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Impact of Probiotics on the Performance of Endurance Athletes: A Systematic Review.
Díaz-Jiménez, J, Sánchez-Sánchez, E, Ordoñez, FJ, Rosety, I, Díaz, AJ, Rosety-Rodriguez, M, Rosety, MÁ, Brenes, F
International journal of environmental research and public health. 2021;18(21)
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The relationship between the gut microbiome and exercise has recently been explored to ascertain potential methods of improving athletic performance. Athletes have begun utilising probiotics to improve performance, support the immune system and reduce gastrointestinal problems, however no systematic review has been done to assess the efficacy behind these notions. The aim of this study is to review the use of probiotics in endurance athletes and assess both the direct and indirect associative factors. This review included nine studies and found improvements in athletic performance, oxidative stress markers, immune support, and incidence of upper respiratory tract infections with probiotic use. While there is little scientific evidence on the causative relationship between probiotics and performance, the authors conclude probiotics can enhance athletic performance by ameliorating the indirect consequences of oxidative stress and infection.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Endurance athletes may take probiotic supplements to support immune or GI health or for other reasons
- Currently there is little evidence that probiotics directly or specifically enhance athletic performance
- Probiotic supplementation potentially impacts on immune health particularly during intensive training and may facilitate muscle recovery or maintain performance
- Whilst probiotics may reduced GI symptom frequency and severity, further research is clearly warranted
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
- There is current interest in the potential therapeutic benefits of probiotic strategies to support training and in-race performance for endurance athletes.
- Probiotic supplements are typically used by endurance athletes to limit or prevent upper respiratory tract infections (URTIs), reduce oxidative stress, support the immune system and modulate gastrointestinal function.
- Based on a limited number of articles sourced in this review (n=26), only 9 met the underlying quality and inclusion criteria. This highlights an important need for further research to be undertaken in this area.
- The review highlighted that different preparations, number of bacterial colony-forming units (CFUs), species type, timecourse and study objectives makes it difficult to determine fundamental conclusions on the efficacy of probiotics.
- That said, papers reviewed indicated the potential for a 55% increase in anti-inflammatory cytokines, reduced prevalence of URTIs, reduced Epstein-Barr and cytomegalovirus citrate antibodies, and improved recovery times.
- Probiotic supplementation likely enhances microbiota diversity and may indirectly support increased training load, and performance maintenance through immune defence. However, there were no indications that endurance performance was specifically enhanced.
Clinical practice applications:
- Most of the papers reviewed used formulae containing either Lactobacillus spp. (e.g. Plantarum, Acidophilus, Casei Shirota) or Bifidobacterium spp. (e.g. animalis subsp., bifidum, lactis, longum subsp.) or combinations. There was little mention of prebiotic or symbiotic strategies.
- Any impact of probiotics on exercise performance is likely to relate to both immune modulation and/or mechanisms leading to reduced muscle damage.
- Surprisingly, there was only partial mention of the use of probiotics for GI support and several notable papers were not included in the review. That said, the authors did note that with increased prevalence of exercise-induced gastrointestinal symptoms with endurance sport due to acute GI hypoperfusion and localised ischemia, acute probiotic strategies have resulted in reduced GI symptom frequency and severity in athletes.
- Importantly no adverse events following probiotic supplementation in endurance athletes were reported.
Considerations for future research:
- Clearly further research is warranted in terms of probiotic strain specific benefits both in training and in-race event effectiveness.
- The authors reported that there were no studies found on the effect of probiotics on hormonal or nervous systems in endurance athletes.
- Further research is needed to consider the impact of acute versus chronic probiotic use on intestinal metabolites, especially considering recent interactions between specific bacterial strains and short-chain fatty acid production being associated with performance (see: https://www.nutrition-evidence.com/article/31235964?term=31235964.
