant inhibition of Tnfα and an enhanced expression of the Hsp90 protein. The antibacterial activity of P. xiamenensis may be related to mucin overexpression, which can suppress bacterial biofilm formation and enhance macrophage uptake. This phenomenon was evaluated using nonstimulated macrophage RAW264.7 cells. Further studies may be warranted to elucidate a complete profile of the probiotic effects, to expand the potential applications of the present P. xiamenensis isolate.

Bacteria-Based Live Vehicle for In Vivo Bioluminescence Imaging

The anticancer therapy strategy mediated by tumor-targeting bacteria needs better visualization tools for imaging and monitoring bacteria in vivo. The probiotic strain Escherichia coli Nissle 1917 (EcN), one of the tumor-targeting bacteria, leads to the potential application for cancer therapy. Here, we report the development and application of a live, EcN-based imageable vehicle for noninvasive in vivo bioluminescence imaging in live mice. Firefly luciferase (Fluc) and luciferin-regenerating enzyme (LRE), an enzyme that contributes to stable bioluminescence, were functionally coexpressed in EcN. The recombinant EcN strain expressing the genomically integrated Fluc-LRE cassette was demonstrated to be a valuable tool for generating robust, continuous, and red-shifted bioluminescence for bacterial tracking in vitro and in vivo, thus providing an optical tumor-targeting system for the in vivo study of bacteria-assisted cancer therapy. Additionally, in vivo imaging of the recombinant EcN strain in the mouse intestinal tract indicated the potential of this strain to be used as a tool in the study of gut.

In Vitro Selective Antibacterial and Antiproliferative Effects of Ethanolic Extracts from Cambodian and Philippine Plants Used in Folk Medicine for Diarrhea Treatment

Bacterial diarrhea remains a global health problem, especially in developing tropical countries. Moreover, dysbiosis caused by diarrheagenic bacteria and inappropriate antimicrobial treatment has been associated with intestinal carcinogenesis. Despite the rich tradition of the use of herbs for the treatment of gastrointestinal disorders in Cambodian and Philippine folk medicine, many of them have not yet been systematically studied for their in vitro selective inhibitory effects on intestinal bacteria and cells. In the present study, in vitro inhibitory activities of 35 ethanolic extracts derived from 32 Cambodian and Philippine medicinal plants were determined by broth microdilution method against 12 pathogenic bacteria. Furthermore, cytotoxicity against intestinal cancer cells (Caco-2 and HT-29) using thiazolyl blue tetrazolium bromide cytotoxicity assay and safety to six beneficial intestinal bacteria (bifidobacteria and lactobacilli) and intestinal normal cells (FHs 74 Int) were determined for the antimicrobially active extracts. Selectivity indices (SIs) were calculated among the averages of minimum inhibitory concentrations (MICs), half-maximal inhibitory concentrations (IC50), and 80% inhibitory concentrations of proliferation (IC80) for each type of the tested agents. The extracts of Artocarpus blancoi (Elmer) Merr. (Moraceae), Ancistrocladus tectorius (Lour.) Merr. (Ancistrocladaceae), and Pentacme siamensis (Miq.) Kurz (Dipterocarpaceae) produced significant growth-inhibitory effects (MICs = 32-512 μg/ml) against intestinal pathogenic bacteria at the concentrations nontoxic to normal intestinal cells (IC80 values >512 μg/ml; SIs = 0.11-0.2). Moreover, the extract of P. siamensis (Miq.) Kurz was relatively safe to beneficial bacteria (MICs ≥512 μg/ml; SI = 0.1), and together with A. blancoi (Elmer) Merr., they selectively inhibited intestinal cancer cells (IC50 values ≥51.98 ± 19.79 μg/ml; SIs = 0.3 and 0.6). Finally, a strong selective antiproliferative effect on cancer cells (IC50 values 37.89 ± 2.68 to 130.89 ± 13.99 μg/ml; SIs = 0.5) was exerted by Ehretia microphylla Lam. (Boraginaceae), Lagerstroemia cochinchinensis Pierre ex Gagnep. (Lythraceae), and Melastoma saigonense (Kuntze) Merr. (Melastomataceae) (leaves with flower buds). The results suggest that the above-mentioned species are promising materials for the development of new selective antibacterial and antiproliferative agents for the treatment of infectious diarrhea and associated intestinal cancer diseases. However, further research is needed regarding the isolation and identification of their active constituents.

