Actual concept of "probiotics": Is it more functional to science or business?

Pichia kudriavzevii UNJCC Y-137 and Candida tropicalis UNJCC Y-140 isolated from Durio kutejensis as potential probiotic agents

Durio kutejensis, commonly known as Lai durian, has a unique characteristics of a creamy texture and a combination of sweet and bitter tastes. This study aimed to isolate and screen yeast from fruits as a potential probiotic agent. The tests consisted of tolerance to bile salt and gastric acid at pH 2, antibacterial activity against Listeria monocytogenes and Salmonella enteriditis, and hemolytic activity on blood agar medium. The results showed that 40 yeasts isolated from Lai durian fruit and 34 of these isolates grew on YMA medium. The two isolates showed high significance in the probiotic tests. These two isolates were able to grow on bile salt up to a concentration of 2% and gastric acid for up to 6 h, with survival rates of 99.06% and 100%, respectively. Two isolates were identified as Pichia kudriavzevii UNJCC Y-137 and Candida tropicalis UN-JCC Y-140 Therefore, these two yeast isolates can be used as potential probiotic agents.

Probiotics, prebiotics, and synbiotics in nonalcoholic fatty liver disease and alcohol-associated liver disease

The use of probiotics, prebiotics, and synbiotics has become an important therapy in numerous gastrointestinal diseases in recent years. Modifying the gut microbiota, this therapeutic approach helps to restore a healthy microbiome. Nonalcoholic fatty liver disease and alcohol-associated liver disease are among the leading causes of chronic liver disease worldwide. A disrupted intestinal barrier, microbial translocation, and an altered gut microbiome metabolism, or metabolome, are crucial in the pathogenesis of these chronic liver diseases. As pro-, pre-, and synbiotics modulate these targets, they were identified as possible new treatment options for liver disease. In this review, we highlight the current findings on clinical and mechanistic effects of this therapeutic approach in nonalcoholic fatty liver disease and alcohol-associated liver disease.

Microbiota-gut-brain axis mechanisms in the complex network of bipolar disorders: potential clinical implications and translational opportunities

Bipolar disorders (BD) represent a severe leading disabling mental condition worldwide characterized by episodic and often progressive mood fluctuations with manic and depressive stages. The biological mechanisms underlying the pathophysiology of BD remain incompletely understood, but it seems that there is a complex picture of genetic and environmental factors implicated. Nowadays, gut microbiota is in the spotlight of new research related to this kind of psychiatric disorder, as it can be consistently related to several pathophysiological events observed in BD. In the context of the so-called microbiota-gut-brain (MGB) axis, it is shown to have a strong influence on host neuromodulation and endocrine functions (i.e., controlling the synthesis of neurotransmitters like serotonin or mediating the activation of the hypothalamic-pituitary-adrenal axis), as well as in modulation of host immune responses, critically regulating intestinal, systemic and brain inflammation (neuroinflammation). The present review aims to elucidate pathophysiological mechanisms derived from the MGB axis disruption and possible therapeutic approaches mainly focusing on gut microbiota in the complex network of BD. Understanding the mechanisms of gut microbiota and its bidirectional communication with the immune and other systems can shed light on the discovery of new therapies for improving the clinical management of these patients. Besides, the effect of psychiatric drugs on gut microbiota currently used in BD patients, together with new therapeutical approaches targeting this ecosystem (dietary patterns, probiotics, prebiotics, and other novelties) will also be contemplated.

Probiotic Use in Preterm Neonates: A Review and Bibliometric Analysis

Background: Necrotizing enterocolitis (NEC) is a major health burden in peterm neonates with mortality rates between 21% and 50%. Prophylaxis is of primary importance as early diagnosis is hindered by the lack of specific signs and laboratory markers. Although probiotics have been routinely used for NEC prophylaxis in neonatal intensive care units around the world, clinical trials provide contradictory data, which fuels an ongoing debate about their efficacy and safety.

