Association between skin barrier development and early-onset atopic dermatitis: A longitudinal birth cohort study.

BACKGROUND: A diagnosis of atopic dermatitis (AD) is common during infancy; however, it is unclear whether differential skin barrier development defines this period and signals disease onset in predisposed individuals. OBJECTIVE: We sought to study (NCT03143504) and assess the feasibility of remote skin testing from birth to monitor skin barrier maturation and model association with an AD diagnosis by age 12 months. METHODS: Biophysical testing and infrared spectroscopy were conducted at the maternity ward and family home. Tape stripping collected samples for desquamatory protease and natural moisturizing factor analysis. The 4 common European filaggrin risk alleles were screened. RESULTS: A total of 128 infants completed the study, with 20% developing mild disease. Significant changes in permeability barrier function, desquamatory protease activity, and molecular composition assessed spectroscopically were observed longitudinally, but only subtle evidence of differential skin barrier development was noted between infant subgroups. Common filaggrin risk alleles were strongly associated with early-onset disease and conferred a significant reduction in natural moisturizing factor and water content by age 4 weeks. Accounting for a family history of atopy, these parameters alongside a greater lipid/protein ratio and reduced chymotrypsin-like activity at birth were associated with AD. Measured in ambient conditions, transepidermal water loss did not signal disease risk at any stage. CONCLUSIONS: Skin barrier dysfunction lacked an acquired modality but was considered proportional to cohort severity and suggests that a portfolio of tests used in a community setting has the potential to improve current AD risk evaluations from birth.

The impact on complication rates of delayed routine pessary reviews during the COVID-19 pandemic.

INTRODUCTION AND HYPOTHESIS: During the COVID-19 pandemic, guidance was issued in the United Kingdom advising a delay in routine pessary reviews. The impact of this has not been fully explored. The null hypothesis for this study is that delayed routine pessary reviews during the COVID-19 pandemic did not result in a statistically significant increase in complication rate. METHODS: A retrospective comparative cohort study was conducted in NHS Tayside, Scotland, involving 150 patients pre-pandemic and 150 patients during the COVID-19 pandemic (before exclusions). Their notes were reviewed identifying age, care provider, pessary type, length of pessary usage, review date, time elapsed since the previous review, bleeding/infection/ulceration, removal issues, pessary replacement and outcome. Patients excluded were those with no pessary in situ at review, reviews at ≤4 months and >8 months (pre-pandemic) and reviews at ≤8 months (COVID-19 pandemic). RESULTS: The pre-pandemic group (n=106) had average review times of 10.1,6.2 and 6.2 months for cubes, rings and all others. Overall rates of bleeding/infection/ulceration; reported removal issues; and pessary subsequently not replaced were 9.4%, 11.3% and 5.7% respectively. The COVID-19 pandemic group (n=125) had average review times of 14.7, 10.8 and 11.4 months for cubes, rings and all others. Overall rates of bleeding/infection/ulceration; reported removal issues; and pessary subsequently not replaced were 21.6%, 16.0%, and 12.0% respectively. CONCLUSIONS: Overall, there was a significant increase in rates of bleeding/ulceration/infection (p=0.01). When individual pessaries were considered, this only remained true for rings (p=0.02). Our data would suggest that routine ring pessary reviews should not be extended beyond 6 months or risk bleeding/ulceration/infection.

Characterisation of skin barrier defects in atopic dermatitis patients using Infrared Spectroscopy.

INTRODUCTION: Atopic dermatitis (AD) is characterised by skin barrier defects often measured by biophysical tools that observe stratum corneum (SC) functional properties. OBJECTIVE: To employ in vivo infrared spectroscopy alongside biophysical measurements to analyse changes in chemical composition of the SC in relation to AD severity. METHODS: We conducted an observational cross-sectional cohort study where attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy measurements were collected on the forearm alongside surface pH, capacitance, erythema and transepidermal water loss (TEWL) combined with tape stripping (STS) in a cohort of 75 participants; 55 AD patients stratified by phenotypic severity, compared to 20 healthy controls. Common filaggrin (FLG) variant alleles were genotyped. RESULTS: Reduced hydration, elevated TEWL and redness all associated with greater AD severity. Spectral analysis showed a reduction in 1465cm-1 (full width half maximum) and 1340 cm-1 peak areas indicative of less orthorhombic lipid ordering and reduced carboxylate functional groups that correlated with clinical severity (lipid structure r=-0.59, carboxylate peak area r=-0.50). CONCLUSION: ATR-FTIR spectroscopy is a suitable tool for the characterisation of structural skin barrier defects in AD and has potential as a clinical tool for directing individual treatments based on chemical structural deficiencies.