Nutritional and Health Potential of Probiotics: A Review

Several products consist of probiotics that are available in markets, and their potential uses are growing day by day, mainly because some strains of probiotics promote the health of gut microbiota, especially Furmicutes and Bacteroidetes, and may prevent certain gastrointestinal tract (GIT) problems. Some common diseases are inversely linked with the consumption of probiotics, i.e., obesity, type 2 diabetes, autism, osteoporosis, and some immunological disorders, for which the disease progression gets delayed. In addition to disease mitigating properties, these microbes also improve oral, nutritional, and intestinal health, followed by a robust defensive mechanism against particular gut pathogens, specifically by antimicrobial substances and peptides producing probiotics (AMPs). All these positive attributes of probiotics depend upon the type of microbial strains dispensed. Lactic acid bacteria (LAB) and Bifidobacteria are the most common microbes used, but many other microbes are available, and their use depends upon origin and health-promoting properties. This review article focuses on the most common probiotics, their health benefits, and the alleviating mechanisms against chronic kidney diseases (CKD), type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), and obesity.

Rapid cell counting and viability detection method of Escherichia coli Nissle using image cytometry

The improvement of cell enumeration methods for the counting of Escherichia coli (E. coli) is important as E. coli gains in popularity as a basis for biopharmaceutical applications. In the biopharmaceutical industry, enumerating, characterizing, and dosing the accurate number of cells is imperative. In this work, we demonstrate the utilization of a chip-based image cytometer using a thin-gap, low volume counting chamber consumable to directly enumerate E. coli in bright field and fluorescence, and measure their viability using SYTOX™ Green. The total E. coli particles can be counted accurately label-free by adjusting the focus and targeting the linear range of the instrument. The E. coli are stained with SYTOX™ Green to count the membrane-compromised dead bacterial cells in the green fluorescence channel, while the total cells are counted using the bright field channel. Optimization of the system settings, image focus, cell counting range, and staining conditions have yielded a precise, rapid, and accurate E. coli cell enumeration and viability measurement.

Glycine Induction Method: Effective Production of Immunoactive Bacterial Membrane Vesicles with Low Endotoxin Content

Bacteria are known to release nanometer scale proteoliposomes termed bacterial membrane vesicles (MVs), and it is considered that native and bioengineered MVs would be applicable for development of acellular vaccines and novel drug delivery systems in medical settings. However, important considerations for manufacturing purposes include the varied productivity of MV among bacterial species and strains, as well as endotoxicity levels due to the lipopolysaccharide component. The method for MV induction using glycine described here is simple and provides a solution to these problems. Glycine weakens bacterial peptidoglycans and significantly increases bacterial MV formation, while the relative endotoxin activity of glycine-induced MVs is extremely reduced as compared to that of noninduced MVs. Nevertheless, glycine-induced MVs elicit strong immune responses at levels nearly equivalent to those of noninduced MVs. Taken together, the present method for induction by glycine is convenient for research studies of bacterial MVs and has potential for use in medical applications including vaccine development.

Functional Foods as a formulation ingredients in beverages: Technological Advancements and Constraints

As a consequence of expanded science and technical research, the market perception of consumers has shifted from standard traditional to valuable foods, which are furthermore nutritional as well as healthier in today’s world. This food concept, precisely referred to as functional, focuses on including probiotics, which enhance immune system activity, cognitive response, and overall health. This review primarily focuses on functional foods as functional additives in beverages and other food items that can regulate the human immune system and avert any possibility of contracting the infection. Many safety concerns must be resolved during their administration. Functional foods must have an adequate amount of specific probiotic strain(s) during their use and storage, as good viability is needed for optimum functionality of the probiotic. Thus, when developing novel functional food-based formulations, choosing a strain with strong technological properties is crucial. The present review focused on probiotics as an active ingredient in different beverage formulations and the exerting mechanism of action and fate of probiotics in the human body. Moreover, a comprehensive overview of the regulative and safety issues of probiotics-based foods and beverages formulations.

