Dietary factors in rheumatic autoimmune diseases: a recipe for therapy?

Saccharomyces boulardii improves clinical and paraclinical indices in overweight/obese knee osteoarthritis patients: a randomized triple-blind placebo-controlled trial

PURPOSE

This study aimed to determine the effect of the probiotic Saccharomyces boulardii (S. boulardii) in patients with knee osteoarthritis (KOA).

METHODS

In this study, 70 patients with KOA were recruited via outpatient clinics between 2020 and 2021 and randomly assigned to receive probiotics or placebo supplements for 12 weeks. The primary outcome was a change in pain intensity according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score.

RESULTS

Sixty-three patients completed the trial. A linear mixed analysis of covariance (ANCOVA) model analysis showed that probiotic was better than placebo in decreasing the pain intensity measured by visual analogue scale (VAS) [-2.11 (-2.59, -1.62) in probiotic group and -0.90 (-1.32, -0.48) in placebo group, p = 0.002] and WOMAC pain score [-3.57 (-4.66, -2.49) in probiotic group and -1.43 (-2.33, -0.53) in placebo group, p < 0.001]. The daily intake of acetaminophen for pain management significantly decreased in the probiotic group [-267.18 (-400.47, -133.89) mg, p < 0.001] that was significantly better than placebo (p = 0.006). Probiotic significantly decreased the serum levels of high-sensitivity C-reactive protein (hs-CRP) inflammatory index [-2.72 (-3.24, -2.20) µg/ml] and malondialdehyde (MDA) oxidative stress index [-1.61 (-2.11, -1.11) nmol/ml] compared to the placebo (p = 0.002 and p < 0.001, respectively). Probiotic was better than placebo in increasing the scores of role disorder due to physical health (p = 0.023), pain (p = 0.048) and physical health (p = 0.031).

CONCLUSION

Probiotic S. boulardii supplementation in patients with KOA significantly improved pain intensity, some dimensions of QoL, and inflammatory and oxidative stress biomarkers with no severe side effects.

TRIAL REGISTRY

Registered on the Iranian clinical trial website ( http://www.irct.ir : IRCT20161022030424N4) on 2019-09-02.

Managing Cardiovascular Risk in Patients with Autoimmune Diseases: Insights from a Nutritional Perspective

PURPOSE OF REVIEW

Autoimmune diseases manifest as an immune system response directed against endogenous antigens, exerting a significant influence on a substantial portion of the population. Notably, a leading contributor to morbidity and mortality in this context is cardiovascular disease (CVD). Intriguingly, individuals with autoimmune disorders exhibit a heightened prevalence of CVD compared to the general population. The meticulous management of CV risk factors assumes paramount importance, given the current absence of a standardized solution to this perplexity. This review endeavors to address this challenge from a nutritional perspective.

RECENT FINDINGS

Emerging evidence suggests that inflammation, a common thread in autoimmune diseases, also plays a pivotal role in the pathogenesis of CVD. Nutritional interventions aimed at reducing inflammation have shown promise in mitigating cardiovascular risk. The integration of nutritional strategies into the management plans for patients with autoimmune diseases offers a holistic approach to reducing cardiovascular risk. While conventional pharmacological treatments remain foundational, the addition of targeted dietary interventions can provide a complementary pathway to improve cardiovascular outcomes.

Mendelian randomization as a tool to gain insights into the mosaic causes of autoimmune diseases

Autoimmune diseases (ADs) are a broad range of disorders which are characterized by long-term inflammation and tissue damage arising from an immune response against one's own tissues. It is now widely accepted that the causes of ADs include environmental factors, genetic susceptibility and immune dysregulation. However, the exact etiology of ADs has not been fully elucidated to date. Because observational studies are plagued by confounding factors and reverse causality, no firm conclusions can be drawn about the etiology of ADs. Over the years, Mendelian randomization (MR) analysis has come into focus, offering unique perspectives and insights into the etiology of ADs and promising the discovery of potential therapeutic interventions. In MR analysis, genetic variation (alleles are randomly dispensed during meiosis, usually irrespective of environmental or lifestyle factors) is used instead of modifiable exposure to explore the link between exposure factors and disease or other outcomes. Therefore, MR analysis can provide a valuable method for exploring the causal relationship between different risk factors and ADs when its inherent assumptions and limitations are fully considered. This review summarized the recent findings of MR in major ADs, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), and type 1 diabetes mellitus (T1DM), focused on the effects of different risk factors on ADs risks. In addition, we also discussed the opportunities and challenges of MR methods in ADs research.

Role of the gut microbiome in multiple sclerosis: From etiology to therapeutics

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS that affects around one million people in the United States. Predisposition or protection from this disease is linked with both genetic and environmental factors. In recent years, gut microbiome has emerged as an important environmental factor in the pathobiology of MS. The gut microbiome supports various physiologic functions, including the development and maintenance of the host immune system, the perturbation of which is known as dysbiosis and has been linked with multiple diseases including MS. We and others have shown that people with MS (PwMS) have gut dysbiosis that is characterized by specific gut bacteria being enriched or depleted. Consequently, there is an emphasis on determining the mechanism(s) through which gut bacteria and/or their metabolites alter the course of MS through their ability to provide protection, predispose individuals, or promote disease progression. Improving our understanding of these mechanisms will allow us to harness the enormous potential of the gut microbiome as a diagnostic and/or therapeutic agent. In this chapter, we will discuss current advances in microbiome research in the context of MS, including a review of specific bacteria that are currently linked with this disease, potential mechanisms of disease pathogenesis, and the utility of microbiome-based therapy for PwMS.

High Estimated 24-Hour Urinary Sodium Excretion Is Related to Symptomatic Knee Osteoarthritis: A Nationwide Cross-Sectional Population-Based Study

OBJECTIVES

High salt intake results in various harmful effects on human health including hypertension, cardiovascular disease, and reduced bone density. Despite this, there are very few studies in the literature that have investigated the association between sodium intake and osteoarthritis (OA). Therefore, we aimed to explore these associations in a Korean population.

METHODS

This study used cross-sectional data from adult subjects aged 50-75 years from two consecutive periods of the Korean National Health and Nutrition Examination Survey V-VII (2010-2011 and 2014-2016). The estimated 24-hour urinary sodium excretion (24HUNa) was used as a surrogate marker of salt intake. In the 2010-2011 dataset, knee OA (KOA) was defined as the presence of the radiographic features of OA and knee pain. The association between KOA and salt intake was analysed using univariable and multivariable logistic regression methods. For the sensitivity analysis, the same procedures were conducted on subjects with self-reported OA (SR-OA) with knee pain in the 2010-2011 dataset and any site SR-OA in the 2014-2016 dataset.

RESULTS

Subjects with KOA had significantly lower energy intake, but higher 24HUNa than those without KOA. The restricted cubic spline plots demonstrated a J-shaped distribution between 24HUNa and prevalent KOA. When 24HUNa was stratified into five groups (<2, 2-3, 3-4, 4-5 and ≥5 g/day), subjects with high sodium intake (≥5 g/day) had a higher risk of KOA (odds ratio [OR] = 1.64, 95% confidence interval [CI] 1.03-2.62) compared to the reference group (3-4 g/day) after adjusting for covariates. The sensitivity analysis based on SR-OA with knee pain showed that high sodium intake was also significantly associated with increased prevalence of OA (OR = 1.84, 95% CI 1.10-3.10) compared with the reference group. Regarding SR-OA at any site in the 2014-2016 dataset, estimated 24HUNa showed a significantly positive association with the presence of SR-OA after adjusting for potential confounders.

