Use of probiotics in gastrointestinal disorders: what to recommend?

Therapeutic effects of probiotics on symptoms of depression in children and adolescents: a systematic review and meta-analysis

This meta-analysis aimed at investigating the therapeutic effects of probiotics against the symptoms of depression in children and adolescents as well as to identify the potential confounders. Following PRISMA guidelines, major databases were searched for randomized controlled trials focusing on effects of probiotics against the symptoms of depression in children and adolescents to analyze the effect size (ES) for primary outcomes (i.e., improvement in depressive symptoms) expressed as standardized mean difference (SMD) and odds ratios (ORs) for continuous and categorical variables, respectively, with 95% confidence interval (CI). Meta-analysis of five studies (692 participants, mean age = 7.33 years, treatment duration 8-104 weeks) demonstrated no significant improvement in depressive symptoms in subjects receiving probiotics (SMD = 0.04, 95% CI: -0.33 to 0.41, p = 0.84, five studies, 692 participants). Subgroup analysis also showed no significant improvement associated with probiotic use relative to controls in the subgroup of studies focusing on individuals diagnosed with neurodevelopmental disorders (SMD = -0.11, 95% CI: -0.73 to 0.51, p = 0.72, three studies, 452 participants) and that recruiting the general population (SMD = 0.24, 95% CI: -0.43 to 0.91, p = 0.48, two studies, 240 participants). However, high levels of heterogeneity were found in both our primary results (I2 = 77%, p = 0.001) and subgroup analyses for those with neurodevelopmental disorders (I2 = 84%, p = 0.002) and the general population (I2 = 79%, p = 0.03). The results did not support the use of probiotics for relieving depressive symptoms compared with controls in children and adolescents diagnosed with neurodevelopmental disorders or in the general population. Nevertheless, given the high level of heterogeneity across the included trials and a lack of studies focusing on those with diagnoses of anxiety or depression in the current meta-analysis, further large-scale clinical investigations are required to elucidate the therapeutic potential of probiotics against depressive symptoms in these populations, especially in those diagnosed with neurodevelopmental disorders or depression.

Can polymeric nanofibers effectively preserve and deliver live therapeutic bacteria?

Probiotics and live therapeutic bacteria (LTB), their strictly regulated therapeutic counterpart, are increasingly important in treating and preventing biofilm-related diseases. This necessitates new approaches to (i) preserve bacterial viability during manufacturing and storage and (ii) incorporate LTB into delivery systems for enhanced therapeutic efficacy. This review explores advances in probiotic and LTB product development, focusing on preservation, protection, and improved delivery. Preservation of bacteria can be achieved by drying methods that decelerate metabolism. These methods introduce stresses affecting viability which can be mitigated with suitable excipients like polymeric or low molecular weight stabilizers. The review emphasizes the incorporation of LTB into polymer-based nanofibers via electrospinning, enabling simultaneous drying, encapsulation, and delivery system production. Optimization of bacterial survival during electrospinning and storage is discussed, as well as controlled LTB release achievable through formulation design using gel-forming, gastroprotective, mucoadhesive, and pH-responsive polymers. Evaluation of the presence of the actual therapeutic strains, bacterial viability and activity by CFU enumeration or alternative analytical techniques is presented as a key aspect of developing effective and safe formulations with LTB. This review offers insights into designing delivery systems, especially polymeric nanofibers, for preservation and delivery of LTB, guiding readers in developing innovative biotherapeutic delivery systems.

Deciphering the mechanism of anti-quorum sensing post-biotic mediators against Streptococcus mutans

OBJECTIVE

Glucosyltransferases (Gtfs) and quorum sensing (QS) mediated transduction genes play critical roles in the pathogenesis of Streptococcus mutan-mediated dental caries. Therefore, targeting gtfs and QS-mediated virulence genes have therefore emerged as an intriguing goal for efficient therapeutic approaches that block cariogenic biofilms.

METHODS

Post-biotic mediators (PMs) obtained from our previously isolated and characterized beneficial bacteria Enterobacter colacae PS-74 was assessed for its antibiofilm potential against S. mutans. According to the transcriptome method, qRT-PCR analysis was performed against virulence genes. For microscopic visualization, SEM and CLSM analyses were used to confirm the inhibitory effects of PMs.

RESULTS

PMs dramatically reduced the expression of QS signal transduction, glucan metabolism, and biofilm-regulated genes such gtfB, gtfC, ComDE, VicR, brpA in S. mutans, which validates the outcomes of in vitro result. Their unique metabolites may help to control biofilm formation by eluding antimicrobial resistance.

CONCLUSION

Considering the above findings, PMs may deem to be an innovative, alluring, and secure method for preventing dental caries due to their biological activity. Our study unravels the inhibitory effect of PMs, which will contribute to instruct drug design strategies for effective inhibition of S. mutans biofilms.

Assessment of Knowledge and Attitudes of Physicians and Pharmacists on Probiotics: A Cross-Sectional Survey

Objectives

Probiotics have been gaining increased attention from the public recently, which originates concerns about their rationale use among healthcare professionals. Although there is evidence on the efficacy and safety of probiotics in certain gastrointestinal disorders, it is important to identify healthcare professionals' opinions on probiotics. This study aimed to identify the opinions of pharmacists and physicians on the use of probiotics.

Materials and Methods

This cross-sectional study was conducted between November, 2017 and August, 2018 among pharmacists and physicians practicing in Ankara, Türkiye. An electronic survey was designed and sent to the participants via e-mail.

Results

A total of 361 pharmacists (74.5% female) and 356 physicians (42.4% female) participated in the study. Approximately two-thirds of pharmacists and physicians were familiar with the mechanism of action and indications of probiotics. Most pharmacists and physicians recommended probiotics to be used in gastrointestinal system disorders (99.7% and 97.7%). Other areas that probiotics are commonly recommended was genitourinary system (29.3%) by pharmacists and dermatological symptoms (15.1%) by phycisians, respectively. Considering patient advice regarding the probiotics, pharmacists (63.3%) seemed to receive more requests compared to physicians (30.9%); and with regard to the probiotic recommendation, 70.7% and 38.2% of pharmacists and physicians, respectively, indicated that they have no concerns, but 61% of physicians have concerns on reimbursement policy when prescribing.

Conclusion

Pharmacists and physicians are healthcare providers commonly asked about probiotics by patients. Therefore, it is important to address healthcare professionals' concerns and increase their knowledge of the use of probiotics for different health conditions. Given that probiotic products can be purchased without a prescription, healthcare professionals in primary care settings should be more vigilant about the rational use of probiotics.

Advancing our understanding of the influence of drug induced changes in the gut microbiome on bone health

The gut microbiome has been implicated in a multitude of human diseases, with emerging evidence linking its microbial diversity to osteoporosis. This review article will explore the molecular mechanisms underlying perturbations in the gut microbiome and their influence on osteoporosis incidence in individuals with chronic diseases. The relationship between gut microbiome diversity and bone density is primarily mediated by microbiome-derived metabolites and signaling molecules. Perturbations in the gut microbiome, induced by chronic diseases can alter bacterial diversity and metabolic profiles, leading to changes in gut permeability and systemic release of metabolites. This cascade of events impacts bone mineralization and consequently bone mineral density through immune cell activation. In addition, we will discuss how orally administered medications, including antimicrobial and non-antimicrobial drugs, can exacerbate or, in some cases, treat osteoporosis. Specifically, we will review the mechanisms by which non-antimicrobial drugs disrupt the gut microbiome's diversity, physiology, and signaling, and how these events influence bone density and osteoporosis incidence. This review aims to provide a comprehensive understanding of the complex interplay between orally administered drugs, the gut microbiome, and osteoporosis, offering new insights into potential therapeutic strategies for preserving bone health.