Efficient markerless integration of genes in the chromosome of probiotic E. coli Nissle 1917 by bacterial conjugation

The probiotic strain Escherichia coli Nissle 1917 (EcN) is a common bacterial chassis in synthetic biology developments for therapeutic applications given its long track record of safe administration in humans. Chromosomal integration of the genes of interest (GOIs) in the engineered bacterium offers significant advantages in genetic stability and to control gene dose, but common methodologies relying on the transformation of EcN are inefficient. In this work, we implement in EcN the use of bacterial conjugation in combination with markerless genome engineering to efficiently insert multiple GOIs at different loci of EcN chromosome, leaving no antibiotic resistance genes, vector sequences or scars in the modified bacterium. The resolution of cointegrants that leads to markerless insertion of the GOIs requires expression of I-SceI endonuclease and its efficiency is enhanced by λ Red proteins. We show the potential of this strategy by integrating different genes encoding fluorescent and bioluminescent reporters (i.e. GFP, mKate2, luxCDABE) both individually and sequentially. We also demonstrate its application for gene deletions in EcN (ΔflhDC) and to replace the endogenous regulation of chromosomal locus (i.e. flhDC) by heterologous regulatory elements (e.g. tetR-Ptet) in order to have an ectopic control of gene expression in EcN with an external inducer to alter bacterial behaviour (e.g. flagellar motility). Whole-genome sequencing confirmed the introduction of the designed modifications without off-target alterations in the genome. This straightforward approach accelerates the generation of multiple modifications in EcN chromosome for the generation of living bacterial therapeutics.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.

Decorating Bacteria with a Therapeutic Nanocoating for Synergistically Enhanced Biotherapy

Disorders in the gut microbiota have been implicated in various diseases, such as inflammatory bowel diseases, diabetes, and cancers. Oral microecologics are of great importance due to their ability to directly intervene the gut microbiome as well as their noninvasiveness and low side effects, while have suffered from low bioavailability and a single therapeutic effect. Here, probiotics are coated with a therapeutic nanocoating for synergistically enhanced biotherapy, a method inspired by the robust protective and therapeutic effectiveness of silkworm cocoon. With its transition from a random coil to β-sheet conformation, silk fibroin can self-assemble onto the surface of bacteria. By a simple layer-by-layer procedure, an entire nanocoating can be formed along with a near quantitative coating ratio and almost uninfluenced bacterial viability. Thanks to its protective barrier role and innate pharmaceutical activity, silk fibroin nanocoating endows the coated bacteria with a markedly improved survival against gastric insults and a synergistically enhanced therapeutic effect in a murine model of intestinal mucositis. This work demonstrates how therapeutic elements can be combined with probiotics via a simple coating strategy and proposes an alternative to enhance bioavailability and treatment efficacy of oral microecologics.

Escherichia coli Nissle 1917 as adjuvant therapy in patients with chronic bacterial prostatitis: a non-blinded, randomized, controlled trial

PURPOSE

To evaluate the efficacy and safety of Escherichia coli Nissle 1917 (EcN) in association with levofloxacin in patients with chronic bacterial prostatitis (CBP).

METHODS

Patients with CBP referred to our clinic from September 2017 to July 2019 were enrolled. At baseline, the symptomatology was assessed with the NIH-Chronic Prostatitis Symptom Index (NIH-CPSI), while the Meares-Stamey test was used to diagnose the infection. Patients were randomized (1:1) in two groups (A and B). All subjects underwent oral administration of Levoxacin® 500 mg once daily for 4 weeks. Only the patients in Group B underwent oral administration of EcN® 320 mg, twice daily for 4 weeks and then once daily for 8 weeks. After 3 months, each patient repeated the NIH-CPSI questionnaire, while the Meares-Stamey test was repeated at 3 and 6 months in patients who reported persistent symptoms. All adverse events (AEs) were recorded.

RESULTS

A total of 110 patients were enrolled. After 3 months patients in Group B reported a significantly lower NIH-CPSI score (5.85 ± 3.07 vs. 7.64 ± 3.86; p = 0.009) and biological recurrences rate (9.8 vs. 26.9%; p = 0.043). At 6 months the biological recurrences rate was significantly lower in Group B (8.7 vs. 28.9%; p = 0.038). Only three patients in Group A and six in Group B (p = 0.25) complained mild AEs.

CONCLUSIONS

Combination therapy with EcN and levofloxacin allows a better control of symptoms and biological recurrences in patients with CBP, without worsening the safety of the treatment.