Enhancement of stratum corneum lipid structure improves skin barrier function and protects against irritation in adults with dry, eczema-prone skin.

BACKGROUND: The skin of patients with atopic dermatitis is characterized by abnormal stratum corneum lipid levels. Consequently, the lamellar matrices are disrupted and skin barrier function is diminished, increasing skin sensitivity to irritants and allergens. OBJECTIVES: To determine whether a cream containing ceramides, triglycerides and cholesterol in a multivesicular emulsion can reinforce the skin barrier and protect against skin irritation. METHODS: A randomized observer-blind intrapatient-controlled study in 34 adults with dry, eczema-prone skin was conducted. Each participant underwent 4 weeks of treatment with the test cream on one forearm and lower leg and a reference emollient cream on the other. Skin properties were determined before and after treatment. Lipid structure was assessed by Fourier-transform infrared spectroscopy using a novel interface. RESULTS: Skin barrier integrity was greater at sites treated with the test cream [effect size for area under the transepidermal water loss curve -162, 95% confidence interval (CI) -206 to -118]. Skin sensitivity to sodium lauryl sulfate was reduced (-0·5 points visual redness, 97·57% CI -1·00 to -0·25), as was transepidermal water loss (-15·3 g m-2 h-1 , 95% CI -20·3 to -10·4) compared with the reference. Sites treated with the test cream displayed enhanced lipid chain ordering, which was significantly associated with skin barrier integrity (r = 0·61). Compared with the reference, treatment with the test cream increased hydration (8·61 capacitance units, 95% CI 6·61-10·6) and decreased signs of dryness. CONCLUSIONS: The test cream facilitates skin barrier restoration and protects the skin from dryness and irritation. Compared with a commonly prescribed emollient in the UK, the test cream is highly suited to the management of dry, sensitive skin.

Pea-protein alginate encapsulation adversely affects development of clinical signs of Citrobacter rodentium-induced colitis in mice treated with probiotics.

The efficacy of two strains of Lactobacillus probiotics (Lactobacillus rhamnosus R0011 and Lactobacillus helveticus R0052) immobilized in microcapsules composed of pea protein isolate (PPI) and alginate microcapsules was assessed using a mouse model of Citrobacter rodentium-induced colitis. Accordingly, 4-week-old mice were fed diets supplemented with freeze-dried probiotics (group P), probiotic-containing microcapsules (group PE) (lyophilized PPI-alginate microcapsules containing probiotics), or PPI-alginate microcapsules containing no probiotics (group E). Half of the mice (controls, groups P, PE, and E) received C. rodentium by gavage 2 weeks after initiation of feeding. Daily monitoring of disease symptoms (abnormal behavior, diarrhea, etc.) and body weights was undertaken. Histopathological changes in colonic and cecal tissues, cytokine expression levels, and pathogen and probiotic densities in feces were examined, and the microbial communities of the distal colon mucosa were characterized by 16S rRNA sequencing. Infection with C. rodentium led to marked progression of infectious colitis, as revealed by symptomatic and histopathological data, changes in cytokine expression, and alteration of composition of mucosal communities. Probiotics led to changes in most of the disease markers but did not have a significant impact on cytokine profiles in infected animals. On the basis of cytokine expression analyses and histopathological data, it was evident that encapsulation materials (pea protein and calcium alginate) contributed to inflammation and worsened a set of symptoms in the cecum. These results suggest that even though food ingredients may be generally recognized as safe, they may in fact contribute to the development of an inflammatory response in certain animal disease models.

