Spatio-temporal dynamics of the human small intestinal microbiome and its response to a synbiotic.

Although fecal microbiota composition is considered to preserve relevant and representative information for distal colonic content, it is evident that it does not represent microbial communities inhabiting the small intestine. Nevertheless, studies investigating the human small intestinal microbiome and its response to dietary intervention are still scarce. The current study investigated the spatio-temporal dynamics of the small intestinal microbiome within a day and over 20 days, as well as its responses to a 14-day synbiotic or placebo control supplementation in 20 healthy subjects. Microbial composition and metabolome of luminal content of duodenum, jejunum, proximal ileum and feces differed significantly from each other. Additionally, differences in microbiota composition along the small intestine were most pronounced in the morning after overnight fasting, whereas differences in composition were not always measurable around noon or in the afternoon. Although overall small intestinal microbiota composition did not change significantly within 1 day and during 20 days, remarkable, individual-specific temporal dynamics were observed in individual subjects. In response to the synbiotic supplementation, only the microbial diversity in jejunum changed significantly. Increased metabolic activity of probiotic strains during intestinal passage, as assessed by metatranscriptome analysis, was not observed. Nevertheless, synbiotic supplementation led to a short-term spike in the relative abundance of genera included in the product in the small intestine approximately 2 hours post-ingestion. Collectively, small intestinal microbiota are highly dynamic. Ingested probiotic bacteria could lead to a transient spike in the relative abundance of corresponding genera and ASVs, suggesting their passage through the entire gastrointestinal tract. This study was registered to http://www.clinicaltrials.gov, NCT02018900.

Assessment of a Multispecies Probiotic Supplement for Relief of Seasonal Allergic Rhinitis: A Randomized Double-Blind Placebo-Controlled Trial.

Background: Early phase clinical research provided initial support for the use of a multispecies probiotic supplement to improve quality of life (QoL) in adults with seasonal allergic rhinitis (AR) and reduce the use of AR symptom relieving medication. This study aimed to confirm these early phase findings in a double-blind randomized placebo-controlled trial. Methods: Individuals, aged 18-65 years, with a minimum 2-year history of AR, moderate-to-severe AR symptoms, and a positive radio-allergosorbent test to Bermuda (Couch) Grass were randomized to receive either a multispecies probiotic supplement (total colony-forming units 4 × 109/day) or placebo twice daily for 8 weeks. A mini-rhinoconjunctivitis quality of life questionnaire (mRQLQ) scale was administered at screening, days 0, 28, and 56. The proportion of participants with a >0.7 improvement in mRQLQ was the primary outcome. Participants also completed a daily symptom and medication diary during the supplementation period. Results: There were 165 participants randomized, with 142 included in the primary outcome analysis. The percentage of participants meeting the threshold for a clinically meaningful reduction in the mRQLQ from days 0 to 56 was not significantly different between groups (61% vs. 62%, p = 0.90). However, 76 participants had a clinically meaningful improvement in QoL (decrease in mRQLQ >0.7) prior to the start of supplementation (screening to day 0). Conclusion: Changes in self-reported QoL and other disease severity metrics between screening and the start of supplementation limited the ability to discern an effect of supplementation and highlight the need for adaptive clinical trial designs in allergy research. Clinical Trial Registration: The trial was registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12619001319167).

Multispecies Probiotic for the Prevention of Antibiotic-Associated Diarrhea in Children: A Randomized Clinical Trial.

Importance: The efficacy of multispecies probiotic formulations in the prevention of antibiotic-associated diarrhea (AAD) remains unclear. Objective: To assess the effect of a multispecies probiotic on the risk of AAD in children. Design, Setting, and Participants: This randomized, quadruple-blind, placebo-controlled trial was conducted from February 2018 to May 2021 in a multicenter, mixed setting (inpatients and outpatients). Patients were followed up throughout the intervention period. Eligibility criteria included age 3 months to 18 years, recruitment within 24 hours following initiation of broad-spectrum systemic antibiotics, and signed informed consent. In total, 646 eligible patients were approached and 350 patients took part in the trial. Interventions: A multispecies probiotic consisting of Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Lactobacillus acidophilus W37, L acidophilus W55, Lacticaseibacillus paracasei W20, Lactiplantibacillus plantarum W62, Lacticaseibacillus rhamnosus W71, and Ligilactobacillus salivarius W24, for a total dose of 10 billion colony-forming units daily, for the duration of antibiotic treatment and for 7 days after. Main Outcomes and Measures: The primary outcome was AAD, defined as 3 or more loose or watery stools per day in a 24-hour period, caused either by Clostridioides difficile or of otherwise unexplained etiology, after testing for common diarrheal pathogens. The secondary outcomes included diarrhea regardless of the etiology, diarrhea duration, and predefined diarrhea complications. Results: A total of 350 children (192 boys and 158 girls; mean [range] age, 50 [3-212] months) were randomized and 313 were included in the intention-to-treat analysis. Compared with placebo (n = 155), the probiotic (n = 158) had no effect on risk of AAD (relative risk [RR], 0.81; 95% CI, 0.49-1.33). However, children in the probiotic group had a lower risk of diarrhea regardless of the etiology (RR, 0.65; 95% CI, 0.44-0.94). No differences were observed between the groups for most of the secondary outcomes, including adverse events. Conclusions and Relevance: A multispecies probiotic did not reduce the risk of AAD in children when analyzed according to the most stringent definition. However, it reduced the overall risk of diarrhea during and for 7 days after antibiotic treatment. Our study also shows that the AAD definition has a significant effect on clinical trial results and their interpretation. Trial Registration: ClinicalTrials.gov Identifier: NCT03334604.