Adverse effects of titanium dioxide nanoparticles on beneficial gut bacteria and host health based on untargeted metabolomics analysis

Titanium dioxide (TiO2) is a common additive in foods, medicines, and personal care products. In recent years, nano-scale particles in TiO2 additives have been an increasing concern due to their potential adverse effects on human health, especially gut health. The objective of this study was to determine the impact of titanium dioxide nanoparticles (TiO2 NPs, 30 nm) on beneficial gut bacteria and host response from a metabolomics perspective. In the in vitro study, four bacterial strains, including Lactobacillus reuteri, Lactobacillus gasseri, Bifidobacterium animalis, and Bifidobacterium longum were subjected to the treatment of TiO2 NPs. The growth kinetics, cell viability, cell membrane permeability, and metabolomics response were determined. TiO2 NPs at the concentration of 200 μg/mL showed inhibitory effects on the growth of all four strains. The confocal microscope results indicated that the growth inhibitory effects could be associated with cell membrane damage caused by TiO2 NPs to the bacterial strains. Metabolomics analysis showed that TiO2 NPs caused alterations in multiple metabolic pathways of gut bacteria, such as tryptophan and arginine metabolism, which were demonstrated to play crucial roles in regulating gut and host health. In the in vivo study, mice were fed with TiO2 NPs (0.1 wt% in diet) for 8 weeks. Mouse urine was collected for metabolomics analysis and the tryptophan metabolism pathway was also significantly affected in TiO2 NPs-fed mice. Moreover, four neuroprotective metabolites were significantly reduced in both in vitro bacteria and in vivo urine samples. Overall, this study provides insights into the potential adverse effects of TiO2 NPs on gut bacteria and the metabolic responses of both bacteria and host. Further research is needed to understand the causality between gut bacteria composition and the metabolism pathway, which is critical to monitor the gut-microbiome mediated metabolome changes in toxicological assessment of food components.

Streptococcus lactarius MB622 and Streptococcus salivarius MB620 isolated from human milk reduce chemokine IL-8 production in response to TNF-α in Caco-2 cell line, an exploratory study

Streptococci are a predominant genera of the human milk microbiome. Among different lactic acid bacteria (LAB) a few Streptococcal strains are also considered as probiotics. Probiotic bacteria are reported to modulate immunity when consumed in adequate amount and bacterial hydrophobicity can be considered as a preliminary experiment for the adhesive capability of probiotic bacteria to the epithelial cells. The present study aimed to investigate the probiotic, hydrophobic and immune modulation property of Streptococcus lactarius MB622 and Streptococcus salivarius MB620, isolated from human milk. S. lactarius MB622 and S. salivarius MB620 displayed higher hydrophobicity (78 % and 59 % respectively) in addition to intrinsic probiotic properties such as gram positive classification, catalase negative activity, resistance to artificially stimulated gastric juice and gastrointestinal bile salt concentration. In conclusion Streptococcus lactarius MB622 and Streptococcus salivarius MB620 isolated from human milk when administered in sufficient amount and for certain duration could be used to reduce inflammation inside the colon by reducing the production of inflammatory booster (IL-8) in diseased state.

Identification and Characterization of Probiotic Lactiplantibacillus plantarum BI-59.1 Isolated from tejuino and Its Capacity to Produce Biofilms

Tejuino is a popular and traditional beverage consumed in north and western of Mexico, due to its biological properties, it is considered a natural source of probiotics. Nevertheless, few studies have been performed on Tejuino microbiota. In this work, the probiotic potential of the tejuino isolated Lactiplantibacillus plantarum BI-59.1 strain was investigated. Its effectiveness was compared with a commercial Lactobacillus spp and identified by 16S rDNA sequence homology. Lactiplantibacillus plantarum BI-59.1 strain showed probiotic properties, i.e., production of antimicrobial compounds (lactic acid and presence of plantaricin A gene), inhibition of entero-pathogens by planktonic cells and metabolites (Salmonella enterica serovar Typhimurium inhibition to HT29-MTX adhesion), biofilm formation, bacterial adhesion (HT29-MTX, 3.96 CFU/cell), and tolerance to stimulated gastrointestinal conditions (tolerance to pH 3 and bile salts). The strain was gamma hemolytic, susceptible to most antibiotics and negative for gelatinase production; thus, the Lactiplantibacillus. plantarum BI-59.1 strain is suitable for its use as a probiotic for nutraceutical or pharmaceutical formulations.

Probiotic modulation of gut microbiota by Bacillus coagulans MTCC 5856 in healthy subjects: A randomized, double-blind, placebo-control study

BACKGROUND

Probiotics are known to rebalance the gut microbiota in dysbiotic individuals, but their impact on the gut microbiome of healthy individuals is seldom studied. The current study is designed to assess the impact and safety of Bacillus coagulans (Weizmannia coagulans) microbial type culture collection 5856 (LactoSpore®) supplementation on microbiota composition in healthy Indian adults.

METHODS

The study participants (N = 30) received either LactoSpore (2 billion colony-forming units/capsule) or placebo for 28 days. The general and digestive health were assessed through questionnaires and safety by monitoring adverse events. Taxonomic profiling of the fecal samples was carried out by 16S rRNA amplicon sequencing using the Illumina MiSeq platform. The bacterial persistence was enumerated by quantitative reverse transcription-polymerase chain reaction.

RESULTS

Gut health, general health, and blood biochemical parameters remained normal in all the participants. No adverse events were reported during the study. Metataxonomic analysis revealed minimal changes to the gut microbiome of otherwise healthy subjects and balance of Bacteroidetes and Firmicutes was maintained by LactoSpore. The relative abundance of beneficial bacteria like Prevotella, Faecalibacterium, Blautia, Megasphaera, and Ruminococcus showed an increase in probiotic-supplemented individuals. The quantitative polymerase chain reaction analysis revealed highly variable numbers of B. coagulans in feces before and after the study.

CONCLUSION

The present study results suggest that LactoSpore is safe for consumption and does not alter the gut microbiome of healthy individuals. Minor changes in a few bacterial species may have a beneficial outcome in healthy individuals. The results reiterate the safety of B. coagulans microbial type culture collection 5856 as a dietary supplement and provide a rationale to explore its effect on gut microbiome composition in individuals with dysbiosis.

Probiotics in vaginal health

Bacterial vaginosis, a type of vaginal inflammation, can be considered the main reason for abnormal discharges of the vagina and vaginal dysbiosis during reproductive years. Epidemiological investigations of females suffering from vaginitis demonstrated that at least 30% to 50% of all women had Bacterial vaginosis (BV). One of the fields of treatment is the use of probiotics, probiotics are commonly defined as viable microorganisms (yeasts or bacteria) that can positively affect the health of their hosts. They are used in foods, notably fermented milk products, and medicine-related products. The development of new probiotic strains is aimed at more active advantageous organisms. Lactobacillus species are the dominant bacteria in a normal vagina that can decrease the pH of the vagina by the production of lactic acid. A number of lactobacilli types can produce hydrogen peroxide as well. The presence of hydrogen peroxide-induced low pH can prevent the growth of several other microorganisms. The vaginal flora of BV cases can modify by replacing the Lactobacillus species with a high density of anaerobic bacteria (i.e. Mobiluncus sp. Bacteroides sp.), Mycoplasma hominis, and Gardnerella vaginalis. More vaginal infections are treated with medications, while there is a possibility of recurrence and chronic infection because of the adverse effects on the indigenous lactobacilli. Probiotics and prebiotics have shown capacities for optimizing, maintaining, and restoring the vaginal microflora. Therefore, biotherapeutics can offer alternative approaches to reduce infections of the vagina and thus promote consumers' health.

Migraine and obesity: what is the real direction of their association?

INTRODUCTION

In recent decades, studies have addressed the issue of how migraine and obesity are related and have suggested obesity as a risk factor for migraine headache. However, the exact direction of this relationship remains under debate. In this review, the authors summarize the evidence that have suggested migraine as a risk factor for obesity and overweightness.

AREAS COVERED

This article reviews the results of the previous research published on PubMed and Scopus databases (from 2000 to 2020) concerning the association between migraine and obesity to determine the actual direction of their association. Special attention has been given to the common mechanistic pathways involved in the pathophysiology of migraine and obesity.

