Basic aspects and pharmacology of probiotics: an overview of pharmacokinetics, mechanisms of action and side-effects

Selection of Fermentation Supernatant from Probiotic Strains Exhibiting Intestinal Epithelial Barrier Protective Ability and Evaluation of Their Effects on Colitis Mouse and Weaned Piglet Models

The intestinal epithelial barrier can prevent the invasion of pathogenic microorganisms and food antigens to maintain a consistent intestinal homeostasis. However, an imbalance in this barrier can result in various diseases, such as inflammatory bowel disease, malnutrition, and metabolic disease. Thus, the aim of this study was to select probiotic strains with epithelial barrier-enhancing ability in cell-based model and further investigate them for their improving effects on colitis mouse and weaned piglet models. The results showed that selected specific cell-free fermentation supernatants (CFSs) from Ligilactobacillus salivarius P1, Lactobacillus gasseri P12, and Limosilactobacillus reuteri G7 promoted intestinal epithelial cell growth and proliferation, strengthening the intestinal barrier in an intestinal epithelial cell line Caco-2 model. Further, the administration of CFSs of L. salivarius P1, L. gasseri P12, and L. reuteri G7 were found to ameliorate DSS-induced colitis in mice. Additionally, spray-dried powders of CFS from the three strains were examined in a weaned piglet model, only CFS powder of L. reuteri G7 could ameliorate the feed/gain ratio and serum levels of D-lactate and endotoxin. In conclusion, a new potential probiotic strain, L. reuteri G7, was selected and showed ameliorating effects in both colitis mouse and weaned piglet models.

Characteristics of Lactococcus petauri GB97 lysate isolated from porcine feces and its in vitro and in vivo effects on inflammation, intestinal barrier function, and gut microbiota composition in mice

IMPORTANCE

Weaning is a crucial step in piglet management to improve pork production. During the weaning phase, disruption of epithelial barrier function and intestinal inflammation can lead to decreased absorption of nutrients and diarrhea. Therefore, maintaining a healthy intestine, epithelial barrier function, and gut microbiota composition in this crucial phase is strategic for optimal weaning in pigs. We isolated a lysate of Lactococcus petauri GB97 (LPL97) from healthy porcine feces and evaluated its anti-inflammatory activities, barrier integrity, and gut microbial changes in LPS-induced murine macrophages and DSS-induced colitis mice. We found that LPL97 regulated the immune response by downregulating the TLR4/NF-κB/MAPK signaling pathway both in vitro and in vivo. Furthermore, LPL97 alleviated the disruption of intestinal epithelial integrity and gut microbiota dysbiosis in colitis mice. This study indicates that LPL97 has the potential to be developed as an alternative feed additive to antibiotics for the swine industry.

Effects of probiotics on pancreatic inflammation and intestinal integrity in mice with acute pancreatitis

BACKGROUND

Severe acute pancreatitis is a potentially life-threatening disease. Despite being a common disorder, acute pancreatitis lacks a specific treatment. The present study aimed to examine the effects of probiotics on pancreatic inflammation and intestinal integrity in mice with acute pancreatitis.

METHODS

Male ICR mice were randomly divided into 4 groups (n = 6 per group). The control group received two intraperitoneal (i.p.) injections of normal saline as a vehicle control. The acute pancreatitis (AP) group received two i.p. injections of L-arginine 450 mg/100 g body weight. AP plus probiotics groups received L-arginine to induce acute pancreatitis as above. In the single-strain and mixed-strain groups, mice received 1 mL of Lactobacillus plantarum B7 1 × 10⁸ CFU/mL and 1 mL of Lactobacillus rhamnosus L34 1 × 10⁸ CFU/mL and Lactobacillus paracasei B13 1 × 10⁸ CFU/mL by oral gavage, respectively for 6 days starting 3 days prior to the AP induction. All mice were sacrificed 72 h after L-arginine injection. Pancreatic tissue was obtained for histological evaluation and immunohistochemical studies for myeloperoxidase, whereas ileal tissue was used for immunohistochemical studies for occludin, and claudin-1. Blood samples were collected for amylase analysis.

RESULTS

Serum amylase levels and pancreatic myeloperoxidase levels in the AP group were significantly higher than in controls and significantly decreased in probiotic groups compared with the AP group. Ileal occludin and claudin-1 levels were significantly lower in the AP group than in controls. Ileal occludin levels significantly increased, whereas ileal claudin-1 levels did not significantly change in both probiotic groups as compared with the AP group. The pancreatic histopathology showed significantly higher degree of inflammation, edema, and fat necrosis in the AP group, and these changes improved in mixed-strained probiotic groups.

CONCLUSIONS

Probiotics, particularly the mixed-strain ones, attenuated AP via the reduction of inflammation and the maintenance of intestinal integrity.

Effects of probiotics administration on lactose intolerance in adulthood: A meta-analysis

This meta-analysis aimed to investigate the effect of probiotic administration on adults with lactose intolerance. Twelve studies were identified from databases such as PubMed, Cochrane Library, and Web of Knowledge based on the inclusion and exclusion criteria. The effect size was estimated using the standardized mean difference (SMD), and Cochrane's Q test was used to evaluate the statistical heterogeneity of the effect size. Moderator analysis, including meta-ANOVA and meta-regression, were performed to determine the cause of heterogeneity in the effect size using a mixed-effect model. Egger's linear regression test was conducted to evaluate publication bias. The results showed that probiotic administration alleviated the symptoms of lactose intolerance, including abdominal pain, diarrhea, and flatulence. Among them, the area under the curve (AUC) showed the greatest decrease following probiotic administration (SMD, -4.96; 95% confidence interval, -6.92 to -3.00). In the meta-ANOVA test, abdominal pain and total symptoms decreased with monostrain probiotic administration. This combination was also effective for flatulence. The dosage of probiotics or lactose was significantly associated with a reduction in the total symptom score, and the linear regression models between the dosage and SMD were found to be Y = 2.3342 × dosage - 25.0400 (R² = 79.68%) and Y = 0.2345 × dosage - 7.6618 (R² = 34.03%), respectively. Publication bias was detected for most items. However, even after effect size correction, the probiotic administration effect for all items remained valid. The administration of probiotics was effective at improving adult lactose intolerance, and it is expected that the results of this study could help improve the nutritional status of adults by increasing their consumption of milk and dairy products in the future.

pH-sustaining nanostructured hydroxyapatite/alginate composite hydrogel for gastric protection and intestinal release of Lactobacillus rhamnosusGG

The gut microbiome is closely linked to gastrointestinal health and disease status. Oral administration of known probiotic strains is now considered a promising therapeutic strategy, especially for refractory diseases such as inflammatory bowel disease. In this study, we developed a nanostructured hydroxyapatite/alginate (HAp/Alg) composite hydrogel that protects its encapsulated probiotic Lactobacillus rhamnosus GG (LGG) by neutralizing hydrogen ions that penetrate the hydrogel in a stomach without inhibiting LGG release in an intestine. Surface and transection analyses of the hydrogel revealed characteristic patterns of crystallization and composite-layer formation. TEM revealed the dispersal of the nanosized HAp crystals and encapsulated LGG in the Alg hydrogel networks. The HAp/Alg composite hydrogel maintained its internal microenvironmental pH, thereby enabling the LGG to survive for substantially longer. At intestinal pH, the encapsulated LGG was completely released upon disintegration of the composite hydrogel. In a dextran sulfate sodium-induced colitis mouse model, we then assessed the therapeutic effect of the LGG-encapsulating hydrogel. This achieved intestinal delivery of LGG with minimal loss of enzymatic function and viability, ameliorating colitis by reducing epithelial damage, submucosal edema, inflammatory cell infiltration, and the number of goblet cells. These findings reveal the HAp/Alg composite hydrogel as a promising intestinal-delivery platform for live microorganisms including probiotics and live biotherapeutic products.

Effects of Probiotic Supplementation on Exercise and the Underlying Mechanisms

Long-term, high-intensity exercise can trigger stress response pathways in multiple organs, including the heart and lungs, gastrointestinal tract, skeletal muscle, and neuroendocrine system, thus affecting their material and energy metabolism, immunity, oxidative stress, and endocrine function, and reducing exercise function. As a natural, safe, and convenient nutritional supplement, probiotics have been a hot research topic in the field of biomedical health in recent years. Numerous studies have shown that probiotic supplementation improves the health of the body through the gut-brain axis and the gut-muscle axis, and probiotic supplementation may also improve the stress response and motor function of the body. This paper reviews the progress of research on the role of probiotic supplementation in material and energy metabolism, intestinal barrier function, immunity, oxidative stress, neuroendocrine function, and the health status of the body, as well as the underlying mechanisms.

