Abstract

BACKGROUND Iron deficiency in athletes is initially treated with a nutritional intervention. If negative iron balance persists, oral iron supplementation (OIS) can be used. Despite the recent proposal for a refinement of treatment strategies for iron-deficient athletes, there is no general consensus regarding the actual efficiency, dosage, or optimal regimen of OIS. OBJECTIVE The aim of this meta-analysis was to evaluate to what extent OIS affects blood iron parameters and physical performance in healthy adult athletes. METHODS PubMed, Web of Science, PEDro, CINAHL, SPORTDiscus, and Cochrane were searched from inception to 2 November 2022. Articles were eligible if they satisfied the following criteria: recruited subjects were healthy, adult and physically active individuals, who used exclusively OIS, irrespective of sex and sports discipline. EXCLUSION CRITERIA simultaneous supplementation with iron and any other micronutrient(s), intravenous iron supplementation or recent exposure to altitude acclimatisation. The methodological quality of included studies was assessed with the PEDro scale, the completeness of intervention reporting with the TIDieR scale, while the GRADE scale was used for quality of evidence synthesis. The present study was prospectively registered in PROSPERO online registry (ID: CRD42022330230). RESULTS From 638 articles identified through the search, 13 studies (n = 449) were included in the quantitative synthesis. When compared to the control group, the results demonstrated that OIS increases serum ferritin (standardized mean difference (SMD) = 1.27, 95% CI 0.44-2.10, p = 0.006), whereas blood haemoglobin (SMD = 1.31, 95% CI - 0.29 to 2.93, p = 0.099), serum transferrin receptor concentration (SMD = - 0.74, 95% CI - 1.89 to 0.41, p = 0.133), and transferrin saturation (SMD = 0.69, 95% CI - 0.84 to 2.22, p = 0.330) remained unaltered. Following OIS, a trend of small positive effect on VO2max (SMD = 0.49, 95% CI - 0.09 to 1.07, p = 0.086) was observed in young healthy athletes. The quality of evidence for all outcomes ranged from moderate to low. CONCLUSIONS Increase in serum ferritin concentration after OIS was evident in subjects with initial pre-supplementation serum ferritin concentration ≤ 12 µg/l, while only minimal, if any effect, was observed in subjects with higher pre-supplementation serum ferritin concentration. The doses of OIS, that induced a beneficial effect on hematological parameters differed from 16 to 100 mg of elementary iron daily, over the period between 6 and 8 weeks. Shorter supplementation protocols have been shown to be ineffective.

Abstract

BACKGROUND Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime), postural stability (PStab), heart rate (HR) and perceived exertion (RPE). METHODS In a randomized double-blind placebo-controlled crossover design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body mass (BM)) and PLA in 26 moderately trained CrossFit practitioners was examined. The study protocol involved five separate testing sessions using the Fight Gone Bad test (FGB) as the exercise performance evaluation and biochemical analyses, HR and RPE monitoring, as well as the assessment of RTime and PStab, with regard to CYP1A2 (rs762551) and ADORA2A (rs5751876) single nucleotide polymorphism (SNP). RESULTS Supplementation of 6 mgCAF/kgBM induced clinically noticeable improvements in FGBTotal results, RTime and pre-exercise motor time. Nevertheless, there were no significant differences between any CAF doses and PLA in FGBTotal, HRmax, HRmean, RPE, pre/post-exercise RTime, PStab variables or pyruvate concentrations. Lactate concentration was higher (p < 0.05) before and after exercise in all CAF doses than in PLA. There was no effect of CYP1A2 or ADORA2A SNPs on performance. CONCLUSIONS The dose-dependent effect of CAF supplementation appears to be limited to statistically nonsignificant but clinically considered changes on specific performance, RTime, PStab, RPE or HR. However, regarding practical CAF-induced performance implications in CrossFit/HIFT, 6 mgCAF/kgBM may be supposed as the most rational supplementation strategy.