Aims: To perform a review and bibliometric analysis on available clinical trials and case reports data on the safety and efficacy of probiotics in preterm neonates and identify relevant publication trends and patterns.

Methods: A bibliometric search for publications on the topic was performed in the Web of Science Core Collection database and the resulting records analyzed in bibliometrix package in R.

Results: Trends in publication activity, historical direct citation network relationships and keyword co-ocurrences were discussed in the context of the most recent therapeutic recommendations.

Conclusion: We took a round view of the potential drawbacks to probiotic use in preterm infants and their possible solutions.

Randomized Double-Blind Crossover Study for Evaluating a Probiotic Mixture on Gastrointestinal and Behavioral Symptoms of Autistic Children

Autism spectrum disorders (ASDs) represent a diagnostic challenge with a still partially uncertain etiology, in which genetic and environmental factors have now been assessed. Among the hypotheses underlying the involvement of biological and environmental factors, the gut–brain axis is of particular interest in autism spectrum disorders. Several studies have highlighted the related incidence of particular gastrointestinal symptoms (GISs) in children suffering from ASDs. Probiotics have shown success in treating several gastrointestinal dysbiotic disorders; therefore, it is plausible to investigate whether they can alleviate behavioral symptoms as well. On these bases, a randomized double-blind crossover study with a placebo was conducted, evaluating the effects of a mixture of probiotics in a group of 61 subjects aged between 24 months and 16 years old with a diagnosis of ASD. Behavioral evaluation was performed through the administration of a questionnaire including a Parenting Stress Index (PSI) test and the Vineland Adaptive Behavior Scale (VABS). The Psycho-Educational Profile and the Autism Spectrum Rating Scale (ASRS) were also evaluated. Microbial composition analyses of fecal samples of the two groups was also performed. The study showed significant improvements in GISs, communication skills, maladaptive behaviors, and perceived parental stress level after the administration of probiotics. Microbiome alpha diversity was comparable between treatment arms and no significant differences were found, although beta diversity results were significantly different in the treatment group between T0 and T1 time points. Streptococcus thermophilus, Bifidobacterium longum, Limosilactobacillus fermentum, and Ligilactobacillus salivarius species were identified as some of the most discriminant taxa positively associated with T1 samples. This preliminary study corroborates the relationship between intestinal microbiota and ASD recently described in the literature.

Strategies for the Identification and Assessment of Bacterial Strains with Specific Probiotic Traits

Early in the 1900s, it was proposed that health could be improved and senility delayed by manipulating gut microbiota with the host-friendly bacteria found in yogurt. Later, in 1990, the medical community reconsidered this idea and today probiotics represent a developed area of research with a billion-dollar global industry. As a result, in recent decades, increased attention has been paid to the isolation and characterization of novel probiotic bacteria from fermented foods and dairy products. Most of the identified probiotic strains belong to the lactic acid bacteria group and the genus Bifidobacterium. However, current molecular-based knowledge has allowed the identification and culture of obligatory anaerobic commensal bacteria from the human gut, such as Akkermansia spp. and Faecalibacterium spp., among other human symbionts. We are aware that the identification of new strains of these species does not guarantee their probiotic effects and that each effect must be proved through in vitro and in vivo preclinical studies before clinical trials (before even considering it as a probiotic strain). In most cases, the identification and characterization of new probiotic strain candidates may lack the appropriate set of in vitro experiments allowing the next assessment steps. Here, we address some innovative strategies reported in the literature as alternatives to classical characterization: (i) identification of alternatives using whole-metagenome shotgun sequencing, metabolomics, and multi-omics analysis; and (ii) probiotic characterization based on molecular effectors and/or traits to target specific diseases (i.e., inflammatory bowel diseases, colorectal cancer, allergies, among others).

Comparison of Publication of Pediatric Probiotic vs Antibiotic Trials Registered on ClinicalTrials.gov

IMPORTANCE

The published evidence in support of probiotic use is conflicting, which may be a result of selective publication of probiotic trials.