Postbiotic yeast fermentation product supplementation to lactating goats increases the efficiency of milk production by enhancing fiber digestibility and ruminal propionate, and reduces energy losses in methane

Although in vitro data with mixed ruminal fluid demonstrated positive effects of posbiotic diet (POS) from lactobacilli on measures of fermentation and microbial profiles, there is a paucity of in vivo data with lactating ruminants. The aim of the study was to evaluate the effects of incorporating POS into diets of lactating goats on energy (E) partitioning, carbon (C) and nitrogen (N) balance, and performance. Ten late-lactation Murciano-Granadina goats were used in a crossover design with 26-d periods. Goats in the control diet (CON) were fed daily at the rate of 1 kg alfalfa hay and 1.5 kg concentrate, and the treatment group (POS) was fed CON with the addition of 3.75 g/d of Probisan Ruminants (PENTABIOL S.L., Navarra, Spain). No differences in DMI were detected. However, ruminal fluid propionate and apparent total tract digestibilities of NDF and ADF were greater (18%, 4.7%, and 5.2%, respectively; P < 0.05) in POS compared with the CON diet. Daily partitioning of E to milk and efficiency of ME intake for milk production greater (11% and 3.0%, respectively; P < 0.05) in POS compared with CON. The nonprotein RQ was greater in POS compared with CON due to greater (P < 0.05) oxidation of carbohydrate (213 vs. 115 kJ/kg of BW0.75 per day) compared with fat (362 vs. 486 kJ/kg of BW0.75 per day). Although no differences were found in C balance, goats in POS had lower (P < 0.05) amounts of C in CH4 (1.1 vs. 1.3 g/kg BW0.75 per day) compared with CON. There were no differences in N intake or N in feces or urine, but N in milk was greater (P < 0.05) in POS compared with the CON diet (0.8 vs. 0.7 g/kg BW0.75 per day). Yield of fat-corrected milk (FCM) (3.20 vs. 2.72 kg/d; P < 0.05) and concentration of true protein (3.4 vs. 3.3 kg/d; P < 0.05) and lactose (4.7 vs. 4.5 kg/d; P < 0.05) were greater in POS compared with CON. These responses were accompanied by lower (P < 0.05) urea (12.3 vs. 16.6 mM/L) and ammonia-N (6.6 vs. 8.8 mg/L) without changes in fat concentration (6.1% vs. 6.0%; P > 0.05) in POS compared with the CON diet. Daily amount of CH4 emission did not differ P > 0.05 between diets. However, when expressed relative to unit of edible product, feeding POS reduced (P < 0.05) the amount of CH4 by 46 g/kg of milk fat, 97 g/kg of milk protein, and 3 g/kg of milk compared with CON. Overall, data indicated that feeding a postbiotic in late-lactation increased energy efficiency for milk production partly by reducing CH4 emission.

Inappropriate Use of Proton Pump Inhibitors Increases Cardiovascular Events in Patients with Coronary Heart Disease

Antiplatelet drugs, as the cornerstone of the treatment of coronary heart disease, control the progression of the disease, but bring a higher risk of gastrointestinal bleeding. Relevant guidelines recommend the use of proton pump inhibitors (PPIs) to minimize the risk of gastrointestinal bleeding in patients receiving dual antiplatelet therapy. But for people at low risk of gastrointestinal bleeding, the harms associated with routine use of PPIs may far outweigh the benefits. PPIs increase the risk of lower gastrointestinal bleeding, inhibit the effect of antiplatelet drugs, impair vascular endothelial function, meanwhile induce hypomagnesemia, iron deficiency, vitamins D and K deficiency, etc. Eventually, PPIs may lead to an increase in cardiovascular events. However, the situation is that PPIs are often overused. This review elucidates the mechanisms by which PPIs increase cardiovascular events, thereby reminding clinicians to rationally prescribe PPIs.

Advances in characterization of probiotics and challenges in industrial application

An unbalanced diet and poor lifestyle are common reasons for numerous health complications in humans. Probiotics are known to provide substantial benefits to human health by producing several bioactive compounds, vitamins, short-chain fatty acids and short peptides. Diets that contain probiotics are limited to curd, yoghurt, kefir, kimchi, etc. However, exploring the identification of more potential probiotics and enhancing their commercial application to improve the nutritional quality would be a significant step to utilizing the maximum benefits. The complex evolution patterns among the probiotics are the hurdles in their characterization and adequate application in the industries and dairy products. This article has mainly discussed the molecular methods of characterization that are based on the analysis of ribosomal RNA, whole genome, and protein markers and profiles. It also has critically emphasized the emerging challenges in industrial applications of probiotics.

Pharmacological Efficacy of Probiotics in Respiratory Viral Infections: A Comprehensive Review

Mortality and morbidity from influenza and other respiratory viruses are significant causes of concern worldwide. Infections in the respiratory tract are often underappreciated because they tend to be mild and incapacitated. On the other hand, these infections are regarded as a common concern in clinical practice. Antibiotics are used to treat bacterial infections, albeit this is becoming more challenging since many of the more prevalent infection causes have acquired a wide range of antimicrobial resistance. Resistance to frontline treatment medications is constantly rising, necessitating the development of new antiviral agents. Probiotics are one of several medications explored to treat respiratory viral infection (RVI). As a result, certain probiotics effectively prevent gastrointestinal dysbiosis and decrease the likelihood of secondary infections. Various probiotic bacterias and their metabolites have shown immunomodulating and antiviral properties. Unfortunately, the mechanisms by which probiotics are effective in the fight against viral infections are sometimes unclear. This comprehensive review has addressed probiotic strains, dosage regimens, production procedures, delivery systems, and pre-clinical and clinical research. In particular, novel probiotics’ fight against RVIs is the impetus for this study. Finally, this review may explore the potential of probiotic bacterias and their metabolites to treat RVIs. It is expected that probiotic-based antiviral research would be benefitted from this review’s findings.

Effects of Postbiotics and Paraprobiotics as Replacements for Antibiotics on Growth Performance, Carcass Characteristics, Small Intestine Histomorphology, Immune Status and Hepatic Growth Gene Expression in Broiler Chickens

Background: This experiment was designed to investigate how replacing antibiotics with postbiotics and paraprobiotics could affect growth performance, small intestine morphology, immune status, and hepatic growth gene expression in broiler chickens. Methods: The experiment followed a completely randomized design (CRD) in which eight treatments were replicated six times with seven birds per replicate. A total of 336, one-day-old (COBB 500) chicks were fed with the eight treatment diets, which include T1 = negative control (Basal diet), T2 = positive control (Basal diet + 0.01% (w/w) Oxytetracycline), T3 = Basal diet + 0.2% (v/w) postbiotic TL1, T4 = Basal diet + 0.2% (v/w) postbiotic RS5, T5 = Basal diet + 0.2% (v/w) paraprobiotic RG11, T6 = Basal diet + 0.2% (v/w) postbiotic RI11, T7 = Basal diet + 0.2% (v/w) paraprobiotic RG14, T8 = Basal diet + 0.2% (v/w) paraprobiotic RI11, for 35 days in a closed house system. Results: The growth performance indicators (final body weight, cumulative weight gain, and feed conversion ratio) were not significantly (p > 0.05) affected by the dietary treatments. However, feed intake recorded a significant (p < 0.05) change in the starter and finisher phases across the dietary treatments. Paraprobiotic RG14 had significantly (p < 0.05) lower abdominal fat and intestines. Villi heights were significantly (p < 0.05) increased, while the crypt depth decreased significantly due to dietary treatments. The dietary treatments significantly influenced colon mucosa sIgA (p < 0.05). Similarly, plasma immunoglobulin IgM level recorded significant (p < 0.05) changes at the finisher phase. In this current study, the hepatic GHR and IGF-1 expressions were significantly (p < 0.05) increased by postbiotics and paraprobiotics supplementation. Conclusions: Therefore, it was concluded that postbiotics and paraprobiotics differ in their effect on broiler chickens. However, they can replace antibiotics without compromising the growth performance, carcass yield, and immune status of broiler chickens.

Best Practices for Probiotic Research in Athletic and Physically Active Populations: Guidance for Future Randomized Controlled Trials

Probiotic supplementation, traditionally used for the prevention or treatment of a variety of disease indications, is now recognized in a variety of population groups including athletes and those physically active for improving general health and performance. However, experimental and clinical trials with probiotics commonly suffer from design flaws and different outcome measures, making comparison and synthesis of conclusions difficult. Here we review current randomized controlled trials (RCTs) using probiotics for performance improvement, prevention of common illnesses, or general health, in a specific target population (athletes and those physically active). Future RCTs should address the key elements of (1) properly defining and characterizing a probiotic intervention, (2) study design factors, (3) study population characteristics, and (4) outcome measures, that will allow valid conclusions to be drawn. Careful evaluation and implementation of these elements should yield improved trials, which will better facilitate the generation of evidence-based probiotic supplementation recommendations for athletes and physically active individuals.

