Effects of Probiotics on Gut Microbiota, Endocannabinoid and Immune Activation and Symptoms of Fatigue in Dancers

Study Overview
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Brief Summary
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The aim of the planned research is to assess the dynamics of changes in the elements of the gut-brain axis (GBA), the cytokine profile and the endocannabinoid system markers, after dietary supplementation with probiotics Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175 by professional dancers. Although in recent years there has been growing interest in the influence of the gut microbiota on the body's adaptation to stress stimuli and on overall health, there is a lack of information on the influence of probiotics on systems involved in maintaining neuropsychiatric balance, such as the endocannabinoid system. In order to determine the validity of the applied therapy with selective probiotics, the following will be assessed: intestinal bacteria and bacterial metabolites in the stool, cannabinoids and cannabinoid receptors and enzymes in the blood, indicators of mental distress in the blood, cytokines responsible for the modulation of the gut-brain axis in the blood, as well as questionnaires regarding the functioning of the digestive tract, fatigue, stress and sleep quality. The study will involve active dancers of the Polish Theater in Poznan, the Polish Dance Theater, the Private School of Dance Art in Poznan and students of the Academy of Physical Education in the field of Dance. Dancers are a group of athletes that is exposed to particular injuries and work-overload. Professional dancers spend multiple hours a week on intensive physical training. The largest percentage of injuries occurring in the group of professional dancers are chronic injuries, including: inflammation of soft tissues, muscle strains and tears. Professional dance is one of the most physically demanding forms of physical activity, and at the same time it is associated with a high burden on the nervous system problems caused by performances in front of an audience or subjective jury, frequent traveling and disturbances in the circadian rhythm.

Detailed Description
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Professional dancers are often referred to as artistic athletes due to their high level of physical activity and competition. Training dance for over 11.5 hours a week increases the risk of injury (women - mostly bone injuries, men - mostly bruises and tendon injuries). One of the reasons for the increased susceptibility to injuries among dancers is psychological stress. The observations results indicate that dancers often decide to continue training despite feeling pain, which limits the smoothness of their movements and leads to a further increase of stress. Highly physically active groups of people are more exposed to functional dyspepsia (FD) and irritable bowel syndrome (IBS), which occurence is correlated to chronic stress. As a result of chronic stress and the activation of the hypothalamic pituitary-adrenal axis (HPA), inflammatory processes in the gastrointestinal mucosa are initiated. The presence of noradrenaline increases the adhesion of bacteria and viruses to the epithelium, which in turn modulates the immune system within the intestines and increases their inflammation. Systemically acting cortisol causes the leakage of tight junctions (TJ) cells and an increase in the permeability of the intestinal barrier. Inflammation stimulates the secretion of cortisol, which initiates the further cycle of inflammation and weakening of the intestinal barrier function. As a consequence, cytokines and inflammatory mediators released in the course of inflammation act directly on the nerve endings that transmit these afferent nerve signals to the brain, becoming an endogenous stressor. When exogenous and endogenous stress factors overlap, the body's perception of stress increases, which ultimately leads to psychological, physiological and behavioral changes. Pain and depression are common comorbidities of neuropsychiatric origin. One of the body's regulatory systems, which in both cases is dysfunctional, is the endocannabinoid system (ECS). It has been suggested that these diseases can be caused by intense and prolonged exercise, which disrupts the intestinal barrier, causing changes in the profile of metabolites and the function of the intestinal microbiota. Overtraining leads to an increase in the levels of cortisol, adrenaline and noradrenaline, and to the translocation of lipopolysaccharide (LPS) outside the gut, increasing the concentration of pro-inflammatory cytokines in the body. This results in dysregulation of the balance between serotonin (5-HT), dopamine (DA) and gamma-aminobutyric acid (GABA) and fatigue. These changes lead to further activation of the endocannabinoid system and, in the long-term, weakening of adaptive abilities. The neuromodulatory properties of the cannabinoid system are manifested e.g. in short- and long-term synaptic plasticity and modulation of pain conduction. Research results indicate that the