Abstract

BACKGROUND & AIMS The COVID-19 pandemic continues to pose unprecedented challenges to worldwide health. While vaccines are effective, additional strategies to mitigate the spread/severity of COVID-19 continue to be needed. Emerging evidence suggests susceptibility to respiratory tract infections in healthy subjects can be reduced by probiotic interventions; thus, probiotics may be a low-risk, low-cost, and easily implementable modality to reduce risk of COVID-19. METHODS In this initial study, we conducted a randomized, double-blind, placebo-controlled trial across the United States testing probiotic Lacticaseibacillus rhamnosus GG (LGG) as postexposure prophylaxis for COVID-19 in 182 participants who had household exposure to someone with confirmed COVID-19 diagnosed within ≤7 days. Participants were randomized to receive oral LGG or placebo for 28 days. The primary outcome was development of illness symptoms within 28 days of COVID-19 exposure. Stool was collected to evaluate microbiome changes. RESULTS Intention-to-treat analysis showed LGG treatment led to a lower likelihood of developing illness symptoms versus placebo (26.4 % vs. 42.9 %, p = 0.02). Further, LGG was associated with a statistically significant reduction in COVID-19 diagnosis (log rank, p = 0.049) via time-to-event analysis. Overall incidence of COVID-19 diagnosis did not significantly differ between LGG and placebo groups (8.8 % vs. 15.4 %, p = 0.17). CONCLUSIONS This data suggests LGG is associated with prolonged time to COVID-19 infection, reduced incidence of illness symptoms, and gut microbiome changes when used as prophylaxis ≤7 days post-COVID-19 exposure, but not overall incidence. This initial work may inform future COVID-19 prevention studies worldwide, particularly in developing nations where Lacticaseibacillus probiotics have previously been utilized to reduce other non-COVID infectious-morbidity. TRIAL REGISTRATION ClinicalTrials.gov, NCT04399252, Date: 22/05/2020. https://clinicaltrials.gov/ct2/show/NCT04399252.

Abstract

OBJECTIVE Animal studies suggest that prebiotic, plant-derived nutrients could improve homoeostatic and hedonic brain functions through improvements in microbiome-gut-brain communication. However, little is known if these results are applicable to humans. Therefore, we tested the effects of high-dosed prebiotic fibre on reward-related food decision-making in a randomised controlled within-subject cross-over study and assayed potential microbial and metabolic markers. DESIGN 59 overweight young adults (19 females, 18-42 years, body mass index 25-30 kg/m2) underwent functional task MRI before and after 14 days of supplementary intake of 30 g/day of inulin (prebiotics) and equicaloric placebo, respectively. Short chain fatty acids (SCFA), gastrointestinal hormones, glucose/lipid and inflammatory markers were assayed in fasting blood. Gut microbiota and SCFA were measured in stool. RESULTS Compared with placebo, participants showed decreased brain activation towards high-caloric wanted food stimuli in the ventral tegmental area and right orbitofrontal cortex after prebiotics (preregistered, family wise error-corrected p <0.05). While fasting blood levels remained largely unchanged, 16S-rRNA sequencing showed significant shifts in the microbiome towards increased occurrence of, among others, SCFA-producing Bifidobacteriaceae, and changes in >60 predicted functional signalling pathways after prebiotic intake. Changes in brain activation correlated with changes in Actinobacteria microbial abundance and associated activity previously linked with SCFA production, such as ABC transporter metabolism. CONCLUSIONS In this proof-of-concept study, a prebiotic intervention attenuated reward-related brain activation during food decision-making, paralleled by shifts in gut microbiota. TRIAL REGISTRATION NUMBER NCT03829189.

Abstract

BACKGROUND There are complicated mechanisms that link the disruption of the gut microbiome to the symptoms and complications of polycystic ovary syndrome (PCOS). In this study, an attempt was made to assess the effects of synbiotics on the health-related quality of life (HRQoL) in women with PCOS . METHODS Fifty-six women with PCOS were enrolled in a triple-blind controlled trial for 12 weeks. They were randomly assigned to receive a daily 2-gram synbiotic sachets (containing Bacillus coagulans (GBI-30), Lactobacillus rhamnosus, Lactobacillus helveticus, and fructooligosaccharide) (n = 28) or placebo (n = 28). To evaluate the impact on the HRQoL, participants were required to fill 26-Item Polycystic Ovary Syndrome Health-Related Quality of Life Questionnaire (PCOSQ-26), 12-Item Short-Form Health Survey (SF-12) and Perceived Stress Scale (PSS-10) pre and post the intervention. RESULTS Finally, statistical analyses were performed on 52 participants who finished the trial. Synbiotic supplementation improved the scores of emotional (P = 0.044), body hair (P = 0.016), weight (P = 0.033) and infertility domains (P = 0.027) of PCOSQ-26 compared to placebo group. The physical score within SF-12 also had a significant enhancement (P = 0.035). No significant improvement was seen in the PSS-10 score at the end of the trial. CONCLUSION This study illustrated the advantageous effects of synbiotics on the health-related quality of life in women with PCOS. Further studies are required to confirm our findings. TRIAL REGISTRATION http://www.irct.ir : IRCT20211108053007N1; date of registration: 14/02/2023.