Probiotics as a treatment for prenatal maternal anxiety and depression: a double-blind randomized pilot trial.

Probiotic use may be an efficacious treatment option to effectively manage symptoms of prenatal maternal anxiety and depression. Our primary aim was to test feasibility and acceptability for a probiotic randomized controlled trial (RCT) in pregnant women with pre-existing symptoms. This double-blind pilot RCT included 40 pregnant women with low-risk pregnancies and elevated depressive symptoms and/or anxiety. Once daily, participants orally consumed a probiotic (Ecologic Barrier) or a placebo, from 26 to 30 weeks gestation until delivery. A priori key progression criteria for primary outcomes were determined to decide whether or not a full RCT was feasible and acceptable. Secondary outcomes included depressive symptoms, anxiety, stress, and maternal bonding to offspring. In 19 months, 1573 women were screened; following screening, 155 women (10%) were invited for participation, of whom 135 (87%) received study information, and 40 women (30%) were included. Four out of six a priori determined criteria for success on feasibility and acceptability were met. After 8 weeks of intervention, there was no significant difference between the probiotic and placebo groups for secondary outcomes. The pilot trial was feasible and acceptable, but hampered by recruitment method and study design. Secondary endpoints did not reveal differences between the groups for improving maternal mood.

Kinetics of Physiological Responses as a Measure of Intensity and Hydration Status During Experimental Physical Stress in Human Volunteers.

INTRODUCTION: Strenuous physical stress induces a range of physiological responses, the extent depending, among others, on the nature and severity of the exercise, a person's training level and overall physical resilience. This principle can also be used in an experimental set-up by measuring time-dependent changes in biomarkers for physiological processes. In a previous report, we described the effects of workload delivered on a bicycle ergometer on intestinal functionality. As a follow-up, we here describe an analysis of the kinetics of various other biomarkers. AIM: To analyse the time-dependent changes of 34 markers for different metabolic and immunological processes, comparing four different exercise protocols and a rest protocol. METHODS: After determining individual maximum workloads, 15 healthy male participants (20-35 years) started with a rest protocol and subsequently performed (in a cross-over design with 1-week wash-out) four exercise protocols of 1-h duration at different intensities: 70% W max in a hydrated and a mildly dehydrated state, 50% W max and intermittent 85/55% W max in blocks of 2 min. Perceived exertion was monitored using the Borg' Rating of Perceived Exertion scale. Blood samples were collected both before and during exercise, and at various timepoints up to 24 h afterward. Data was analyzed using a multilevel mixed linear model with multiple test correction. RESULTS: Kinetic changes of various biomarkers were exercise-intensity-dependent. Biomarkers included parameters indicative of metabolic activity (e.g., creatinine, bicarbonate), immunological and hematological functionality (e.g., leukocytes, hemoglobin) and intestinal physiology (citrulline, intestinal fatty acid-binding protein, and zonulin). In general, responses to high intensity exercise of 70% W max and intermittent exercise i.e., 55/85% W max were more pronounced compared to exercise at 50% W max . CONCLUSION: High (70 and 55/85% W max ) and moderate (50% W max ) intensity exercise in a bicycle ergometer test produce different time-dependent changes in a broad range of parameters indicative of metabolic activity, immunological and hematological functionality and intestinal physiology. These parameters may be considered biomarkers of homeostatic resilience. Mild dehydration intensifies these time-related changes. Moderate intensity exercise of 50% W max shows sufficient physiological and immunological responses and can be employed to test the health condition of less fit individuals.

The relationship of prenatal and infant antibiotic exposure with childhood overweight and obesity: a systematic review.

