Probiotics function mechanistically as delivery vehicles for neuroactive compounds: Microbial endocrinology in the design and use of probiotics

Chapter 6 - Microbial Endocrinology: Context and Considerations for Probiotic Selection

Probiotics are live nonpathogenic microorganisms. Many of these microorganisms are part of the normal human gut flora, where they live in a symbiotic relationship. Probiotics have been used to treat gastrointestinal (GI) and non-GI medical conditions. However, the data supporting their use are often conflicting, especially for non-GI-associated illnesses. The strongest evidence supporting the use of probiotics is related to the treatment of acute diarrhea and pouchitis. Atopic eczema in children and genitourinary infections are the only non-GI-related medical conditions where probiotics may have some beneficial effects. Product selection and dosing are not the same in all conditions, and the beneficial effects of each probiotic strain cannot be generalized.The purpose of this article is to provide most recent information about probiotics and its uses. In contrast with previously published reviews on probiotics, we also discuss the composition of various products (Table 1), indications for their use (Table 2), product selection, and dosing of probiotics.Probiotics are safe and appear to exert some beneficial effects in GI-related illnesses. The use of probiotics in non-GI illnesses is not sufficiently supported by current data.

Probiotics comprise a large group of microorganisms, which have different properties and thus confer different benefits. The use of probiotics has shown promising results in the management of diarrheal diseases. While the availability of probiotic products has flourished in the marketplace, there is limited guidance on the selection of probiotics for clinical use. This position paper is aimed at informing clinicians about the proper selection criteria of probiotics based on current evidence on strain‐specific efficacy and safety for the management of diarrheal diseases. Members of the working group discussed issues on probiotic use in clinical practice, which were then drafted into statements. Literature to support or refute the statements were gathered through a search of medical literature from 2011 to 2020. Recommendations were formulated based on the drafted statements and evidence gathered, revised as necessary, and finalized upon agreement of all members. Twelve statements and recommendations were developed covering the areas of quality control in the manufacturing of probiotics, criteria for selection of probiotics, and established evidence for use of probiotics in diarrheal diseases in adults and children. Recommendations for the use of specific probiotic strains in clinical practice were categorized as proven and probable efficacy based on strength of evidence. Robust evidence is available to support the use of probiotics for diarrheal diseases in clinical practice. Based on the results obtained, we strongly advocate the careful evaluation of products, including manufacturing practices, strain‐specific evidence, and contraindications for at‐risk populations when choosing probiotics for use in clinical practice.

Probiotics in irritable bowel syndrome: Has the time arrived?

Gastrointestinal (GI) health significantly impacts overall well-being. Probiotics, defined as live microorganisms that confer health benefits when consumed in adequate amounts, have been associated with improvements in digestion, immunity, and gut microbiota balance. Despite evidence supporting their role in managing conditions like bloating, irritable bowel syndrome (IBS), and antibiotic-associated symptoms, awareness and clinical use of probiotics remain limited in many populations, including Saudi Arabia. The aim of this study was to evaluate the association between probiotic consumption and gastrointestinal health outcomes among adults in Saudi Arabia, and to explore factors influencing probiotic intake. A web-based, cross-sectional study was conducted using an online questionnaire targeting adults across Saudi Arabia. Data on demographics, dietary habits, probiotic use, and gastrointestinal symptoms were collected and analyzed using chi-square tests and multivariate logistic regression. Among 442 participants, the majority were young adults (18-30 years), female, and students. Most (87%) had heard of probiotics, though only 16.6% used them regularly. Yogurt and pickled foods were common sources; supplements were less used (13.8%). A significant association was observed between frequent probiotic use and better self-reported digestive health (χ2 = 20.93, p = 0.013), though this did not persist in multivariate analysis. Employment status and higher fruit/vegetable intake were significant predictors of probiotic use (OR = 1.60 and OR = 2.08, respectively). Although awareness of probiotics is high, regular usage is limited and influenced by lifestyle and dietary behaviors. These findings underscore the need for targeted public health initiatives to improve probiotic literacy and promote their integration into dietary strategies for digestive health support.

INTRODUCTION: Probiotic use for management of GI conditions is becoming more popular, as it is perceived to be a natural and low-risk therapeutic option. Despite their increasing use, how patients choose to use probiotics or how GI providers make recommendations has not been well-studied. This survey aims to characterize the pattern of probiotic use by patients and GI providers. METHODS: Surveys were distributed to patients seen at a GI clinic at a single tertiary medical center. Surveys were also distributed to GI providers who attended a regional postgraduate course. Survey questions included basic demographics, indication for probiotic use, subjective clinical response to probiotics, side effects, brand of probiotics, and factors that influenced choice of probiotics. RESULTS: 76 patient surveys and 58 provider responses were collected. Patients used probiotics for general digestive health (22%), IBS (17%), and GERD (16%), while providers recommended probiotics for IBS (81%), Clostridioides difficile infection (64%), and IBD (45%). For symptoms, patients used probiotics to treat abdominal pain (38%) and bloating (26%), while providers recommended it for bloating (76%) and diarrhea (71%). 45% of patients reported improvement of GI symptoms, whereas 21% reported no improvement. Side effects were uncommon, but bloating and diarrhea were most frequently reported. Providers recommended specific brands and bacterial strains, while patients took a wide variety of brands without knowing specific strains. Most patients (82%) chose to take probiotics without their provider’s recommendations. Patients’ selection of probiotics was driven by cost, variety of strain, and number of colonies forming units. 91% of providers felt the need for more specific guidelines on probiotic use. CONCLUSION: This study shows that patients and their gastroenterologists have vastly different probiotic “prescribing” patterns. Despite a relative lack of evidence for many conditions, probiotics were frequently utilized. Patients use probiotics for different symptoms and conditions than physicians and have remarkably different factors that influence selection of a probiotic. Providers should proactively discuss current evidence on probiotic use and help patients identify key features and differences between probiotic products.