Hysteroscopic and laparoscopic management of caesarean scar (niche) defects in symptomatic patients.

INTRODUCTION: Worldwide, rates of caesarean section are rising. The term 'niche' describes the presence of an hypoechoic area within the myometrium of the lower uterine segment, reflecting a discontinuation of the myometrium at the site of a previous caesarean section. A defect in caesarean section scar is associated with symptoms like abnormal uterine bleeding, infertility and complications in subsequent pregnancy including: risk of rupture and morbidly adherent placenta. It can also increase rates of complications during gynaecological procedures: IUCD insertion, evacuation of retained products of conception, hysteroscopy and risk of ectopic pregnancy at scar site. AIMS: To assess the use of surgical techniques to repair niche defects in symptomatic patients, with regards to operative complications, symptomatic relief, postop lower segment thickness and fertility. METHODS: Patients were identified between August 2015-March 2017. INCLUSION CRITERIA: Patients who had one previous caesarean section, symptomatic i.e. abnormal uterine bleeding, dysmenorrhoea, dyspareunia, infertility. EXCLUSION CRITERIA: Asymptomatic patients. No previous caesarean section. RESULTS: Between August 2015 and March 2017, six patients underwent surgical management of niche defect. Four patients reported post menstrual bleeding, one patient had infertility and one had intermenstrual bleeding and dyspareunia. All patients had one caesarean section previously. Mean lower segment measurement preoperatively was 2.5 mm ± 1.6 mm. EBL intraoperatively was 130 ml (10-180 ml). Mean operating time was 90 mins (70-150 min). One patient was pregnant after niche repair and delivered by CS at 38 w. In all six cases, TVS in 3-5 months after surgery revealed restored lower segment to normal thickness 9.2 mm ± 1.8 mm. Symptom resolution was noted in all patients. There were no operative complications. CONCLUSIONS: Anterior uterine wall should be explored in the case of symptomatic patients with previous caesarean section scar. Hysteroscopic resection should not be proposed when RMT is <3 mm. Laparoscopic/vaginal repair allows restoration of the anatomy of the lower uterine segment when residual myometrium is <3 mm. Laparoscopic repair allows antefixation in cases of retroverted uterus. Consideration of a surgical approach should be determined by the patient's plans for fertility and by niche thickness. For women who do not desire pregnancy and whose niche thickness is >3 mm, a hysteroscopic approach should be considered. Women with symptomatic caesarean scar defects who do not desire fertility may also be candidates for hysterectomy. Patients who desire future fertility, especially those with <3 mm of myometrium at the niche site, should undergo laparoscopic resection.

Bile Acid Administration Elicits an Intestinal Antimicrobial Program and Reduces the Bacterial Burden in Two Mouse Models of Enteric Infection.

In addition to their chemical antimicrobial nature, bile acids are thought to have other functions in the homeostatic control of gastrointestinal immunity. However, those functions have remained largely undefined. In this work, we used ileal explants and mouse models of bile acid administration to investigate the role of bile acids in the regulation of the intestinal antimicrobial response. Mice fed on a diet supplemented with 0.1% chenodeoxycholic acid (CDCA) showed an upregulated expression of Paneth cell α-defensins as well as an increased synthesis of the type-C lectins Reg3b and Reg3g by the ileal epithelium. CDCA acted on several epithelial cell types, by a mechanism independent from farnesoid X receptor (FXR) and not involving STAT3 or ß-catenin activation. CDCA feeding did not change the relative abundance of major commensal bacterial groups of the ileum, as shown by 16S analyses. However, administration of CDCA increased the expression of ileal Muc2 and induced a change in the composition of the mucosal immune cell repertoire, decreasing the proportion of Ly6G+ and CD68+ cells, while increasing the relative amount of IgGκ+ B cells. Oral administration of CDCA to mice attenuated infections with the bile-resistant pathogens Salmonella enterica serovar Typhimurium and Citrobacter rodentium, promoting lower systemic colonization and faster bacteria clearance, respectively. Our results demonstrate that bile acid signaling in the ileum triggers an antimicrobial program that can be potentially used as a therapeutic option against intestinal bacterial infections.