CONCLUSIONS

This nationwide Korean representative study showed a significant association between symptomatic KOA and high sodium intake (≥5 g/day). Avoidance of a diet high in salt might be beneficial as a non-pharmacologic therapy for OA.

Monitoring and Managing Cardiovascular Risk in Immune Mediated Inflammatory Diseases

Cardiovascular disease (CVD) is common in immune-mediated inflammatory diseases (IMIDs) and it is predominately attributed to the interplay between chronic inflammation and traditional CVD risk factors. CVD has significant impact on the survival of patients with IMIDs as it is associated with increased morbidity and mortality. Despite recommendations for monitoring and managing CVD in patients with IMIDs, the individual CVD risk assessment remains problematic as CVD risk calculators for the general population consistently underestimate the risk in patients with IMIDs. Application of new technologies utilizing artificial intelligence techniques have shown promising potential for tailoring predictive medicine to the individual patient, but further validation of their role in clinical decision-making is warranted. In the meantime, individuals with IMIDs should be encouraged to adopt behavioral interventions targeting at modifiable lifestyle CVD risk factors, whereas rheumatologists need to be well aware of the unfavorable effects of antirheumatic medication on various CVD risk factors and outcomes. In the current paper, we aim to provide an overview of current and emerging strategies for mitigating CVD risk in patients with IMIDs, based on a practical approach.

Temporal patterns of microglial activation in white matter following experimental mild traumatic brain injury: a systematic literature review

Mild traumatic brain injuries (mTBIs) are a prevalent form of injury that can result in persistent neurological impairments. Microglial activation has become increasingly recognized as a key process regulating the pathology of white matter in a wide range of brain injury and disease contexts. As white matter damage is known to be a major contributor to the impairments that follow mTBI, microglia have rightfully become a common target of investigation for the development of mTBI therapies and biomarkers. Recent work has demonstrated that the efficacy of microglial manipulation as a therapeutic intervention following injury or disease is highly time-sensitive, emphasizing the importance of advancing our understanding of the dynamics of post-mTBI microglial activation from onset to resolution. Current reporting of microglial activation in experimental studies of mTBI is non-standardized, which has limited our ability to identify concrete patterns of post-mTBI microglial activation over time. In this review, we examine preclinical studies of mTBI that report on microglial activation in white matter regions to summarize our current understanding of these patterns. Specifically, we summarize timecourses of post-mTBI microglial activation in white matter regions of the brain, identify factors that influence this activation, examine the temporal relationship between microglial activation and other post-mTBI assessments, and compare the relative sensitivities of various methods for detecting microglial activation. While the lack of replicated experimental conditions has limited the extent of conclusions that can confidently be drawn, we find that microglia are activated over a wide range of timecourses following mTBI and that microglial activation is a long-lasting outcome of mTBI that may resolve after most typical post-mTBI assessments, with the exception of those measuring oligodendrocyte lineage cell integrity. We identify several understudied parameters of post-mTBI microglial activation in white matter, such as the inclusion of female subjects. This review summarizes our current understanding of the progression of microglial activation in white matter structures following experimental mTBI and offers suggestions for important future research directions.

Immune-Mediated Diseases Associated With Cancer Risks

Question

What are the profiles of cancer risk associated with immune-mediated diseases?

Findings

In this cohort study of 478 753 participants, immune-mediated diseases were associated with an increased risk of total cancer. Organ-specific immune-mediated diseases had stronger associations with risk of local cancers than extralocal cancers, and many immune-mediated diseases were associated with increased risk of cancer in the involved organs and in the near and distant organs or different systems.

Meaning

The findings suggest that immune-mediated diseases are associated with risk of cancer at the local and systemic levels, supporting the role of local and systemic immunoregulation in carcinogenesis.

Importance

Immune regulation is important for carcinogenesis; however, the cancer risk profiles associated with immune-mediated diseases need further characterization.

Objective

To assess the prospective association of 48 immune-mediated diseases with the risk of total and individual cancers and the prospective association of organ-specific immune-mediated diseases with the risk of local and extralocal cancers.

Design, Setting, and Participants

This prospective cohort study used data from the UK Biobank cohort study on adults aged 37 to 73 years who were recruited at 22 assessment centers throughout the UK between January 1, 2006, and December 31, 2010, with follow-up through February 28, 2019.

Exposures

Immune-mediated diseases.

Main Outcomes and Measures

The association of immune-mediated diseases with risk of cancer was assessed with multivariable hazard ratios (HRs) and 95% CIs after adjusting for various potential confounders using time-varying Cox proportional hazards regression. Heterogeneity in the associations of organ-specific immune-mediated diseases with local and extralocal cancers was assessed using the contrast test method.

Results

A total of 478 753 participants (mean [SD] age, 56.4 [8.1] years; 54% female) were included in the study. During 4 600 460 person-years of follow-up, a total of 2834 cases of cancer were documented in 61 496 patients with immune-mediated diseases and 26 817 cases of cancer in 417 257 patients without any immune-mediated diseases (multivariable HR, 1.08; 95% CI, 1.04-1.12). Five of the organ-specific immune-mediated diseases were significantly associated with higher risk of local but not extralocal cancers: asthma (HR, 1.34; 95% CI, 1.14-1.56), celiac disease (HR, 6.89; 95% CI, 2.18-21.75), idiopathic thrombocytopenic purpura (HR, 6.94; 95% CI, 3.94-12.25), primary biliary cholangitis (HR, 42.12; 95% CI, 20.76-85.44), and autoimmune hepatitis (HR, 21.26; 95% CI, 6.79-66.61) (P < .002 for heterogeneity). Nine immune-mediated diseases were associated with an increased risk of cancers in the involved organs (eg, asthma with lung cancer [HR, 1.34; 95% CI, 1.14-1.57; P < .001] and celiac disease with small intestine cancer [HR, 6.89; 95% CI, 2.18-21.75; P = .001]); 13 immune-mediated diseases were associated with an increased risk of cancer in the near organs (eg, Crohn disease with liver cancer: [HR, 4.01; 95% CI, 1.65-9.72; P = .002]) or distant organs (eg, autoimmune hepatitis with tongue cancer [HR, 27.75; 95% CI, 3.82-199.91; P = .001]) or in different systems (eg, idiopathic thrombocytopenic purpura with liver cancer [HR, 11.96; 95% CI, 3.82-37.42; P < .001]).

Conclusions and Relevance

In this cohort study, immune-mediated diseases were associated with an increased risk of total cancer. Organ-specific immune-mediated diseases had stronger associations with risk of local cancers than extralocal cancers. The associations for individual immune-mediated diseases were largely organ specific but were also observed for some cancers in the near and distant organs or different systems. Our findings support the role of local and systemic immunoregulation in cancer development.

The role of T cells in age-related diseases

Age-related T cell dysfunction can lead to failure of immune tolerance mechanisms, resulting in aberrant T cell-driven cytokine and cytotoxic responses that ultimately cause tissue damage. In this Review, we discuss the role of T cells in the onset and progression of age-associated conditions, focusing on cardiovascular disorders, metabolic dysfunction, neuroinflammation and defective tissue repair and regeneration. We present different mechanisms by which T cells contribute to inflammageing and might act as modulators of age-associated diseases, including through enhanced pro-inflammatory and cytotoxic activity, defective clearance of senescent cells or regulation of the gut microbiota. Finally, we propose that 'resetting' immune system tolerance or targeting pathogenic T cells could open up new therapeutic opportunities to boost resilience to age-related diseases.

