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Time-restricted eating effects on performance, immune function, and body composition in elite cyclists: a randomized controlled trial.
Moro, T, Tinsley, G, Longo, G, Grigoletto, D, Bianco, A, Ferraris, C, Guglielmetti, M, Veneto, A, Tagliabue, A, Marcolin, G, et al
Journal of the International Society of Sports Nutrition. 2020;17(1):65
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Adequate nutrition is important for elite athletes, as nutrient availability influences energy expenditure, body composition, performance and exercise-induced immune responses. Time-restricted eating (TRE) is a form of intermittent fasting that has received much interest in recent years. Previous research of TRE suggested beneficial effects on performance in untrained individuals, by allowing weight loss whilst maintaining muscle functions. These qualities are of interest for endurance cyclists hence the authors of this study sought to investigate the impact of TRE in elite cyclists. Sixteen under-23 year old, elite cyclists were randomly assigned to eat within a TRE window of 8-hr or 15hr window during a 4-week, high-level endurance training phase. Both groups consumed their full estimated energy needs and markers such as fat and fat-free mass, VO2 max, basal metabolism, blood counts, anabolic hormones and inflammatory markers were measured. As a result, TRE produced weight loss, improved body composition and increased peak power output in relation to body weight without compromising aerobic performance. Furthermore, the TRE pattern proved helpful in mitigating some of the exercise-induced suppressions of the immune system. The authors concluded that TRE could be considered as part of a performance nutrition plan in endurance athletes. Particularly where there is a need to reduce body fat mass or for the management of training-induced depression of the immune system and associated respiratory infection susceptibility. This can be of clinical relevance in the support of endurance athletes.
Abstract
BACKGROUND Although there is substantial interest in intermittent fasting as a dietary approach in active individuals, information regarding its effects in elite endurance athletes is currently unavailable. The present parallel randomized trial investigated the effects of a particular intermittent fasting approach, called time-restricted eating (TRE), during 4 weeks of high-level endurance training. METHODS Sixteen elite under-23 cyclists were randomly assigned either to a TRE group or a control group (ND). The TRE group consumed 100% of its estimated daily energy needs in an 8-h time window (from 10:00 a.m. to 6:00 p.m.) whilst energy intake in the ND group was distributed in 3 meals consumed between 7:00 a.m. and 9:00 p.m. Fat and fat-free mass were estimated by bioelectrical impedance analysis and VO2max and basal metabolism by indirect gas analyzer. In addition, blood counts, anabolic hormones (i.e. free testosterone, IGF-1) and inflammatory markers (i.e. IL-6, TNF-α) were assessed. RESULTS TRE reduced body weight (- 2%; p = 0.04) and fat mass percentage (- 1.1%; p = 0.01) with no change in fat-free mass. Performance tests showed no significant differences between groups, however the peak power output/body weight ratio (PPO/BW) improved in TRE group due to weight loss (p = 0.02). Free testosterone and IGF-1 decreased significantly (p = 0.01 and p = 0.03 respectively) in TRE group. Leucocyte count decreased in ND group (p = 0.02) whilst the neutrophils-to-lymphocytes ratio (NLR) decreased significantly (p = 0.03) in TRE group. CONCLUSIONS Our results suggest that a TRE program with an 8-h feeding window elicits weight loss, improves body composition and increases PPO/BW in elite cyclists. TRE could also be beneficial for reducing inflammation and may have a protective effect on some components of the immune system. Overall, TRE could be considered as a component of a periodized nutrition plan in endurance athletes. TRIAL REGISTRATION This trial was retrospectively registered at clinicaltrials.gov as NCT04320784 on 25 March 2020.
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Nutrition, the digestive system and immunity in COVID-19 infection.
Bold, J, Harris, M, Fellows, L, Chouchane, M
Gastroenterology and hepatology from bed to bench. 2020;13(4):331-340
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Covid-19 needs both prevention and recovery strategies to reduce complications. This review study aimed to discuss the associations between nutrition, obesity, and the impact these have on stomach symptoms associated with Covid-19. Obesity has been identified as a risk factor for Covid-19 and this could be due to several factors such as impaired immune function, increased inflammation, increased susceptibility to infection and the high number of cells on fat tissue, which express the receptor known to allow Covid-19 into cells. The involvement of the gut microbiota of obese individuals was extensively reviewed and gut dysbiosis has been associated with many diseases, thus improving gut microbiota may go some way to improving Covid-19 outcomes. Nutritional interventions to reduce obesity need to be part of a multi-pronged strategy and the possible introduction of vitamin D supplements and probiotics. The paper did not draw any conclusions; however this paper could be used by healthcare professionals to understand the role of obesity in increasing the risk of Covid-19 infection, complications that may arise upon and after infection and nutritional strategies as part of a management plan.