Dietary Lipid Type, Rather Than Total Number of Calories, Alters Outcomes of Enteric Infection in Mice.

Dietary lipids modulate immunity, yet the means by which specific fatty acids affect infectious disease susceptibility remains unclear. Deciphering lipid-induced immunity is critical to understanding the balance required for protecting against pathogens while avoiding chronic inflammatory diseases. To understand how specific lipids alter susceptibility to enteric infection, we fed mice isocaloric, high-fat diets composed of corn oil (rich in n-6 polyunsaturated fatty acids [n-6 PUFAs]), olive oil (rich in monounsaturated fatty acids), or milk fat (rich in saturated fatty acids) with or without fish oil (rich in n-3 PUFAs). After 5 weeks of dietary intervention, mice were challenged with Citrobacter rodentium, and pathological responses were assessed. Olive oil diets resulted in little colonic pathology associated with intestinal alkaline phosphatase, a mucosal defense factor that detoxifies lipopolysaccharide. In contrast, while both corn oil and milk fat diets resulted in inflammation-induced colonic damage, only milk fat induced compensatory protective responses, including short chain fatty acid production. Fish oil combined with milk fat, unlike unsaturated lipid diets, had a protective effect associated with intestinal alkaline phosphatase activity. Overall, these results reveal that dietary lipid type, independent of the total number of calories associated with the dietary lipid, influences the susceptibility to enteric damage and the benefits of fish oil during infection.

The Effect of an Emollient Containing Urea, Ceramide NP, and Lactate on Skin Barrier Structure and Function in Older People with Dry Skin.

Xerosis affects up to 75% of older people and develops as a result of a skin barrier defect. Emollients are widely used to treat xerosis; however, there is limited understanding of the differences between them and their effects on the skin barrier in older people. This study aimed to compare the effect of a commercially available emollient containing 5% urea, ceramide NP and lactate (test emollient) to an alternative emollient without these additives (control emollient) on the properties of the skin barrier in older people. Two cohorts of 21 volunteers aged >60 years with dry skin were recruited. The first applied the test emollient to one forearm and no treatment to the other for 28 days. The second compared the test emollient to the control emollient observing the same parameters. Effects on the skin barrier were determined by measuring skin barrier function, hydration, skin surface pH and by analysing Fourier transform infrared spectra before and after treatment. A third cohort of 6 young adults was recruited to investigate the effect of a single treatment with the test emollient on the molecular structure of the skin barrier at greater depths by employing the tape-stripping technique. The test emollient hydrated the skin to a significantly greater extent and for a longer period of time compared to the control emollient, an effect associated with a significant elevation of carboxylate groups (a marker of natural moisturizing factor content) within the stratum corneum. Furthermore, the test emollient imparted additional benefits to the structure and function of the skin barrier not exhibited by the control emollient. In conclusion, the test emollient addressed the pathological features of xerotic aged skin, supporting its use as first-line therapy for xerotic skin conditions in this population.

The effect of 14 weeks of vitamin D3 supplementation on antimicrobial peptides and proteins in athletes.

Heavy training is associated with increased respiratory infection risk and antimicrobial proteins are important in defence against oral and respiratory tract infections. We examined the effect of 14 weeks of vitamin D3 supplementation (5000 IU/day) on the resting plasma cathelicidin concentration and the salivary secretion rates of secretory immunoglobulin A (SIgA), cathelicidin, lactoferrin and lysozyme in athletes during a winter training period. Blood and saliva were obtained at the start of the study from 39 healthy men who were randomly allocated to vitamin D3 supplement or placebo. Blood samples were also collected at the end of the study; saliva samples were collected after 7 and 14 weeks. Plasma total 25(OH)D concentration increased by 130% in the vitamin D3 group and decreased by 43% in the placebo group (both P = 0.001). The percentage change of plasma cathelicidin concentration in the vitamin D3 group was higher than in the placebo group (P = 0.025). Only in the vitamin D3 group, the saliva SIgA and cathelicidin secretion rates increased over time (both P = 0.03). A daily 5000 IU vitamin D3 supplement has a beneficial effect in up-regulating the expression of SIgA and cathelicidin in athletes during a winter training period, which could improve resistance to respiratory infections.