Faculty Opinions recommendation of Probiotics function mechanistically as delivery vehicles for neuroactive compounds: Microbial endocrinology in the design and use of probiotics.

A Gastroenterologist's Guide to Probiotics

Clinical use of probiotics in pediatrics.

Therapeutic Use of Prebiotics, Probiotics, and Postbiotics to Prevent Necrotizing Enterocolitis: What is the Current Evidence?

Pediatric eczema is a common disease which causes economic and social burden. Its incidence differs among the societies, with an incidence reported to reach up to 20% in developed countries. Eczema is the first allergic disease seen in the childhood, and it is recognized as a precursor for the development of atopic diseases such as asthma, allergic rhinitis, and food allergy in the forthcoming years of children. Increased incidence of eczema in recent years has led to new research in epidemiology, prevention, and intervention of this disease. It is no doubt important to treat itching, rash, and excoriation of the skin; however, treatment of pediatric eczema should not be considered only as a treatment of skin lesions. Considering skin treatment as the tip of the iceberg, proper management of the allergic processes can be accepted as the rest of the iceberg. The role of probiotics in the prevention of atopic eczema is yet to be clarified. Evidence presented by existing studies suggesting that probiotics may prevent pediatric eczema is not strong enough. A positive effect, if any, may be related with onset time, dose, duration, and use of specific probiotics. To date, there is no strong evidence for use of probiotics in the treatment of eczema; however, administration of probiotics in breast-feeding mothers in the prenatal period and in infants in the postnatal period can be accepted as a safe and helpful option in the prevention of eczema. Nevertheless, there are still questions to be answered in the future about probiotic administration for eczema. Clinical use of probiotics will gradually become more widespread when these questions are answered. Based on current information, the administration of probiotics for pediatric eczema topic is addressed in this review.

Cystic fibrosis (CF) primarily affects the lung, however, gastrointestinal disorders and symptoms, including dysbiosis, also impact on morbidity and quality of life. There is interest in strategies to modulate the gastrointestinal microbiota, including probiotics, although the evidence remains inadequate to guide practice, and information on use is limited. The present study aimed to characterise probiotic use, beliefs and experiences of adults with CF. A cross-sectional questionnaire study was conducted in adults with CF (n = 205) and a general population Control group (n = 158), recruited from Victoria, Australia. Participants were classified as probiotic 'Ever Users' or 'Never Users'. Outcomes included self-reported probiotic use and factors associated with probiotic use, which were analysed using logistic regression analysis. Open-ended questionnaire responses were thematically analysed. In total, 70% of adults with CF had ever used probiotics (supplements and/or foods), comparable to Controls (80%) (p = 0.03). Key reasons for CF probiotic use were gastrointestinal- and antibiotic-related (75%). Most CF Ever Users (73%) did not discuss probiotic use with CF clinicians and 33% were uncertain if probiotics had been helpful. Female gender (odds ratio [OR]=2.82; 95% confidence interval [CI]=1.36-5.87; p = 0.005), university-level education (OR=2.73; 95% CI=1.24-6.01; p = 0.01) and bloating on antibiotics (OR=2.14; 95% CI=1.04-4.40; p = 0.04) were independently associated with probiotic use in CF; as was female gender in Controls (OR=2.84; 95% CI=1.20-6.71; p = 0.02). Probiotics were used by adults with CF for gastrointestinal- and antibiotic-related reasons often without informing clinicians and despite uncertainty about perceived helpfulness. Further research investigating gastrointestinal outcomes of probiotics will inform practice recommendations guiding their use in CF and other chronic diseases.

Neuroactive compounds in foods: Occurrence, mechanism and potential health effects.

The ecology of gut microflora, which colonizes all body surfaces, has long coevolved with its hosts in a complicated fashion. Health benefits conferred by gut microflora include defense against invading pathogens, improvement of nutritional bioavailability, and development of the regional and systemic immune systems. The past decade has witnessed growing interest in the fact that the gut microflora affects the host's energy homeostasis by means of various mechanisms, including supplying nourishment from indigestible compounds, producing small biomolecules responsible for lipid profiles, and participating in the absorption, distribution, metabolism and excretion of nutrition. Much in vitro and in vivo research has indicated that aberrant gut microflora plays an important role in the pathogenesis of a wide spectrum of diseases. This is accomplished by a shift in focus, from laying an emphasis on pharmacotherapy to placing more effort on gut microflora normalization. The objectives of this review include illustrating trends in the clinical application of probiotics on diseases, as well as discussing current methodology limitations on probiotic selection. Furthermore, it is expected to shed light on the nature of probiotics, with the aim of giving greater insight into the implications for clinical use of probiotics in the treatment of diseases.

The mechanisms by which probiotics may influence host physiology are still incompletely understood. Microbial endocrinology, a field representing the union of microbiology, endocrinology and neurobiology, has theorized that microorganisms have the capacity to serve as neurochemical delivery vehicles [1]. According to microbial endocrinology, neurochemicals can serve as a common language between host and bacterium, enabling bidirectional communication. We report herein the first demonstration that Enterococcus sp. has the capacity to produce dopamine in a gastrointestinal-like environment when supplied with the dopamine precursor L-3,4 dihydroxyphenylalanine (L-dopa). The results presented herein provide a means to select probiotics based on neurochemical-producing potential and suggest the possibility that probiotics containing E. faecium may serve to influence the host through dopaminergic pathways.