Abstract

OBJECTIVES A starch- and sucrose-reduced diet has been found to improve gastrointestinal and extraintestinal symptoms in irritable bowel syndrome, as well as reduce weight and improve psychological well-being. Our hypothesis was that a starch- and sucrose-reduced diet would also be beneficial in other conditions with similar symptoms. The aim of the present research letter was to describe the role of a starch- and sucrose-reduced diet in a pilot project in patients with diarrhea having varying causes. METHODS One man, age 36 y, suffering from functional diarrhea and one woman, 56 y, suffering from microscopic colitis, were randomized to a starch- and sucrose-reduced diet for 4 wk. At baseline, dietary information was given, and blood samples collected. Weight and waist circumference were measured. The participants completed the irritable bowel syndrome severity scoring system for evaluating specific gastrointestinal and extraintestinal symptoms and visual analog scale for irritable bowel syndrome for evaluation of specific gastrointestinal symptoms and psychological well-being. The degrees of satiety and sweet craving were measured on visual analog scales. After 4 wk, all procedures were repeated. RESULTS Weight, body mass index, and waist circumference were decreased during the intervention. The total amount of gastrointestinal symptoms was decreased in the participants with functional diarrhea, and diarrhea and bloating were decreased in both participants. Both had reduced extraintestinal symptoms and improved psychological well-being. Blood levels had mainly unchanged or slightly increased values of measurements reflecting nutrient intake. CONCLUSIONS A starch- and sucrose-reduced diet may lead to weight reduction, reduced symptoms, and improved well-being in several patient categories, not only in patients suffering from irritable bowel syndrome. Future randomized trials should be done.

Abstract

BACKGROUND Chemotherapy is an important approach for lung cancer patients. The study was designed to evaluate the feasibility of the compound probiotic supplements in improving the quality of life for lung cancer patients undergoing chemotherapy. METHODS This randomized, double-blind, placebo-controlled trial enrolled chemotherapy-naive patients with lung cancer who were scheduled to receive platinum-based doublet chemotherapy. All eligible patients were randomly administered (1:1) compound probiotic supplements (group BP-1) or placebo (group C) for two chemotherapy cycles. The EORTC QLQ C30 questionnaire scores were evaluated before the first, second, and third cycles of chemotherapy. The primary endpoint was the difference in the EROTC QLQ C30 questionnaire score between the two groups after two cycles of chemotherapy. RESULTS A total of 110 patients were recruited from March 2021 to January 2022. After undergoing two cycles of chemotherapy, group BP-1 were significantly better in various dimensions of the overall quality of life, role function, nausea and vomiting, appetite loss, constipation, and diarrhea relative to group C (76.90 ± 18.31 vs. 58.89 ± 17.17; 93.33 ± 11.58 vs. 85.93 ± 15.06; 0.00 ± 0.00 vs. 27.04 ± 29.15; 6.67 ± 13.53 vs. 22.22 ± 18.80; 0.95 ± 5.63 vs. 28.15 ± 22.42; 2.86 ± 9.47 vs. 15.56 ± 16.82; p < 0.05, respectively). The incidence of nausea and vomiting, appetite loss, constipation, and diarrhea in group BP-1 was significantly lower than in group C (0% vs. 71.43%, 16.67% vs. 57.14%, 2.38% vs. 63.27%, and 7.14% vs. 42.86%, respectively, p < 0.001). CONCLUSIONS Compound probiotic supplements can improve the quality of life and relieve chemotherapy-related gastrointestinal side effects for lung cancer patients receiving platinum-based doublet chemotherapy. (Chinese Clinical Trial Registry: ChiCTR1800019269).