Induction of Immunogenic Response in BALB/c Mice by Live and Killed Form of Recombinant Lactococcus lactis Displaying EG95 of Echinococcus granulosus

Background:

CE is a zoonotic parasitic infection caused by Echinococcus granulosus worldwide and is associated with economic losses among livestock animals. EG95 is an immunogenic antigen from the E. granulosus.Lactococcus lactis has been prested as a safe vehicle for antigen delivery. The goal of this study was to design a novel L. lactis strain displaying EG95 as a vaccine delivery system.

Methods:

The eg95 encoding gene fragment fused to the M6 anchoring protein was cloned into the pNZ7021 vector, and L. lactis NZ9000 displaying recombinant EG95 was constructed. The expression of an approximately 32-kDa EG95 protein was confirmed by Western blotting and immunofluorescence analysis. The immune responses were evaluated in BALB/c mice immunized orally and subcutaneously with the live and killed recombinant L. lactis, respectively.

Results:

Total IgG level in mice immunized with heat-killed recombinant L. lactis (pNZ7021-eg95) significantly increased compared to the control group. sIgA was significantly higher in mice received live recombinant L. lactis (pNZ7021-eg95) compared to the control mice. Splenic lymphocytes from immunized mice represented the high levels of IFN-γ and the low-levels of IL-4 and IL-10.

Conclusion:

Our results indicate that immunization with EG95-expressing L. lactis can induce both specific humoral and cellular immune responses in mice.

The effect of microbial composition and proteomic on improvement of functional constipation by Chrysanthemum morifolium polysaccharide

In this paper, SD rat constipation model was established with loperamide hydrochloride to study the effect of Chrysanthemum morifolium polysaccharide on the improvement of functional constipation, and the mechanism of improving constipation was investigated with the proteomics and intestinal flora. The results showed that the HD group of C. morifolium polysaccharide could significantly increase the levels of water content of stool pellets, small intestine propulsion rate, gastrin (MTL), gastrin (GAS) and substance P (SP), decrease the level of growth inhibitor (SS) and improved gastrointestinal motility in rats. Gut microbial studies showed that C. morifolium polysaccharide could significantly increase species abundance and flora diversity and improve flora structure. The relative abundance of Lactobacillus and Romboutsia increased, while the relative abundance of Lachnospiraceae_NK4A136_group and Roseburia decreased compared with the MC group. Proteomics studies suggested that C. morifolium polysaccharides could reduce intestinal lesions, enhance intestinal homeostasis, increase amino acid uptake, promote intestinal motility and relieve constipation by regulating the expression of RAS, FABP1 and SLC1A5 proteins.

The Effects of Supplementation with Probiotic on Biomarkers of Oxidative Stress in Adult Subjects: a Systematic Review and Meta-analysis of Randomized Trials

Previous studies have supposed that probiotic supplementation led to a positive effect on different health outcomes. Furthermore, several studies indicated that probiotics supplementation improved antioxidant status, while some studies did not indicate these effects. Hence, current systematic review and meta-analysis study was conducted to determine the effect of probiotic supplementation on some oxidative stress biomarkers among adult subjects. We searched four electronic databases PubMed, SCOPUS, ISI Web of Science, and the Cochrane Library till November 2017. Clinical trials that compared the effects of probiotic supplementation with the control group were included. A random-effect model was used to pool weighted mean difference (WMD). Finding of 11 included studies (n = 577) indicated that probiotic supplementation increased total antioxidant capacity (TAC) (WMD 77.30 mmol/L; 95% confidence interval [CI] 2.60, 152.01; I² = 88.3%) and reduced malondialdehyde (MDA) (WMD - 0.31 μmol/L; 95% CI - 0.54, - 0.08; I² = 71.5%) significantly compared to the control group. However, its effects on glutathione (GSH) was not significant (WMD = 19.32 μmol/L; 95% CI - 18.70, 57.33; I² = 64.9%). The current meta-analysis revealed that probiotic supplementation may result in increasing TAC and lowering MDA, which improve antioxidant status. However, due to high heterogeneity, findings should be interpreted with caution. Further investigations are required to elucidate the effect of supplementation with probiotics on biomarkers of antioxidants.