Exploring the role of polyphenols in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory and autoimmune disorder which is mainly characterized by inflammation in joints, bone erosions and cartilaginous destruction that leads to joint dysfunction, deformation, and/or permanent functional impairment. The prevalence of RA is increasing, incurring a considerable burden on healthcare systems globally. The exact etiology of RA is unknown, with various pathways implicated in its pathophysiology. Non-steroidal anti-inflammatory drugs (NSAIDs) including celecoxib, diclofenac and ibuprofen, disease-modifying anti-rheumatic drugs (DMARD) including azathioprine, methotrexate and cyclosporine, biological agents including anakinra, infliximab, and rituximab and immunosuppressants are used for symptomatic relief in patients with RA, but these medications have severe adverse effects such as gastric ulcers, hypertension, hepatotoxicity and renal abnormalities which restrict their use in the treatment of RA; new RA treatments with minimal side-effects are urgently required. There is accumulating evidence that dietary polyphenols may show therapeutic efficacy in RA through their antioxidant, anti-inflammatory, apoptotic, and immunosuppressant activities and modulation of the tumor necrosis factor-α (TNF-α), interleukin (IL)-6, mitogen-activated protein kinase (MAPK), IL-1β, c-Jun N-terminal kinase (JNK), and nuclear factor κ light-chain-enhancer of activated B cell (NF-κB) pathways. While resveratrol, genistein, carnosol, epigallocatechin gallate, curcumin, kaempferol, and hydroxytyrosol have also been studied for the treatment of RA, the majority of data are derived from animal models. Here, we review the various pathways involved in the development of RA and the preclinical and clinical data supporting polyphenols as potential therapeutic agents in RA patients. Our review highlights that high-quality clinical studies are required to decisively establish the anti-rheumatic efficacy of polyphenolic compounds.

The Emerging World of Microbiome in Autoimmune Disorders: Opportunities and Challenges

Trillions of commensal bacteria colonizing humans (microbiome) have emerged as essential player(s) in human health. The alteration of the same has been linked with diseases including autoimmune disorders such as multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis. Gut bacteria are separated from the host through a physical barrier such as skin or gut epithelial lining. However, the perturbation in the healthy bacterial community (gut dysbiosis) can compromise gut barrier integrity, resulting in translocation of bacterial contents across the epithelial barrier (leaky gut). Bacterial contents such as lipopolysaccharide and bacterial antigens can induce a systemic inflammatory environment through activation and induction of immune cells. The biggest question in the field is whether inflammation causes gut dysbiosis or dysbiosis leads to disease induction or propagation, i.e., it is inside out or outside in or both. In this review, we first discuss the microbiome profiling studies in various autoimmune disorders, followed by a discussion of potential mechanisms through which microbiome is involved in the pathobiology of diseases. A better understanding of the role of the microbiome in health and disease will help us harness the power of commensal bacteria for the development of novel therapeutic agents to treat autoimmune disorders.

Resistant starch intake alleviates collagen-induced arthritis in mice by modulating gut microbiota and promoting concomitant propionate production

Gut dysbiosis precedes clinic symptoms in rheumatoid arthritis (RA) and has been implicated in the initiation and persistence of RA. The early treatment of RA is critical to better clinical outcome especially for joint destruction. Although dietary interventions have been reported to be beneficial for RA patients, it is unclear to whether diet-induced gut microbiome changes can be a preventive strategy to RA development. Here, we investigated the effect of a high fiber diet (HFD) rich with resistant starch (RS) on collagen-induced arthritis (CIA) and gut microbial composition in mice. RS-HFD significantly reduced arthritis severity and bone erosion in CIA mice. The therapeutic effects of RS-HFD were correlated with splenic regulatory T cell (Treg) expansion and serum interleukin-10 (IL-10) increase. The increased abundance of Lactobacillus and Lachnoclostridium genera concomitant with CIA were eliminated in CIA mice fed the RS-HFD diet. Notably, RS-HFD also led to a predominance of Bacteroidetes, and increased abundances of Lachnospiraceae_NK4A136_group and Bacteroidales_S24-7_group genera in CIA mice. Accompanied with the gut microbiome changes, serum levels of the short-chain fatty acid (SCFA) acetate, propionate and isobutyrate detected by GC-TOFMS were also increased in CIA mice fed RS-HFD. While, addition of β-acids from hops extract to the drinking water of mice fed RS-HFD significantly decreased serum propionate and completely eliminated RS-HFD-induced disease improvement, Treg cell increase and IL-10 production in CIA mice. Moreover, exogenous propionate added to drinking water replicated the protective role of RS-HFD in CIA including reduced bone damage. The direct effect of propionate on T cells in vitro was further explored as at least one mechanistic explanation for the dietary effects of microbial metabolites on immune regulation in experimental RA. Taken together, RS-HFD significantly reduced CIA and bone damage and altered gut microbial composition with concomitant increase in circulating propionate, indicating that RS-rich diet might be a promising therapy especially in the early stage of RA.

Epigenetics, pregnancy and autoimmune rheumatic diseases

Autoimmune rheumatic diseases (ARDs) are chronic conditions with a striking female predominance, frequently affecting women of childbearing age. Sex hormones and gender dimorphism of immune response are major determinants in the multifactorial pathogenesis of ARDs, with significant implications throughout reproductive life. Particularly, pregnancy represents a challenging condition in the context of autoimmunity, baring profound hormonal and immunologic changes, which are responsible for the bi-directional interaction between ARDs outcome and pregnancy course. In the latest years epigenetics has proven to be an important player in ARDs pathogenesis, finely modulating major immune functions and variably tuning the significant gender effects in autoimmunity. Additionally, epigenetics is a recognised influencer of the physiological dynamic modifications occurring during pregnancy. Still, there is currently little evidence on the pregnancy-related epigenetic modulation of immune response in ARDs patients. This review aims to overview the current knowledge of the role of epigenetics in the context of autoimmunity, as well as during physiologic and pathologic pregnancy, discussing under-regarded aspects in the interplay between ARDs and pregnancy pathology. The outline of a new ongoing European project will be presented.

Beverages in Rheumatoid Arthritis: What to Prefer or to Avoid

Background: The role of nutrition in the pathogenesis of rheumatic diseases, including rheumatoid arthritis (RA), has gained increasing attention in recent years. A growing number of studies have focussed on the diverse nutritional contents of beverages, and their possible role in the development and progression of RA. Main body: We aimed to summarise the current knowledge on the role of a range of beverages in the context of RA. Beverages have a key role within the mosaic of autoimmunity in RA and potential to alter the microbiome, leading to downstream effects on inflammatory pathways. The molecular contents of beverages, including coffee, tea, and wine, have similarly been found to interfere with immune signalling pathways, some beneficial for disease progression and others less so. Finally, we consider beverages in the context of wider dietary patterns, and how this growing body of evidence may be harnessed by the multidisciplinary team in patient management. Conclusions: While there is increasing work focussing on the role of beverages in RA, integration of discussions around diet and lifestyle in our management of patients remains sparse. Nutrition in RA remains a controversial topic, but future studies, especially on the role of beverages, are likely to shed further light on this in coming years.

Dietary inflammatory index is associated with pain intensity and some components of quality of life in patients with knee osteoarthritis

OBJECTIVES

We aim to measure dietary inflammatory index (DII) and its association with functional status, pain intensity and quality of life (QOL) in patients with knee osteoarthritis (KOA). Dietary information from 220 qualified patients with KOA was collected by a 168-item food frequency questionnaire. The functional status, pain intensity and QOL were evaluated by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, Visual Analogue Scale (VAS) and SF36 questionnaire respectively.