EXPERT OPINION

The majority of research conducted thus far has considered obesity as a risk factor for migraine. However, because of the cross-sectional design of available research, we cannot be certain of the proposed direction of this association. There is evidence supporting the hypothesis that obesity can serve as a consequence of migraine through the effects of neuropeptides, inflammatory mediators, adipokines, gut microbiota and modifications in eating behavior and lifestyle. However, the real direction of the relationship between migraine and obesity should be further investigated in large prospective studies.

Probiotics media: significance, challenges, and future perspective - a mini review

The health benefits associated with probiotics have increased their application in pharmaceutical formulations and functional food development. High production of probiotic biomass requires a cost-effective production method and nutrient media optimization. The biomass production of probiotics can be enhanced by optimizing growth parameters such as substrate, pH, incubation time, etc. For economical industrial production of probiotic biomass, it is required to design a new medium with low cost. Wastes from the food industries are promising components for the development of the low-cost medium. Industrial wastes such as cheese whey and corn steep liquor are excellent examples of reliable sources of nitrogen for the biomass production of probiotic bacteria. The increased yield of biomass reduced the cost of production. This review focuses on the importance of probiotic media for biomass production and its challenges.

Graphical Abstract

New Insights into the Gut Microbiota in Neurodegenerative Diseases from the Perspective of Redox Homeostasis

An imbalance between oxidants and antioxidants in the body can lead to oxidative stress, which is one of the major causes of neurodegenerative diseases. The gut microbiota contains trillions of beneficial bacteria that play an important role in maintaining redox homeostasis. In the last decade, the microbiota-gut-brain axis has emerged as a new field that has revolutionized the study of the pathology, diagnosis, and treatment of neurodegenerative diseases. Indeed, a growing number of studies have found that communication between the brain and the gut microbiota can be accomplished through the endocrine, immune, and nervous systems. Importantly, dysregulation of the gut microbiota has been strongly associated with the development of oxidative stress-mediated neurodegenerative diseases. Therefore, a deeper understanding of the relationship between the gut microbiota and redox homeostasis will help explain the pathogenesis of neurodegenerative diseases from a new perspective and provide a theoretical basis for proposing new therapeutic strategies for neurodegenerative diseases. In this review, we will describe the role of oxidative stress and the gut microbiota in neurodegenerative diseases and the underlying mechanisms by which the gut microbiota affects redox homeostasis in the brain, leading to neurodegenerative diseases. In addition, we will discuss the potential applications of maintaining redox homeostasis by modulating the gut microbiota to treat neurodegenerative diseases, which could open the door for new therapeutic approaches to combat neurodegenerative diseases.

A budding concept with certain microbiota, anti-proliferative family proteins, and engram theory for the innovative treatment of colon cancer

Inflammatory bowel disease (IBD) is a multifactorial chronic disease. Patients with IBD have an increased risk of developing colorectal cancer which has become a major health concern. IBD might exert a role of engrams for making the condition of specific inflammation in the gut. Dysregulation of immune cells induced by the command of engrams might be crucial in the pathogenesis of damages in gut epithelium. The anti-proliferative (APRO) family of anti-proliferative proteins characterized by immediate early responsive gene-products that might be involved in the machinery of the carcinogenesis in IBD. Herein, it is suggested that some probiotics with specific bacteria could prevent the development and/or progression of the IBD related tumors. In addition, consideration regarding the application of studying APRO family proteins for the comprehension of IBD related tumors has been presented. It is hypothesized that overexpression of Tob1, a member of APRO family proteins, in the epithelium of IBD could suppress the function of adjacent cytotoxic immune cells possibly via the paracrine signaling.

Antioxidant and Antibacterial Effects of Potential Probiotics Isolated from Korean Fermented Foods

A total of sixteen bacterial strains were isolated and identified from the fourteen types of Korean fermented foods that were evaluated for their in vitro probiotic potentials. The results showed the highest survivability for Bacillus sp. compared to Lactobacillus sp. in simulated gastric pH, and it was found to be maximum for B. inaquosorum KNUAS016 (8.25 ± 0.08 log10 CFU/mL) and minimum for L. sakei KNUAS019 (0.8 ± 0.02 log10 CFU/mL) at 3 h of incubation. Furthermore, B. inaquosorum KNUAS016 and L. brevis KNUAS017 also had the highest survival rates of 6.86 ± 0.02 and 5.37 ± 0.01 log10 CFU/mL, respectively, in a simulated intestinal fluid condition at 4 h of incubation. The percentage of autoaggregation at 6 h for L. sakei KNUAS019 (66.55 ± 0.33%), B. tequilensis KNUAS015 (64.56 ± 0.14%), and B. inaquosorum KNUAS016 (61.63 ± 0.19%) was >60%, whereas it was lower for L. brevis KNUAS017 (29.98 ± 0.09%). Additionally, B. subtilis KNUAS003 showed higher coaggregation at 63.84 ± 0.19% while B. proteolyticus KNUAS001 found at 30.02 ± 0.33%. Among them, Lactobacillus sp. showed the best non-hemolytic activity. The highest DPPH and ABTS radical scavenging activity was observed in L. sakei KNUAS019 (58.25% and 71.88%). The cell-free supernatant of Lactobacillus sp. considerably inhibited pathogenic growth, while the cell-free supernatant of Bacillus sp. was moderately inhibited when incubated for 24 h. However, the overall results found that B. subtilis KNUAS003, B. proteolyticus KNUAS012, L. brevis KNUAS017, L. graminis KNUAS018, and L. sakei KNUAS019 were recognized as potential probiotics through different functional and toxicity assessments.

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.

Selective Probiotic Treatment Positively Modulates the Microbiota-Gut-Brain Axis in the BTBR Mouse Model of Autism

Recent studies have shown promise for the use of probiotics in modulating behaviour through the microbiota–gut–brain axis. In the present study, we assessed the impact of two probiotic strains in mitigating autism-related symptomology in the BTBR T⁺ Itpr3^tf/J mouse model of autism spectrum disorder (ASD). Male juvenile BTBR mice were randomized into: (1) control, (2) Lr probiotic (1 × 10⁹ CFU/mL Lacticaseibacillus rhamnosus HA-114), and (3) Ls probiotic groups (1 × 10⁹ CFU/mL Ligilactobacillus salivarius HA-118) (n = 18–21/group), receiving treatments in drinking water for 4 weeks. Gut microbiota profiling by 16S rRNA showed Lr, but not Ls supplementation, to increase microbial richness and phylogenetic diversity, with a rise in potential anti-inflammatory and butyrate-producing taxa. Assessing serum and brain metabolites, Lr and Ls supplementation produced distinct metabolic profiles, with Lr treatment elevating concentrations of potentially beneficial neuroactive compounds, such as 5-aminovaleric acid and choline. As mitochondrial dysfunction is often observed in ASD, we assessed mitochondrial oxygen consumption rates in the prefrontal cortex and hippocampus. No differences were observed for either treatment. Both Lr and Ls treatment reduced behavioural deficits in social novelty preference. However, no changes in hyperactivity, repetitive behaviour, and sociability were observed. Results show Lr to impart positive changes along the microbiota–gut–brain axis, exhibiting beneficial effects on selected behaviour, gut microbial diversity, and metabolism in BTBR mice.

Potential role of gut microbiota in patients with COVID-19, its relationship with lung axis, central nervous system (CNS) axis, and improvement with probiotic therapy

Coronavirus Disease 2019 (COVID-19) is a pandemic disease caused by a new corona virus. COVID-19 affects different people in different ways. COVID-19 could affect the gastrointestinal system via gut microbiota impairment. Gut microbiota could affect lung health through a relationship between gut and lung microbiota, which is named gut-lung axis. Gut microbiota impairment plays a role in pathogenesis of various pulmonary disease states, so GI diseases were found to be associated with respiratory diseases. Moreover, most infected people will develop mild to moderate gastrointestinal (GI) symptoms such as diarrhea, vomiting, and stomachache, which is caused by impairment in gut microbiota. Therefore, the current study aimed to review potential role of gut microbiota in patients with COVID-19, its relation with lung axis, Central Nervous System (CNS) axis and improvement with probiotic therapy. Also, this review can be a guide for potential role of gut microbiota in patients with COVID-19.