Abstract
The current review aimed to synthesize the literature on the complex relationship between food consumption and nutritional status as well as the digestive system in order to examine the relationship between immunity and potential responses to COVID-19 infection. The goal is to help inform the many healthcare professionals working with COVID-19 patients. A literature search was performed on PubMed, Scopus, and EMBASE databases. Hand searches were also undertaken using Google and reference lists to identify recent evidence. Studies were critically appraised, and the findings were analyzed by narrative synthesis. Nutritional status can impact immunity in several ways, including affecting susceptibility to infection, severity of disease, and recovery time, and is therefore a significant consideration in the management of COVID-19. COVID-19 can also impact digestive function, which can further impact nutritional status. The role of Vitamin D deficiency in vulnerability to severe respiratory infections, including COVID-19, has been recognized, and it may have a role in treatment where deficiency is indicated. Healthcare professionals should be aware that obesity may be accompanied by micronutrient malnutrition including vitamin D deficiency and alterations in the microbiome and inflammatory responses, which can further impact immunity and disease severity. Multidisciplinary team-work is recommended in the management of patients with COVID-19, and approaches should include a consideration of nutritional status (both macronutrients and micronutrients), body weight, and gastrointestinal signs and symptom.
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The Long Haul of COVID-19 Recovery: Immune Rejuvenation versus Immune Support.
Bland, JS
Integrative medicine (Encinitas, Calif.). 2020;19(6):18-22
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Following Covid-19 infection, sufferers have reported various residual symptoms, which have been likened to those experienced by chronic fatigue sufferers and those with Gulf War syndrome. This review paper aimed to assess whether the body has a similar immune response to these diseases during Covid-19, and if so, what therapies could be used. It also reviewed any diet and lifestyle factors that may be affecting the immune response. The paper stated that Covid-19 infection is associated with inflammation, which can damage immune cells and inflammation prior to Covid-19 infection may contribute to severity of the infection. Prior research in seemingly healthy individuals indicates that environment, diet, and lifestyle factors can all contribute to differing “immune identities” and eliminating immune cells which carry the imprint of memories should be a therapy focus in Covid-19 patients. Fasting, diets low in refined sugars and high in omega-3 and plant chemicals were discussed as ways for the body to clear out immune cells. It was concluded that personalising therapy strategies based on an individual’s immune identity to reduce inflammation could ultimately support the immune system. This paper could be used by healthcare professionals to understand the importance of diet and lifestyle changes to reduce inflammation and support the immune system.
Abstract
With the COVID-19 pandemic still affecting communities all over the world and "Long Haul" chronic health issues emerging, it is time for us to look back at past multi-symptom health conditions that required a different approach to their treatment, beyond just managing symptoms. It is important for us to consider how to apply what we have learned about immune rejuvenation and its impact on conditions associated with chronic immune dysfunction. We know more than we ever have before about how to reduce chronic inflammation at its source through the support of selective immune cell autophagy/mitophagy and improved immune cell mitochondrial activity, followed by remodeling of the immune epigenome, and-ultimately-a reset of immune function.
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COVID-19 and diabetes: The why, the what and the how.