Effects of Bacillus amyloliquefaciens Instead of Antibiotics on Growth Performance, Intestinal Health, and Intestinal Microbiota of Broilers

The aim of this study was to evaluate the dietary effects of Bacillus amyloliquefaciens SC06 (SC06) instead of antibiotics on the growth performance, intestinal health, and intestinal microbiota of broilers. A total of 360 30-day-old Lingnan yellow broilers were randomly allocated into two groups with six replicates per group (30 birds per replicate). The broilers were fed either a non-supplemented diet or a diet supplemented with 10⁸ colony-forming units lyophilized SC06 per kilogram feed for 30 days. Results showed that SC06 supplementation had no effect on the growth performance compared with that of the control group. SC06 treatment significantly (P <0.05) increased the total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD) activity in the liver, and the activities of trypsin, α-amylase (AMS), and Na⁺K⁺-ATPase in the ileum, whereas it decreased (P < 0.05) lipase, gamma glutamyl transpeptidase (γ-GT), and maltase activities in the ileum. Meanwhile, SC06 treatment also improved the immune function indicated by the significantly (P < 0.05) increased anti-inflammatory cytokine [interleukin (IL)-10] level and the decreased (P < 0.05) pro-inflammatory cytokine [IL-6 and tumor necrosis factor (TNF)-α] levels in the ileum. Furthermore, we also found that SC06 enhanced the intestinal epithelial intercellular integrity (tight junction and adhesion belt) in the ileum. Microbial analysis showed that SC06 mainly increased the alpha diversity indices in the jejunum, ileum, and cecum. SC06 treatment also significantly (P < 0.05) increased the abundances of Bacteroidetes, Bacteroidales, Bacteroides, Fusobacteria, Clostridiaceae, and Veillonellaceae in the cecum and simultaneously decreased the abundances of Planococcaceae in the duodenum, Microbacteriaceae in the jejunum, and Lachnospiraceae, [Ruminococcus] and Ruminococcus in cecum. In conclusion, these results suggested that B. amyloliquefaciens instead of antibiotics showed a potential beneficial effect on the intestinal health of broilers.

Probiotics, Photobiomodulation, and Disease Management: Controversies and Challenges

In recent decades, researchers around the world have been studying intensively how micro-organisms that are present inside living organisms could affect the main processes of life, namely health and pathological conditions of mind or body. They discovered a relationship between the whole microbial colonization and the initiation and development of different medical disorders. Besides already known probiotics, novel products such as postbiotics and paraprobiotics have been developed in recent years to create new non-viable micro-organisms or bacterial-free extracts, which can provide benefits to the host with additional bioactivity to probiotics, but without the risk of side effects. The best alternatives in the use of probiotics and postbiotics to maintain the health of the intestinal microbiota and to prevent the attachment of pathogens to children and adults are highlighted and discussed as controversies and challenges. Updated knowledge of the molecular and cellular mechanisms involved in the balance between microbiota and immune system for the introspection on the gut-lung-brain axis could reveal the latest benefits and perspectives of applied photobiomics for health. Multiple interconditioning between photobiomodulation (PBM), probiotics, and the human microbiota, their effects on the human body, and their implications for the management of viral infectious diseases is essential. Coupled complex PBM and probiotic interventions can control the microbiome, improve the activity of the immune system, and save the lives of people with immune imbalances. There is an urgent need to seek and develop innovative treatments to successfully interact with the microbiota and the human immune system in the coronavirus crisis. In the near future, photobiomics and metabolomics should be applied innovatively in the SARS-CoV-2 crisis (to study and design new therapies for COVID-19 immediately), to discover how bacteria can help us through adequate energy biostimulation to combat this pandemic, so that we can find the key to the hidden code of communication between RNA viruses, bacteria, and our body.