Abstract
BACKGROUND Probiotic supplements contain different strains of living microorganisms that promote the health of the host. These dietary supplements are increasingly being used by athletes to improve different aspects such as athletic performance, upper respiratory tract infections (URTIs), the immune system, oxidative stress, gastrointestinal (GI) problems, etc. This study aimed to identify the current evidence on the management of probiotics in endurance athletes and their relationship with sports performance. METHODS A systematic review of the last five years was carried out in PubMed, Scopus, Web of science, Sportdiscus and Embase databases. RESULTS Nine articles met the quality criteria. Of these, three reported direct benefits on sports performance. The remaining six articles found improvements in the reduction of oxidative stress, increased immune response and decreased incidence of URTIs. There is little scientific evidence on the direct relationship between the administration of probiotics in endurance athletes and sports performance. CONCLUSIONS Benefits were found that probiotics could indirectly influence sports performance by improving other parameters such as the immune system, response to URTIs and decreased oxidative stress, as well as the monitoring of scheduled workouts.
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Recent Advances in Psoriasis Research; the Clue to Mysterious Relation to Gut Microbiome.
Komine, M
International journal of molecular sciences. 2020;21(7)
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Psoriasis is a chronic inflammatory disease where the skin forms bumpy red patches covered with white scales. There is no cure, but medications have focused on supressing the immune response. There is a link between the gut microbiome and psoriasis but it is poorly understood. This review includes the current understanding of how psoriasis develops and discusses the recent findings to support further research in this area. The composition of the gut microbiome affects inflammation in the whole body. This inflammation is associated with cardiovascular disease, diabetes mellitus and other inflammatory disorders. Recent studies have linked cardiovascular disease, insulin resistance, and metabolic syndrome to an imbalance in the gut microbiome. Psoriasis is often found alongside these conditions with similar abnormalities in gut bacteria. An imbalance in gut microbiome could cause certain people to develop psoriasis. The role of the gut microbiome needs to be further clarified but mounting evidence for this gut/skin link means that other therapeutic options may be available for treatment in the future.
Abstract
Psoriasis is a chronic inflammatory cutaneous disease, characterized by activated plasmacytoid dendritic cells, myeloid dendritic cells, Th17 cells, and hyperproliferating keratinocytes. Recent studies revealed skin-resident cells have pivotal roles in developing psoriatic skin lesions. The balance in effector T cells and regulatory T cells is disturbed, leading Foxp3-positive regulatory T cells to produce proinflammatory IL-17. Not only acquired but also innate immunity is important in psoriasis pathogenesis, especially in triggering the disease. Group 3 innate lymphoid cell are considered one of IL-17-producing cells in psoriasis. Short chain fatty acids produced by gut microbiota stabilize expression of Foxp3 in regulatory T cells, thereby stabilizing their function. The composition of gut microbiota influences the systemic inflammatory status, and associations been shown with diabetes mellitus, cardiovascular diseases, psychomotor diseases, and other systemic inflammatory disorders. Psoriasis has been shown to frequently comorbid with diabetes mellitus, cardiovascular diseases, psychomotor disease and obesity, and recent report suggested the similar abnormality in gut microbiota as the above comorbid diseases. However, the precise mechanism and relation between psoriasis pathogenesis and gut microbiota needs further investigation. This review introduces the recent advances in psoriasis research and tries to provide clues to solve the mysterious relation of psoriasis and gut microbiota.
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Anxiety, Depression, and the Microbiome: A Role for Gut Peptides.
Lach, G, Schellekens, H, Dinan, TG, Cryan, JF
Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics. 2018;15(1):36-59
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Hormones released in the gut can have an impact in the brain through a bidirectional relationship, known as the gut-brain axis. The release of these hormones may be controlled by the gut microbiota, however exact mechanisms are not fully understood. Most hormones originating in the gut may have a role in obesity development, which is often associated with psychiatric disorders. Understanding the relationship between gut microbiota and depression through gut derived signalling molecules may be of benefit and was the focus of this review. Diversity and stability of the gut microbiota is important for health, which is disrupted during depression and anxiety. The gut microbiota serves to produce brain, hormone and immune signals that can travel to the brain, and can be affected by poor gut health. For those with depression, side effects of anti-depressants can be a disruption of the gut microbiota, however how this impacts symptoms is not fully understood. It was concluded that although there is strong research on the gut microbiota and depression it is still in its infancy. The role of gut microbiota on signalling with the brain and the rest of the body seems to be important for depression and anxiety. This study could be used by healthcare professionals to understand how the gut microbiota can play a role in depression.