endocannabinoid system, in addition to its key role in regulating intestinal motility, also affects the secretory functions of the gastrointestinal tract and the integrity of the intestinal epithelium, which may be an alternative way to regulate the immune system and inflammation in the intestines. Type 1 cannabinoid receptors (CB1) are located presynaptically in the cell membrane of central and peripheral nervous system neurons, and their activation inhibits the release of many neurotransmitters, i.e. acetylcholine, noradrenaline, dopamine, serotonin, glutamate and γ-aminobutyric acid. Type 2 cannabinoid receptors (CB2) are found mainly on the surface of cells of the immune system, especially B-lymphocytes, macrophages and monocytes. Their activation inhibits pro-inflammatory cytokines release and increases the release of anti-inflammatory cytokines. Cannabinoid receptors are found in both, the immune and digestive systems. Endogenous cannabinoids modify the body's response to stress by influencing the hypothalamic pituitary-adrenal axis (HPA). Stress leads to an increased activity of endocannabinoids which, mainly through the CB1 cannabinoid receptors, lead to the inhibition of the release of corticosteroids. In addition, the activation of CB1 receptors in the gastrointestinal tract reduces the intensity of pain conduction (nociception), which is induced by activation, e.g. TRPV1 vanilloid receptors. It has been shown that inflammation within the intestinal epithelium of the gastrointestinal tract causes an increase in the neural conduction of neurons containing CB1 receptors, which contributes to a change in the proportion of these receptors in relation to the TRPV1 located mainly in the cell membrane of dorsal root ganglion afferents (DRGs). As a result, two different receptors interact and the TRPV1 receptor activity is abolished. Inflammatory mediators released from the intestinal epithelium stimulate visceral pain, while activation of CB2 receptors probably reduces their action. There are indications that a qualitative and quantitative change in the intestinal microbiota may affect the activity of endogenous ligands and mediators of the endocannabinoid system (ECS). Although the mechanisms of regulation of the level of endocannabinoids and related bioactive lipids by selected bacteria are not fully understood, it has been shown that probiotic supplementation can induce an increase in the concentration of endogenous cannabinoids, i.e. 2-AG, 2-OG (oleoylglycerol) and 2-PG (palmitoylglycerol). In an animal experiment, the use of monoacylglycerol lipase inhibition reduced the degradation of 2-AG, which reduced endotoxemia and systemic inflammation. In another study, the deletion of the Myd88 gene encoding the TLR (toll-like receptor) receptor protein in intestinal epithelial cells changed the composition of the intestinal microbiota, decreased the synthesis of anandamide (AEA) and increased the synthesis of anti-inflammatory endocannabinoids, such as: 2-AG, 2-PG, 2 OG. Released endocannabinoids with anti-inflammatory properties have the ability to activate so-called orphan GPR119 receptors, which are associated with the secretion of anti-inflammatory mediators. Moreover, it has been shown that an increase in LPS concentration induces AEA synthesis and a decrease in fatty-acid amide hydrolase (FAAH) in macrophages, as well as an increase in AEA production in peripheral lymphocytes, which may be important for the regulation of the intestinal barrier function and the level of inflammation. The results of studies carried out on a mouse model revealed the importance of the intestinal microbiota in the regulation of the expression of the NAPE-PLD gene (phospholipase D specific for n-acylphosphatidylethanolamine), i.e. an enzyme involved in the synthesis of anandamide and in the selective regulation of CB1 mRNA expression. In an obese mouse model, it was observed that the administration of a probiotic decreased the expression level of CB1 receptor mRNA while reducing the concentration of AEA ligand and increasing the expression of FAAH mRNA. In other studies, administration of a probiotic to mice resulted in a decrease in the concentration of LPS in the blood plasma, which correlated with both the level of AEA and the expression of CB1 mRNA in the colon epithelium. In in vitro and in vivo experiments on animal models, it has been observed that CB2 receptors are activated when an imbalance in the innate immune system occurs. The NLRP3 inflammasomes are suppressed by autophagy, a mechanism that may be involved in the suppression of inflammation and the regulation of the intestinal barrier, e.g. in irritable bowel syndrome. Another factor that is a potential NLRP3 inhibitor is the intestinal microbiota metabolite, butyrate, which belongs to the short-chain fatty acids. Its action has a positive effect on the functions of the intestinal epithelial cells and the stability of the intestinal barrier. In studies conducted on germ-free mice, after the intestinal microbiota was transferred, the metabolism of endocannabinoids in the gastrointestinal tract changed. The use of probiotic therapy