"Osteomicrobiology": The Nexus Between Bone and Bugs

A growing body of scientific evidence supports the notion that gut microbiota plays a key role in the regulation of various physiological and pathological processes related to human health. Recent findings have now established that gut microbiota also contributes to the regulation of bone homeostasis. Studies on animal models have unraveled various underlying mechanisms responsible for gut microbiota-mediated bone regulation. Normal gut microbiota is thus required for the maintenance of bone homeostasis. However, dysbiosis of gut microbiota communities is reported to be associated with several bone-related ailments such as osteoporosis, rheumatoid arthritis, osteoarthritis, and periodontitis. Dietary interventions in the form of probiotics, prebiotics, synbiotics, and postbiotics have been reported in restoring the dysbiotic gut microbiota composition and thus could provide various health benefits to the host including bone health. These dietary interventions prevent bone loss through several mechanisms and thus could act as potential therapies for the treatment of bone pathologies. In the present review, we summarize the current knowledge of how gut microbiota and its derived microbial compounds are associated with bone metabolism and their roles in ameliorating bone health. In addition to this, we also highlight the role of various dietary supplements like probiotics, prebiotics, synbiotics, and postbiotics as promising microbiota targeted interventions with the clinical application for leveraging treatment modalities in various inflammatory bone pathologies.

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.

Why use nutraceutical strategies for the Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic functional bowel disorder, often stress-related, identified by many abdominal symptoms, the most important of which is the chronic visceral abdominal pain. Therefore, IBS commonly impairs the quality of life of patients, moreover it is frequently linked to depressive and anxiety symptoms. The treatment of IBS primarily focuses on symptoms relief. Unfortunately, up to now, no efficacious therapies have been found. Therefore, it would be important to develop new anti-IBS interventions. The aim of this brief review is to summarize the current evidence of nutraceutical supplementation in IBS treatment, with probiotics, prebiotics, synbiotics, butyrate, palmitoylethanolamide and colostrum. Since nutraceutics are over the counter products, the review has the purpose to better inform the medicinal chemist and the practitioner about the possible benefit mechanisms and the many advantages that these therapies offer. All of these compounds present multiple mechanisms of action, such as restoring the physiological microbiota, potentiating gastrointestinal barrier's function, immunomodulatory, anti-inflammatory and antinociceptive activities. From the literature data it results that these compounds are not only capable to improve IBS symptomatology, but mainly display an optimal safety and tolerability profile. Although extensive studies must be carried out to reinforce the evidences from the so far limited clinical trials, the supplementation with these compounds may be useful considering the warnings of prescription medicines for special populations of patients, such as elders, youngsters, or patients who need a combination therapy. Finally, the nutraceutical approach may improve adherence to treatment, given its better acceptance by the patients compared to pharmacological therapy.

Orally Administered Probiotics Decrease Aggregatibacter actinomycetemcomitans but Not Other Periodontal Pathogenic Bacteria Counts in the Oral Cavity: A Systematic Review and Meta-Analysis

Introduction: At the initial part of the gastrointestinal tract, multiple tissues serve the normal function of food delivery. Periodontal structures are integral elements of these. When they deteriorate, it is extremely challenging to regenerate and reconstruct them. The conventional intervention for periodontal disease is scaling and root planning with the aim of reducing pathogenic bacteria. However, periodontal pathogens can rapidly recolonize treated areas. Probiotics have been proposed as novel tools for managing oral health by suppressing pathogenic bacteria through their anti-inflammatory effect, but the available data are controversial. Aim: Therefore, we performed a meta-analysis to study the effect of probiotics on periodontal pathogenic bacteria. Methods: The study was registered in PROSPERO under registration number CRD42018094903. A comprehensive literature search from four electronic databases (PubMed, Cochrane CENTRAL, Embase, and Web of Science) yielded nine eligible records for statistical analysis. Studies measuring bacterial counts in saliva and supra- and subgingival plaque were included. Bacterial counts were analyzed using standard mean difference (SMD) and by a random effects model with the DerSimonian-Laird estimation. Results: The results showed a significant decrease in the overall count of Aggregatibacter actinomycetemcomitans in the probiotic-treated group compared to the control at 4 weeks (SMD: -0.28; 95% CI: -0.56--0.01; p = 0.045) but not later. Analyzing the bacterial counts in subgroups, namely, in saliva and supra- and subgingival plaque, separately, yielded no significant difference. Probiotics had no significant effect on the overall count of Porphyromonas gingivalis at 4 weeks (SMD: -0.02; 95% CI: -0.35-0.31; p = 0.914) or later. Subgroup analysis also revealed no significant difference between treatment and control groups nor did probiotics significantly decrease the overall and subgroup bacterial counts of Prevotella intermedia, Tannerella forsythia, and Fusobacterium nucleatum. Conclusion: Our data support the beneficial effect of probiotics in reducing A. actinomycetemcomitans counts, but not of other key periodontal pathogenic bacteria in periodontal disease patients. However, due to the complex mechanism associated with periodontal disease and the limitations of the available studies, there is a further need for well-designed randomized clinical trials to assess the efficacy of probiotics.

The Gut-Brain Axis: Literature Overview and Psychiatric Applications

IMPORTANCE

Literature exploring the relationship between the intestinal microbiome and its effects on general health and well-being has grown significantly in recent years, and our knowledge of this subject continues to grow. Mounting evidence indicates that the intestinal microbiome is a potential target for therapeutic intervention in psychiatric illness and in neurodegenerative disorders such as Alzheimer disease. It is reasonable to consider modulating not just a patient's neurochemistry, behavior, or cognitive habits, but also their intestinal microbiome in an effort to improve psychiatric symptoms.

OBSERVATIONS

In this review paper, we show that intestinal microbiota possess the ability to directly influence both physical and mental well-being; therefore, should be included in future discussions regarding psychiatric treatment.

CONCLUSIONS

Clinicians are encouraged to consider patients' gut health when evaluating and treating psychiatric conditions, such as anxiety and depression. Optimization and diversification of gut flora through the use of psychobiotics-probiotics that confer mental health benefits-may soon become standard practice in conjunction with traditional psychiatric treatment modalities such as pharmacotherapy and psychotherapy.

Novel Indigenous Probiotic Lactobacillus reuteri Strain Produces Anti-biofilm Reuterin against Pathogenic Periodontal Bacteria

OBJECTIVE

 The aim of this study was to evaluate the effect of reuterin produced by a novel probiotic strain of Lactobacillus reuteri against periodontal biofilms.

MATERIALS AND METHODS

 L. reuteri LC382415 (an indigenous Indonesian strain) was cultured in Man, Rogosa, and Sharpe (MRS) agar in anaerobic conditions for 24 hours. To isolate reuterin, L. reuteri was suspended in 300-mM glycerol in MRS broth and incubated under anaerobic conditions for 3 hours, and the supernatant fraction was filtered. The presence of reuterin was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and its concentration was determined. The effect of reuterin on Porphyromonas gingivalis ATCC 33277 and T. denticola ATCC 35405 biofilms was evaluated using biofilm assays. Biofilms were formed by incubating bacteria in 96-well microplates for 48 hours. A dose-dependent experiment was performed with reuterin concentrations of 12.5, 25, 50, and 100 μg/mL on biofilms. The inhibitory effect was measured at 1, 3, 6, and 24 hours. The biofilm masses were measured at 490 nm. Statistical analysis was using one-way ANOVA.

RESULTS

 The SDS-PAGE assay confirmed the presence of reuterin (52 kDa) in the culture supernatant of the L. reuteri strain. Reuterin in a concentration as low as 12.5 μg/mL significantly inhibited single- and mixed-species biofilms (p < 0.05).

CONCLUSIONS

 This is the first study to demonstrate the promising effect of reuterin isolated from L. reuteri LC382415 against periodontal bacteria. Further studies are warranted to explore the mechanism of this active component.