OBJECTIVES

To compare the proportion of registered trials that evaluate pediatric probiotics vs those that evaluate antibiotics that are published and to identify study-related factors associated with publication status.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study evaluated eligible trials registered in ClinicalTrials.gov, an online clinical trials registry, from July 1, 2005, to June 30, 2016. Eligible studies included participants younger than 18 years, evaluated a probiotic or 1 of the 5 most commonly prescribed antibiotics in children and adolescents, and randomized study participants. All searches were updated and finalized as of September 9, 2020.

EXPOSURES

Probiotic or antibiotic.

MAIN OUTCOMES AND MEASURES

The primary outcome was study publication status. In addition, exposure status (probiotic vs antibiotic), trial result, and funding source were assessed for independent association with publication status. Whether study design elements, publication journal impact factor, and the interval from study completion to publication differed by exposure status were also evaluated.

RESULTS

A total of 401 unique trials (265 probiotic and 136 antibiotic) met eligibility criteria. A greater proportion of antibiotic compared with probiotic studies were published (83 [61.0%] vs 119 [44.9%]; difference, 16.1% [95% CI, 5.8%-25.9%]). After adjustment for funding source, blinding, and purpose, studies evaluating an antibiotic were more likely to be published (odds ratio, 2.1 [95% CI, 1.3-3.4]). No other covariates included in the model were independently associated with publication status. Antibiotic trials, compared with probiotic trials, were more likely to have a therapeutic purpose (114 [83.8%] vs 117 [44.2%]; difference, 39.6% [95% CI, 31.1%-48.3%]) and to be multicenter (46 [33.8%] vs 46 [17.4%]; difference, 16.5% [95% CI, 7.5%-25.7%]). The median impact factor of the journals in which the studies were published was higher for the antibiotic trials (7.2 [IQR, 2.8-20.5] vs 3.0 [IQR, 2.3-4.2]; P < .001). The median number of days to publication did not differ between the probiotic and antibiotic trials (683 [IQR, 441-1036] vs 801 [IQR, 550-1183]; P = .24).

CONCLUSIONS AND RELEVANCE

The findings of this cross-sectional study suggest that probiotic studies are less likely to be published than antibiotic trials. No other study characteristics were associated with publication status. This finding raises concerns regarding the results of meta-analyses of probiotic trials.

Interactions between the Gut Microbiome, Lung Conditions, and Coronary Heart Disease and How Probiotics Affect These

The importance of a healthy microbiome cannot be overemphasized. Disturbances in its composition can lead to a variety of symptoms that can extend to other organs. Likewise, acute or chronic conditions in other organs can affect the composition and physiology of the gut microbiome. Here, we discuss interorgan communication along the gut–lung axis, as well as interactions between lung and coronary heart diseases and between cardiovascular disease and the gut microbiome. This triangle of organs, which also affects the clinical outcome of COVID-19 infections, is connected by means of numerous receptors and effectors, including immune cells and immune-modulating factors such as short chain fatty acids (SCFA) and trimethlamine–N–oxide (TMAO). The gut microbiome plays an important role in each of these, thus affecting the health of the lungs and the heart, and this interplay occurs in both directions. The gut microbiome can be influenced by the oral uptake of probiotics. With an improved understanding of the mechanisms responsible for interorgan communication, we can start to define what requirements an ‘ideal’ probiotic should have and its role in this triangle.

Manganese accumulation in probiotic Lactobacillus paracasei ATCC 55544 analyzed by synchrotron X-ray fluorescence microscopy and impact of accumulation on the bacterial viability following encapsulation