Abstract

The gut microbiota is vital for human body development and function. Its development in early life is influenced by various environmental factors. In this randomized controlled trial, the gut microbiota was obtained as a secondary outcome measure in a study on the effects of one hour of daily skin-to-skin contact (SSC) for five weeks in healthy full-term infants. Specifically, we studied the effects on alpha/beta diversity, volatility, microbiota maturation, and bacterial and gut-brain-axis-related functional abundances in microbiota assessed thrice in the first year. Pregnant Dutch women (n = 116) were randomly assigned to the SSC or care-as-usual groups. The SSC group participants engaged in one hour of daily SSC from birth to five weeks of age. Stool samples were collected at two, five, and 52 weeks and the V4 region was sequenced. We observed significant differences in the microbiota composition, bacterial abundances, and predicted functional pathways between the groups. The SSC group exhibited lower microbiota volatility during early infancy. Microbiota maturation was slower in the SSC group during the first year and our results suggested that breastfeeding duration may have partially mediated this relation. Our findings provide evidence that postpartum SSC may influence microbiota development. Replication is necessary to validate and generalize these results. Future studies should include direct stress measurements and extend microbiota sampling beyond the first year to investigate stress as a mechanism and research SSC's impact on long-term microbiota maturation trajectories.

Abstract

BACKGROUND AND AIM Functional bowel disorders (FBDs), including irritable bowel syndrome (IBS) and others, are conditions without a physically identifiable etiology that, as a result, are difficult to treat. Alternatives to traditional medical interventions are needed because IBS patients require more of physician time and higher healthcare spending. The goal of this study was to determine the efficacy of alternative lifestyle interventions for patients with FBDs seen in an integrative medicine (IM) clinic at an academic medical center. METHODS We performed a retrospective chart review to determine whether patients with FBDs had improvement in symptoms following predominantly nutrition-based IM interventions that included recommendations for dietary supplements and elimination diets. We measured symptoms before and after intervention (average time between measurements 8.75 months) using a medical symptoms questionnaire (MSQ) commonly used to quantify symptom change in IM clinics. RESULTS Digestive tract symptoms, as measured by the MSQ, improved significantly in patients (n = 57) with FBDs following IM intervention. The MSQ Digestive Tract subtotal for FBD patients decreased from 10.2 (SD, 5.4) to 7.2 (SD, 5.2) (P < 0.001) after IM intervention. CONCLUSIONS Patients in an IM clinic had improved digestive tract symptoms scores following IM intervention. Because nutrition-based interventions were the primary intervention recommended by IM providers, primary care physicians and gastroenterologists may wish to consider referring FBD patients to registered dietitian-nutritionists (RDNs) skilled in implementing elimination diets.

Abstract

INTRODUCTION There is large variation in response to diet in irritable bowel syndrome (IBS) and determinants for differential response are poorly understood. OBJECTIVES Our aim was to investigate differential clinical and molecular responses to provocation with fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) and gluten in individuals with IBS. METHODS Data were used from a crossover study with week-long interventions with either FODMAPs, gluten or placebo. The study also included a rapid provocation test. Molecular data consisted of fecal microbiota, short chain fatty acids, and untargeted plasma metabolomics. IBS symptoms were evaluated with the IBS severity scoring system. IBS symptoms were modelled against molecular and baseline questionnaire data, using Random Forest (RF; regression and clustering), Parallel Factor Analysis (PARAFAC), and univariate methods. RESULTS Regression and classification RF models were in general of low predictive power (Q2 ≤ 0.22, classification rate < 0.73). Out of 864 clustering models, only 2 had significant associations to clusters (0.69 < CR < 0.73, p < 0.05), but with no associations to baseline clinical measures. Similarly, PARAFAC revealed no clear association between metabolome data and IBS symptoms. CONCLUSION Differential IBS responses to FODMAPs or gluten exposures could not be explained from clinical and molecular data despite extensive exploration with different data analytical approaches. The trial is registered at www. CLINICALTRIALS gov as NCT03653689 31/08/2018.