Role of probiotics in prevention and treatment of enteric infections: a comprehensive review

Microorganisms that inhabits human digestive tract affect global health and enteric disorders. Previous studies have documented the effectiveness and mode of action of probiotics and classified as human-friendly biota and a competitor to enteric pathogens. Statistical studies reported more than 1.5 billion cases of gastrointestinal infections caused by enteric pathogens and their long-term exposure can lead to mental retardation, temporary or permanent physical weakness, and leaving the patient susceptible for opportunistic pathogens, which can cause fatality. We reviewed previous literature providing evidence about therapeutic approaches regarding probiotics to cure enteric infections efficiently by producing inhibitory substances, immune system modulation, improved barrier function. The therapeutic effects of probiotics have shown success against many foodborne pathogens and their therapeutic effectiveness has been exponentially increased using genetically engineered probiotics. The bioengineered probiotic strains are expected to provide a better and alternative approach than traditional antibiotic therapy against enteric pathogens, but the novelty of these strains also raise doubts about the possible untapped side effects, for which there is a need for further studies to eliminate the concerns relating to the use and safety of probiotics. Many such developments and optimization of the classical techniques will revolutionize the treatments for enteric infections.

Heat-killed Lactobacillus brevis KB290 attenuates visceral fat accumulation induced by high-fat diet in mice

AIMS

This study aimed to evaluate the anti-adiposity effect of heat-killed Lactobacillus brevis KB290 originating from traditional Japanese fermented pickles in mice fed a high-fat diet (HFD).

METHODS AND RESULTS

C57BL/6J mice were fed a normal-fat diet, HFD or HFD supplemented with heat-killed KB290 for 8 weeks. Epididymal and renal adipose tissue weights, as well as areas of epididymal adipocytes, were significantly lower in the mice fed a HFD supplemented with KB290 than in those fed an unsupplemented HFD. Mice whose diets were supplemented with KB290 had elevated adiponectin and β3-adrenergic receptor expression in epididymal adipose tissue and an accompanying higher serum free fatty acid level. Furthermore, the HFD-induced elevations in serum glucose, insulin and HOMA-IR were significantly suppressed by dietary supplementation with KB290. Amplicon sequencing of 16S rRNA genes revealed that KB290 ingestion altered the composition of the intestinal microbiota.

CONCLUSIONS

Heat-killed L. brevis KB290 suppressed diet-induced visceral fat accumulation and ameliorated diet-induced metabolic symptoms and intestinal gut microbiota modifications, suggesting possibility of novel paraprobiotic.

SIGNIFICANCE AND IMPACT OF THE STUDY

Heat-killed L. brevis KB290 is useable as a material to develop functional foods that attenuate visceral fat accumulation.

Physiological activity of E. coli engineered to produce butyric acid

Faecalibacterium prausnitzii (F. prausnitzii) is one of the most abundant bacteria in the human intestine, with its anti‐inflammatory effects establishing it as a major effector in human intestinal health. However, its extreme sensitivity to oxygen makes its cultivation and physiological study difficult. F. prausnitzii produces butyric acid, which is beneficial to human gut health. Butyric acid is a short‐chain fatty acid (SCFA) produced by the fermentation of carbohydrates, such as dietary fibre in the large bowel. The genes encoding butyryl‐CoA dehydrogenase (BCD) and butyryl‐CoA:acetate CoA transferase (BUT) in F. prausnitzii were cloned and expressed in E. coli to determine the effect of butyric acid production on intestinal health using DSS‐induced colitis model mice. The results from the E. coli Nissle 1917 strain, expressing BCD, BUT, or both, showed that BCD was essential, while BUT was dispensable for producing butyric acid. The effects of different carbon sources, such as glucose, N‐acetylglucosamine (NAG), N‐acetylgalactosamine (NAGA), and inulin, were compared with results showing that the optimal carbon sources for butyric acid production were NAG, a major component of mucin in the human intestine, and glucose. Furthermore, the anti‐inflammatory effects of butyric acid production were tested by administering these strains to DSS‐induced colitis model mice. The oral administration of the E. coli Nissle 1917 strain, carrying the expression vector for BCD and BUT (EcN‐BCD‐BUT), was found to prevent DSS‐induced damage. Introduction of the BCD expression vector into E. coli Nissle 1917 led to increased butyric acid production, which improved the strain’s health‐beneficial effects.

Bioactive compounds and probiotics-a ray of hope in COVID-19 management

The use of bioactive compounds and probiotic bacteria against the viral diseases in human is known for a long time. Anti-viral, anti-inflammatory and anti-allergic properties of bioactive compounds and bacteria with probiotic properties in respiratory viral diseases may have significance to enhance immunity. This review highlights some of the important bioactive compounds and probiotic bacteria, suggesting them as a ray of hope in the milieu of the COVID-19 management.