Lactobacillus spp. are known to accumulate large amounts of inorganic manganese, which protects against oxidative damage by scavenging free radicals. The ability of probiotic L. paracasei ATCC 55544 to maintain viability during long-term ambient storage may be enhanced by this microorganism's ability to accumulate manganese, which may act as a free radical scavenger. To investigate this hypothesis, X-ray fluorescence microscopy (XFM) was employed to determine the changes in the elemental composition of L. paracasei during growth in the MRS medium with or without added manganese. Moreover, manganese uptake by cells as a function of physiological growth state, early log vs. stationary phase was evaluated. The semiquantitative X-ray fluorescence microscopy results revealed that lower levels of manganese accumulation occurred during the early log phase of bacterial growth of L. paracasei cells (0.0064 µg/cm²) compared with the stationary phase cells (0.1355 µg/cm²). L. paracasei cells grown in manganese deficient MRS medium resulted in lower manganese uptake by cells (0.0027 µg/cm²). The L. paracasei cells were further embedded in milk powder matrix using a fluidized-bed drying technique and stored at a water activity (a_w) of 0.33 at 25 °C for 15 days. The viability counts of L. paracasei cells grown in MRS medium harvested after 18 h growth and embedded in milk powder matrix retained viability of (9.19 ± 0.12 log CFU/g). No viable L. paracasei cells were observed in the case of embedded L. paracasei cells grown in manganese-deficient MRS medium harvested after 18 h growth or in the case of L. paracasei cells harvested after 4 h when grown in MRS medium. The lower level of manganese accumulation was found to be related to the loss of bacterial viability during storage.

Supranational Assessment of the Quality of Probiotics: Collaborative Initiative between Independent Accredited Testing Laboratories

Recent acquisitions about the role of the microbiota in the functioning of the human body make it possible to envisage an increasing use of beneficial microbes, and more particularly of probiotics as well as their metabolites, as nutritional supplements. National and EU authorities are engaged in assuring the safety and quality of food supplements and in defining rules to assess and communicate their efficacy on human health. The quality of probiotics, intended as strains' identification, viability, and stability over time, is a crucial factor of credibility with consumers and health professionals. Analytical technologies for the quality control of probiotics must also be adapted to new preparations, such as those including new multistrains complex combinations. Accredited laboratories face this relevant challenge on a daily basis. Through its close collaboration with the laboratory commissioned to produce the specifications for its ESLP quality label (identification and quantitative analyses) together with its scientific committee, the ESLP has been focusing on this issue for 10 years. Recently, as part of the internationalization of the ESLP quality label, a new and unique initiative in Europe for the evaluation of the quality of probiotic preparations has been carried out. The collaboration between two accredited laboratories in Belgium and in Italy represented a concrete example of supranational collaboration in the assessment of the quality of probiotic preparations. Results show that both laboratories are in line as expected in terms of performance. Common approaches to the qualitative assessment of probiotic preparations, especially for complex and composite recipes, in terms of number of strains and included substances, should be encouraged and promoted all over the EU.

Efficacy of probiotics on anxiety-A meta-analysis of randomized controlled trials

BACKGROUND

The concept "psychobiotics" claims potential beneficial effect of probiotics on anxiety, whereas findings from clinical trials are inconsistent. Thus, a meta-analysis is needed to clarify the effect of probiotics on anxiety.

METHODS

Randomized controlled trials (RCTs) assessing the effect of probiotics on anxiety were systematically retrieved from online databases and manually screened for references of relevant published literature through September 1, 2017. Standardized mean difference in change from baseline of anxiety rating scales between probiotics groups and placebo groups was selected as the main effect index. Subgroup analyses were conducted with respect to overall health status of the sample, existence of gastrointestinal symptoms, strains of flora, trial duration, and risk of bias assessment. Publication bias was evaluated by funnel plot and Egger's test. The reliability of the result was assessed by leave-one-out sensitivity analysis.

RESULTS

Twelve studies with 1,551 subjects (871 in probiotics group and 680 in control group) were included. All the studies were rated as low or moderate risk of bias. The meta-analysis and subgroup analyses all showed no significant difference between probiotics and placebo in alleviating anxiety symptoms. The Egger's test revealed no evidence of significant publication bias. Sensitivity analysis showed that leaving out one study would result in marginal significance.