Comparing the Effect of a Twice-weekly Tacrolimus and Betamethasone Valerate Dose on the Subclinical Epidermal Barrier Defect in Atopic Dermatitis.

The proactive use of topical anti-inflammatory (TAI) therapy to address subclinical inflammation is an effective, contemporary clinical strategy for the management of atopic dermatitis (AD). The interaction of a proactive TAI dose with the subclinical epidermal barrier defect in AD is yet to be determined. A randomised, observer-blind, functional mechanistic study in 17 subjects with quiescent AD was performed to compare the effect of a twice-weekly dose of betamethasone valerate (0.1%) cream (BMVc), against tacrolimus (0.1%) ointment (TACo) on the biophysical and biological properties of the epidermal barrier. Application of BMVc preserved epidermal barrier function and stratum corneum (SC) integrity, but significantly elevated skin-surface pH with concomitant loss of SC cohesion. By contrast, TACo improved SC integrity, exerted an overall hydrating action, and significantly reduced caseinolytic and trypsin-like protease activity. The differential effects reported support the proactive use of TACo to promote reparation of the subclinical barrier defect in AD.

Systematic review of incidental physical activity community interventions.

BACKGROUND: Increasing incidental physical activity (IPA) such as active transport has substantial public health potential. OBJECTIVE: This systematic review describes community-based and community-wide IPA interventions and assesses their effectiveness. METHOD: Data sources (Medline, Embase, PsycINFO and CINAHL) were searched along with the reference lists of identified systematic reviews and included articles. Eligibility criteria; 4+ weeks in duration; 20+ participants; community-based or community-wide; stated aim to increase IPA. RESULTS: Forty three studies were identified from 42 original articles; more than half (60%) aimed to increase stair use compared to escalator and/or lift use; a quarter (23%) aimed to increase active transport; and, 16% to increase playground energy expenditure. More than two-thirds of studies reported a significant increase in IPA. Accurate comparisons between studies were not possible due to substantial heterogeneity in study design. Critical appraisal of studies revealed that the level of bias was moderate-high in most of the studies (77%). CONCLUSION: Due to the heterogeneity and bias of included studies, only limited conclusions can be drawn about the effectiveness of IPA interventions. However, this systematic review provides a timely summary of current evidence that can be used to inform decision-makers in designing IPA interventions in the community.

Maintenance of an Acidic Skin Surface with a Novel Zinc Lactobionate Emollient Preparation Improves Skin Barrier Function in Patients with Atopic Dermatitis.

INTRODUCTION: The skin of patients with atopic dermatitis (AD) is characterised by elevated pH. As a central homeostatic regulator, an increased pH accelerates desquamation and suppresses lipid processing, resulting in diminished skin barrier function. The aim of this study was to determine whether a novel zinc lactobionate emollient cream can strengthen the skin barrier by lowering skin surface pH. METHODS: A double-blind, forearm-controlled cohort study was undertaken in patients with AD. Participants applied the test cream to one forearm and a vehicle cream to the other (randomised allocation) twice daily for 56 days. Skin surface pH and barrier function (primary outcomes) were assessed at baseline and after 28 days and 56 days of treatment, amongst other tests. RESULTS: A total of 23 adults with AD completed the study. During and after treatment, a sustained difference in skin surface pH was observed between areas treated with the test cream and vehicle (4.50 ± 0.38 versus 5.25 ± 0.54, respectively, p < 0.0001). This was associated with significantly reduced transepidermal water loss (TEWL) on the test cream treated areas compared with control (9.71 ± 2.47 versus 11.20 ± 3.62 g/m2/h, p = 0.0005). Improvements in skin barrier integrity, skin sensitivity to sodium lauryl sulphate, skin hydration, and chymotrypsin-like protease activity were all observed at sites treated with the test cream compared with the control. CONCLUSION: Maintenance of an acidic skin surface pH and delivery of physiologic lipids are beneficial for skin health and may help improve AD control by reducing sensitivity to irritants and allergens.