RESULTS

Linear regression analysis showed that the DII was significantly associated with VAS (p = 0.040; β = 0.151), and physical function (p = 0.039; β = - 0.184), emotional wellbeing (p = 0.048; β = - 0.158) and pain (p = 0.020; β = 0.161) scales and physical health (p = 0.047; β = 0.110) subscale of QOL after adjusting for age, sex, body mass index, and physical activity. There was no significant differences concerning WOMAC across the DII tertiles with and without adjustment to probable confounders (Ptrend = 0.091 and 0.181, respectively). After adjustment, a significantly increased severe pain odds was observed in the highest tertile of DII score in comparison with the lowest tertile (OR tertile 3 vs. 1 = 1.55, 95% CI 1.04-2.31; Ptrend = 0.04).

Caffeine intake influences disease activity and clinical phenotype in systemic lupus erythematosus patients

OBJECTIVE

Caffeine, one of the most widely consumed products in the world, seems to interact with multiple components of the immune system by acting as a non-specific phosphodiesterase inhibitor. In vitro dose-dependent treatment with caffeine down-regulates mRNA levels of key inflammation-related genes in peripheral blood mononuclear cells. So far, no robust data are available about the possible contribution of caffeine in systemic lupus erythematosus (SLE). The aim of this study was to evaluate the impact of caffeine consumption on SLE-related disease phenotype and activity, in terms of clinimetric assessment and cytokine serum levels.

METHODS

We performed a cross-sectional study, enrolling consecutive patients and reporting their clinical and laboratory data. Disease activity was assessed by SLE Disease Activity Index 2000 (SLEDAI-2K). Caffeine intake was evaluated by a 7-day food frequency questionnaire, including all the main sources of caffeine. As previously reported, patients were divided into four groups according to the daily caffeine intake: <29.1 mg/day (group 1), 29.2-153.7 mg/day (group 2), 153.8-376.5 mg/day (group 3) and >376.6 mg/day (group 4). At the end of questionnaire filling, blood samples were collected from each patient to assess cytokine levels. These were assessed by using a panel by Bio-Plex assays to measure the levels of IL-6, IL-10, IL-17, IL-27, IFNγ, IFNα and BLyS.

RESULTS

We enrolled 89 consecutive SLE patients. We observed a negative correlation between caffeine consumption and disease activity, measured with SLEDAI-2K. A significantly higher prevalence of lupus nephritis, neuropsychiatric involvement, haematological manifestations, hypocomplementaemia and anti-dsDNA positivity was observed in patients with a low intake of caffeine. Furthermore, patients with a low intake of caffeine were more frequently treated with glucocorticoids. Regarding cytokine analysis, a negative correlation between daily caffeine consumption and serum level of IFNγ was found (p = 0.03, r = -0.2); furthermore, patients with a high intake of caffeine showed lower serum levels of IFNα (p = 0.02), IL-17 (p = 0.01) and IL-6 (p = 0.003).

CONCLUSIONS

In this report we demonstrated the impact of caffeine on SLE disease activity status, as confirmed by the inverse correlation between its intake and both SLEDAI-2K values and cytokine levels. Moreover, patients with a low caffeine consumption seem to have a more severe disease phenotype.

Host-microbiota interactions in immune-mediated diseases

Host-microbiota interactions are fundamental for the development of the immune system. Drastic changes in modern environments and lifestyles have led to an imbalance of this evolutionarily ancient process, coinciding with a steep rise in immune-mediated diseases such as autoimmune, allergic and chronic inflammatory disorders. There is an urgent need to better understand these diseases in the context of mucosal and skin microbiota. This Review discusses the mechanisms of how the microbiota contributes to the predisposition, initiation and perpetuation of immune-mediated diseases in the context of a genetically prone host. It is timely owing to the wealth of new studies that recently contributed to this field, ranging from metagenomic studies in humans and mechanistic studies of host-microorganism interactions in gnotobiotic models and in vitro systems, to molecular mechanisms with broader implications across immune-mediated diseases. We focus on the general principles, such as breaches in immune tolerance and barriers, leading to the promotion of immune-mediated diseases by gut, oral and skin microbiota. Lastly, the therapeutic avenues that either target the microbiota, the barrier surfaces or the host immune system to restore tolerance and homeostasis will be explored.

Dietary Intake of Free Sugars is Associated with Disease Activity and Dyslipidemia in Systemic Lupus Erythematosus Patients

Diet has been closely associated with inflammatory autoimmune diseases, including systemic lupus erythematosus (SLE). Importantly, the consumption of dietary sugars has been positively linked to elevated levels of some inflammation markers, but the potential role of their consumption on the prognosis of autoimmune diseases has not yet been examined. The aim of this study was to evaluate the association between the dietary intake of free sugars and clinical parameters and cardiovascular (CVD) risk markers in patients with SLE. A cross-sectional study including a total of 193 patients with SLE (aged 48.25 ± 12.54 years) was conducted. The SLE Disease Activity Index (SLEDAI-2K) and the SDI Damage Index were used to asses disease activity and disease-related damage, respectively. Levels of C-reactive protein (CRP; mg/dL), homocysteine (Hcy; µmol/L), anti-double stranded DNA antibodies (anti-dsDNA) (IU/mL), complement C3 (mg/dL), and complement C4 (mg/dL), among other biochemical markers, were measured. The main factors we considered as risk factors for CVD were obesity, diabetes mellitus, hypertension, and blood lipids. The dietary-intrinsic sugar and added-sugar content participants consumed were obtained via a 24-h patient diary. Significant differences were observed in dietary sugar intake between patients with active and inactive SLE (in grams: 28.31 ± 24.43 vs. 38.71 ± 28.87; p = 0.035) and free sugar intake (as a percentage: 6.36 ± 4.82 vs. 8.60 ± 5.51; p = 0.020). Linear regression analysis revealed a significant association between free sugars intake (by gram or percentage) and the number of complications (β (95% CI) = 0.009 (0.001, 0.0018), p = 0.033)); (β (95% CI) = 0.046 (0.008, 0.084), p = 0.018)), and SLEDAI (β (95% CI) = 0.017 (0.001, 0.034), p = 0.043)); (β (95% CI) = 0.086 (0.011, 0.161), p = 0.024)) after adjusting for covariates. Free sugars (g and %) were also associated with the presence of dyslipidaemia (β (95% CI) = −0.003 (−0.005, 0.000), p = 0.024)) and (β (95% CI) = −0.015 (−0.028, −0.002), p = 0.021)). Our findings suggest that a higher consumption of free sugars might negatively impact the activity and complications of SLE. However, future longitudinal research on SLE patients, including dietary intervention trials, are necessary to corroborate these preliminary data.

Nutrition in RMDs: is it really food for thought? Focus on rheumatoid arthritis

Background

The relationship between food and health is known since the antiquity and in the field of rheumatic and musculoskeletal diseases (RMDs), mainly rheumatoid arthritis (RA), a large number of studies has been published over the last 50 years encompassing different aspects of nutrition. This led to postulate a role of nutrients for both primary prevention of RMDs in the general population and secondary prevention of disease flares and complications in patients with an established RMD.

Main body of abstract

We aimed to summarise and critically discuss current evidence on the role of different nutrients and dietary regimens in RMDs with a focus on RA. Over the last years, some seminal papers proved that some compounds, such as salt, can directly modulate the immune system and large epidemiological studies have been linking dietary patters with the risk to develop RMDs. However, physicians' knowledge about the role of diet in disease prevention and treatment is often poor and ultimately diet is rarely perceived as a companion of pharmacological treatment.