CONCLUSIONS

The evidence for the efficacy of probiotics in alleviating anxiety, as presented in currently published RCTs, is insufficient. More reliable evidence from clinical trials is needed before a case can be made for promoting the use of probiotics for alleviating anxiety.

Saccharomyces cerevisiae from Brazilian kefir-fermented milk: An in vitro evaluation of probiotic properties

The therapeutic use of probiotics for supporting the antibiotic action against gastrointestinal disorders is a current trend and emerging applications have gained popularity because of their support for various microbiological activities in digestive processes. Microorganisms isolated from kefir with great probiotic properties, in addition to high resistance to harsh environmental conditions, have been widely researched. Administration of probiotic yeasts offers a number of advantages, when compared to bacteria, because of particular characteristics as their larger cell size. In the present study, 28 strains of Saccharomyces cerevisiae were isolated, after in vitro digestion of kefir-fermented milk, and identified by molecular based approaches. A screening was performed to determine important quality requirements for probiotics including: antagonistic and antioxidant activities, β-galactosidase synthesis, autoaggregation, surface hydrophobicity and adhesion to epithelial cells. The results showed strains: with antagonistic activity against microbial pathogens such as Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis; able to produce β-galactosidase; with antioxidant activity levels higher than 90%; with hydrophobicity activity and autoaggregation ability (evaluated by adhesion test, where all the strains presented adhesion to mice ileal epithelial cells). These findings are relevant and the strains are recommended for further in vivo studies as well as for potential therapeutic applications.

A Review of Research Conducted with Probiotic E. coli Marketed as Symbioflor

This review article summarizes the scientific literature that is currently available about a probiotic E. coli that is known under the name Symbioflor E. coli. The probiotic is marketed for human use and has been subjected to over 20 years of scientific research. As is presented here, the available literature not only contains multiple works to investigate and analyse the probiotic activity of this E. coli, but also describes a variety of other research experiments, dealing with a surprising and interesting range of subjects. By compiling all these works into one review article, more insights into this interesting probiotic E. coli were obtained.

Does the scientific evidence support the advertising claims made for products containing Lactobacillus casei and Bifidobacterium lactis? A systematic review

BACKGROUND

To analyse the scientific evidence that exists for the advertising claims made for two products containing Lactobacillus casei and Bifidobacterium lactis and to conduct a comparison between the published literature and what is presented in the corporate website.

METHODS

Systematic review, using Medline through Pubmed and Embase. We included human clinical trials that exclusively measured the effect of Lactobacillus casei or Bifidobacterium lactis on a healthy population, and where the objective was related to the health claims made for certain products in advertising. We assessed the levels of evidence and the strength of the recommendation according to the classification criteria established by the Oxford Centre for Evidence Based Medicine (CEBM). We also assessed the outcomes of the studies published on the website that did not appear in the search.

RESULTS

Of the 440 articles identified, 16 met the inclusion criteria. Only four (25%) of these presented a level of evidence of 1b and a recommendation grade of A, all corresponding to studies on product containing Bifidobacterium lactis, and only 12 of the 16 studies were published on the corporate website (47).

CONCLUSIONS

There is insufficient scientific evidence to support the health claims made for these products, especially in the case of product containing Lactobacillus casei.

Insights from 100 Years of Research with Probiotic E. Coli

A century ago, Alfred Nissle discovered that intentional intake of particular strains of Escherichia coli could treat patients suffering from infectious diseases. Since then, one of these strains became the most frequently used probiotic E. coli in research and was applied to a variety of human conditions. Here, properties of that E. coli Nissle 1917 strain are compared with other commercially available E. coli probiotic strains, with emphasis on their human applications. A literature search formed the basis of a summary of research findings reported for the probiotics Mutaflor, Symbioflor 2, and Colinfant. The closest relatives of the strains in these products are presented, and their genetic content, including the presence of virulence, genes is discussed. A similarity to pathogenic strains causing urinary tract infections is noticeable. Historic trends in research of probiotics treatment for particular human conditions are identified. The future of probiotic E. coli may lay in what Alfred Nissle originally discovered: to treat gastrointestinal infections, which nowadays are often caused by antibiotic-resistant pathogens.