Cuschieri, S, Grech, S
Journal of diabetes and its complications. 2020;34(9):107637
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Early reports have shown that individuals with diabetes who contract Covid-19 have higher hospital admissions and mortality rates, classing them as a vulnerable group. This review paper aimed to explain why this group of people are vulnerable and what measures could be recommended. The paper outlined that individuals with diabetes have a compromised immune system due to uncontrolled blood sugar levels. In addition to this, individuals with diabetes and Covid-19 may have a higher risk of organ damage due to the effects of the body's immune response combined with the disordered biological processes associated with their pre-existing condition. Conversely, it was discussed that Covid-19 could exacerbate diabetes progression if the Covid-19 virus entered the cells of the pancreas, causing a blood sugar imbalance. As a result, the importance of optimal blood sugar control was outlined. Several medications were addressed and their benefits/disadvantages discussed. Amongst those reviewed were medications such as GLP-1 agonists, which may help with controlling blood sugar levels and may prevent Covid-19 entering the body's own cells, and metformin, which was initially developed as an anti-influenza drug. Finally the paper discussed diabetes specific precautions to avoid contracting Covid-19. Vitamin D supplementation, regular blood sugar checks, lifestyle measures such as exercise and dietary requirements and allowing individuals with diabetes to have large supplies of their medications to avoid leaving the house were discussed. It was concluded that during the Covid-19 pandemic, individuals with diabetes require particular care in order to avoid additional burden on healthcare systems. For those individuals with diabetes who haven’t contracted Covid-19, this paper could be used to recommend any extra precautions to take to avoid contracting this virus.
Abstract
BACKGROUND The novel coronavirus SARS-CoV-2 has taken the world by storm. Alongside COVID-19, diabetes is a long-standing global epidemic. The diabetes population has been reported to suffer adverse outcomes if infected by COVID-19. The aim was to summarise information and resources available on diabetes and COVID-19, highlighting special measures that individuals with diabetes need to follow. METHODS A search using keywords "COVID-19" and "Diabetes" was performed using different sources, including PubMed and World Health Organization. RESULTS COVID-19 may enhance complications in individuals with diabetes through an imbalance in angiotension-converting enzyme 2 (ACE2) activation pathways leading to an inflammatory response. ACE2 imbalance in the pancreas causes acute β-cell dysfunction and a resultant hyperglycemic state. These individuals may be prone to worsened COVID-19 complications including vasculopathy, coagulopathy as well as psychological stress. Apart from general preventive measures, remaining hydrated, monitoring blood glucose regularly and monitoring ketone bodies in urine if on insulin is essential. All this while concurrently maintaining physical activity and a healthy diet. Different supporting entities are being set up to help this population. CONCLUSION COVID-19 is a top priority. It is important to remember that a substantial proportion of the world's population is affected by other co-morbidities such as diabetes. These require special attention during this pandemic to avoid adding on to the burden of countries' healthcare systems.
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Antiviral Functional Foods and Exercise Lifestyle Prevention of Coronavirus.
Alkhatib, A
Nutrients. 2020;12(9)
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In lieu of a vaccine, complementary therapies have a major role to play in the Covid-19 pandemic. This review paper aimed to highlight how lifestyle approaches such as consumption of functional foods and increased physical activity could optimise the immune system in response to viral infections such as respiratory tract infections and Covid-19, and act as a possible adjuvant to vaccination. The paper outlined the role of exercise as being controversial. Although exercise has been shown to activate white blood cells, intense exercise in elite athletes has been linked to higher upper respiratory tract infection rates. It appears that varying intensity and type of exercise may optimise the immune system and have an additive effect to immunisation against viruses like influenza. The authors also stated that having a sedentary lifestyle may impair the immune system and diseases such as obesity and diabetes may increase susceptibility to infections such as Covid-19. The antiviral effect of functional foods was discussed. The paper paid particular attention to olive oil, vitamin D, traditional herbs and roots, coffee and caffeine. The reviewed mechanisms included enhanced gut bacteria profiles and promotion of anti-oxidants and anti-inflammatories. The authors also stated that supplementation as well as adequate dietary intake might be of importance against Covid-19, especially in deficient individuals. It was concluded that moderate intensity exercise alongside dietary intake of functional foods, may prevent communicable diseases, such as Covid-19. Clinicians could use this paper to recommend specific functional foods plus moderate exercise, to help prevent viral infections like Covid-19.