Abstract
The complex bidirectional communication between the gut and the brain is finely orchestrated by different systems, including the endocrine, immune, autonomic, and enteric nervous systems. Moreover, increasing evidence supports the role of the microbiome and microbiota-derived molecules in regulating such interactions; however, the mechanisms underpinning such effects are only beginning to be resolved. Microbiota-gut peptide interactions are poised to be of great significance in the regulation of gut-brain signaling. Given the emerging role of the gut-brain axis in a variety of brain disorders, such as anxiety and depression, it is important to understand the contribution of bidirectional interactions between peptide hormones released from the gut and intestinal bacteria in the context of this axis. Indeed, the gastrointestinal tract is the largest endocrine organ in mammals, secreting dozens of different signaling molecules, including peptides. Gut peptides in the systemic circulation can bind cognate receptors on immune cells and vagus nerve terminals thereby enabling indirect gut-brain communication. Gut peptide concentrations are not only modulated by enteric microbiota signals, but also vary according to the composition of the intestinal microbiota. In this review, we will discuss the gut microbiota as a regulator of anxiety and depression, and explore the role of gut-derived peptides as signaling molecules in microbiome-gut-brain communication. Here, we summarize the potential interactions of the microbiota with gut hormones and endocrine peptides, including neuropeptide Y, peptide YY, pancreatic polypeptide, cholecystokinin, glucagon-like peptide, corticotropin-releasing factor, oxytocin, and ghrelin in microbiome-to-brain signaling. Together, gut peptides are important regulators of microbiota-gut-brain signaling in health and stress-related psychiatric illnesses.
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Gut Microbiota-Immune System Crosstalk and Pancreatic Disorders.
Pagliari, D, Saviano, A, Newton, EE, Serricchio, ML, Dal Lago, AA, Gasbarrini, A, Cianci, R
Mediators of inflammation. 2018;2018:7946431
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Gut microbiota homeostasis plays a central role in modulating the mucosal immune system. Increasing research has shown a correlation between an imbalanced gut microbiota, called dysbiosis, and various pancreatic disorders. The aim of this review was to analyse current data linking the gut microbiome and several pancreatic disorders. The current evidence demonstrates gut dysbiosis is correlated with the duration and prognosis of pancreatic disorders. While this may lead to early detection of several pancreatic disorders, it remains unclear whether dysbiosis is a cause or effect of pancreatic disorders. Based on these results, the authors conclude future studies are required to better understand the crosstalk between gut microbiota and the immune system to improve diagnostic and treatment strategies for pancreatic disorders.
Abstract
Gut microbiota is key to the development and modulation of the mucosal immune system. It plays a central role in several physiological functions, in the modulation of inflammatory signaling and in the protection against infections. In healthy states, there is a perfect balance between commensal and pathogens, and microbiota and the immune system interact to maintain gut homeostasis. The alteration of such balance, called dysbiosis, determines an intestinal bacterial overgrowth which leads to the disruption of the intestinal barrier with systemic translocation of pathogens. The pancreas does not possess its own microbiota, and it is believed that inflammatory and neoplastic processes affecting the gland may be linked to intestinal dysbiosis. Increasing research evidence testifies a correlation between intestinal dysbiosis and various pancreatic disorders, but it remains unclear whether dysbiosis is the cause or an effect. The analysis of specific alterations in the microbiome profile may permit to develop novel tools for the early detection of several pancreatic disorders, utilizing samples, such as blood, saliva, and stools. Future studies will have to elucidate the mechanisms by which gut microbiota is modulated and how it tunes the immune system, in order to be able to develop innovative treatment strategies for pancreatic disorders.
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The Effect of Bifidobacterium animalis ssp. lactis HN019 on Cellular Immune Function in Healthy Elderly Subjects: Systematic Review and Meta-Analysis.