Exfoliated bentonite/alginate nanocomposite hydrogel enhances intestinal delivery of probiotics by resistance to gastric pH and on-demand disintegration

In this study, we developed Lactobacillus rhamnosus GG (LGG)-encapsulating exfoliated bentonite/alginate nanocomposite hydrogels for protecting probiotics by delaying gastric fluid penetration into the nanocomposite and their on-demand release in the intestine. The pore size of the bentonite/alginate nanocomposite hydrogels (BA15) was two-fold smaller than that of alginate hydrogel (BA00). Following gastric pH challenge, the survival of LGG in BA15 decreased by only 1.43 log CFU/g as compared to the 6.25 log CFU/g decrease in alginate (BA00). Further, the internal pH of BA15 decreased more gradually than that of BA00. After oral administration in mice, BA15 maintained shape integrity during gastric passage, followed by appropriate disintegration within the target intestinal area. Additionally, a fecal recovery experiment in mice showed that the viable counts of LGG in BA15 were six-fold higher than those in BA00. The findings suggest the exfoliated bentonite/alginate nanocomposite hydrogel as a promising platform for intestinal delivery of probiotics.

Microbial Therapeutics in Neurocognitive and Psychiatric Disorders

Microbial therapeutics, which include gut biotics and fecal transplantation, are interventions designed to improve the gut microbiome. Gut biotics can be considered as the administration of direct microbial populations. The delivery of this can be done through live microbial flora, certain food like fiber, microbial products (metabolites and elements) obtained through the fermentation of food products, or as genetically engineered substances, that may have therapeutic benefit on different health disorders. Dietary intervention and pharmacological supplements with gut biotics aim at correcting disruption of the gut microbiota by repopulating with beneficial microorganism leading to decrease in gut permeability, inflammation, and alteration in metabolic activities, through a variety of mechanisms of action. Our understanding of the pharmacokinetics of microbial therapeutics has improved with in vitro models, sampling techniques in the gut, and tools for the reliable identification of gut biotics. Evidence from human studies points out that prebiotics, probiotics and synbiotics have the potential for treating and preventing mental health disorders, whereas with paraprobiotics, proteobiotics and postbiotics, the research is limited at this point. Some animal studies point out that gut biotics can be used with conventional treatments for a synergistic effect on mental health disorders. If future research shows that there is a possibility of synergistic effect of psychotropic medications with gut biotics, then a gut biotic or nutritional prescription can be given along with psychotropics. Even though the overall safety of gut biotics seems to be good, caution is needed to watch for any known and unknown side effects as well as the need for risk benefit analysis with certain vulnerable populations. Future research is needed before wide spread use of natural and genetically engineered gut biotics. Regulatory framework for gut biotics needs to be optimized. Holistic understanding of gut dysbiosis, along with life style factors, by health care providers is necessary for the better management of these conditions. In conclusion, microbial therapeutics are a new psychotherapeutic approach which offer some hope in certain conditions like dementia and depression. Future of microbial therapeutics will be driven by well-done randomized controlled trials and longitudinal research, as well as by replication studies in human subjects.

Host microbiota can facilitate pathogen infection

Animals live in symbiosis with numerous microbe species. While some can protect hosts from infection and benefit host health, components of the microbiota or changes to the microbial landscape have the potential to facilitate infections and worsen disease severity. Pathogens and pathobionts can exploit microbiota metabolites, or can take advantage of a depletion in host defences and changing conditions within a host, to cause opportunistic infection. The microbiota might also favour a more virulent evolutionary trajectory for invading pathogens. In this review, we consider the ways in which a host microbiota contributes to infectious disease throughout the host's life and potentially across evolutionary time. We further discuss the implications of these negative outcomes for microbiota manipulation and engineering in disease management.

Diversion Colitis: Macro and Microscopic Findings after Probiotics Stimulation

Simple Summary

The observations presented in this study conclude that the preoperative stimulation with probiotics of the efferent loop through the dysfunctional bowel, to allow the slow infusion, can have a reducing effect on the endoscopic and histopathological alterations of diversion colitis. This procedure may be an alternative treatment to resolve the inflammation in patients where the surgical option is not feasible or available.

Abstract

The use of a loop ileostomy as the defunctioning procedure of choice to protect a distal colonic anastomosis causes histological and endoscopic changes in the intestinal mucosal architecture, which have been related to chronic inflammation and changes in the microflora that consequently impact the intestinal structure and function following fecal stream diversion. The aim of this study was to evaluate the histological and endoscopic changes on the colonic mucosa in patients with diversion colitis after stimulation of the efferent loop with probiotics prior to closure of the protective ileostomy. A prospective, randomized, double-blind, controlled study was designed. All patients who underwent surgery for colorectal carcinoma with protective ileostomy between January 2017 and December 2018 were included. These patients were pending reconstructive surgery and were diagnosed with endoscopic and histological diversion colitis. Divided into two groups, a group stimulated with probiotics (SG) and a control group (CG). 34 cases and 35 controls were included in the study. Histological and endoscopic changes were evaluated after stimulation, after restorative surgery and during the short-term follow-up after surgery. A decrease in endoscopic pathological findings (mucosal friability, mucous erosions, polyps, edema, erythema and stenosis) and in histological findings (follicular hyperplasia, eosinophils, cryptic abscesses, lymphocyte infiltration, plasma cell infiltration and architecture distortion) was observed in SG. These results were statistically significant with a p < 0.001. The stimulation of the efferent loop of the ileostomy in patients with diversion colitis produced a decrease of the endoscopic and histological severity of colitis in the short term.

In Vitro Assessment of Probiotic Potential of Saccharomyces Cerevisiae DABRP5 Isolated from Bollo Batter, a Traditional Goan Fermented Food

Bollo is a traditional Goan fermented food in which coarse wheat/wheat and finger millet is leavened with toddy. We here isolated 42 yeast strains from Bollo batter. Initial screening of the isolates with probiotic properties yielded four yeast isolates (DABRP1, DABRP2, DABRP5 and DABRP12). These isolates exhibited tolerance to high bile salt concentration and acidic pH and resistance to various antibiotics, which indicated their probiotic nature. All these yeast isolates were identified as Saccharomyces cerevisiae through D1D2-LSU-rDNA sequencing. These yeast isolates also showed higher percent hydrophobicity towards chloroform followed by n-hexadecane and o-xylene indicating their mucosal surface-adhesive property. To evaluate the safety of the isolates for them to be called as generally recognized as safe, the pathogenic behavior of the isolates determined through the in vitro hemolysis assay and evaluation of DNase and gelatinase activities. None of the isolates exhibited hemolysis or produced DNase or gelatinase and thus were considered potentially safe. In terms of beneficial effects, the most potent isolate S. cerevisiae DABRP5 showed antibacterial activity against the test pathogens. It also showed excellent antioxidant activity with DPPH free radical scavenging activity of 68.85 ± 0.69%, anti-inflammatory activity with 60.39 ± 0.34% inhibition of protein denaturation, and antidiabetic activity with 71.75 ± 0.45% inhibition of α-amylase activity. The isolate produced α-amylase, lipase, and β-galactosidase. The probiotic potential of the isolate S. cerevisiae DABRP5 was similar to that of the reference strain (Saccharomyces boulardii CNCM I-745) used in this study. The results thus indicate that yeast isolates from Bollo batter have probiotic potential.

Probiotics in Medicine: A Long Debate

During the last years probiotics gained the attention of clinicians for their use in the prevention and treatment of multiple diseases. Probiotics main mechanisms of action include enhanced mucosal barrier function, direct antagonism with pathogens, inhibition of bacterial adherence and invasion capacity in the intestinal epithelium, boosting of the immune system and regulation of the central nervous system. It is accepted that there is a mutual communication between the gut microbiota and the liver, the so-called “microbiota-gut-liver axis” as well as a reciprocal communication between the intestinal microbiota and the central nervous system through the “microbiota-gut-brain axis.” Moreover, recently the “gut-lung axis” in bacterial and viral infections is considerably discussed for bacterial and viral infections, as the intestinal microbiota amplifies the alveolar macrophage activity having a protective role in the host defense against pneumonia. The importance of the normal human intestinal microbiota is recognized in the preservation of health. Disease states such as, infections, autoimmune conditions, allergy and other may occur when the intestinal balance is disturbed. Probiotics seem to be a promising approach to prevent and even reduce the symptoms of such clinical states as an adjuvant therapy by preserving the balance of the normal intestinal microbiota and improving the immune system. The present review states globally all different disorders in which probiotics can be given. To date, Stronger data in favor of their clinical use are provided in the prevention of gastrointestinal disorders, antibiotic-associated diarrhea, allergy and respiratory infections. We hereby discuss the role of probiotics in the reduction of the respiratory infection symptoms and we focus on the possibility to use them as an adjuvant to the therapeutic approach of the pandemic COVID-19. Nevertheless, it is accepted by the scientific community that more clinical studies should be undertaken in large samples of diseased populations so that the assessment of their therapeutic potential provide us with strong evidence for their efficacy and safety in clinical use.

Probiotics at War Against Viruses: What Is Missing From the Picture?