Effect of olive and sunflower seed oil on the adult skin barrier: implications for neonatal skin care.

Natural oils are advocated and used throughout the world as part of neonatal skin care, but there is an absence of evidence to support this practice. The goal of the current study was to ascertain the effect of olive oil and sunflower seed oil on the biophysical properties of the skin. Nineteen adult volunteers with and without a history of atopic dermatitis were recruited into two randomized forearm-controlled mechanistic studies. The first cohort applied six drops of olive oil to one forearm twice daily for 5 weeks. The second cohort applied six drops of olive oil to one forearm and six drops of sunflower seed oil to the other twice daily for 4 weeks. The effect of the treatments was evaluated by determining stratum corneum integrity and cohesion, intercorneocyte cohesion, moisturization, skin-surface pH, and erythema. Topical application of olive oil for 4 weeks caused a significant reduction in stratum corneum integrity and induced mild erythema in volunteers with and without a history of atopic dermatitis. Sunflower seed oil preserved stratum corneum integrity, did not cause erythema, and improved hydration in the same volunteers. In contrast to sunflower seed oil, topical treatment with olive oil significantly damages the skin barrier, and therefore has the potential to promote the development of, and exacerbate existing, atopic dermatitis. The use of olive oil for the treatment of dry skin and infant massage should therefore be discouraged. These findings challenge the unfounded belief that all natural oils are beneficial for the skin and highlight the need for further research.

Athletes' access to, attitudes towards and experiences of help-seeking for mental health: a scoping review protocol.

INTRODUCTION: Athletes are not immune to mental health issues but are less likely to seek help than non-athletes and experience barriers including lack of access to services, lack of knowledge as to how to access services and negative past experiences for help-seeking. Formal (eg, university counsellors, general practitioners and psychologists) and semi-formal (eg, academic tutor, sports coach and physiotherapist) sources of support provided in healthcare, the sport context and higher education are key places for athletes to seek help for mental health, and there is a need to synthesise the evidence on athletes' access, attitudes to and experiences of these services, to understand how to improve these services specific to athletes' mental health needs. This protocol outlines a scoping review that will be used to map the evidence, identify gaps in the literature and summarise findings on athletes' access, attitudes to and experiences of help-seeking for their mental health. METHODS AND ANALYSIS: The methodological frameworks of Arksey and O'Malley (2005), Levac et al (2010) and the Joanna Briggs Institute (2020 and 2021) were used to inform this scoping review protocol alongside the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols checklist and published scoping review protocols within sport and health. The six stages of Arksey and O'Malley's (2005) framework have been used for this scoping review. The searches were conducted between 30 March 2022 and 3 April 2022 in the following databases: APA PsycINFO (via OVID), Embase (via Ovid), MEDLINE (via Ovid), APA PsycArticles Full Text (via OVID), Web of Science Core Collection, SPORTDiscus (via EBSCO), CINAHL (via EBSCO), Scopus, ProQuest (Education Database), ProQuest (Education Collection), ProQuest (Health & Medical Collection), ProQuest (Nursing & Allied Health database), ProQuest (Psychology Database), ProQuest (Public Health Database) and ProQuest (Sports Medicine & Education). The main inclusion criteria of this review are: papers that focus on past help-seeking behaviour, attitudes towards help-seeking and future behavioural intentions, papers that refer to formal and semi-formal sources of support and peer-reviewed literature, primary research articles, systematic or scoping reviews and interventions. During title and abstract screening and full-text review, at least two reviewers will be involved. Data to be extracted from studies includes: details of the study population, whether the paper focuses on formal and/or semi-formal sources of support and whether the focus is on access, attitudes or experiences to help-seeking for mental health. ETHICS AND DISSEMINATION: The evidence will be mapped numerically and through content analysis to describe studies and highlight key concepts, themes and gaps in the literature. The published scoping review will be disseminated to relevant stakeholders and policymakers including those in healthcare, the sporting context and the higher education system. The resulting outputs will be in the form of both peer-reviewed and non-peer reviewed publications (eg, multimedia in the form of a blog post and at conferences). The dissemination plan will be informed by patient and public involvement. Ethics approval was not required for this study.