Gut to brain interaction in Autism Spectrum Disorders: a randomized controlled trial on the role of probiotics on clinical, biochemical and neurophysiological parameters

BACKGROUND

A high prevalence of a variety of gastrointestinal (GI) symptoms is frequently reported in patients with Autism Spectrum Disorders (ASD). The GI disturbances in ASD might be linked to gut dysbiosis representing the observable phenotype of a "gut-brain axis" disruption. The exploitation of strategies which can restore normal gut microbiota and reduce the gut production and absorption of toxins, such as probiotics addition/supplementation in a diet, may represent a non-pharmacological option in the treatment of GI disturbances in ASD. The aim of this randomized controlled trial is to determine the effects of supplementation with a probiotic mixture (Vivomixx®) in ASD children not only on specific GI symptoms, but also on the core deficits of the disorder, on cognitive and language development, and on brain function and connectivity. An ancillary aim is to evaluate possible effects of probiotic supplementation on urinary concentrations of phthalates (chemical pollutants) which have been previously linked to ASD.

METHODS

A group of 100 preschoolers with ASD will be classified as belonging to a GI group or to a Non-GI (NGI) group on the basis of a symptom severity index specific to GI disorders. In order to obtain four arms, subjects belonging to the two groups (GI and NGI) will be blind randomized 1:1 to regular diet with probiotics or with placebo for 6 months. All participants will be assessed at baseline, after three months and after six months from baseline in order to evaluate the possible changes in: (1) GI symptoms; (2) autism symptoms severity; (3) affective and behavioral comorbid symptoms; (4) plasmatic, urinary and fecal biomarkers related to abnormal intestinal function; (5) neurophysiological patterns.

DISCUSSION

The effects of treatments with probiotics on children with ASD need to be evaluated through rigorous controlled trials. Examining the impact of probiotics not only on clinical but also on neurophysiological patterns, the current trial sets out to provide new insights into the gut-brain connection in ASD patients. Moreover, results could add information to the relationship between phthalates levels, clinical features and neurophysiological patterns in ASD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02708901 . Retrospectively registered: March 4, 2016.

Reviewing Classical and Molecular Techniques Regarding Profiling of Probiotic Character of Microorganisms

In recent years the roles of probiotics as functional ingredients in food has been highly adopted by the consumers and are under constant investigation by the scientific community. As a result, several probiotic-containing foods have been introduced in the market with an annual share of several billion dollars. Of particular interest in the probiotics research is the profiling of probiotic character of the microbes involving both in vitro and in vivo approaches. Initially traditional microbiological techniques were used; however they suffer by many limitations and therefore the development of new techniques, which are primarily based on the analysis of nucleic acids have been introduced. The scope of this review is to present current knowledge about the methodological approaches that are used to quantify and characterize the potential probiotic character of microorganisms. Moreover, it will focus on molecular and non-molecular tools and finally will report some new perspectives in the study of probiotics using omics techniques.

Novel anti-Helicobacter pylori therapies

Helicobacter pylori is a ubiquitous gastropathogen infecting more than half of the world population. It is associated with dyspepsia, gastritis, gastroduodenal ulcers, mucus-associated lymphoid tissue lymphoma and gastric carcinoma. Current recommended therapy does not eradicate infection in all treated cases and at least 20% post-treatment patients continue to suffer. Salvage therapy helps some of these nonresponders, but resistance to available antibiotics is mounting. Hence, its treatment still remains a daunting task for the practicing physician. Novel medications with improved efficacy and tolerability and with less chances of resistance are required. The present review attempts to discuss the newer patents in this field, which demonstrate a promising future role in the management of H. pylori infection and its consequent problems.