Our world is now facing a multitude of novel infectious diseases. Bacterial infections are treated with antibiotics, albeit with increasing difficulty as many of the more common causes of infection have now developed broad spectrum antimicrobial resistance. However, there is now an even greater challenge from both old and new viruses capable of causing respiratory, enteric, and urogenital infections. Reports of viruses resistant to frontline therapeutic drugs are steadily increasing and there is an urgent need to develop novel antiviral agents. Although this all makes sense, it seems rather strange that relatively little attention has been given to the antiviral capabilities of probiotics. Over the years, beneficial strains of lactic acid bacteria (LAB) have been successfully used to treat gastrointestinal, oral, and vaginal infections, and some can also effect a reduction in serum cholesterol levels. Some probiotics prevent gastrointestinal dysbiosis and, by doing so, reduce the risk of developing secondary infections. Other probiotics exhibit anti-tumor and immunomodulating properties, and in some studies, antiviral activities have been reported for probiotic bacteria and/or their metabolites. Unfortunately, the mechanistic basis of the observed beneficial effects of probiotics in countering viral infections is sometimes unclear. Interestingly, in COVID-19 patients, a clear decrease has been observed in cell numbers of Lactobacillus and Bifidobacterium spp., both of which are common sources of intestinal probiotics. The present review, specifically motivated by the need to implement effective new counters to SARS-CoV-2, focusses attention on viruses capable of co-infecting humans and other animals and specifically explores the potential of probiotic bacteria and their metabolites to intervene with the process of virus infection. The goal is to help to provide a more informed background for the planning of future probiotic-based antiviral research.

Effects of postbiotic supplementation on growth performance, ruminal fermentation and microbial profile, blood metabolite and GHR, IGF-1 and MCT-1 gene expression in post-weaning lambs

Background

Postbiotics have been established as potential feed additive to be used in monogastric such as poultry and swine to enhance health and growth performance. However, information on the postbiotics as feed additive in ruminants is very limited. The aim of this study was to elucidate the effects of supplementation of postbiotics in newly-weaned lambs on growth performance, digestibility, rumen fermentation characteristics and microbial population, blood metabolite and expression of genes related to growth and volatile fatty acid transport across the rumen epithelium.

Results

Postbiotic supplementation increased weight gain, feed intake, nutrient intake and nutrient digestibility of the lambs. No effect on ruminal pH and total VFA, whereas butyrate and ruminal ammonia-N concentration were improved. The lambs fed with postbiotics had higher blood total protein, urea nitrogen and glucose. However, no difference was observed in blood triglycerides and cholesterol levels. Postbiotics increased the population of fibre degrading bacteria but decreased total protozoa and methanogens in rumen. Postbiotics increased the mRNA expression of hepatic IGF-1 and ruminal MCT-1.

Conclusions

The inclusion of postbiotics from L. plantarum RG14 in newly-weaned lambs improved growth performance, nutrient intake and nutrient digestibility reflected from better rumen fermentation and microbial parameters, blood metabolites and upregulation of growth and nutrient intake genes in the post-weaning lambs.

Effects of Feeding Different Postbiotics Produced by Lactobacillus plantarum on Growth Performance, Carcass Yield, Intestinal Morphology, Gut Microbiota Composition, Immune Status, and Growth Gene Expression in Broilers under Heat Stress

Simple Summary

Heat stress is a serious issue in commercial broiler production in hot and humid countries, including Malaysia. Exposure of broilers to heat stress affects their health and productivity. In this context, antibiotics are widely used at sub-therapeutic levels as growth promoters to reduce stress and infectious diseases in order to sustain productivity in commercial broiler farms. However, the extensive use of antibiotics as growth promoters for a long time leads to the development of antibiotic-resistant bacteria and the possibility of antibiotic-resistant genes being transferred among organisms. Recently, postbiotics produced by Lactobacillus plantarum have been widely studied as a feed additive in order to replace in-feed antibiotics. However, to date, no studies have investigated the role of postbiotics in feed for broilers under heat stress.

Abstract

The effects of feeding different postbiotics on growth performance, carcass yield, intestinal morphology, gut microbiota, immune status, and growth hormone receptor (GHR) and insulin-like growth factor 1 (IGF-1) gene expression in broilers under heat stress were assessed in this study. A total of 252 one-day-old male broiler chicks (Cobb 500) were randomly assigned in cages in identical environmentally controlled chambers. During the starter period from 1 to 21 days, all the birds were fed the same basal diet. On day 22, the birds were weighed and randomly divided into six treatment groups and exposed to cyclic high temperature at 36 ± 1 °C for 3 h per day from 11:00 to 14:00 until the end of the experiment. From day 22 to 42 (finisher period), an equal number of birds were subjected to one of the following diets: NC (negative control) basal diet; PC (positive control) basal diet + 0.02% oxytetracycline; or AA (ascorbic acid) basal diet + 0.02% ascorbic acid. The other three groups (RI11, RS5 and UL4) were basal diet + 0.3% different postbiotics (produced from different Lactobacillus plantarum strains, and defined as RI11, RS5 and UL4, respectively). The results demonstrated that birds fed RI11 diets had significantly higher final body weight, total weight gain and average daily gain than the birds that received the NC, PC and AA treatments. The feed conversion ratio was significantly higher in the RI11 group compared with the other groups. Carcass parameters were not affected by the postbiotic-supplemented diet. Postbiotic supplementation improved villi height significantly in the duodenum, jejunum and ileum compared to the NC, PC and AA treatments. The crypt depth of the duodenum and ileum was significantly higher in NC group compared to other treatment groups except RI11 in duodenum, and UL4 in ileum was not different with NC groups. The villus height to crypt depth ratio of duodenum and ileum was significantly higher for the postbiotic treatment groups and AA than the PC and NC treatment groups. The postbiotic RI11 group recorded significantly higher caecum total bacteria and Lactobacillus count and lower Salmonella count compared to the NC and PC treatment groups. The Bifidobacterium population in the NC group was significantly lower compared to the other treatment groups. The postbiotic (RI11, RS5 and UL4) and AA treatment groups showed lower Enterobacteriaceae and E. coli counts and caecal pH than the NC and PC treatment groups. The plasma immunoglobulin M (IgM) level was significantly higher in the birds receiving postbiotic RI11 than those receiving other treatments. The plasma immunoglobulin G (IgG) level was higher in the RI11 treatment group than in the NC, AA and RS5 groups. The plasma immunoglobulin A (IgA) level was not affected by postbiotic supplements. The hepatic GHR mRNA expression level was significantly increased in birds fed postbiotics RI11, RS5 and UL4, AA and PC compared to the NC-fed birds. Postbiotic RI11 led to significantly higher hepatic IGF-1 mRNA expression level compared to the NC, PC, and AA treatments. Mortality was numerically lesser in the postbiotic treatment groups, but not significantly different among all the treatments. In conclusion, among the postbiotics applied in the current study as compared with NC, PC and AA, RI11 could be used as a potential alternative antibiotic growth promoter and anti-stress treatment in the poultry industry.

Migration of Bacteriocins Across Gastrointestinal Epithelial and Vascular Endothelial Cells, as Determined Using In Vitro Simulations

Little is known about the migration of bacteriocins across human cells. In this study, we report on migration of three bacteriocins nisin, plantaricin 423 and bacST4SA across colonic adenocarcinoma (Caco-2) cells and human umbilical vein endothelial cells (HUVECs). Bacteriocins were fluorescently labelled while still maintaining antimicrobial activity. Migration of fluorescently labelled bacteriocins across monolayers was assessed in vitro using transmigration well inserts. After 3 h, 75% of nisin, 85% of plantaricin 423 and 82% of bacST4SA migrated across the Caco-2 cell monolayer. Over the same time span, 88% nisin, 93% plantaricin 423 and 91% bacST4SA migrated across the HUVEC monolayer. The viability of both cell types remained unchanged when exposed to 50 µM of nisin, plantaricin 423 or bacST4SA. The effect of human plasma on bacteriocin activity was also assessed. Activity loss was dependent on bacteriocin type and concentration, with the class-IIa bacteriocins retaining more activity compared to nisin. This is the first report of bacteriocins migrating across simulated gastrointestinal- and vascular-barriers. This study provides some of the first evidence that bacteriocins are capable of crossing the gut-blood-barrier. However, in vivo studies need to be performed to confirm these findings and expand on the role of bacteriocin migration across cell barriers.

Postbiotic L. plantarum RG14 improves ruminal epithelium growth, immune status and upregulates the intestinal barrier function in post-weaning lambs

We investigate the effects of postbiotic Lactobacillus plantarum RG14 on gastrointestinal histology, haematology, mucosal IgA concentration, microbial population and mRNA expression related to intestinal mucosal immunity and barrier function. Twelve newly weaned lambs were randomly allocated to two treatment groups; the control group without postbiotic supplementation and postbiotic group with supplementation of 0.9% postbiotic in the diet over a 60-day trial. The improvement of rumen papillae height and width were observed in lambs fed with postbiotics. In contrast, no difference was shown in villi height of duodenum, jejunum and ileum between the two groups. Lambs received postbiotics had a lower concentration of IgA in jejunum but no difference in IgA concentration in serum and mucosal of the rumen, duodenum and ileum. In respect of haematology, postbiotics lowered leukocyte, lymphocyte, basophil, neutrophil and platelets, no significant differences in eosinophil. The increase in of IL-6 mRNA and decrease of IL-1β, IL-10, TNF mRNA were observed in the jejunum of lambs receiving postbiotics. Postbiotics also improved the integrity of the intestinal barrier by the upregulation of TJP-1, CLDN-1 and CLDN-4 mRNA. Postbiotic supplementation derived from L. plantarum RG14 in post-weaning lambs enhance the ruminal papillae growth, immune status and gastrointestinal health.