Putative Probiotic Strains Isolated from Kefir Improve Gastrointestinal Health Parameters in Adults: a Randomized, Single-Blind, Placebo-Controlled Study

The dairy products remain as the largest reservoir for isolation of probiotic microorganisms. While probiotics have been immensely reported to exert various health benefits, it is also a common notion that these health potentials are strain and host dependent, leading to the need of more human evidence based on specific strains, health targets, and populations. This randomized, single-blind, and placebo-controlled human study aimed to evaluate the potential benefits of putative probiotic strains isolated from kefir on gastrointestinal parameters in fifty-six healthy adults. The consumption of AB-kefir (Bifidobacterium longum, Lactobacillus acidophilus, L. fermentum, L. helveticus, L. paracasei, L. rhamnosus, and Streptococcus thermophiles; total 10 log CFU/sachet) daily for 3 week reduced symptoms of abdominal pain, bloating (P = 0.014), and appetite (P = 0.041) in male subjects as compared to the control. Gut microbiota distribution profiles were shifted upon consumption of AB-kefir compared to baseline, where the abundance of bifidobacteria was increased in male subjects and maintained upon cessation of AB-kefir consumption. The consumption of AB-kefir also increased gastrointestinal abundance of total anaerobes (P = 0.038) and total bacterial (P = 0.049) in female subjects compared to the control after 3 weeks. Our results indicated that AB-kefir could potentially be developed as a natural strategy to improve gastrointestinal functions in adults.

Assessing the post-treatment therapeutic effect of pinaverium in irritable bowel syndrome: a randomized controlled trial

Irritable bowel syndrome (IBS) is the most common gastrointestinal disorder significantly decreasing patients' lives of quality and placing huge economic burden on our society. Existing studies indicated that the therapeutic effects maintained for a period of time after the treatments were discontinued. It is clinically important to assess these post-treatment therapeutic effects (PTTE), which prevent IBS from relapsing. To assess the PTTE in pinaverium treatment and obtain high-quality evidence to justify the use of PTTE for long-term IBS management, we performed this controlled, double blind study on patients with IBS who were randomized to pinaverium 50 mg (n = 132) or placebo (n = 132), three times daily, for 4 weeks, and were followed up for 57 weeks after the treatments. The primary endpoints were abdominal pain and stool consistency. The secondary endpoints were pain frequency and stool frequency. The tertiary endpoints were global overall symptom and adverse events. Three days after pinaverium was discontinued, endpoints rebounded only 23.2-42.8% (P < 0.015 cf. placebo). The PTTE (P < 0.05 cf. placebo) lasted 9-17 weeks, which is similar to other antispasmodics with a 15-week treatment in striking contrast to ≥ 1 year PTTE in cognitive behavior therapy and < 1 week PTTE in serotonin antagonist treatment indicating that PTTE length markedly depends on the medication class used for the treatment and less depends on treatment length. After 17 weeks, the stage could be considered as an IBS natural history [no significant differences between pinaverium and placebo (all endpoints' P's > 0.05)], during which an average of 51.5-56.4% of patients (pool pinaverium and placebo data together) had IBS symptoms. These results provide clinical insights into efficient and cost-effective management of refractory IBS, and lend support to the IBS management that the selection of a therapy should consider both its effectiveness during treatment and its PTTE after the treatment.Trial registration number: NCT02330029 (16/08/2016).

Effects of various polysaccharides (alginate, carrageenan, gums, chitosan) and their combination with prebiotic saccharides (resistant starch, lactosucrose, lactulose) on the encapsulation of probiotic bacteria Lactobacillus casei 01 strain

The probiotics are extremely sensitive to various environmental factors, which imposes limitation on their health and functional effectiveness. Thus, development of delivery system for protection of viable cells while passing through different stages of the human digestion system is key factor in application of probiotic products. In our study, the effects of several polysaccharides such as alginate, κ-carrageenan, locust bean gum, gellan gum, xanthan gum and their combination with various prebiotic components (resistant starch, lactulose, lactosucrose) on encapsulation of probiotic Lactobacillus casei 01 strain were studied. Both regular and unregular beads with size distributions from 2 mm up to 5 mm were obtained. The encapsulation efficiencies varied from 64.4% up to 79%. Based on the texture's profiles, the capsules can be grouped into 5 clusters with squared Euclidean distance 3.5. Meanwhile, the starch-alginate and the lactosucrose LS55L - alginate beads were found to be the most stable and to have massive textural properties, whereas the gellan gum - xanthan gum and the chitosan coated alginate beads emerged as the softest. Encapsulation significantly improved the degree of gastric tolerance of probiotic cells even in the presence of pepsin. The INFOGEST in vitro digestion protocol was adapted to investigate the protection effects of different capsules. The highest survival (with loss rate of lower than 1 log CFU/g) was observed in the case of the cells encapsulated in starch-alginate beads. Moreover, the alginate microcapsules combined with lactosucrose LS55L also provided very promising shield for probiotics from the low pH of gastric conditions. Our findings suggest that incorporation of prebiotics into alginate-base encapsulation would be good idea in development of micro delivery systems that helps the survival of probiotics and their delivery to the target sites of action in human body.

Vaginal Probiotics for Reproductive Health and Related Dysbiosis: Systematic Review and Meta-Analysis

The use of probiotics in reproductive-related dysbiosis is an area of continuous progress due to the growing interest from clinicians and patients suffering from recurrent reproductive microbiota disorders. An imbalance in the natural colonization sites related to reproductive health—vaginal, cervicovaginal, endometrial, and pregnancy-related altered microbiota—could play a decisive role in reproductive outcomes. Oral and vaginal administrations are in continuous discussion regarding the clinical effects pursued, but the oral route is used and studied more often despite the need for further transference to the colonization site. The aim of the present review was to retrieve the standardized protocols of vaginal probiotics commonly used for investigating their microbiota modulation capacities. Most of the studies selected focused on treating bacterial vaginosis (BV) as the most common dysbiosis; a few studies focused on vulvovaginal candidiasis (VVC) and on pretreatment during in vitro fertilization (IVF). Vaginal probiotic doses administered were similar to oral probiotics protocols, ranging from ≥10⁷ CFU/day to 2.5 × 10¹⁰ CFU/day, but were highly variable regarding the treatment duration timing. Moderate vaginal microbiota modulation was achieved; the relative abundance of abnormal microbiota decreased and Lactobacillus species increased.

COVID-19: Immunology, Immunopathogenesis and Potential Therapies

The Coronavirus Disease-2019 (COVID-19) imposed public health emergency and affected millions of people around the globe. As of January 2021, 100 million confirmed cases of COVID-19 along with more than 2 million deaths were reported worldwide. SARS-CoV-2 infection causes excessive production of pro-inflammatory cytokines thereby leading to the development of "Cytokine Storm Syndrome." This condition results in uncontrollable inflammation that further imposes multiple-organ-failure eventually leading to death. SARS-CoV-2 induces unrestrained innate immune response and impairs adaptive immune responses thereby causing tissue damage. Thus, understanding the foremost features and evolution of innate and adaptive immunity to SARS-CoV-2 is crucial in anticipating COVID-19 outcomes and in developing effective strategies to control the viral spread. In the present review, we exhaustively discuss the sequential key immunological events that occur during SARS-CoV-2 infection and are involved in the immunopathogenesis of COVID-19. In addition to this, we also highlight various therapeutic options already in use such as immunosuppressive drugs, plasma therapy and intravenous immunoglobulins along with various novel potent therapeutic options that should be considered in managing COVID-19 infection such as traditional medicines and probiotics.