in mice with previously induced intestinal dysbiosis changed the activation of endocannabinoid receptors, the behavior of animals and a decrease in intestinal inflammation. Other research results indicate that inhibition of the CB1 receptor in obese mice stimulates the secretion of mucin, which is the primary source of nutrients for the development of Akkermansia muciniphila. This observation confirms the results of studies by other authors, who demonstrated the possibility of regulation of CB2 receptors by some species of intestinal bacteria and the related immune response. The mechanisms of the transmission of inflammatory signals from the gut to the CNS are not fully elucidated. The results of the research indicate, however, that the systemic inflammation accompanying depressive symptoms is associated with changes in the ecosystem of the intestinal microbiota and the production of SCFA and other metabolites of a neurobiological nature. Moreover, it can also lead to changes in the synthesis and release of endocannabinoids or the metabolic pathways of tryptophan and kynurenine (KYN). So far, it has been observed that there is a link between ECS and the kynurenine pathway in neurological disorders such as epilepsy or migraine headaches, which are associated with excessive cell stimulation and excitotoxicity. The latest research results indicate the possibility of modifying the transformations of tryptophan and kynurenine by probiotic therapy. There is limited number of human research on the role of the gut microbiota in the modulation of the ECS. The available literature lacks studies describing the relationship of changes in the intestinal microbiota and its metabolome under the influence of targeted, multi-strain probiotic therapy on the response of the endocannabinoid and immune system in people subjected to high physical and mental stress. Observations that will be made in dancers supplemented with a multi strain probiotic containing Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175 may help finding effective tools in the treatment of gastrointestinal disorders and stress related to it. A potential mechanism behind this action may be the restoration of the normal gut microbiota and the profile of its metabolites, as well as the improvement of the gut barrier and endocannabinoid function.

Official Title
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Effects of 3-month Probiotic Mix Supplementation (L. Helveticus R-0052, B. Longum R-0175) on Gut Microbiota and Metabolome, Endocannabinoid and Immune Systems Activation, Along With Symptoms of Fatigue in Professional Dancers

Conditions
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Fatigue, Stress, Job

Intervention / Treatment
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* Dietary Supplement: Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175 (Sanprobi Stress)
* Dietary Supplement: Starch (placebo)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18, <36 years old; Professional dancing activity with over 8 hours of training per week. Exclusion Criteria: Age <18,> 36 y.o.; Being injured within 3 months from the start of the study; Taking pre- and / or probiotics in the last 3 months before the study; Hospitalization during the last 4 weeks before starting of the study; Traveling to tropical countries during the last 4 weeks before study; Taking antibiotics, steroids and anabolic steroids in the last 4 weeks before study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 36 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: a Randomized, Double-blind, Placebo-controlled Study
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Probiotic treatment group<br>ca. 30 participants | Dietary Supplement: Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175 (Sanprobi Stress)<br>* 3-month, multi-strain probiotic supplementation (one a day, 3 x 10⁹ CFU)<br>* Other names: L. helveticus R-0052, B. longum R-0175;|
| Placebo Comparator: Placebo group<br>ca. 30 participants | Dietary Supplement: Starch (placebo)<br>* 3-month placebo<br>* Other names: capsules containing starch;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Qualitative assessment of intestinal microbiota in stool samples | • gut bacteria species in stool will be assessed using the shallow shotgun sequencing method, NGS (Next Generation Sequencing); | up to 10 months | 
| Quantitive change in intestinal microbiota in stool samples | • determination of quantitative (Colony forming units - CFU) changes in bacteria in the stool - the shallow shotgun sequencing method, NGS (Next Generation Sequencing) molecular analysis will be used to assess the changes; | up to 10 months | 
| Intestinal metabolome in stool samples | • metabolomic analysis (non-targeted metabolome, short-chain fatty acids, trimethylamines, tryptophan catabolites) will be performed on a quadrupole mass spectrometer coupled with a time-of-flight (QToF) analyzer connected to the AB Sciex - TripleTOF® 6600+ high performance liquid chromatograph (UHPLC) | up to 10 months | 