Conclusions

Based on the currently available evidence, we are not (yet?) in the phase of putting diet on the same level as pharmacological treatment in RMDs and in particular, RA, but future studies will likely shed additional light on this controversial topic and at least might suggest a value as dietary prevention of risk factors.

Cardiovascular Risk Reduction in High-Risk Pediatric Patients: A Scientific Statement From the American Heart Association

This scientific statement presents considerations for clinical management regarding the assessment and risk reduction of select pediatric populations at high risk for premature cardiovascular disease, including acquired arteriosclerosis or atherosclerosis. For each topic, the evidence for accelerated acquired coronary artery disease and stroke in childhood and adolescence and the evidence for benefit of interventions in youth will be reviewed. Children and adolescents may be at higher risk for cardiovascular disease because of significant atherosclerotic or arteriosclerotic risk factors, high-risk conditions that promote atherosclerosis, or coronary artery or other cardiac or vascular abnormalities that make the individual more vulnerable to the adverse effects of traditional cardiovascular risk factors. Existing scientific statements and guidelines will be referenced when applicable, and suggestions for risk identification and reduction specific to each setting will be described. This statement is directed toward pediatric cardiologists, primary care providers, and subspecialists who provide clinical care for these young patients. The focus will be on management and justification for management, minimizing information on pathophysiology and epidemiology.

Maternal elevated salt consumption and the development of autism spectrum disorder in the offspring

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental condition with no known etiology or cure. Several possible contributing factors, both genetic and environmental, are being actively investigated. Amongst these, maternal immune dysregulation has been identified as potentially involved in promoting ASD in the offspring. Indeed, ASD-like behaviors have been observed in studies using the maternal immune activation mouse model. Furthermore, recent studies have shed light on maternal dietary habits and their impact on the gut microbiome as factors possibly facilitating ASD. However, most of these studies have been limited to the effects of high fat and/or high sugar. More recent data, however, have shown that elevated salt consumption has a significant effect on the immune system and gut microbiome, often resulting in gut dysbiosis and induction of pro-inflammatory pathways. Specifically, high salt alters the gut microbiome and induces the differentiation of T helper-17 cells that produce pro-inflammatory cytokines such as interleukin-17 and interleukin-23. Moreover, elevated salt can also reduce the differentiation of regulatory T cells that help maintaining a balanced immune system. While in the innate immune system, high salt can cause over activation of M1 pro-inflammatory macrophages and downregulation of M2 regulatory macrophages. These changes to the immune system are alarming because excessive consumption of salt is a documented worldwide problem. Thus, in this review, we discuss recent findings on high salt intake, gut microbiome, and immune system dysregulation while proposing a hypothesis to link maternal overconsumption of salt and children’s ASD.

Dietary Bioactive Fatty Acids as Modulators of Immune Function: Implications on Human Health

Diet is major modifiable risk factor for cardiovascular disease that can influence the immune status of the individual and contribute to persistent low-grade inflammation. In recent years, there has been an increased appreciation of the role of polyunsaturated fatty acids (PUFA) in improving immune function and reduction of systemic inflammation via the modulation of pattern recognition receptors (PRR) on immune cells. Extensive research on the use of bioactive lipids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their metabolites have illustrated the importance of these pro-resolving lipid mediators in modulating signaling through PRRs. While their mechanism of action, bioavailability in the blood, and their efficacy for clinical use forms an active area of research, they are found widely administered as marine animal-based supplements like fish oil and krill oil to promote health. The focus of this review will be to discuss the effect of these bioactive fatty acids and their metabolites on immune cells and the resulting inflammatory response, with a brief discussion about modern methods for their analysis using mass spectrometry-based methods.

Targeted Metabolomic Analysis of Serum Fatty Acids for the Prediction of Autoimmune Diseases

Autoimmune diseases (ADs) are rapidly increasing worldwide and accumulating data support a key role of disrupted metabolism in ADs. This study aimed to identify an improved combination of Total Fatty Acids (TFAs) biomarkers as a predictive factor for the presence of autoimmune diseases. A retrospective nested case-control study was conducted in 403 individuals. In the case group, 240 patients diagnosed with rheumatoid arthritis, thyroid disease, multiple sclerosis, vitiligo, psoriasis, inflammatory bowel disease, and other AD were included and compared to 163 healthy individuals. Targeted metabolomic analysis of serum TFAs was performed using GC-MS, and 28 variables were used as input for the predictive models. The primary analysis identified 12 variables that were statistically significantly different between the two groups, and metabolite-metabolite correlation analysis revealed 653 significant correlation coefficients with 90% level of significance (p < 0.05). Three predictive models were developed, namely (a) a logistic regression based on Principal Component Analysis (PCA), (b) a straightforward logistic regression model and (c) an Artificial Neural Network (ANN) model. PCA and straightforward logistic regression analysis, indicated reasonably well adequacy (74.7 and 78.9%, respectively). For the ANN, a model using two hidden layers and 11 variables was developed, resulting in 76.2% total predictive accuracy. The models identified important biomarkers: lauric acid (C12:0), myristic acid (C14:0), stearic acid (C18:0), lignoceric acid (C24:0), palmitic acid (C16:0) and heptadecanoic acid (C17:0) among saturated fatty acids, Cis-10-pentadecanoic acid (C15:1), Cis-11-eicosenoic acid (C20:1n9), and erucic acid (C22:1n9) among monounsaturated fatty acids and the Gamma-linolenic acid (C18:3n6) polyunsaturated fatty acid. The metabolic pathways of the candidate biomarkers are discussed in relation to ADs. The findings indicate that the metabolic profile of serum TFAs is associated with the presence of ADs and can be an adjunct tool for the early diagnosis of ADs.

Polyphenols in the treatment of autoimmune diseases

In addition to protecting body from infections and diseases, the immune system produces auto-antibodies that can cause complex autoimmune disorders, such as Type I diabetes, primary biliary cirrhosis, rheumatoid arthritis, and multiple sclerosis, to name a few. In such cases, the immune system fails to recognize between foreign agents and its own body cells. Different factors, such as genetic factors (CD25, STAT4), epigenetic factors (DNA methylation, histone modifications) and environmental factors (xenobiotics, drugs, hormones) trigger autoimmunity. Glucocorticoids, non-steroidal anti-inflammatory drugs (NSAIDs), immunosuppressive and biological agents are currently used to manage autoimmune diseases of different origins. However, complete cure remains elusive. Many dietary and natural products including polyphenols have been widely studied as possible alternative treatment strategies for the management of autoimmune disorders. Polyphenols possess a wide-range of pharmacological and therapeutic properties, including antioxidant and anti-inflammatory activities. As immunomodulatory agents, polyphenols are emerging pharmaceutical tools for management of various autoimmune disorders including vitiligo, ulcerative colitis and multiple sclerosis (MS). Polyphenols activate intracellular pathways such as arachidonic acid dependent pathway, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway, mitogen-activated protein kinases (MAPKs) pathway, phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway and epigenetic modulation, which regulate the host's immune response. This timely review discusses putative points of action of polyphenols in autoimmune diseases, characterizing their efficacy and safety as therapeutic agents in managing autoimmune disorders.