Combined effect of arginine and fluoride on the growth of Lactobacillus rhamnosus GG

The objectives of the in vitro study were: (1) to investigate the effect of combining L-arginine (Arg) and NaF on the growth of Lactobacillus rhamnosus GG (LRG); and (2) to identify an optimum synergistic concentration for the synbiotic (Arg + LRG)-fluoride (SF) therapy. 1% Arg + 2000-ppm NaF (A-SF) and 2% Arg + 2000-ppm NaF (B-SF) demonstrated antagonism against LRG (FIC > 4.0). Both XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) and WST-8 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt) assays showed that A-SF and B-SF enhanced the growth of LRG when compared to 2000-ppm NaF and LRG control. Colony forming units, bacterial weight, and biofilm thickness of A-SF and B-SF were significantly higher than 2000-ppm NaF and LRG control. Biofilm imaging depicted that 2000-ppm NaF inhibited biofilm formation; while 1%/2% Arg, A-SF, and B-SF increased biofilm growth of LRG. Lactic acid formation was the lowest for 2000-ppm NaF, followed by A-SF and then B-SF. The SF buffer potential after 24 h was the highest for B-SF, and then A-SF. Biofilm pH for B-SF was closest to neutral. Fluoride, Arg and LRG bioavailability remained unaffected in B-SF. The relative gene expression for arcA, argG, and argH was significantly higher for B-SF than the respective controls. In conclusion, combining 2% Arg, 2000-ppm NaF, and LRG provides an optimum synbiotic-fluoride synergism.

Diabetes mellitus and congestive heart failure: the prevalence of congestive heart failure in patients with and without diabetes in Poland

INTRODUCTION

Diabetes mellitus is a systemic disease and has a negative effect on the cardiovascular system. This paper aimed to present a retrospective analysis of morbidity associated with heart failure in subgroups of patients with and without diabetes in Poland in 2012.

MATERIAL AND METHODS

Data from the National Health Fund were used for the study. In general, 656,937 patients with heart failure, including 281,538 males and 375,354 females, were studied. In this population, additionally, 201,043 patients with heart failure (main diagnosis) and diabetes were studied, including 82,117 males and 118,926 females.

RESULTS

The mean index of morbidity associated with heart failure in the whole subpopulation of diabetes patients was 9.03%; 8.42% for males and 9.50% for females. Morbidity associated with heart failure in the population of patients diagnosed with diabetes in Poland in 2012 was seven times higher compared to morbidity associated with heart failure in non-diabetes patients. Morbidity associated with heart failure in females was significantly higher compared to morbidity in males in the whole population, in both the subpopulations of patients with and without diabetes.

CONCLUSIONS

Diabetes mellitus significantly increases risk of heart failure in both women and men. The risk is significantly high after the age of 60 years and higher in females.

Probiotic Pediococcus acidilactici strain from tomato pickle displays anti-cancer activity and alleviates gut inflammation in-vitro

The present study characterized the potential probiotic properties of Pediococcus acidilactici TMAB26 strain isolated from traditional Indian tomato pickle, and evaluated its possible therapeutic applications as an anti-cancer and anti-inflammatory agent in vitro. The 16S rRNA sequencing and primary screening demarcated TMAB26 strain as an ideal probiotic candidate, with distinctive properties of acid tolerance (58.02% at pH 2.5), bile tolerance (55.53% at 0.5%), and efficient adherence to the mucosal surface of the human intestinal cells in vitro, along with antagonistic, anti-inflammatory, and anti-cancer properties. The strain exhibited antagonism against standard intestinal pathogenic strains Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, E. coli, Klebsiella pneumonia, and Salmonella typhi with zones of inhibition in the range of 6-18 mm. The cytotoxicity evaluation of the probiotic isolate TMAB26 culture supernatant (1:1 dilution) showed significant cytotoxicity on HT-29 (94.91% ± 1.27) and Caco-2 (92.63% ± 0.63) cancer cells when compared to that of the peripheral blood mononuclear cells (PBMCs) alone. Furthermore, the strain culture supernatant reduced the mRNA levels of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) by threefold, Interleukin-6 (IL-6) by eightfold and increased the mRNA levels of the anti-inflammatory cytokine Interleukin-10 (IL-10) in lipopolysaccharide (LPS) pretreated HT-29 and peripheral blood mononuclear cells (PBMCs), suggesting the potential role of TMAB26 isolate, i.e., Pediococcus acidilactici MTCC 13014 in alleviating gut inflammation.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-020-02570-1.

Lactobacillus plantarum DR7 improved brain health in aging rats via the serotonin, inflammatory and apoptosis pathways

Aging processes affect the brain in many ways, ranging from cellular to functional levels which lead to cognitive decline and increased oxidative stress. The aim of this study was to investigate the potentials of Lactobacillus plantarum DR7 on brain health including cognitive and memory functions during aging and the impacts of high fat diet during a 12-week period. Male Sprague-Dawley rats were separated into six groups: (1) young animals on normal diet (ND, (2) young animals on a high fat diet (HFD), (3) aged animals on ND, (4) aged animals on HFD, (5) aged animals on HFD and L. plantarum DR7 (10⁹ cfu/day) and (6) aged animals receiving HFD and lovastatin. To induce ageing, all rats in group 3 to 6 were injected sub-cutaneously at 600 mg/kg/day of D-galactose daily. The administration of DR7 has reduced anxiety accompanied by enhanced memory during behavioural assessments in aged-HFD rats (P<0.05). Hippocampal concentration of all three pro-inflammatory cytokines were increased during aging but reduced upon administration of both statin and DR7. Expressions of hippocampal neurotransmitters and apoptosis genes showed reduced expressions of indoleamine dioxygenase and P53 accompanied by increased expression of TPH1 in aged- HFD rats administered with DR7, indicating potential effects of DR7 along the pathways of serotonin and oxidative senescence. This study provided an insight into potentials of L. plantarum DR7 as a prospective dietary strategy to improve cognitive functions during aging. This study provided an insight into potentials of L. plantarum DR7 as a prospective dietary strategy to improve cognitive functions during aging.

A Systematic Review and Meta-Analysis: The Effectiveness of Probiotics for Viral Gastroenteritis

BACKGROUND

Probiotics can be used for the treatment of viral gastroenteritis.

OBJECTIVE

This systematic review is to evaluate the evidence regarding the effect of probiotics on human cases of viral gastroenteritis.

METHODS

The objective of this review is to evaluate the effectiveness of probiotics against placebo or standard treatment for viral gastroenteritis. A comprehensive search of Cochrane Library, EMBASE, MEDLINE via PubMed and Ovid databases, and unpublished studies (till 27 January 2018) was conducted followed by a process of study selection and critical appraisal by two independent reviewers. Randomized controlled trials assessing probiotic administration in human subjects infected with any species of gastroenteritis viruses were considered for inclusion. Only studies with a confirmed viral cause of infection were included. This study was developed using the JBI methodology for systematic reviews, which is in accordance with the PRISMA guideline. Meta-analysis was conducted where feasible. Data were pooled using the inverse variance method with random effects models and expressed as Mean Differences (MDs) with 95% Confidence Intervals (CIs). Heterogeneity was assessed by Cochran Q statistic and quantified by the I2 statistic. We included 17 RCTs, containing 3,082 patients.

RESULTS

Probiotics can improve symptoms of viral gastroenteritis, including the duration of diarrhea (mean difference 0.7 days, 95% CI 0.31 to 1.09 days, n = 740, ten trials) and duration of hospitalization (mean difference 0.76 days, 95% CI 0.61 to 0.92 days, n = 329, four trials).

CONCLUSION

The results of this review show that the administration of probiotics in patients with viral gastroenteritis should be considered.

Application of Probiotic Yeasts on Candida Species Associated Infection

Superficial and life-threatening invasive Candida infections are a major clinical challenge in hospitalized and immuno-compromised patients. Emerging drug-resistance among Candida species is exacerbated by the limited availability of antifungals and their associated side-effects. In the current review, we discuss the application of probiotic yeasts as a potential alternative/ combination therapy against Candida infections. Preclinical studies have identified several probiotic yeasts that effectively inhibit virulence of Candida species, including Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, Candida krusei and Candida auris. However, Saccharomyces cerevisiae var. boulardii is the only probiotic yeast commercially available. In addition, clinical studies have further confirmed the in vitro and in vivo activity of the probiotic yeasts against Candida species. Probiotics use a variety of protective mechanisms, including posing a physical barrier, the ability to aggregate pathogens and render them avirulent. Secreted metabolites such as short-chain fatty acids effectively inhibit the adhesion and morphological transition of Candida species. Overall, the probiotic yeasts could be a promising effective alternative or combination therapy for Candida infections. Additional studies would bolster the application of probiotic yeasts.