Abstract
Novel coronavirus (COVID-19) is causing global mortality and lockdown burdens. A compromised immune system is a known risk factor for all viral influenza infections. Functional foods optimize the immune system capacity to prevent and control pathogenic viral infections, while physical activity augments such protective benefits. Exercise enhances innate and adaptive immune systems through acute, transient, and long-term adaptations to physical activity in a dose-response relationship. Functional foods prevention of non-communicable disease can be translated into protecting against respiratory viral infections and COVID-19. Functional foods and nutraceuticals within popular diets contain immune-boosting nutraceuticals, polyphenols, terpenoids, flavonoids, alkaloids, sterols, pigments, unsaturated fatty-acids, micronutrient vitamins and minerals, including vitamin A, B6, B12, C, D, E, and folate, and trace elements, including zinc, iron, selenium, magnesium, and copper. Foods with antiviral properties include fruits, vegetables, fermented foods and probiotics, olive oil, fish, nuts and seeds, herbs, roots, fungi, amino acids, peptides, and cyclotides. Regular moderate exercise may contribute to reduce viral risk and enhance sleep quality during quarantine, in combination with appropriate dietary habits and functional foods. Lifestyle and appropriate nutrition with functional compounds may offer further antiviral approaches for public health.
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Coronavirus disease 2019 (COVID-19) and obesity. Impact of obesity and its main comorbidities in the evolution of the disease.
Cornejo-Pareja, IM, Gómez-Pérez, AM, Fernández-García, JC, Barahona San Millan, R, Aguilera Luque, A, de Hollanda, A, Jiménez, A, Jimenez-Murcia, S, Munguia, L, Ortega, E, et al
European eating disorders review : the journal of the Eating Disorders Association. 2020;28(6):799-815
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The Covid-19 pandemic has caused thousands of deaths worldwide. Being obese is associated with worse outcomes following infection with Covid-19. This review aimed to summarise the data available on the relationship between Covid-19 and obesity, and explored some of the possible reasons for this relationship. The researchers found that obesity is an independent and strong risk factor for severe infection, Intensive Care Unit (ICU) admission and death. The impact of obesity might be of particular relevance in males and in younger individuals. Long‐term complications of Covid‐19 could also be more frequent and severe in obese subjects. There are many potential mechanisms that could explain this relationship. These include the effects of obesity and related diseases such as diabetes, high blood pressure and heart disease on the immune system, lung function, vitamin D deficiency and male hormones. The researchers also discussed the possibility of fat cells acting as a possible reservoir for Covid-19 infection. Research into Covid-19 is still at a very early stage and more studies are needed.
Abstract
The COVID-19 pandemic is posing a great challenge worldwide. Its rapid progression has caused thousands of deaths worldwide. Although multiple aspects remain to be clarified, some risk factors associated with a worse prognosis have been identified. These include obesity and some of its main complications, such as diabetes and high blood pressure. Furthermore, although the possible long-term complications and psychological effects that may appear in survivors of COVID-19 are not well known yet, there is a concern that those complications may be greater in obese patients. In this manuscript, we review some of the data published so far and the main points that remain to be elucidated are emphasized.
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Weight reduction improves immune system and inflammatory cytokines in obese asthmatic patients.
Al-Sharif, FM, Abd El-Kader, SM, Neamatallah, ZA, AlKhateeb, AM
African health sciences. 2020;20(2):897-902
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Asthma is a common condition characterised by attacks of obstruction, chronic inflammation and hyper-responsiveness of the airways. Obesity increases severity of asthmatic symptoms through mechanical, anatomical and/or inflammatory mechanisms. 80 adults with asthma were randomly allocated to a weight reduction programme, including aerobic exercise and a calorie reduced diet, or control group with no intervention. After 3 months, body mass index (BMI) reduced significantly in the intervention group (from 31.7 to 27.9). This was associated with significant reductions in the pro-inflammatory markers TNF-alpha, interleukin-6 and interleukin-8, and significant increases in CD4 and CD8 cell counts (important immune cells). There were no changes in the control group in any of the parameters and the results were statistically significantly better in the intervention compared to the control group. The authors conclude that weight reduction improved immunological and inflammatory markers in obese asthma patients.
Abstract
BACKGROUND Activation of immunological and systemic inflammation markers are common in obesity and asthma. OBJECTIVE The target of this study was to assess impact of weight reduction on immunological and systemic inflammation markers in obese asthma patients. MATERIAL AND METHODS Eighty asthmatic patients of both sex; their age and body mass index (BMI) mean were 38.72 ± 7.14 year and 32.65 ± 3.18 Kg/m2 respectively. Exclusion criteria included smokers, infections, vaccinations, cancer, surgery, immune system disorders and medications that may influence immune system function as anti-inflammatory medications, analgesics and anti-depressant. All subjects were randomly enrolled in weight reduction group (group A) or control group (group B). RESULTS The main findings in the present study indicated that weight reducing program in group (A) was associated with significant reduction in the mean values of IL6, TNF-α, and IL8 in addition to significant increase in the mean values of CD4 and CD8 cell count . However, findings of group (B) showed no significant changes. Moreover, Comparison between both groups at the end of the study revealed significant differences. CONCLUSION Weight reduction improved immunological and systemic inflammation markers in obese asthma patients.