The Immunomodulatory Properties of Extracellular Vesicles Derived from Probiotics: A Novel Approach for the Management of Gastrointestinal Diseases

Probiotics, included in functional foods, nutritional supplements, or nutraceuticals, exhibit different beneficial effects on gut function. They are extensively used to improve the digestive processes as well as reduce the symptoms and progression of different diseases. Probiotics have shown to improve dysbiosis and modulate the immune response of the host by interacting with different cell types. Probiotics and the host can interact in a direct way, but it is becoming apparent that communication occurs also through extracellular vesicles (EVs) derived from probiotics. EVs are key for bacteria-bacteria and bacteria-host interactions, since they carry a wide variety of components that can modulate different signaling pathways, including those involved in the immune response. Interestingly, EVs are recently starting to be considered as an alternative to probiotics in those cases for which the use of live bacteria could be dangerous, such as immunocompromised individuals or situations where the intestinal barrier is impaired. EVs can spread through the mucus layer and interact with the host, avoiding the risk of sepsis. This review summarizes the existing knowledge about EVs from different probiotic strains, their properties, and their potential use for the prevention or treatment of different gastrointestinal diseases.

Divergent Effectiveness of Multispecies Probiotic Preparations on Intestinal Microbiota Structure Depends on Metabolic Properties

A growing body of evidence suggests that probiotic functionality is not accurately predicted by their taxonomy. Here, we have set up a study to investigate the effectiveness of two probiotic formulations containing a blend of seven bacterial species in modulating intestinal inflammation in two rodent models of colitis, induced by treating mice with 2,4,6-Trinitrobenzenesulfonic acid (TNBS) or dextran sodium sulfate (DSS). Despite the taxonomy of the bacterial species in the two probiotic formulations being similar, only one preparation (Blend 2-Vivomixx) effectively attenuated the development of colitis in both models. In the TNBS model of colitis, Blend 2 reduced the expression of pro-inflammatory genes while increasing the production of anti-inflammatory cytokines, promoting the expansion M2 macrophages and the formation of IL-10-producing Treg cells in the colon's lamina propria. In the DSS model of colitis, disease attenuation and Treg formation was observed only in mice administered with Blend 2, and this effect was associated with intestinal microbiota remodeling and increased formation of lactate, butyrate, and propionate. None of these effects were observed in mice administered with Blend 1 (VSL#3). In summary, we have shown that two probiotic mixtures obtained by combining taxonomically similar species produced with different manufacturing methods exert divergent effects in mouse models of colitis.

An Overview on Probiotics as an Alternative Strategy for Prevention and Treatment of Human Diseases

Probiotics are viable and useful microorganisms, which are beneficial factors for human and animal health by altering their microbial flora. Most of the probiotics belong to a large group of bacteria in the human gastrointestinal tract. There are several clinical shreds of evidence that show anti-carcinogenic effects of probiotics through altering digestive enzymes, inhibition of carcinogenic agents, and modulating the immune responses in experimental animals. Many studies have been performed to evaluate the potential effectiveness of probiotics in treating or preventing neurological diseases such as MS and novel treatment modality for T1D. The purpose of this study is to have an overview on probiotic microorganisms and to review the previous researches on the effects of probiotics on health through currently available literatures. The study was performed using following keywords; Probiotics, Cancer, Immune system, Multiple Sclerosis (MS) and Diabetes mellitus. PubMed/Medline, Clinicaltrials.gov, Ovid, Google Scholar, and Reaxcys databases used to find the full text of related articles. According to the current available data on probiotics and related health-promoting benefits, it seems that, consumption of probiotics can lead to the prevention and reduction the risk of cancer, diabetes, and multiple sclerosis. Although for the better and more decisive conclusion, there is a need to larger sample size clinical studies with more focus on the safety of these biological agents and their possible beneficial effects on different population.

Cross-species examination of single- and multi-strain probiotic treatment effects on neuropsychiatric outcomes

Interest in elucidating gut-brain-behavior mechanisms and advancing neuropsychiatric disorder treatments has led to a recent proliferation of probiotic trials. Yet, a considerable gap remains in our knowledge of probiotic efficacy across populations and experimental contexts. We conducted a cross-species examination of single- and multi-strain combinations of established probiotics. Forty-eight human (seven infant/child, thirty-six young/middle-aged adult, five older adult) and fifty-eight non-human (twenty-five rat, twenty-seven mouse, five zebrafish, one quail) investigations met the inclusion/exclusion criteria. Heterogeneity of probiotic strains, substrains, and study methodologies limited our ability to conduct meta-analyses. Human trials detected variations in anxiety, depression, or emotional regulation (single-strain 55.6%; multi-strain 50.0%) and cognition or social functioning post-probiotic intake (single-strain 25.9%; multi-strain 31.5%). For the non-human studies, single- (60.5%) and multi-strain (45.0%) combinations modified stress, anxiety, or depression behaviors in addition to altering social or cognitive performance (single-strain 57.9%; multi-strain 85.0%). Rigorous trials that confirm existing findings, investigate additional probiotic strain/substrain combinations, and test novel experimental paradigms, are necessary to develop future probiotic treatments that successfully target specific neuropsychiatric outcomes.

A Review: The Fate of Bacteriocins in the Human Gastro-Intestinal Tract: Do They Cross the Gut-Blood Barrier?

The intestinal barrier, consisting of the vascular endothelium, epithelial cell lining, and mucus layer, covers a surface of about 400 m2. The integrity of the gut wall is sustained by transcellular proteins forming tight junctions between the epithelial cells. Protected by three layers of mucin, the gut wall forms a non-permeable barrier, keeping digestive enzymes and microorganisms within the luminal space, separate from the blood stream. Microorganisms colonizing the gut may produce bacteriocins in an attempt to outcompete pathogens. Production of bacteriocins in a harsh and complex environment such as the gastro-intestinal tract (GIT) may be below minimal inhibitory concentration (MIC) levels. At such low levels, the stability of bacteriocins may be compromised. Despite this, most bacteria in the gut have the ability to produce bacteriocins, distributed throughout the GIT. With most antimicrobial studies being performed in vitro, we know little about the migration of bacteriocins across epithelial barriers. The behavior of bacteriocins in the GIT is studied ex vivo, using models, flow cells, or membranes resembling the gut wall. Furthermore, little is known about the effect bacteriocins have on the immune system. It is generally believed that the peptides will be destroyed by macrophages once they cross the gut wall. Studies done on the survival of neurotherapeutic peptides and their crossing of the brain-blood barrier, along with other studies on small peptides intravenously injected, may provide some answers. In this review, the stability of bacteriocins in the GIT, their effect on gut epithelial cells, and their ability to cross epithelial cells are discussed. These are important questions to address in the light of recent papers advocating the use of bacteriocins as possible alternatives to, or used in combination with, antibiotics.

Timing of probiotic milk consumption during pregnancy and effects on the incidence of preeclampsia and preterm delivery: a prospective observational cohort study in Norway

OBJECTIVES

To investigate whether the timing of probiotic milk intake before, during early or late pregnancy influences associations with preeclampsia and preterm delivery.

DESIGN

Population based prospective cohort study.

SETTING

Norway, between 1999 and 2008.

PARTICIPANTS

70 149 singleton pregnancies resulting in live-born babies from the Norwegian Mother and Child Cohort Study (no chronic disease, answered questionnaires, no placenta previa/cerclage/serious malformation of fetus, first enrolment pregnancy). Only nulliparous women (n=37 050) were included in the preeclampsia analysis. Both iatrogenic and spontaneous preterm delivery (between gestational weeks 22+0 and 36+6) with spontaneous term controls (between gestational weeks 39+0 and 40+6) were included in the preterm delivery analysis resulting in 34 458 cases.

MAIN OUTCOME MEASURES

Adjusted OR for preeclampsia and preterm delivery according to consumption of probiotic milk at three different time periods (before pregnancy, during early and late pregnancy).

RESULTS

Probiotic milk intake in late pregnancy (but not before or in early pregnancy) was significantly associated with lower preeclampsia risk (adjusted OR: 0.80 (95% CI 0.68 to 0.94) p-value: 0.007). Probiotic intake during early (but not before or during late pregnancy) was significantly associated with lower risk of preterm delivery (adjusted OR: 0.79 (0.64 to 0.97) p-value: 0.03).