Gastrointestinal Disorders and Metabolic Syndrome: Dysbiosis as a Key Link and Common Bioactive Dietary Components Useful for their Treatment

Gastrointestinal (GI) diseases, which include gastrointestinal reflux disease, gastric ulceration, inflammatory bowel disease, and other functional GI disorders, have become prevalent in a large part of the world population. Metabolic syndrome (MS) is cluster of disorders including obesity, hyperglycemia, hyperlipidemia, and hypertension, and is associated with high rate of morbidity and mortality. Gut dysbiosis is one of the contributing factors to the pathogenesis of both GI disorder and MS, and restoration of normal flora can provide a potential protective approach in both these conditions. Bioactive dietary components are known to play a significant role in the maintenance of health and wellness, as they have the potential to modify risk factors for a large number of serious disorders. Different classes of functional dietary components, such as dietary fibers, probiotics, prebiotics, polyunsaturated fatty acids, polyphenols, and spices, possess positive impacts on human health and can be useful as alternative treatments for GI disorders and metabolic dysregulation, as they can modify the risk factors associated with these pathologies. Their regular intake in sufficient amounts also aids in the restoration of normal intestinal flora, resulting in positive regulation of insulin signaling, metabolic pathways and immune responses, and reduction of low-grade chronic inflammation. This review is designed to focus on the health benefits of bioactive dietary components, with the aim of preventing the development or halting the progression of GI disorders and MS through an improvement of the most important risk factors including gut dysbiosis.

The canine gastrointestinal microbiota: early studies and research frontiers

The canine gut microbiota is a complex microbial population that is potentially related to metabolism, immunologic activity and gastrointestinal (GI) diseases. Early studies revealed that the canine gut microbiota was dynamic, and bacterial populations in the adjacent gut segments were similar, with anaerobes predominating. Metagenomics analysis revealed that nutrient contents in the diet modulated bacterial populations and metabolites in the canine gut. Further research revealed significant correlations between dietary factors and canine gut core microbiomes. Canine GI diseases are closely correlated with gut microbiota dysbiosis and metabolic disorders. Probiotic-related therapies can effectively treat canine GI diseases. Recent studies have revealed that the canine gut microbiota is similar to the human gut microbiota, and dietary factors affect both. Studying canine intestinal microorganisms enables clarifying changes in the canine intestinal bacteria under different conditions, simulating human diseases in dog models, and conducting in-depth studies of the interactions between intestinal bacteria and disease.

Probiotic Strains and Intervention Total Doses for Modulating Obesity-Related Microbiota Dysbiosis: A Systematic Review and Meta-analysis

Obesity is a growing health threat worldwide. Administration of probiotics in obesity has also parallelly increased but without any protocolization. We conducted a systematic review exploring the administration pattern of probiotic strains and effective doses for obesity-related disorders according to their capacity of positively modulating key biomarkers and microbiota dysbiosis. Manuscripts targeting probiotic strains and doses administered for obesity-related disorders in clinical studies were sought. MEDLINE, Scopus, Web of Science, and Cochrane Library databases were searched using keywords during the last fifteen years up to April 2020. Two independent reviewers screened titles, abstracts, and then full-text papers against inclusion criteria according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. From 549 interventional reports identified, we filtered 171 eligible studies, from which 24 full-text assays were used for calculating intervention total doses (ITD) of specific species and strains administered. Nine of these reports were excluded in the second-step because no specific data on gut microbiota modulation was found. Six clinical trials (CT) and 9 animal clinical studies were retained for analysis of complete outcome prioritized (body mass index (BMI), adiposity parameters, glucose, and plasma lipid biomarkers, and gut hormones). Lactobacillus spp. administered were double compared to Bifidobacterium spp.; Lactobacillus as single or multispecies formulations whereas most Bifidobacteria only through multispecies supplementations. Differential factors were estimated from obese populations' vs. obesity-induced animals: ITD ratio of 2 × 106 CFU and patterns of administrations of 11.3 weeks to 5.5 weeks, respectively. Estimation of overall probiotics impact from selected CT was performed through a random-effects model to pool effect sizes. Comparisons showed a positive association between the probiotics group vs. placebo on the reduction of BMI, total cholesterol, leptin, and adiponectin. Moreover, negative estimation appeared for glucose (FPG) and CRP. While clinical trials including data for positive modulatory microbiota capacities suggested that high doses of common single and multispecies of Lactobacillus and Bifidobacterium ameliorated key obesity-related parameters, the major limitation was the high variability between studies and lack of standardized protocols. Efforts in solving this problem and searching for next-generation probiotics for obesity-related diseases would highly improve the rational use of probiotics.

Mini-Review on the Possible Interconnections between the Gut-Brain Axis and the Infertility-Related Neuropsychiatric Comorbidities

Both the gut-brain axis (GBA) and the hypothalamic–pituitary–adrenal (HPA) axis remain an intriguing yet obscure network with a strong influence over other systems of organs. Recent reports have sought to describe the multitude of harmful stressors that may impact the HPA axis along with the interconnections between these. This has improved our knowledge of how the underlying mechanisms working to establish homeostasis are affected. A disruption to the HPA axis can amplify the chances of gastrointestinal deficiencies, whilst also increasing the risk of a wide spectrum of neuropsychiatric disorders. Thus, the influence of microorganisms found throughout the digestive tract possess the ability to affect both physiology and behaviour by triggering responses, which may be unfavourable. This is sometimes the case in of infertility. Numerous supplements have been formulated with the intention of rebalancing the gut microflora. Accordingly, the gut flora may alter the pharmacokinetics of drugs used as part of fertility treatments, potentially exacerbating the predisposition for various neurological disorders, regardless of the age and gender.

Therapeutic Effect of Enteral Nutrition Supplemented with Probiotics in the Treatment of Severe Craniocerebral Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Whether early enteral nutrition with probiotics can reduce the mortality and infection rate of patients with severe craniocerebral injury (SCI), improve their gastrointestinal function, and shorten the length of stay in the intensive care unit (ICU) has not been determined.

METHODS

PubMed, China National Knowledge Infrastructure, and Embase were electronically searched for the purpose of identifying randomized controlled trials investigated the potential of early enteral nutrition supplemented with probiotics on patients with SCI from the establishment of databases to August 26, 2019. STATA software version 12.0 was used to perform meta-analysis.

RESULTS

A total of 39 trials enrolling 3387 patients were included. Early enteral nutrition supplemented with probiotics was associated with decreased risk of infection (pooled risk ratio [RR], 0.486; 95% confidence interval [CI], 0.394-0.599), decreased risk of 7-, 14-, and 28-day mortality (pooled RRs, 0.415, 0.497, and 0.385; 95% CIs, 0.196-0.878, 0.297-0.833, and 0.197-0.751, respectively), and decreased risk of gastrointestinal complications (pooled RR, 0.363; 95% CI, 0.274-0.481). It also shortened the time course recovery of enteral function and shortened the length of stay in hospital and length of ICU stay (standardized mean differences, -3.327 and -1.461; 95% CIs, -6.213 to -0.440 and -2.111 to -0.811, respectively).

CONCLUSIONS

Enteral nutrition supplemented with probiotics effectively decreases the risk of mortality, gastrointestinal complications, and infection, and shortens the stays in ICU; therefore, it should be extensively adopted to manage these given patients.

Improving causality in microbiome research: can human genetic epidemiology help?