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The effect of L-theanine supplementation on the immune system of athletes exposed to strenuous physical exercise.
Juszkiewicz, A, Glapa, A, Basta, P, Petriczko, E, Żołnowski, K, Machaliński, B, Trzeciak, J, Łuczkowska, K, Skarpańska-Stejnborn, A
Journal of the International Society of Sports Nutrition. 2019;16(1):7
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According to previous studies, strenuous exercise may contribute towards an imbalance in Th1/Th2 cytokines that are secreted by the immune system, resulting in an impairment of the immune system. The main aim of this study was to analyse the effect of L-theanine on cytokines of the immune system and establish the role of L-Theanine as immunomodulatory. This double blind randomised study recruited 20 men from the Polish rowing team. The subjects were randomised to the supplemented group and placebo group. The supplemented group received gelatine capsules with 150 mg L-theanine extract whilst the placebo group received visually identical capsules with corn starch. The participants in the study were asked to take two capsules per day for 6 weeks. Athletes from both the groups did not differ significantly in terms of their mean age, body height, body weight and years of training. After 24 hour recovery, the athletes in the supplemented group showed lower amount of cytotoxic cell. The authors concluded based on the study that supplementation with L- theanine in athletes exposed to strenuous exercise had beneficial effect.
Abstract
BACKGROUND The aim of this study was to analyze the response of selected components of the immune system in rowers to maximal physical exercise, and to verify if this response could be modulated by supplementation with L-theanine. METHOD The double-blind study included 20 members of the Polish Rowing Team. The subjects were randomly assigned to the supplemented group (n = 10), receiving 150 mg of L-theanine extract for 6 weeks, or to the placebo group (n = 10). The participants performed a 2000-m test on a rowing ergometer at the beginning (1st examination) and at the end of the supplementation period (2nd examination). Blood samples were obtained from the antecubital vein before each exercise test, 1 min after completing the test, and after a 24-h recovery. Subpopulations of T regulatory lymphocytes (Tregs) (CD4+/CD25+/CD127-), cytotoxic lymphocytes (CTLs) (CD8+/TCRαβ+), natural killer (NK) cells (CD3-/CD16+/CD56+) and TCRδγ-positive (Tδγ) cells were determined by means of flow cytometry. The levels of interleukin 2 (IL-2), interleukin 4 (IL-4), interleukin 10 (IL-10), interferon gamma (INF-ɤ) and total antioxidant capacity (TAC) were determined with commercially available diagnostic kits. RESULTS Supplementation with L-theanine contributed to a significant post-exercise decrease in IL-10 concentration, which was reflected by higher values of IL-2 to IL-10 and IFN-γ to IL-10 ratios. Moreover, a significant post-recovery decrease in CTL count, Treg to NK and Treg to CTL ratios was observed in the supplemented group. CONCLUSION Despite the decrease in the number of some cytotoxic cells (CTLs) and an increase in the proportion of Tregs to CTLs, supplementation with LTE seems to exert a beneficial effect on a disrupted Th1/Th2 balance in elite athletes, as shown by the decrease in IL-10 concentration.
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Danger signals and inflammaging in osteoarthritis.
Millerand, M, Berenbaum, F, Jacques, C
Clinical and experimental rheumatology. 2019;37 Suppl 120(5):48-56
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Osteoarthritis (OA) is the most common and disabling joint disease worldwide and aging is the most important risk factor for its development. It was considered a ‘wear and tear’ disease for a long time, however it is now clear that low-grade inflammation is at the root of OA. This process is called ‘inflammaging’ – the presence of low-grade inflammation and decreased efficiency of the immune system with aging. This highly technical review paper describes the reaction of the immune system to small molecules that begin to circulate after cell stress or damage in the joints (known as damage-associated molecular patterns or DAMPs), causing inflammation. The paper includes a discussion on potential medication targets, including anti-inflammatory compounds such as ginger. Nutrition Practitioners working with OA and wanting to understand the inflammatory process involved will find this paper useful.