Probiotics: definition, scope and mechanisms of action

For a subject area of science, medicine and commerce to be so recently defined and investigated, few can compare to probiotics for the controversy they have incited. Barely a paper is published without the use of a different definition, or challenging the most used one, or proposing a different nuance of it. The situation has become even more surreal with the European Food and Safety Authority banning the word probiotic for use on labels. The reiteration of the FAO/WHO definition by the world's leading group of probiotic experts, should provide relative consistency in the near future, but what are the causes of these aberrations? This review will discuss the rationale for the definition, and the scope of the subject area and why alternatives emerge. While mechanisms of action are not widely proven, in vitro and some in vivo experiments support several. Ultimately, the goal of any field or product is to be understood by lay people and experts alike. Probiotics have come a long way in 100 years since Metchnikoff and 10 years since their globalization, but their evolution is far from over.

Gut microbiota in autism and mood disorders

The hypothesis of an important role of gut microbiota in the maintenance of physiological state into the gastrointestinal (GI) system is supported by several studies that have shown a qualitative and quantitative alteration of the intestinal flora in a number of gastrointestinal and extra-gastrointestinal diseases. In the last few years, the importance of gut microbiota impairment in the etiopathogenesis of pathology such as autism, dementia and mood disorder, has been raised. The evidence of the inflammatory state alteration, highlighted in disorders such as schizophrenia, major depressive disorder and bipolar disorder, strongly recalls the microbiota alteration, highly suggesting an important role of the alteration of GI system also in neuropsychiatric disorders. Up to now, available evidences display that the impairment of gut microbiota plays a key role in the development of autism and mood disorders. The application of therapeutic modulators of gut microbiota to autism and mood disorders has been experienced only in experimental settings to date, with few but promising results. A deeper assessment of the role of gut microbiota in the development of autism spectrum disorder (ASD), as well as the advancement of the therapeutic armamentarium for the modulation of gut microbiota is warranted for a better management of ASD and mood disorders.

[The potential role of microbiota in major psychiatric disorders: Mechanisms, preclinical data, gastro-intestinal comorbidities and therapeutic options]

While forecasts predict an increase in the prevalence of mental health disorders in the worldwide general population, the response rate to classical psychiatric treatment remains unsatisfactory. Resistance to psychotropic drugs can be due to clinical, pharmacological, pharmacokinetic, and pharmacodynamic factors. Among these factors, recent animal findings suggest that microbiota may have an underestimated influence on its host's behavior and on drug metabolism that may explain ineffectiveness or increased side effects of psychiatric medications such as weight gain. The following issues were identified in the present review: (i) microbiota dysbiosis and putative consequences on central nervous system functioning; (ii) chronic microbiota dysbiosis-associated illnesses in humans; (iii) microbiota-oriented treatments and their potential therapeutic applications in psychiatry.

Microbiome Disturbances and Autism Spectrum Disorders

Autism spectrum disorders (ASDs) are considered a heterogenous set of neurobehavioral diseases, with the rates of diagnosis dramatically increasing in the past few decades. As genetics alone does not explain the underlying cause in many cases, attention has turned to environmental factors as potential etiological agents. Gastrointestinal disorders are a common comorbidity in ASD patients. It was thus hypothesized that a gut-brain link may account for some autistic cases. With the characterization of the human microbiome, this concept has been expanded to include the microbiota-gut-brain axis. There are mounting reports in animal models and human epidemiologic studies linking disruptive alterations in the gut microbiota or dysbiosis and ASD symptomology. In this review, we will explore the current evidence that gut dysbiosis in animal models and ASD patients correlates with disease risk and severity. The studies to date have surveyed how gut microbiome changes may affect these neurobehavioral disorders. However, we harbor other microbiomes in the body that might impact brain function. We will consider microbial colonies residing in the oral cavity, vagina, and the most recently discovered one in the placenta. Based on the premise that gut microbiota alterations may be causative agents in ASD, several therapeutic options have been tested, such as diet modulations, prebiotics, probiotics, synbiotics, postbiotics, antibiotics, fecal transplantation, and activated charcoal. The potential benefits of these therapies will be considered. Finally, the possible mechanisms by which changes in the gut bacterial communities may result in ASD and related neurobehavioral disorders will be examined.