CONCLUSIONS

In this observational study, we found an association between timing of probiotic milk consumption during pregnancy and the incidence of the adverse pregnancy outcomes preeclampsia and preterm delivery. If future randomised controlled trials could establish a causal association between probiotics consumption and reduced risk of preeclampsia and preterm delivery, recommending probiotics would be a promising public health measure to reduce these adverse pregnancy outcomes.

Bifidobacterium animalis in combination with human origin of Lactobacillus plantarum ameliorate neuroinflammation in experimental model of multiple sclerosis by altering CD4+ T cell subset balance

BACKGROUND

Multiple Sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS). Recent reports have shown that probiotics can induce immunomodulatory activity with promising effects in inflammatory diseases. This study was designed to reveal the molecular and cellular mechanisms underlying the effect of Lactobacillus plantarum A7, which comprises human commensal bacteria, and Bifidobacterium animalis, a potential probiotic strain, on alleviation of experimental autoimmune encephalomyelitis (EAE), an animal model of MS.

METHODS

To evaluate the therapeutic effects of probiotic strains, female C57BL/6 mice (8-10 wks old) received Lactobacillus plantarum A7, Bifidobacterium animalis PTCC 1631or a mixture of both strains through oral administration daily for 22days beginning simultaneous with induction of EAE. The clinical parameters were recorded daily. On Day 22, each mouse was bled, and their spinal cord was removed for histology analysis. The effects of the treatments on regulatory T (Treg) cells level were evaluated using flow cytometry, and T-cell proliferation was assessed using a BrdU incorporation assay. The supernatants of spleen and lymph nodes cultured and mononuclear cells were collected for quantification of different panel of pro and anti-inflammatory cytokines by ELISA. The analysis of gene expression was performed at RNA level for transcription factors by real-time PCR.

RESULTS

The results showed that treatment with a mixture of the two strains caused a more significant delay in the time of disease onset and clinical score compared to when the strains were used alone. The pathological features of the disease, such as mononuclear infiltration into the CNS, were also inhibited more significantly by the combinational approach. The results also revealed that treatment with combination of both strains enhanced the population of CD4⁺CD25⁺Foxp3⁺-expressing T-cells in the lymph nodes and the spleen.

TREATMENT

with our probiotic strains markedly inhibited disease associated cytokines while increased anti-inflammatory cytokines. Additionally, L. plantarumA7 and B. animalis ameliorated EAE condition by favoring Th2 and Treg differentiation via up-regulation of Foxp3 and GATA3 in the brain and spleen as well as inhibited the differentiation of Th1 and Th17 cells.

CONCLUSIONS

The current research provided evidence that probiotic therapy with L. plantarum and B. animalis can effectively attenuate EAE progression as well as reinforce the polarization of regulatory T-cells.

Cross Talk: The Microbiota and Neurodevelopmental Disorders

Humans evolved within a microbial ecosystem resulting in an interlinked physiology. The gut microbiota can signal to the brain via the immune system, the vagus nerve or other host-microbe interactions facilitated by gut hormones, regulation of tryptophan metabolism and microbial metabolites such as short chain fatty acids (SCFA), to influence brain development, function and behavior. Emerging evidence suggests that the gut microbiota may play a role in shaping cognitive networks encompassing emotional and social domains in neurodevelopmental disorders. Drawing upon pre-clinical and clinical evidence, we review the potential role of the gut microbiota in the origins and development of social and emotional domains related to Autism spectrum disorders (ASD) and schizophrenia. Small preliminary clinical studies have demonstrated gut microbiota alterations in both ASD and schizophrenia compared to healthy controls. However, we await the further development of mechanistic insights, together with large scale longitudinal clinical trials, that encompass a systems level dimensional approach, to investigate whether promising pre-clinical and initial clinical findings lead to clinical relevance.

Effects of Probiotics, Prebiotics, and Synbiotics on Human Health

The human gastrointestinal tract is colonised by a complex ecosystem of microorganisms. Intestinal bacteria are not only commensal, but they also undergo a synbiotic co-evolution along with their host. Beneficial intestinal bacteria have numerous and important functions, e.g., they produce various nutrients for their host, prevent infections caused by intestinal pathogens, and modulate a normal immunological response. Therefore, modification of the intestinal microbiota in order to achieve, restore, and maintain favourable balance in the ecosystem, and the activity of microorganisms present in the gastrointestinal tract is necessary for the improved health condition of the host. The introduction of probiotics, prebiotics, or synbiotics into human diet is favourable for the intestinal microbiota. They may be consumed in the form of raw vegetables and fruit, fermented pickles, or dairy products. Another source may be pharmaceutical formulas and functional food. This paper provides a review of available information and summarises the current knowledge on the effects of probiotics, prebiotics, and synbiotics on human health. The mechanism of beneficial action of those substances is discussed, and verified study results proving their efficacy in human nutrition are presented.

Probiotics for preventing urinary tract infection in people with neuropathic bladder

BACKGROUND

Neuropathic or neurogenic bladder describes a process of dysfunctional voiding as the result of injury in the brain, spinal cord or nerves innervating the bladder. People with neuropathic bladder, such as from spinal cord injury (SCI), are at significant risk of morbidity from urinary tract infections (UTI). Effective methods to prevent UTI in people with SCI have been sought for many years. Probiotics (micro-organisms that exert beneficial health effects in the host) have been recommended for bacterial interference of the urological tract to reduce colonisation by uropathogen and to manage the dual problems of infection and antibiotic resistance.

OBJECTIVES

This review looked at the benefits and harms of probiotics in preventing symptomatic UTI in people with neuropathic bladder compared with placebo, no therapy, or non-antibiotic prophylaxis (cranberry juice, methenamine hippurate, topical oestrogen).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 10 March 2017 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs), quasi-RCTs and cross-over RCTs looking at the use of probiotics for the prophylaxis of UTI in people with neuropathic bladders was considered for inclusion. Men, women and children of all ages with neuropathic bladders from neurological injury such as suprapontine, supra sacral and sacral aetiologies was included. All bladder management types, including reflex voiding, time voiding, indwelling and intermittent catheterization were eligible for this review.Studies comparing probiotics to placebo, no treatment or other non-antibiotic prophylaxis was included. Studies comparing probiotics with antibiotics or in combination with antibiotics were excluded.

DATA COLLECTION AND ANALYSIS

Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) or standardised mean difference (SMD) and 95% CI were planned for continuous outcomes.

MAIN RESULTS

This review includes a total of three studies (one cross-over and two parallel RCTs) which involved 110 participants. All three studies looked at intravesical instillation of a low virulent Escherichia coli (E. coli) strain in reducing the risk of symptomatic UTI in participants with neuropathic bladder, predominantly from SCI. Two studies used the E. coli 83972 strain and one study used the E. coli HU2117 strain.We did not find any RCTs involving other probiotics or other routes of administration for preventing UTI in people with neuropathic bladder.There was consistency in definition of symptomatic UTI in all three studies. Symptoms that all studies considered were relevant to diagnose UTI were adequately defined. All three studies defined microbiological diagnosis of symptomatic UTI.Asymptomatic bacteriuria was not considered an outcome measure in any of the included studies; however it was defined in two studies to establish successful inoculation.It is uncertain if the risk of symptomatic UTI is reduced with bladder inoculation using E. coli because the certainty of the evidence is very low (3 studies, 110 participants: RR 0.32, 95% CI 0.08 to 1.19; I2 = 82%).Two studies reported adverse events. One study reported one episode of autonomic dysreflexia. One study reported three symptomatic UTI occurring in two patients, and two studies mentioned the absence of septicaemia and pyelonephritis. Intravesical instillation was reported as "generally safe". One study reported high attrition rates in participants due to the need to adhere to strict instillation protocols.The overall quality of the studies was poor. All three studies had high risk of attrition bias due to failure of an intention-to-treat analysis which undermines the randomisation process and weakened the results of the studies. All three studies also had high risk of reporting bias.

AUTHORS' CONCLUSIONS

In this review, there were no studies identified addressing oral probiotics in preventing UTI in people with neuropathic bladder. It is uncertain if the risk of symptomatic UTI is reduced in people with neuropathic bladders via intravesical instillation of non-pathogenic E. coli as data were derived from small studies with high risk of bias.Although very minimal levels of harm was reported with this procedure, due to variable success rates, the need for strict adherence to instillation protocols together with high attrition rates in these studies, it is doubtful bladder instillation will be a widely accepted intervention in its current form.It is recommended that further appropriately powered RCTs with more robust methodological reporting be carried out.