Abstract
Osteoarthritis (OA) is the most common age-related chronic and disabling joint disease. Long considered to be a "wear and tear" disease, OA is now seen as a low-grade inflammation disease that affects all tissues of the joint, involving cartilage degradation, bone remodelling, osteophytes, and synovitis. The process, called inflammaging, is characterised by the association of low-grade inflammation, profound changes in intra-cellular mechanisms, and the decreased efficiency of the immune system with ageing. The activation of innate immunity plays a critical role in the development and progression of OA. Innate immunity, including inflammasome activation, is triggered by small endogenous molecules called alarmins or damage-associated molecular patterns (DAMPs). These molecules are released in the extracellular media after cell stress or damage, bind to pathogen-recognition receptors (PRRs), such as Toll-like receptors (TLRs) and the receptor for advanced glycation end products (RAGE), and activate the secretion of pro-inflammatory factors, leading to joint inflammation. Moreover, such sterile inflammation triggers cell senescence, characterised by a senescence-associated secretory phenotype (SASP). Understanding the substantial age-related changes of joint tissues that influence the pathogenesis of OA is critical to improving the quality of life of elderly people in the context of increased life expectancy. This review will focus on age-related sterile inflammation in OA and highlight the various innovative and promising therapies targeting the mechanisms of aging.
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Four weeks of probiotic supplementation reduces GI symptoms during a marathon race.
Pugh, JN, Sparks, AS, Doran, DA, Fleming, SC, Langan-Evans, C, Kirk, B, Fearn, R, Morton, JP, Close, GL
European journal of applied physiology. 2019;119(7):1491-1501
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Gastrointestinal (GI) symptoms are common in athletes participating in marathon running. The purpose of this study was to evaluate the effects of probiotic supplementation on GI symptoms and markers of GI permeability and damage during marathon training and racing. 24 runners took part in this double-blind, randomised trial. Participants took a probiotic supplement containing 25 billion organisms (Lactobacilli and bifidobacterial) or placebo for 4 weeks prior to the marathon race. Blood samples were taken before supplementation, pre and post marathon. Participants also completed a questionnaires regarding GI symptoms. All runners experienced GI symptoms during the marathon. Runners supplementing with probiotics reported fewer and less severe GI symptoms, both in training and during the race, and also showed increased performance during the race compared to the placebo group. There was no association between GI symptoms and markers of GI permeability and damage, although both were increased post-race in all participants. The authors conclude that athletes participating in endurance events, where GI symptoms are common and likely to affect performance, could consider probiotic supplementation in the weeks prior to competition.
Abstract
PURPOSE To evaluate the effects of probiotic supplementation on gastrointestinal (GI) symptoms, circulatory markers of GI permeability, damage, and markers of immune response during a marathon race. METHODS Twenty-four recreational runners were randomly assigned to either supplement with a probiotic (PRO) capsule [25 billion CFU Lactobacillus acidophilus (CUL60 and CUL21), Bifidobacterium bifidum (CUL20), and Bifidobacterium animalis subs p. Lactis (CUL34)] or placebo (PLC) for 28 days prior to a marathon race. GI symptoms were recorded during the supplement period and during the race. Serum lactulose:rhamnose ratio, and plasma intestinal-fatty acid binding protein, sCD14, and cytokines were measured pre- and post-races. RESULTS Prevalence of moderate GI symptoms reported were lower during the third and fourth weeks of the supplement period compared to the first and second weeks in PRO (p < 0.05) but not PLC (p > 0.05). During the marathon, GI symptom severity during the final third was significantly lower in PRO compared to PLC (p = 0.010). The lower symptom severity was associated with a significant difference in reduction of average speed from the first to the last third of the race between PLC (- 14.2 ± 5.8%) and PRO (- 7.9 ± 7.5%) (p = 0.04), although there was no difference in finish times between groups (p > 0.05). Circulatory measures increased to a similar extent between PRO and PLC (p > 0.05). CONCLUSION Probiotics supplementation was associated with a lower incidence and severity of GI symptoms in marathon runners, although the exact mechanisms are yet to be elucidated. Reducing GI symptoms during marathon running may help maintain running pace during the latter stages of racing.