The "psychomicrobiotic": Targeting microbiota in major psychiatric disorders: A systematic review

The gut microbiota is increasingly considered as a symbiotic partner in the maintenance of good health. Metagenomic approaches could help to discover how the complex gut microbial ecosystem participates in the control of the host's brain development and function, and could be relevant for future therapeutic developments, such as probiotics, prebiotics and nutritional approaches for psychiatric disorders. Previous reviews focused on the effects of microbiota on the central nervous system in in vitro and animal studies. The aim of the present review is to synthetize the current data on the association between microbiota dysbiosis and onset and/or maintenance of major psychiatric disorders, and to explore potential therapeutic opportunities targeting microbiota dysbiosis in psychiatric patients.

Microorganisms with claimed probiotic properties: an overview of recent literature

Probiotics are defined as live microorganisms, which when administered in adequate amounts, confer a health benefit on the host. Health benefits have mainly been demonstrated for specific probiotic strains of the following genera: Lactobacillus, Bifidobacterium, Saccharomyces, Enterococcus, Streptococcus, Pediococcus, Leuconostoc, Bacillus, Escherichia coli. The human microbiota is getting a lot of attention today and research has already demonstrated that alteration of this microbiota may have far-reaching consequences. One of the possible routes for correcting dysbiosis is by consuming probiotics. The credibility of specific health claims of probiotics and their safety must be established through science-based clinical studies. This overview summarizes the most commonly used probiotic microorganisms and their demonstrated health claims. As probiotic properties have been shown to be strain specific, accurate identification of particular strains is also very important. On the other hand, it is also demonstrated that the use of various probiotics for immunocompromised patients or patients with a leaky gut has also yielded infections, sepsis, fungemia, bacteraemia. Although the vast majority of probiotics that are used today are generally regarded as safe and beneficial for healthy individuals, caution in selecting and monitoring of probiotics for patients is needed and complete consideration of risk-benefit ratio before prescribing is recommended.

Gleaning evolutionary insights from the genome sequence of a probiotic yeast Saccharomyces boulardii

Background

The yeast Saccharomyces boulardii is used worldwide as a probiotic to alleviate the effects of several gastrointestinal diseases and control antibiotics-associated diarrhea. While many studies report the probiotic effects of S. boulardii, no genome information for this yeast is currently available in the public domain.

Results

We report the 11.4 Mbp draft genome of this probiotic yeast. The draft genome was obtained by assembling Roche 454 FLX + shotgun data into 194 contigs with an N50 of 251 Kbp. We compare our draft genome with all other Saccharomyces cerevisiae genomes.

Conclusions

Our analysis confirms the close similarity of S. boulardii to S. cerevisiae strains and provides a framework to understand the probiotic effects of this yeast, which exhibits unique physiological and metabolic properties.

Influence of gut microbiota on subclinical inflammation and insulin resistance

Obesity is the main condition that is correlated with the appearance of insulin resistance, which is the major link among its comorbidities, such as type 2 diabetes, nonalcoholic fatty liver disease, cardiovascular and neurodegenerative diseases, and several types of cancer. Obesity affects a large number of individuals worldwide; it degrades human health and quality of life. Here, we review the role of the gut microbiota in the pathophysiology of obesity and type 2 diabetes, which is promoted by a bacterial diversity shift mediated by overnutrition. Whole bacteria, their products, and metabolites undergo increased translocation through the gut epithelium to the circulation due to degraded tight junctions and the consequent increase in intestinal permeability that culminates in inflammation and insulin resistance. Several strategies focusing on modulation of the gut microbiota (antibiotics, probiotics, and prebiotics) are being experimentally employed in metabolic derangement in order to reduce intestinal permeability, increase the production of short chain fatty acids and anorectic gut hormones, and promote insulin sensitivity to counteract the inflammatory status and insulin resistance found in obese individuals.