Interactions between microbiota, diet/nutrients and immune/inflammatory response in rheumatic diseases: focus on rheumatoid arthritis

Rheumatic and musculoskeletal diseases (RMDs) are chronic systemic immune/inflammatory conditions characterized by the interaction between gene predisposition, autoimmunity and environmental factors. A growing scientific interest has focused on the role of diet in RMDs, suggesting its significant contribution to the pathogenesis and prognosis of these diseases. It is now clear that diet can directly modulate the immune response by providing a wide range of nutrients, which interfere with multiple pathways at both the gastro-intestinal and systemic level. Moreover, diet critically shapes the human gut microbiota, which is recognized to have a central role in the modulation of the immune response and in RMD pathogenesis. We hereby provide an in-depth analysis on the role of the microbiota in RMDs and on nutritional intervention as an integral part of a multidisciplinary approach. Particular attention will be given to the Mediterranean diet, as the only diet proven to support substantial benefits in RMD management.

The Impact of Intermittent Fasting (Ramadan Fasting) on Psoriatic Arthritis Disease Activity, Enthesitis, and Dactylitis: A Multicentre Study

Intermittent circadian fasting, namely Ramadan, is a common worldwide practice. Such fasting has a positive impact on psoriasis, but no data exist on its role in psoriatic arthritis (PsA)—a disease that is clearly linked to body mass index. We enrolled 37 patients (23 females and 14 males) with a mean age 43.32 ± 7.81 and they fasted for 17 h for one month in 2016. The baseline PsA characteristics were collected and 12 (32.4%) patients had peripheral arthritis, 13 (35.1%) had axial involvement, 24 (64.9%) had enthesitis, and 13 (35.1%) had dactylitis. Three patients (8.1%) were treated with methotrexate, 28 (75.7%) with TNF-α blockers, and 6 (16.2%) with IL-17 blockers. After a month of intermittent fasting, C-reactive protein (CRP) levels decreased from 14.08 ± 4.65 to 12.16 ± 4.46 (p < 0.0001), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) decreased from 2.83 ± 1.03 to 2.08 ± 0.67 (p = 0.0078), Psoriasis Area Severity Index (PASI) decreased from 7.46 ± 2.43 to 5.86 ± 2.37 (p < 0.0001), and Disease Activity index for PSoriatic Arthritis (DAPSA) decreased from 28.11 ± 4.51 to 25.76 ± 4.48 (p < 0.0001). Similarly, enthesitis improved after fasting, with Leeds Enthesitis Index (LEI) decreasing from 2.25 ± 1.11 to 1.71 ± 0.86 (p < 0.0001) and dactylitis severity score (DSS) decreasing from 9.92 ± 2.93 to 8.54 ± 2.79 (p = 0.0001). Fasting was found to be a predictor of a decrease in PsA disease activity scores (DAPSA, BASDAI, LEI, DSS) even after adjustment for weight loss. IL-17 therapy was found to be an independent predictor of decreases in LEI after fasting. These preliminary data may support the use of chronomedicine in the context of rheumatic diseases, namely PsA. Further studies are needed to support our findings.

Aberrant Expressions of Co-stimulatory and Co-inhibitory Molecules in Autoimmune Diseases

Co-signaling molecules include co-stimulatory and co-inhibitory molecules and play important roles in modulating immune responses. The roles of co-signaling molecules in autoimmune diseases have not been clearly defined. We assessed the expressions of co-stimulatory and co-inhibitory molecules in autoimmune diseases through a bioinformatics-based study. By using datasets of whole-genome transcriptome, the expressions of 54 co-stimulatory or co-inhibitory genes in common autoimmune diseases were analyzed using Robust rank aggregation (RRA) method. Nineteen array datasets and 6 RNA-seq datasets were included in the RRA discovery study and RRA validation study, respectively. Significant genes were further validated in several autoimmune diseases including Graves' disease (GD). RRA discovery study suggested that CD160 was the most significant gene aberrantly expressed in autoimmune diseases (Adjusted P = 5.9E-12), followed by CD58 (Adjusted P = 5.7E-06) and CD244 (Adjusted P = 9.5E-05). RRA validation study also identified CD160 as the most significant gene aberrantly expressed in autoimmune diseases (Adjusted P = 5.9E-09). We further found that the aberrant expression of CD160 was statistically significant in multiple autoimmune diseases including GD (P < 0.05), and CD160 had a moderate role in diagnosing those autoimmune diseases. Flow cytometry confirmed that CD160 was differentially expressed on the surface of CD8⁺ T cells between GD patients and healthy controls (P = 0.002), which proved the aberrant expression of CD160 in GD at the protein level. This study suggests that CD160 is the most significant co-signaling gene aberrantly expressed in autoimmune diseases. Treatment strategy targeting CD160-related pathway may be promising for the therapy of autoimmune diseases.

The Impact of Ramadan Fasting on the Reduction of PASI Score, in Moderate-To-Severe Psoriatic Patients: A Real-Life Multicenter Study

Fasting during the month of Ramadan consists of alternate abstinence and re-feeding periods (circadian or intermittent fasting). Nothing is currently known on the impact of this kind of fasting on psoriasis. A sample of 108 moderate-to-severe plaque psoriasis patients (aged 42.84 ± 13.61 years, 62 males, 46 females) volunteered to take part in the study. A significant decrease in the “Psoriasis Area and Severity Index” (PASI) score after the Ramadan fasting (mean difference = −0.89 ± 1.21, p < 0.0001) was found. At the multivariate regression, the use of cyclosporine (p = 0.0003), interleukin-17 or IL-17 blockers (p < 0.0001), and tumor necrosis factor or TNF blockers (p = 0.0107) was independently associated with a low PASI score, while the use of apremilast (p = 0.0009), and phototherapy (p = 0.0015) was associated with a high PASI score before the Ramadan fasting. Similarly, the consumption of cyclosporine (p < 0.0001), IL-17 blockers (p < 0.0001), mammalian target of rapamycin or mTOR inhibitors (p = 0.0081), and TNF blockers (p = 0.0017) predicted a low PASI score after the Ramadan fasting. By contrast, narrow band ultraviolet light B or NB-UVB (p = 0.0015) was associated with a high PASI score after Ramadan fasting. Disease duration (p = 0.0078), use of apremilast (p = 0.0005), and of mTOR inhibitors (p = 0.0034) were independent predictors of the reduction in the PASI score after the Ramadan fasting. These findings reflect the influence of dieting strategy, the biological clock, and circadian rhythm on the treatment of plaque psoriasis.

Anti-Inflammatory, Antioxidative, and Hepatoprotective Effects of Trans Δ9-Tetrahydrocannabinol/Sesame Oil on Adjuvant-Induced Arthritis in Rats

Rheumatoid arthritis (RA) is a painful chronic autoimmune disease affecting the joints. Its first-line therapy, Methotrexate (MTX), although effective in ameliorating the progress of the disease, induces hepatotoxicity over long-term usage. Thus, seeking natural compounds with fewer side effects could be an alternative therapeutic approach. This study aimed to investigate the anti-inflammatory, antiarthritic, and antioxidative effects of synthetic trans-Δ9-tetrahydrocannabinol (Δ9-THC) dissolved in sesame oil (Dronabinol) against MTX in adjuvant-induced arthritis (AIA) rat model. Daily oral administration of Δ9-THC/sesame oil, over a period of 21 days, was well tolerated in arthritic rats with no particular psychoactive side effects. It markedly attenuated the severity of clinical manifestations, recovered the histopathological changes in tibiotarsal joints, and repressed the splenomegaly in arthritic rats. Δ9-THC/sesame oil therapy showed similar effects to MTX in neutralizing the inflammatory process of AIA, through attenuating erythrocyte sedimentation rate (ESR) scores and proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1β), and interleukin-6 (IL-6) levels, to normal values. As opposed to MTX, this natural combination markedly protected the liver of arthritic rats and downregulated the induced oxidative stress by increasing the antioxidant defense system such as activities of catalase and superoxide dismutase (SOD) and levels of glutathione (GSH). These results suggest promising effects for the clinical use of Δ9-THC/sesame oil therapy in alleviating arthritic clinical signs as well as arthritis-induced liver injury.