Evidence supports associations between human gut microbiome variation and multiple health outcomes and diseases. Despite compelling results from in vivo and in vitro models, few findings have been translated into an understanding of modifiable causal relationships. Furthermore, epidemiological studies have been unconvincing in their ability to offer causal evidence due to their observational nature, where confounding by lifestyle and behavioural factors, reverse causation and bias are important limitations. Whilst randomized controlled trials have made steps towards understanding the causal role played by the gut microbiome in disease, they are expensive and time-consuming. This evidence that has not been translated between model systems impedes opportunities for harnessing the gut microbiome for improving population health. Therefore, there is a need for alternative approaches to interrogate causality in the context of gut microbiome research. The integration of human genetics within population health sciences have proved successful in facilitating improved causal inference (e.g., with Mendelian randomization [MR] studies) and characterising inherited disease susceptibility. MR is an established method that employs human genetic variation as natural "proxies" for clinically relevant (and ideally modifiable) traits to improve causality in observational associations between those traits and health outcomes. Here, we focus and discuss the utility of MR within the context of human gut microbiome research, review studies that have used this method and consider the strengths, limitations and challenges facing this research. Specifically, we highlight the requirements for careful examination and interpretation of derived causal estimates and host (i.e., human) genetic effects themselves, triangulation across multiple study designs and inter-disciplinary collaborations. Meeting these requirements will help support or challenge causality of the role played by the gut microbiome on human health to develop new, targeted therapies to alleviate disease symptoms to ultimately improve lives and promote good health.

Improving causality in microbiome research: can human genetic epidemiology help?

Evidence supports associations between human gut microbiome variation and multiple health outcomes and diseases. Despite compelling results from in vivo and in vitro models, few findings have been translated into an understanding of modifiable causal relationships. Furthermore, epidemiological studies have been unconvincing in their ability to offer causal evidence due to their observational nature, where confounding by lifestyle and behavioural factors, reverse causation and bias are important limitations. Whilst randomized controlled trials have made steps towards understanding the causal role played by the gut microbiome in disease, they are expensive and time-consuming. This evidence that has not been translated between model systems impedes opportunities for harnessing the gut microbiome for improving population health. Therefore, there is a need for alternative approaches to interrogate causality in the context of gut microbiome research. The integration of human genetics within population health sciences have proved successful in facilitating improved causal inference (e.g., with Mendelian randomization [MR] studies) and characterising inherited disease susceptibility. MR is an established method that employs human genetic variation as natural "proxies" for clinically relevant (and ideally modifiable) traits to improve causality in observational associations between those traits and health outcomes. Here, we focus and discuss the utility of MR within the context of human gut microbiome research, review studies that have used this method and consider the strengths, limitations and challenges facing this research. Specifically, we highlight the requirements for careful examination and interpretation of derived causal estimates and host (i.e., human) genetic effects themselves, triangulation across multiple study designs and inter-disciplinary collaborations. Meeting these requirements will help support or challenge causality of the role played by the gut microbiome on human health to develop new, targeted therapies to alleviate disease symptoms to ultimately improve lives and promote good health.

Probiotics Dietary Supplementation for Modulating Endocrine and Fertility Microbiota Dysbiosis

Human microbiota seems to play a key role in endocrine and reproductive systems. Fortunately, microbiota reproductive dysbiosis start to be treated by probiotics using typical species from genus Lactobacillus. This work presents the compiled and analysed results from the most up-to-date information from clinical trials regarding microbiota, fertility, probiotics and oral route administration, reviewing open access scientific documents. These studies analyse the clinical impact of probiotics administered on several endocrine disorders' manifestations in women: mastitis; vaginal dysbiosis; pregnancy complication disorders; and polycystic ovary syndrome. In all cases, the clinical modulation achieved by probiotics was evaluated positively through the improvement of specific disease outcomes with the exception of the pregnancy disorders studies, where the sample sizes results were statistically insufficient. High amounts of studies were discarded because no data were provided on specific probiotic strains, doses, impact on the individual autochthon microbiota, or data regarding specific hormonal values modifications and endocrine regulation effects. However, most of the selected studies with probiotics contained no protocolised administration. Therefore, we consider that intervention studies with probiotics might allocate the focus, not only in obtaining a final outcome, but in how to personalise the administration according to the disorder to be palliated.

Safety Assessment of Bacteroides Uniformis CECT 7771, a Symbiont of the Gut Microbiota in Infants

The formulation of next-generation probiotics requires competent preclinical studies to show their efficacy and safety status. This study aims to confirm the safety of the prolonged oral use of Bacteroides uniformis CECT 7771, a strain that protected against metabolic disorders and obesity in preclinical trials, in a sub-chronic 90 day trial in animals. The safety assessment was conducted in male and female Wistar rats (n = 50) administered increasing doses (108 CFU/day, 109 CFU/day, or 1010 CFU/day) of B. uniformis CECT 7771, 1010 CFU/day of B. longum ATCC 15707T, which complies with the qualifying presumption of safety (QPS) status of the EU, or vehicle (placebo), as the control. Pancreatic, liver, and kidney functions and cytokine concentrations were analyzed. Bacterial translocation to peripheral tissues was evaluated, and colon integrity was investigated histologically. No adverse metabolic or tissue integrity alterations were associated with treatments; however, alanine aminotransferase levels and the ratio of anti-inflammatory to pro-inflammatory cytokines in serum indicated a potentially beneficial role of B. uniformis CECT 7771 at specific doses. Additionally, the microbial community structure was modified by the interventions, and potentially beneficial gut bacteria were increased. The results indicated that the oral consumption of B. uniformis CECT 7771 during a sub-chronic 90 day study in rats did not raise safety concerns.

Strain-Specific Probiotic Properties of Bifidobacteria and Lactobacilli for the Prevention of Diarrhea Caused by Rotavirus in a Preclinical Model

Probiotic supplementation with different lactobacilli and bifidobacterial strains has demonstrated beneficial effects in infectious diarrhea caused by rotavirus (RV) in young children. Preclinical models of RV infection might be a good strategy to screen for the efficacy of new probiotic strains or to test their comparative efficacy. Neonatal Lewis rats were supplemented with Bifidobacterium breve M-16V, Lactobacillus acidophilus NCFM, Lactobacillus helveticus R0052, or Lactobacillus salivarius PS2 from days 2–14 of life. On day five, animals received RV SA-11 orally. Fecal samples were collected daily, weighed, and scored for the calculation of severity and incidence of diarrhea. In addition, fecal pH and fecal viral shedding were measured. Animals were sacrificed at the end of the study and their blood was obtained for the quantification of RV-specific immunoglobulins. RV infection was induced in ~90% of the animals. All probiotics caused a reduction of several clinical variables of severity and incidence of diarrhea, except L. salivarius PS2. L. acidophilus NCFM, B. breve M-16V, and L. helveticus R0052 seemed to be very effective probiotic strains. In addition, all Lactobacillus strains reduced the viral elimination one day post-inoculation. No differences were detected in the specific anti-RV humoral response. The present study highlights the strain-specific effects of probiotics and identifies promising probiotics for use in ameliorating and preventing RV-induced diarrhea in children, for example by including them in infant formulas.

Hepatic dysfunction after spinal cord injury: A vicious cycle of central and peripheral pathology?

The liver is essential for numerous physiological processes, including filtering blood from the intestines, metabolizing fats, proteins, carbohydrates and drugs, and regulating iron storage and release. The liver is also an important immune organ and plays a critical role in response to infection and injury throughout the body. Liver functions are regulated by autonomic parasympathetic innervation from the brainstem and sympathetic innervation from the thoracic spinal cord. Thus, spinal cord injury (SCI) at or above thoracic levels disrupts major regulatory mechanisms for hepatic functions. Work in rodents and humans shows that SCI induces liver pathology, including hepatic inflammation and fat accumulation characteristic of a serious form of non-alcoholic fatty liver disease (NAFLD) called non-alcoholic steatohepatitis (NASH). This hepatic pathology is associated with and likely contributes to indices of metabolic dysfunction often noted in SCI individuals, such as insulin resistance and hyperlipidemia. These occur at greater rates in the SCI population and can negatively impact health and quality of life. In this review, we will: 1) Discuss acute and chronic changes in human and rodent liver pathology and function after SCI; 2) Describe how these hepatic changes affect systemic inflammation, iron regulation and metabolic dysfunction after SCI; 3) Describe how disruption of the hepatic autonomic nervous system may be a key culprit in post-injury chronic liver pathology; and 4) Preview ongoing and future research that aims to elucidate mechanisms driving liver and metabolic dysfunction after SCI.