This study aimed to assess the evidence regarding the relationship between early-life antibiotic exposure and childhood overweight/obesity by reviewing observational studies on prenatal antibiotic exposure and systematic reviews on infant antibiotic exposure. A search in Pubmed, Embase and Google Scholar covering the period 1st January till 1st December 2018 led to the identification of five studies on prenatal antibiotic exposure and four systematic reviews on infant antibiotic exposure. Positive trends between prenatal antibiotic exposure and overweight/obesity were reported in all studies; two studies reported a significant overall relationship and the other three reported significant relationships under certain conditions. Effect sizes ranged from odds ratio (OR): 1.04 (0.62-1.74) to relative risk (RR): 1.77 (1.25-2.51). Regarding infant antibiotics, one review concluded there was substantial evidence that infant antibiotic exposure increased the risk of childhood overweight/obesity [pooled effect sizes: RR: 1.21 (1.09-1.33) for overweight and RR: 1.18 (1.12-1.25) for obesity]. Two reviews concluded there was some evidence for a relationship [pooled effect sizes: OR: 1.05 (1.00-1.11) and OR: 1.11 (1.02-1.20)]. The fourth review concluded the studies were too heterogeneous for meta-analyses and the evidence regarding the relationship between infant antibiotic exposure and childhood overweight/obesity was inconclusive. More well-designed studies are needed that include data on intra-partum antibiotics and address important potential confounders (including maternal and childhood infections). This review points to some evidence of a relationship between early-life antibiotic exposure and childhood overweight/obesity; this is especially evident in certain children (i.e. exposed to multiple and broad-spectrum antibiotics, earlier postnatal exposure and male gender) and merits further research.

Digital Immune Gene Expression Profiling Discriminates Allergic Rhinitis Responders from Non-Responders to Probiotic Supplementation.

Probiotic supplementation for eight weeks with a multi-strain probiotic by individuals with allergic rhinitis (AR) reduced overall symptom severity, the frequency of medication use and improved quality of life. The purported mechanism of action is modulation of the immune system. This analysis examined changes in systemic and mucosal immune gene expression in a subgroup of individuals, classified as either responders or non-responders based on improvement of AR symptoms in response to the probiotic supplement. Based on established criteria of a beneficial change in the mini-rhinoconjunctivitis quality of life questionnaire (mRQLQ), individuals with AR were classified as either responders or non-responders. Systemic and mucosal immune gene expression was assessed using nCounter PanCancer Immune Profiling (Nanostring Technologies, Seattle, WA, USA) kit on blood samples and a nasal lysate. There were 414 immune genes in the blood and 312 immune genes in the mucosal samples expressed above the background threshold. Unsupervised hierarchical clustering of immune genes separated responders from non-responders in blood and mucosal samples at baseline and after supplementation, with key T-cell immune genes differentially expressed between the groups. Striking differences in biological processes and pathways were evident in nasal mucosa but not blood in responders compared to non-responders. These findings support the use of network approaches to understand probiotic-induced changes to the immune system.

A Specifically Designed Multispecies Probiotic Supplement Relieves Seasonal Allergic Rhinitis Symptoms.

BACKGROUND: Probiotics are purported to reduce symptoms of allergic rhinitis. This study sought to determine the proportion of participants with an improvement in the mini Rhinoconjunctivitis Quality of Life Questionnaire (mRQLQ) in response to a multispecies probiotic supplement with a Simon Two-Stage design. METHODS: This study was based on a Simon Two-Stage Design for p1-p0 = 0.18 to account for seasonal variation in symptoms. Under this design, ≥10 patients are required to exhibit an improvement in quality-of-life scores to determine that there was sufficient activity for the supplement to be considered effective. Participants consumed a probiotic supplement (Ecologic® AllergyCare; probiotik®pur) twice daily for 8 weeks. The primary outcome measure was based on a change in mRQLQ scores following supplementation. Secondary outcomes include assessment of change in symptoms and medication usage with a twice-weekly symptom and medication diary, nasal congestion by rhinomanometry, and total serum Immunoglobulin E (IgE) and specific IgE for Bermuda grass. RESULTS: A total of 40 participants completed the study. A total of 25 participants (63%, 49-76%, p < 0.001; mean, 95% confidence interval, p-value) out of 40 participants had a clinically meaningful response to treatment based on assessment of mRQLQ. On average, mRQLQ scores changed from 2.83 ± 1.51 at baseline to 1.66 ± 1.36 at week 4 and 1. 38 ± 1.13 at week 8 (p < 0.01) (mean ± SD, p-value). Sum of individual symptom scores and overall symptom scores over the course of treatment was significantly reduced (p = 0.036 and p = 0.039, respectively). A moderate reduction in frequency of allergy-related medication use in the final 4 weeks of supplementation period was observed (52.5% weeks 0-4 to 41.4% weeks 4-8; average proportion of total diary responses, p = 0.085). The supplement was largely well tolerated by participants at the dose provided. CONCLUSIONS: The proportion of participants exhibiting improvement in quality-of-life metrics warrants continued investigation in the form of a phase III placebo-controlled trial.