Vaccine-induced autoimmunity: the role of molecular mimicry and immune crossreaction

Since the early 1800s vaccines have saved numerous lives by preventing lethal infections. However, during the past two decades, there has been growing awareness of possible adverse events associated with vaccinations, cultivating heated debates and leading to significant fluctuations in vaccination rates. It is therefore pertinent for the scientific community to seriously address public concern of adverse effects of vaccines to regain public trust in these important medical interventions. Such adverse reactions to vaccines may be viewed as a result of the interaction between susceptibility of the vaccinated subject and various vaccine components. Among the implicated mechanisms for these reactions is molecular mimicry. Molecular mimicry refers to a significant similarity between certain pathogenic elements contained in the vaccine and specific human proteins. This similarity may lead to immune crossreactivity, wherein the reaction of the immune system towards the pathogenic antigens may harm the similar human proteins, essentially causing autoimmune disease. In this review, we address the concept of molecular mimicry and its application in explaining post vaccination autoimmune phenomena. We further review the principal examples of the influenza, hepatitis B, and human papilloma virus vaccines, all suspected to induce autoimmunity via molecular mimicry. Finally, we refer to possible implications on the potential future development of better, safer vaccines.

Dietary intervention and health in patients with systemic lupus erythematosus: A systematic review of the evidence

Objective: The aim of this study was to evaluate the scientific evidence of dietary intervention, either through diet or supplementation, and its effects on the health of patients with systemic lupus erythematosus. Methods: Literature searches were conducted using Scopus, PubMed, BioMed Central and Science Direct databases. The terms used for the search were diet, nutritional support, nutrition therapy and systemic lupus erythematosus. Results: Eleven studies with interventions related to supplementation of omega-3 fatty acids, vitamin D and turmeric, as well as changes in diet composition, such as low glycaemic index diet were identified. Conclusions: The studies evidenced that omega-3 supplementation reduced inflammation, disease activity, endothelial dysfunction and oxidative stress; vitamin D supplementation increased serum levels, reduced inflammatory and hemostatic markers; turmeric supplementation reduced proteinuria, hematuria and systolic blood pressure; and low glycaemic index diet caused weight loss and reduced fatigue.

A Potential Benefit of "Balanced Diet" for Rheumatoid Arthritis

Although it is largely unknown how diet might modulate rheumatoid arthritis (RA), dietary interventions, including so-called “low-carbohydrate” diets, may be considered for RA patients because of the high incidence of cardiovascular comorbidity. However, it has been shown that restriction or skewed intake of particular nutrient may alter the components of the intestinal flora. Changes to the gut microbiota or dysbiosis may be relevant to the pathogenesis of RA because the gut microbiota is reported to regulate the T cell phenotype and T cell-mediated immunity. RA patients should be advised that a balanced diet that includes appropriate amounts of carbohydrate, especially dietary fiber, is important for maintaining the symbiosis of intestinal flora, which could be beneficial for preventing autoimmunity. The review attempts to focus current findings regarding the suggested relationship between diet-derived carbohydrate, gut microbiota, and the pathogenesis of RA.

Curcumin, A Polyphenolic Curcuminoid With Its Protective Effects and Molecular Mechanisms in Diabetes and Diabetic Cardiomyopathy

As the leading cause of morbidity and mortality in patients with diabetes, diabetic cardiomyopathy (DCM) imposes enormous burden on individuals and public health. Therapeutic regimes for DCM treatment have proven to be challenging, with limited efficacy, low compliance, and potential adverse effects. Curcumin, as the most active compound derived from the root of turmeric, exhibits strong anti-inflammation, antioxidant, and anti-apoptosis properties. Recently, clinical trials and preclinical studies have shown that curcumin exerts protective effects against a variety of diseases, including diabetes and its cardiovascular complications. In this review, the clinical trials about curcumin supplementation on diabetes and DCM are presented, and the specific mechanisms by which curcumin might mitigate diabetes and DCM are fully discussed. A better understanding of the pharmacological role of curcumin on diabetes and DCM can provide clinical implications for the intervention of the onset and development of diabetes and DCM.

A randomized controlled cross-over trial investigating the effect of anti-inflammatory diet on disease activity and quality of life in rheumatoid arthritis: the Anti-inflammatory Diet In Rheumatoid Arthritis (ADIRA) study protocol

Background

Rheumatoid arthritis (RA) is a chronic inflammatory disease that affects 0.5–1.0% of the population, and where many patients in spite of modern pharmacological treatment fail to reach remission. This affects physical as well as mental wellbeing and leads to severely reduced quality of life and reduced work capacity, thus yielding high individual as well as societal costs. As a complement to modern pharmacological treatment, lifestyle intervention should be evaluated as a treatment option. Scientific evidence exists for anti-inflammatory effects by single foods on RA, but no study exists where these foods have been combined to obtain maximum effect and thus offer a substantial improvement in patient life quality. The main goal of the randomized cross-over trial ADIRA (Anti-inflammatory Diet In Rheumatoid Arthritis) is to test the hypothesis that an anti-inflammatory diet intervention, compared to a regular diet, will decrease disease activity and improve quality of life in patients with stable established RA.

Methods

In total, 50 RA patients with moderate disease activity are randomized to receive initially either a portfolio diet based on several food items with suggested anti-inflammatory effects or a control diet during 2 × 10 weeks with 3 months wash-out between diets. Food bags are delivered weekly by a home food delivery chain and referred to as the fiber bag and the protein bag, respectively, to partially blind participants. Both groups continue with regular pharmacological treatment. Known food biomarkers will be analyzed to measure intervention compliance. Impact on disease severity (measured by DAS28, a composite score which predicts disability and progression of RA), risk markers for cardiovascular disease and quality of life are evaluated after each diet regimen. Metabolomics will be used to evaluate the potential to predict responders to dietary treatment. A health economic evaluation is also included.

Discussion

The nutritional status of patients with RA often is poor and many ask their physician for diet advice. No evidence-based dietary guidelines for patients with RA exist because of the paucity of well-conducted sufficiently large diet intervention trials. ADIRA is an efficacy study and will provide evidence as to whether dietary treatment of RA can reduce disease activity and improve quality of life as well as reduce individual and societal costs.

Trial registration

ClinicalTrials.gov Registration Number: NCT02941055.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0354-x) contains supplementary material, which is available to authorized users.

Increased salt exposure affects both lymphoid and myeloid effector functions, influencing innate-associated disease but not T-cell-associated autoimmunity

High salt consumption has since long been associated with elevated blood pressure and cardiovascular disease. Recently, mouse studies suggested that a high dietary salt intake exacerbates the clinical manifestations of autoimmunity. Using naïve cells ex vivo after pre-exposure of mice to high salt intake, we showed that increased salt exposure affects the viability and effector functions of immune cells. CD4+ T-cells evidenced a pro-inflammatory phenotype characterized by increased secretion of IFNγ and IL-17A, when exposed to high salt concentrations in vitro. Interestingly, this phenotype was associated with osmotic pressure, as replacing salt for d-mannitol resulted in similar observations. However, high salt intake did not alter the development of T-cell-dependent autoimmunity. Instead, recruitment of peritoneal macrophages was increased in mice pre-exposed to high salt concentrations. These cells had an increased production of both TNFα and IL-10, suggesting that salt stimulates expansion and differentiation of different subsets of macrophages. Moreover, mice pre-exposed to high salt intake developed exacerbated symptoms of colitis, when induced by dextran sulphate sodium. The aggravated colitis in salt-exposed animals was associated with a higher frequency of CD4+ T-cells and CD11b+ CD64+ macrophages producing TNFα. These phenotypes correlated with elevated titres of faecal IgA and higher lymphocytic cellularity in the colon, mesenteric lymph nodes and spleen. In conclusion, we report here that high salt intake affects both lymphoid and myeloid cells ex vivo. However, the effects of high salt intake in vivo seem less pronounced in terms of CD4+ T-cell responses, whereas macrophage-dependent pathologies are significantly influenced.