Microbiota alters the metabolome in an age- and sex- dependent manner in mice.

Commensal bacteria are major contributors to mammalian metabolism. We used liquid chromatography mass spectrometry to study the metabolomes of germ-free, gnotobiotic, and specific-pathogen-free mice, while also evaluating the influence of age and sex on metabolite profiles. Microbiota modified the metabolome of all body sites and accounted for the highest proportion of variation within the gastrointestinal tract. Microbiota and age explained similar amounts of variation the metabolome of urine, serum, and peritoneal fluid, while age was the primary driver of variation in the liver and spleen. Although sex explained the least amount of variation at all sites, it had a significant impact on all sites except the ileum. Collectively, these data illustrate the interplay between microbiota, age, and sex in the metabolic phenotypes of diverse body sites. This provides a framework for interpreting complex metabolic phenotypes and will help guide future studies into the role that the microbiome plays in disease.

Intestinal colonization regulates systemic anti-commensal immune sensitivity and hyperreactivity.

Healthy host-microbial mutualism with our intestinal microbiota relies to a large degree on compartmentalization and careful regulation of adaptive mucosal and systemic anti-microbial immune responses. However, commensal intestinal bacteria are never exclusively or permanently restricted to the intestinal lumen and regularly reach the systemic circulation. This results in various degrees of commensal bacteremia that needs to be appropriately dealt with by the systemic immune system. While most intestinal commensal bacteria, except for pathobionts or opportunistic pathogen, have evolved to be non-pathogenic, this does not mean that they are non-immunogenic. Mucosal immune adaptation is carefully controlled and regulated to avoid an inflammatory response, but the systemic immune system usually responds differently and more vigorously to systemic bacteremia. Here we show that germ-free mice have increased systemic immune sensitivity and display anti-commensal hyperreactivity in response to the addition of a single defined T helper cell epitope to the outer membrane porin C (OmpC) of a commensal Escherichia coli strain demonstrated by increased E. coli-specific T cell-dependent IgG responses following systemic priming. This increased systemic immune sensitivity was not observed in mice colonized with a defined microbiota at birth indicating that intestinal commensal colonization also regulates systemic, and not only mucosal, anti-commensal responses. The observed increased immunogenicity of the E. coli strain with the modified OmpC protein was not due to a loss of function and associated metabolic changes as a control E. coli strain without OmpC did not display increased immunogenicity.

Non-Pharmacological Therapies for Post-Viral Syndromes, Including Long COVID: A Systematic Review.

BACKGROUND: Post-viral syndromes (PVS), including Long COVID, are symptoms sustained from weeks to years following an acute viral infection. Non-pharmacological treatments for these symptoms are poorly understood. This review summarises the evidence for the effectiveness of non-pharmacological treatments for PVS. METHODS: We conducted a systematic review to evaluate the effectiveness of non-pharmacological interventions for PVS, as compared to either standard care, alternative non-pharmacological therapy, or placebo. The outcomes of interest were changes in symptoms, exercise capacity, quality of life (including mental health and wellbeing), and work capability. We searched five databases (Embase, MEDLINE, PsycINFO, CINAHL, MedRxiv) for randomised controlled trials (RCTs) published between 1 January 2001 to 29 October 2021. The relevant outcome data were extracted, the study quality was appraised using the Cochrane risk-of-bias tool, and the findings were synthesised narratively. FINDINGS: Overall, five studies of five different interventions (Pilates, music therapy, telerehabilitation, resistance exercise, neuromodulation) met the inclusion criteria. Aside from music-based intervention, all other selected interventions demonstrated some support in the management of PVS in some patients. INTERPRETATION: In this study, we observed a lack of robust evidence evaluating the non-pharmacological treatments for PVS, including Long COVID. Considering the prevalence of prolonged symptoms following acute viral infections, there is an urgent need for clinical trials evaluating the effectiveness and cost-effectiveness of non-pharmacological treatments for patients with PVS. REGISTRATION: The study protocol was registered with PROSPERO [CRD42021282074] in October 2021 and published in BMJ Open in 2022.