Miller, LE, Lehtoranta, L, Lehtinen, MJ
Nutrients. 2017;9(3)
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Elderly individuals are more susceptible to infections and cancer, due to lowered immune system function. The gut bacteria play a key role in human immune system function and there is an interest in a potential role for probiotics in strengthening the immune system through manipulation of the microbiome. This systematic review and meta-analysis of 4 randomised controlled trials aimed to examine the efficacy of Bifidobacterium animalis lactis HN019 on the cellular immune activity of healthy elderly adults age 60-70 years. The authors concluded that supplementation with this bacterial strain at a range of potencies for 3-6 weeks duration had a significant positive impact on the part of the immune system that is responsible for removing pathogens and cell debris (phagocytosis) and a lesser but nevertheless significant impact on natural killer cells responsible for tumour destruction.
Abstract
Elderly people have increased susceptibility to infections and cancer that are associated with decline in cellular immune function. The objective of this work was to determine the efficacy of Bifidobacterium (B.) animalis ssp. lactis HN019 (HN019) supplementation on cellular immune activity in healthy elderly subjects. We conducted a systematic review of Medline and Embase for controlled trials that reported polymorphonuclear (PMN) cell phagocytic capacity or natural killer (NK) cell tumoricidal activity following B. lactis HN019 consumption in the elderly. A random effects meta-analysis was performed with standardized mean difference (SMD) and 95% confidence interval between probiotic and control groups for each outcome. A total of four clinical trials were included in this analysis. B. lactis HN019 supplementation was highly efficacious in increasing PMN phagocytic capacity with an SMD of 0.74 (95% confidence interval: 0.38 to 1.11, p < 0.001) and moderately efficacious in increasing NK cell tumoricidal activity with an SMD of 0.43 (95% confidence interval: 0.08 to 0.78, p = 0.02). The main limitations of this research were the small number of included studies, short-term follow-up, and assessment of a single probiotic strain. In conclusion, daily consumption of B. lactis HN019 enhances NK cell and PMN function in healthy elderly adults.
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Fast food fever: reviewing the impacts of the Western diet on immunity.
Myles, IA
Nutrition journal. 2014;13:61
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This 2014 review delves into the impact that an over-indulgence in foods high in sugar, salt, saturated fats, genetically modified foods, gluten and artificial sweeteners may have on our immune system. The modern western diet is generally characterised as being abundant in these nutrient-poor foods, which exert an unhealthful impact on the body. They report that sugars increase inflammatory markers and reduce white blood cell production. Artificial sweeteners appear to be less inflammatory however data is limited. There is some suggestion that saccharin and sucralose interfere with digestive enzymes and are implicated in Inflammatory Bowel Disease. High salt may increase inflammatory cytokines. Saturated fats and high omega 6 fatty acids from vegetable oils increase inflammatory immune markers such as C-Reactive protein. Omega 3 polyunsaturated fats are generally associated with anti-inflammatory effects and regulating immune mediators. Gluten inappropriately activates an immune T-cell response. GM foods may have protective effects against malnutrition but have been shown to induce an allergic response in some cases. There is also concern that genetic modifications can be internalised by our gut bacteria and passed on to offspring. The review concludes that poor dietary choices are encoded into our gut and increase inflammation, and thus reduce our immune resilience to control infection.
Abstract
While numerous changes in human lifestyle constitute modern life, our diet has been gaining attention as a potential contributor to the increase in immune-mediated diseases. The Western diet is characterized by an over consumption and reduced variety of refined sugars, salt, and saturated fat. Herein our objective is to detail the mechanisms for the Western diet's impact on immune function. The manuscript reviews the impacts and mechanisms of harm for our over-indulgence in sugar, salt, and fat, as well as the data outlining the impacts of artificial sweeteners, gluten, and genetically modified foods; attention is given to revealing where the literature on the immune impacts of macronutrients is limited to either animal or in vitro models versus where human trials exist. Detailed attention is given to the dietary impact on the gut microbiome and the mechanisms by which our poor dietary choices are encoded into our gut, our genes, and are passed to our offspring. While today's modern diet may provide beneficial protection from micro- and macronutrient deficiencies, our over abundance of calories and the macronutrients that compose our diet may all lead to increased inflammation, reduced control of infection, increased rates of cancer, and increased risk for allergic and auto-inflammatory disease.