Effect of dark sweet cherry powder consumption on the gut microbiota, short-chain fatty acids, and biomarkers of gut health in obese db/db mice

Cherries are fruits containing fiber and bioactive compounds (e.g., polyphenolics) with the potential of helping patients with diabetes and weight disorders, a phenomenon likely related to changes in the complex host-microbiota milieu. The objective of this study was to investigate the effect of cherry supplementation on the gut bacterial composition, concentrations of caecal short-chain fatty acids (SCFAs) and biomarkers of gut health using an in vivo model of obesity. Obese diabetic (db/db) mice received a supplemented diet with 10% cherry powder (supplemented mice, n = 12) for 12 weeks; obese (n = 10) and lean (n = 10) mice served as controls and received a standard diet without cherry. High-throughput sequencing of the 16S rRNA gene and quantitative real-time PCR (qPCR) were used to analyze the gut microbiota; SCFAs and biomarkers of gut health were also measured using standard techniques. According to 16S sequencing, supplemented mice harbored a distinct colonic microbiota characterized by a higher abundance of mucin-degraders (i.e., Akkermansia) and fiber-degraders (the S24-7 family) as well as lower abundances of Lactobacillus and Enterobacteriaceae. Overall this particular cherry-associated colonic microbiota did not resemble the microbiota in obese or lean controls based on the analysis of weighted and unweighted UniFrac distance metrics. qPCR confirmed some of the results observed in sequencing, thus supporting the notion that cherry supplementation can change the colonic microbiota. Moreover, the SCFAs detected in supplemented mice (caproate, methyl butyrate, propionate, acetate and valerate) exceeded those concentrations detected in obese and lean controls except for butyrate. Despite the changes in microbial composition and SCFAs, most of the assessed biomarkers of inflammation, oxidative stress, and intestinal health in colon tissues and mucosal cells were similar in all obese mice with and without supplementation. This paper shows that dietary supplementation with cherry powder for 12 weeks affects the microbiota and the concentrations of SCFAs in the lower intestinal tract of obese db/db diabetic mice. These effects occurred in absence of differences in most biomarkers of inflammation and other parameters of gut health. Our study prompts more research into the potential clinical implications of cherry consumption as a dietary supplement in diabetic and obese human patients.

Breastfeeding and autoimmunity: Programing health from the beginning

Breast milk is not only a completely adapted nutrition source for the newborn but also an impressive array of immune-active molecules that afford protection against infections and shape mucosal immune responses. Decisive imprinting events might be modulated during the first months of life with potential health long-term effects, enhancing the importance of breastfeeding as a major influence on the immune system correct development and modifying disease susceptibility. The aim of this review was to clarify the link between breastfeeding and autoimmune diseases, inquiring the related mechanisms, based on data available in the literature. Being breastfed was associated with a lower incidence of diabetes, celiac disease, multiple sclerosis and asthma, explained by the protection against early infections, anti-inflammatory properties, antigen-specific tolerance induction, and regulation of infant's microbiome. The protective role of human milk in idiopathic juvenile arthritis, rheumatoid arthritis, and inflammatory bowel diseases remains controversial. On the other hand, the breastfeeding mother faces a health-challenging period in life. High levels of prolactin may lead either to the development of autoimmune diseases in susceptible mothers or exacerbations of current immune-mediated disorders. These features raise the question if mothers with autoimmune diseases, mainly systemic lupus erythematosus, should avoid breastfeeding.

The Gut Microbiome Feelings of the Brain: A Perspective for Non-Microbiologists

Objectives: To comprehensively review the scientific knowledge on the gut-brain axis. Methods: Various publications on the gut-brain axis, until 31 July 2017, were screened using the Medline, Google, and Cochrane Library databases. The search was performed using the following keywords: "gut-brain axis", "gut-microbiota-brain axis", "nutrition microbiome/microbiota", "enteric nervous system", "enteric glial cells/network", "gut-brain pathways", "microbiome immune system", "microbiome neuroendocrine system" and "intestinal/gut/enteric neuropeptides". Relevant articles were selected and reviewed. Results: Tremendous progress has been made in exploring the interactions between nutrients, the microbiome, and the intestinal, epithelium-enteric nervous, endocrine and immune systems and the brain. The basis of the gut-brain axis comprises of an array of multichannel sensing and trafficking pathways that are suggested to convey the enteric signals to the brain. These are mediated by neuroanatomy (represented by the vagal and spinal afferent neurons), the neuroendocrine-hypothalamic-pituitary-adrenal (HPA) axis (represented by the gut hormones), immune routes (represented by multiple cytokines), microbially-derived neurotransmitters, and finally the gate keepers of the intestinal and brain barriers. Their mutual and harmonious but intricate interaction is essential for human life and brain performance. However, a failure in the interaction leads to a number of inflammatory-, autoimmune-, neurodegenerative-, metabolic-, mood-, behavioral-, cognitive-, autism-spectrum-, stress- and pain-related disorders. The limited availability of information on the mechanisms, pathways and cause-and-effect relationships hinders us from translating and implementing the knowledge from the bench to the clinic. Implications: Further understanding of this intricate field might potentially shed light on novel preventive and therapeutic strategies to combat these disorders. Nutritional approaches, microbiome manipulations, enteric and brain barrier reinforcement and sensing and trafficking modulation might improve physical and mental health outcomes.

Coffee and autoimmunity: More than a mere hot beverage!

Coffee is one of the world's most consumed beverage. In the last decades, coffee consumption has attracted a huge body of research due to its impact on health. Recent scientific evidences showed that coffee intake could be associated with decreased mortality from cardiovascular and neurological diseases, diabetes type II, as well as from endometrial and liver cancer, among others. In this review, on the basis of available data in the literature, we aimed to investigate the association between coffee intake and its influence on the immune system and the insurgence of the most relevant autoimmune diseases. While some studies reported conflicting results, general trends have been identified. Coffee consumption seems to increase the risk of developing rheumatoid arthritis (RA) and type 1 diabetes mellitus (T1DM). By contrast, coffee consumption may exert a protective role against multiple sclerosis, primary sclerosing cholangitis, and ulcerative colitis. Concerning other autoimmune diseases such as systemic lupus erythematosus, psoriasis, primary biliary cholangitis and Crohn's disease, no significant association was found. In other studies, coffee consumption was shown to influence disease course and management options. Coffee intake led to a decrease in insulin sensitivity in T1DM, in methotrexate efficacy in RA, and in levothyroxine absorption in Hashimoto's disease. Further, coffee consumption was associated with cross reactivity with gliadin antibodies in celiac patients. Data on certain autoimmune diseases like systemic sclerosis, Sjögren's syndrome, and Behçet's disease, among others, are lacking in the existent literature. As such, further research is warranted.