Probiotics, D-Lactic acidosis, oxidative stress and strain specificity

The existence of an implicit living microscopic world, composed primarily of bacteria, has been known for centuries. The exact mechanisms that govern the contribution of bacteria to human health and disease have only recently become the subject of intense research efforts. Within this very evident shift in paradigms, the rational design of probiotic formulations has led to the creation of an industry that seeks to progress the engineering of probiotic bacteria that produce metabolites that may enhance human host health and prevent disease. The promotion of probiotics is often made in the absence of quality scientific and clinically plausible data. The latest incursions into the probiotic market of claims have posited the amelioration of oxidative stress via potent antioxidant attributes or limiting the administration of probiotics to those species that do not produce D-Lactic acid (i.e., claims that D-Lactic acid acidosis is linked to chronic health conditions) or are strain-specific (shaping an industry point of difference) for appraising a therapeutic effect. Evidence-based research should guide clinical practice, as there is no place in science and medicine that supports unsubstantiated claims. Extravagant industry based notions continue to fuel the imprimatur of distrust and skepticism that is leveled by scientists and clinicians at an industry that is already rife with scientific and medical distrust and questionable views on probiotics. Ignoring scientifically discordant data, when sorting through research innovations and false leads relevant to the actions of probiotics, drives researcher discomfit and keeps the bar low, impeding the progress of knowledge. Biologically plausible posits are obligatory in any research effort; companies formulating probiotics often exhibit a lack of analytical understanding that then fuels questionable investigations failing to build on research capacity.

Effects of dietary postbiotic and inulin on growth performance, IGF1 and GHR mRNA expression, faecal microbiota and volatile fatty acids in broilers

Background

Postbiotics (metabolic products by lactic acid bacteria) and prebiotics have been established as substitute to antibiotics in order to enhance immunity and growth performance in broiler chickens. Nonetheless, insufficient information is available on the effects of postbiotics and prebiotics combination on growth performance, faecal microbiota, pH and volatile fatty acids (VFA), as well as liver insulin like growth factor 1 (IGF1) and growth hormone receptor (GHR) mRNA expressions in broiler chickens. The aim of this experiment was to evaluate the effects of different types of postbiotics with different levels of prebiotic (inulin) on broiler for those parameters.

Results

The results showed that birds fed T3: (0.3 % RI11 + 0.8 % Inulin), T4: (0.3 % RI11 + 1.0 % Inulin), and T6: (0.3 % RG14+ 1.0 % Inulin) had higher (p < 0.05) final body weight (BW) and total weight gain (WG) than other treatments. Birds fed T3 had lower feed conversion ratio (FCR) which was significantly different from those fed with negative control diet but was similar to other treatments. Postbiotic and inulin increased (p < 0.05) faecal lactic acid bacteria (LAB) and reduced (p < 0.05) Enterobacteriaceae count. Birds fed T4 and T6 had higher faecal acetic acid and propionic acid respectively, and both had higher total VFA and lactic acid bacteria but lower pH and Enterobacteriaceae (ENT) counts compared to other treatments. The liver of birds fed T4 and T6 had higher IGF1 expression compared to other treatments while T6 had higher GHR mRNA expression compared to other treatments.

Conclusions

Results indicate that the addition of postbiotics and inulin combinations had beneficial effects on total BW, feed efficiency, mucosa architecture and IGF1 and GHR mRNA expression in broiler chickens.

Probiotic supplementation can positively affect anxiety and depressive symptoms: a systematic review of randomized controlled trials

Gastrointestinal microbiota, consisting of microbial communities in the gastrointestinal tract, play an important role in digestive, metabolic, and immune functioning. Preclinical studies on rodents have linked behavioral and neurochemical changes in the central nervous system with deficits or alterations in these bacterial communities. Moreover, probiotic supplementation in rodents has been shown to markedly change behavior, with correlated changes in central neurochemistry. While such studies have documented behavioral and mood-related supplementation effects, the significance of these effects in humans, especially in relation to anxiety and depression symptoms, are relatively unknown. Thus, the purpose of this paper was to systematically evaluate current literature on the impact of probiotic supplementation on anxiety and depression symptoms in humans. To this end, multiple databases, including Medline, PsycINFO, PubMed, Scopus, and Web of Science were searched for randomized controlled trials published between January 1990 and January 2016. Search results led to a total of 10 randomized controlled trials (4 in clinically diagnosed and 6 in non-clinical samples) that provided limited support for the use of some probiotics in reducing human anxiety and depression. Despite methodological limitations of the included trials and the complex nature of gut-brain interactions, results suggest the detection of apparent psychological benefits from probiotic supplementation. Nevertheless a better understanding of developmental, modulatory, and metagenomic influences on the GI microbiota, specifically as they relate to mood and mental health, represent strong priorities for future research in this area.

Brain-gut-microbiota axis: challenges for translation in psychiatry

PURPOSE

The accruing data linking the gut microbiome to the development and function of the central nervous system has been proposed as a paradigm shift in neuroscience. The gut microbiota can communicate with the brain via neuroimmune, neuroendocrine, and neural pathways comprising the brain-gut-microbiota axis. Dysfunctional neuroimmune pathways are implicated in stress-related psychiatric disorders.

METHODS

Using depression as our primary example, we review both the preclinical and clinical evidence supporting the possible role played by the gut microbiota in stress-related psychiatric disorders. We consider how this can inform future treatment strategies and outline the challenges and necessary studies for moving the field forward.

RESULTS

The role played by the gut microbiota has not been fully elucidated in psychiatric populations. Although tempting to speculate that psychiatric patients may benefit from therapeutic modulation of the brain-gut-microbiota axis, the translational applications of the results obtained in rodent studies have yet to be demonstrated.

CONCLUSIONS

Evidence of altered gut microbiota composition and function in psychiatric patients is limited and cannot be regarded as proven. Moreover the efficacy of targeting the gut microbiota has not yet been established, and needs further investigation.

Calcium phosphate supplementation increases faecal Lactobacillus spp. in a randomised trial of young adults

The aim of the studies was to determine the effects of calcium carbonate and calcium phosphate supplementation on faecal Lactobacillus spp., with and without a probiotic supplement, in healthy adults. Study 1 comprised of a randomised, double-blind, crossover design; participants (n=15) received 2 capsules/d of 250 mg elemental calcium as calcium carbonate (Ca1) and calcium phosphate (Ca2) each for 2-week periods, with 2-week baseline and washout periods. Study 2 was a randomised, double-blind, crossover design; participants (n=17) received 2 capsules/d of Lactobacillus helveticus R0052 and Lactobacillus rhamnosus R0011 (probiotic) alone, the probiotic with 2 capsules/d of Ca1, and probiotic with 2 capsules/d of Ca2 each for 2-week periods with 2-week baseline and washout periods. In both studies, stools were collected during the baseline, intervention and washout periods for Lactobacillus spp. quantification and qPCR analyses. Participants completed daily questionnaires of stool frequency and compliance. In Study 1, neither calcium supplement influenced viable counts of resident Lactobacillus spp., genome equivalents of lactic acid bacteria or stool frequency. In Study 2, faecal Lactobacillus spp. counts were significantly enhanced from baseline when the probiotic was administered with Ca2 (4.83±0.30, 5.79±0.31) (P=0.02), but not with Ca1 (4.98±0.31) or with the probiotic alone (5.36±0.31, 5.55±0.29) (not significant). Detection of L. helveticus R0052 and L. rhamnosus R0011 was significantly increased with all treatments, but did not differ among treatments. There were no changes in weekly stool frequency. Calcium phosphate co-administration may increase gastrointestinal survival of orally-administered Lactobacillus spp.

Quantitative Risk-Benefit Analysis of Probiotic Use for Irritable Bowel Syndrome and Inflammatory Bowel Disease

Probiotics have seen widespread use for a variety of gastrointestinal problems, especially in two common disorders: irritable bowel syndrome and inflammatory bowel disease. Since a wide variety of probiotic preparations has been used, and despite a large number of studies performed, a great deal of heterogeneity exists among them. Straightforward evidence-based recommendations for the use of probiotics in irritable bowel syndrome and inflammatory bowel disease have thus been difficult to formulate. In an effort to improve understanding of the risk-benefit balance of probiotics in these conditions, this study (1) queried the US FDA Adverse Event Reporting System (FAERS) database for all reported adverse drug events related to probiotics in 2013, and (2) constructed risk-benefit planes for both irritable bowel syndrome and inflammatory bowel disease using a geometric approximation of the confidence region between risk and benefit. The results show that adverse events from probiotics vary widely by disease, and when they occur, they are mild and may be difficult to distinguish from the natural history of the underlying disorders they are used to treat. The risk-benefit plane for irritable bowel syndrome straddles the risk-benefit threshold, so patients can expect a balance between a low chance of risk and also a low chance of benefit. The risk-benefit plane for inflammatory bowel disease largely lies above the risk-benefit threshold, so patients may expect more benefit than risk in most cases. More standardized and high-quality research is needed to improve our understanding of risk and benefit for these complex biopharmaceuticals.