| Quantitive change in endocannabinoids levels in blood samples | • determination of endocannabinoids and cannabinoid receptors: anandamide (AEA) and 2-arachidonylglycerol (2-AG) using ELISA Kit (nanograms per millilitre (ng/mL)); | up to 10 months | 
| Quantitive change in endocannabinoids' receptors levels in blood samples | • determination of cannabinoid receptors: Endocannabinoid Receptor 1 (CNR1) and Endocannabinoid Receptor 2 (CNR2) using ELISA Kit (nanograms per millilitre (ng/mL)); | up to 10 months | 
| Quantitive change in endocannabinoids metabolism enzymes in blood | • determination of cannabinoid metabolism enzymes: fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) using ELISA Kit (nanograms per millilitre (ng/mL)); | up to 10 months | 
| Quantitive change in intestinal barrier proteins in blood samples | • determination of blood biomarkers of a disturbed intestinal barrier concentrations: zonulin, calprotectin (CALPRO) using ELISA Kit (nanograms per millilitre (ng/mL)); | up to 10 months | 
| Quantitive change in intestinal barrier biomarkers in blood samples | • determination of blood biomarkers of a disturbed intestinal barrier concentrations: lipopolysaccharide (LPS), secretory immunoglobulin A (sIgA) using ELISA Kit (picograms per millilitre (pg/mL)); | up to 10 months | 
| Quantitive change in tumor necrosis factor-alpha (TNF-α) in blood samples | • determination of blood tumor necrosis factor-alpha (TNF-α) concentration using leukemia inhibitory factor (LIF) concentration using ELISA Kit (nanograms per millilitre (ng/mL)); | up to 10 months | 
| Quantitive change in leukemia inhibitory factor (LIF) in blood samples | • determination of blood leukemia inhibitory factor (LIF) concentration using ELISA Kit (nanograms per millilitre (ng/mL)); | up to 10 months | 
| Quantitive change in blood interleukins profile | • determination of interleukins concentrations: IL-1α, IL-1β, IL-10 and IL-18 using ELISA Kit using ELISA Kit (picograms per millilitre (pg/mL)); | up to 10 months | 
| Quantitive change in chronic stress biomarker in blood samples - cortisol | • determination of blood cortisol concentration using ELISA Kit (nanograms per millilitre (ng/mL)); | up to 10 months | 
| Quantitive change in inflammation biomarker in blood samples - C-reactive protein | • determination of C-reactive protein (CRP) concentration using ELISA Kit (picograms per millilitre (pg/mL)); | up to 10 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Coping with stress questionnaire | • determination of methods of coping with stress using the Inventory for Measuring Coping with Stress (Mini-COPE); It is designed to establish how a study participant behaves when experiences particular events; The scale: 0 = I hardly ever do this, 1 = I rarely do this, 2 = I do this often, 3 = I almost always do this; | up to 10 months | 
| Fatigue questionnaire | • assessment of the level of fatigue using the Fatigue Assessment Scale (FAS); the statements of the questionnaire relate to the feeling of well-being; The scale: 1. Never, 2. Sometimes (once a month or less), 3. Regularly (several times a month), 4. Often (weekly) and 5. Always (everyday); | up to 10 months | 
| Gastrointestinal disorders questionnaire | • assessment of gastrointestinal disorders using the Rome IV Questionnaire for adults (selected questions on irritable bowel syndrome, constipation and diarrhea); the statements of the questionnaire relate to frequency and intensity of disorders; higher scores mean worse outcome; | up to 10 months | 
| Sleep quality questionnaire | • assessment of the sleep quality level using Pittsburgh Sleep Quality Questionnaire, PSQI; the statements of the questionnaire relate to frequency of sleep disorders; higher scores mean worse outcome; | up to 10 months | 
| Body mass analysis (BMI, kg/m^2) | • determination of body weight and composition using the electrical bioimpedance method; | up to 10 months | 
| Body composition analysis (percent of total body mass) | • assessment of bone, fat and fat-free mass using the electrical bioimpedance method; | up to 10 months | 
| Composite measure of Diet composition assessed by food diaries | • assessment of protein, fat, carbohydrates and fibre intake using food diaries (grams); | up to 10 months | 
| Pain threshold test (Newtons) | • mechanical stimuli pain threshold assessment using an algometer (Wagner FPX ™) | up to 10 months | 
| Changes in red blood cells count | • determination of red blood cell counts using flow cytometry (trillion cells per Litre); | up to 10 months | 
| Changes in white blood cells count | • determination of white blood cells counts using flow cytometry (billion cells per Litre); | up to 10 months | 
| Changes in hemoglobin level | • determination of hemoglobin level using flow cytometry (grams per Litre); | up to 10 months | 
| Changes in hematocrit | • determination of hematocrit using flow cytometry (percentage of red blood cells in blood); | up to 10 months | 
| Changes in platelets counts | • determination of platelets counts using flow cytometry (billions per Litre) | up to 10 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gut microbiome, Probiotics, Professional dancers, Cannabinoids, Inflammation