Phenylketonuria: a review of current and future treatments

Phenylketonuria (PKU) is an autosomal recessive inborn error of metabolism caused by a deficiency in the hepatic enzyme phenylalanine hydroxylase (PAH). If left untreated, the main clinical feature is intellectual disability. Treatment, which includes a low Phe diet supplemented with amino acid formulas, commences soon after diagnosis within the first weeks of life. Although dietary treatment has been successful in preventing intellectual disability in early treated PKU patients, there are major issues with dietary compliance due to palatability of the diet. Other potential issues associated with dietary therapy include nutritional deficiencies especially vitamin D and B12. Suboptimal outcomes in cognitive and executive functioning have been reported in patients who adhere poorly to dietary therapy. There have been continuous attempts at improving the quality of medical foods including their palatability. Advances in dietary therapy such as the use of large neutral amino acids (LNAA) and glycomacropeptides (GMP; found within the whey fraction of bovine milk) have been explored. Gene therapy and enzyme replacement or substitution therapy have yielded more promising data in the recent years. In this review the current and possible future treatments for PKU are discussed.

The treatment of gastroparesis, constipation and small intestinal bacterial overgrowth syndrome in patients with Parkinson's disease

INTRODUCTION

Parkinson's disease (PD) affects the nerves of the entire gastrointestinal (GI) tract and may result in profound gastrointestinal (GI) dysfunction leading to poor patient outcomes. Common GI disturbances in patients with PD include gastroparesis (GP), constipation and small intestinal bacterial overgrowth syndrome (SIBO). In particular, GP is difficult to treat due to the limited options available and precautions, contraindications and adverse effects associated with the approved treatments. Moreover, some commonly used medications can worsen pre-existing PD.

AREAS COVERED

Our review will focus on treatment options for GP and SIBO with motilin agonists, dopamine receptor antagonists, Ghrelin agonists muscarinic agonists, 5-HT4 receptor agonists, antibiotics, probiotics and herbal formulation such as iberogast. Constipation occurs in the majority of patients with PD and fortunately many treatments are now available. Our review is based on original papers or reviews selected from PUBMED search and Cochrane reviews.

EXPERT OPINION

Motility disorders of the GI tract are found frequently in patients with PD and treating the underlying GI disorders caused by PD with various prokinetics and laxatives is paramount in achieving improvements in patient's motor function. Various prokinetics and laxatives are now available to provide some relief of the GI morbidity caused by PD leading even to better absorption of even the PD treatments.

Targeting the Microbiome in Inflammatory Bowel Disease: Critical Evaluation of Current Concepts and Moving to New Horizons

Microorganisms present in the intestine possess proinflammatory or anti-inflammatory activities which may modulate inflammatory bowel disease (IBD). The concepts followed by researchers in trying to target the microbiota in IBD were to decrease pathogens or pathobionts, or only the microbial load, and more recently, to favor growth and persistence of favorable microorganisms. We review, here, those concepts and critically analyze the clinical data (especially randomized controlled trials) obtained using antibiotics and probiotics. We eventually present and criticize the rational and data obtained so far following new research strategies including the use of new probiotics, genetically modified organisms and fecal transplantation.

Roles of Commensal Microbiota in Pancreas Homeostasis and Pancreatic Pathologies

The pancreas plays a central role in metabolism, allowing ingested food to be converted and used as fuel by the cells throughout the body. On the other hand, the pancreas may be affected by devastating diseases, such as pancreatitis, pancreatic adenocarcinoma (PAC), and diabetes mellitus (DM), which generally results in a wide metabolic imbalance. The causes for the development and progression of these diseases are still controversial; therefore it is essential to better understand the underlying mechanisms which compromise the pancreatic homeostasis. The interest in the study of the commensal microbiome increased extensively in recent years, when many discoveries have illustrated its central role in both human physiology and maintenance of homeostasis. Further understanding of the involvement of the microbiome during the development of pathological conditions is critical for the improvement of new diagnostic and therapeutic approaches. In the present review, we discuss recent findings on the behavior and functions played by the microbiota in major pancreatic diseases and provide further insights into its potential roles in the maintenance of pancreatic steady-state activities.

Co-administration of a probiotic strain Lactobacillus plantarum LS/07 CCM7766 with prebiotic inulin alleviates the intestinal inflammation in rats exposed to N,N-dimethylhydrazine

The aim of this study was to determine the anti-inflammatory effects of preventive administration of a probiotic strain Lactobacillus plantarum LS/07 CCM7766 alone or in combination with prebiotic inulin or with flax-seed oil in the gut of rats, which developed chronic inflammation following administration of the pro-carcinogen N,N-dimethylhydrazine (DMH). After 28weeks administration of probiotic/prebiotic-containing diet, rats were killed and their colons were examined by immunohistological criteria, whereas cytokines were determined in the jejunal mucosa. Application of DMH triggered the production of pro-inflammatory cytokines IL-2, IL-6, IL-17, and TNF-α, expression of pro-inflammatory mediators NF-κB, COX-2 and iNOS and caused depletion of goblet cells. Supplementing the diet with L. plantarum and its combination with the prebiotic abolished DMH-induced inflammatory process in the jejunal mucosa by inhibiting the production of pro-inflammatory cytokines and by stimulation of anti-inflammatory IL-10 cytokine synthesis, whereas concentration of TGF-β1 was not influenced significantly. Diet prevented a decrease in goblet cell numbers but numbers of mast cells were lowered only moderately. However, combined treatment of rats with L. plantarum and flax-seed oil had no significant effect on the parameters examined, except for decreased expression of NF-κB, in comparison with the negative control. Results indicate that the preventive administration of probiotic L. plantarum LS/07 CCM7766 alone or in combination with prebiotic inulin to rats with DMH-induced chronic inflammation can reduce inflammatory process in the jejunal and colon mucosa, probably indirectly, and involves down-regulation of synthesis of pro-inflammatory cytokines and suppression of NF-κB activity in mucosal cells.

The effect of probiotics for preventing radiation-induced morphological changes in intestinal mucosa of rats

Radiation therapy is an important treatment modality for abdominal or pelvic cancer, but there is a common and serious complication such as radiation-induced enteritis. Probiotics is reported to have positive effects against radiation-induced enteropathy. In this study, morphological changes of bowel mucosa were analyzed in rats to presume the effect of probiotics on radiation-induced enteritis and its correlation with radiation dose. A total of 48 adult male Sprague-Dawley rats were randomly assigned to two groups and received a solution containing 1.0×10(8) colony-forming units of Lactiobacillus acidophilus or water once daily for 10 days. Each of two groups was divided into three subgroups and abdomino-pelvic area of each subgroup was irradiated with 10, 15, and 20 Gy, respectively on the seventh day of feeding the solutions. All rats were sacrificed 3 days after irradiation and the mucosal thickness and villus height of jejunum, ileum and colon were measured. The morphological parameters of the small intestine represented significant differences between two solution groups irradiated 10 or 15 Gy, except for villus height of jejunum in 15 Gy-subgroup (P=0.065). There was no significant morphometric difference between two groups irradiated with 20 Gy of radiation. Probiotics appear to be effective for the morphological shortening of small intestinal mucosa damaged by radiation less than or equal to 15 Gy.

Effects of feeding different postbiotic metabolite combinations produced by Lactobacillus plantarum strains on egg quality and production performance, faecal parameters and plasma cholesterol in laying hens

Background

Probiotics are beneficial bacteria that are able to colonize the host digestive system, increasing the natural flora and preventing colonization of pathogenic organisms and thus, securing optimal utility of the feed. However, commercial probiotic often do not meet the expected standards and the viability of the efficacy of these strains remains questionable. Another major issue has been highlighted in relation to the application of antibiotic resistant probiotics, the antibiotic resistant gene can be transferred between organisms. Recently, postbiotic metabolites produced from microbes have been extensively studied as feed additive in order to substitute in-feed antibiotics.

Results

No significant difference (P > 0.05) was found among the treatment groups on overall feed intake, egg weight, egg mass and feed conversion efficiency. COM456 had a significant reduction (P < 0.05) in faecal pH compared to the other groups at 28 weeks of age onwards. COM456 had significant higher (P < 0.05) level of lactic acid bacteria counts from 30 weeks of age onwards, followed by COM246 and COM345 at 32 and 34 weeks of age, respectively. Significant reduction of faecal Enterobacteriaceae (P < 0.05) were observed in COM246 and COM456 from 30 weeks of age onwards. The lowest levels (P < 0.05) of plasma and egg yolk cholesterol were observed in COM456, followed by COM345 and COM246. There was no significant difference in terms of yolk weight between the treatment groups. Significant higher (P < 0.05) content of C18:3, C20:2 and C22:6 were found in treatments supplemented with metabolite combinations as compared with the control group.

Conclusions

The present study demonstrated the positive effects of metabolite combinations supplementation in laying hens. Increase in hen-day egg production was observed in all treatments supplemented with metabolite combinations. In addition, the metabolite combinations, COM456 had reduced the faecal pH and faecal Enterobacteriaceae population, improved the faecal lactic acid bacteria, reduced the plasma and yolk cholesterol and improved the faecal volatile fatty acids content. Postbiotic metabolite combinations can be used as an alternative feed additive to achieve high productivity and better animal health while reducing the use of conventional chemotherapeutic agents such as in-feed antimicrobials.