Decrease in anti-Proteus mirabilis but not anti-Escherichia coli antibody levels in rheumatoid arthritis patients treated with fasting and a one year vegetarian diet

Efficacy of therapeutic fasting and plant-based diet in patients with rheumatoid arthritis (NutriFast): study protocol for a randomised controlled clinical trial

BACKGROUND

Previous studies have shown beneficial effects of therapeutic fasting and plant-based dietary interventions on disease activity in patients with rheumatoid arthritis (RA) for a duration of up to 1 year. To date, the effects of such interventions on the gut microbiome and on modern diagnostic markers in patients with RA have not been studied. This trial aims to investigate the clinical effects of therapeutic fasting and a plant-based diet in patients with RA, additionally considering current immunological diagnostic tools and microbiome analyses.

METHODS/DESIGN

This trial is an open-label, single-centre, randomised, controlled, parallel-group clinical trial. We will randomly assign 84 patients with RA under a stable standard therapy to either (1) therapeutic fasting followed by a plant-based dietary intervention or (2) to a conventional nutritional counselling focusing on an anti-inflammatory dietary pattern according to the recommendations of the Deutsche Gesellschaft für Ernährung (German society for nutrition). Primary outcome parameter is the group difference from baseline to 12 weeks on the Health Assessment Questionnaire (HAQ). Other secondary outcomes include established clinical criteria for disease activity and treatment response in RA (Disease Activity Score 28, Simple Disease Activity Index, ACR-Response Criteria), changes in self-reported health and physical functional ability, mood, stress, quality of life, dietary behaviour via 3-day food records and a modified Food Frequency Questionnaire, body composition, changes in the gut microbiome, metabolomics and cytometric parameters. Outcomes will be assessed at baseline and day 7, after 6 weeks, 12 weeks and after 6 months.

ETHICS AND DISSEMINATION

Ethical approval to process and analyse data, and to publish the results was obtained through the institutional review board of Charité-Universitätsmedizin Berlin. Results of this trial will be disseminated through peer-reviewed publications and scientific presentations.

TRIAL REGISTRATION NUMBER

NCT03856190.

RNA and CRISPR Interferences: Past, Present, and Future Perspectives

RNA interference (RNAi), a natural gene silencing process, is a widely used technique in basic research, preclinical studies, and drug development strategies. Although the technique has great potential to generate new human therapies and treat undruggable diseases, the clinical application of RNAi is still challenging primarily because of the delivery problem and potential off-target effects. Over the past two decades, great efforts have been undertaken to develop delivery agents and chemical modifications to overcome these challenges. Such advances in RNA delivery and chemical modifications have benefited researchers who are developing gene-editing therapies based on CRISPR-Cas9, an RNA-guided endonuclease, which is already having a major impact on biology and medicine. Here, I review the discovery of these two interference tools, identify the technical challenges yet to be overcome and provide some perspectives on how these two RNA-based technologies can be harnessed to treat human diseases.

Changes in human gut microbiota composition are linked to the energy metabolic switch during 10 d of Buchinger fasting

Fasting is increasingly popular to manage metabolic and inflammatory diseases. Despite the role that the human gut microbiota plays in health and diseases, little is known about its composition and functional capacity during prolonged fasting when the external nutrient supply is reduced or suppressed. We analysed the effects of a 10-d periodic fasting on the faecal microbiota of fifteen healthy men. Participants fasted according to the peer-reviewed Buchinger fasting guidelines, which involve a daily energy intake of about 1046 kJ (250 kcal) and an enema every 2 d. Serum biochemistry confirmed the metabolic switch from carbohydrates to fatty acids and ketones. Emotional and physical well-being were enhanced. Faecal 16S rRNA gene amplicon sequencing showed that fasting caused a decrease in the abundance of bacteria known to degrade dietary polysaccharides such as Lachnospiraceae and Ruminococcaceae. There was a concomitant increase in Bacteroidetes and Proteobacteria (Escherichia coli and Bilophila wadsworthia), known to use host-derived energy substrates. Changes in taxa abundance were associated with serum glucose and faecal branched-chain amino acids (BCAA), suggesting that fasting-induced changes in the gut microbiota are associated with host energy metabolism. These effects were reversed after 3 months. SCFA levels were unchanged at the end of the fasting. We also monitored intestinal permeability and inflammatory status. IL-6, IL-10, interferon γ and TNFα levels increased when food was reintroduced, suggesting a reactivation of the postprandial immune response. We suggest that changes in the gut microbiota are part of the physiological adaptations to a 10-d periodic fasting, potentially influencing its beneficial health effects.

Individuality, phenotypic differentiation, dormancy and 'persistence' in culturable bacterial systems: commonalities shared by environmental, laboratory, and clinical microbiology

For bacteria, replication mainly involves growth by binary fission. However, in a very great many natural environments there are examples of phenotypically dormant, non-growing cells that do not replicate immediately and that are phenotypically 'nonculturable' on media that normally admit their growth. They thereby evade detection by conventional culture-based methods. Such dormant cells may also be observed in laboratory cultures and in clinical microbiology. They are usually more tolerant to stresses such as antibiotics, and in clinical microbiology they are typically referred to as 'persisters'. Bacterial cultures necessarily share a great deal of relatedness, and inclusive fitness theory implies that there are conceptual evolutionary advantages in trading a variation in growth rate against its mean, equivalent to hedging one's bets. There is much evidence that bacteria exploit this strategy widely. We here bring together data that show the commonality of these phenomena across environmental, laboratory and clinical microbiology. Considerable evidence, using methods similar to those common in environmental microbiology, now suggests that many supposedly non-communicable, chronic and inflammatory diseases are exacerbated (if not indeed largely caused) by the presence of dormant or persistent bacteria (the ability of whose components to cause inflammation is well known). This dormancy (and resuscitation therefrom) often reflects the extent of the availability of free iron. Together, these phenomena can provide a ready explanation for the continuing inflammation common to such chronic diseases and its correlation with iron dysregulation. This implies that measures designed to assess and to inhibit or remove such organisms (or their access to iron) might be of much therapeutic benefit.

Individuality, phenotypic differentiation, dormancy and 'persistence' in culturable bacterial systems: commonalities shared by environmental, laboratory, and clinical microbiology

For bacteria, replication mainly involves growth by binary fission. However, in a very great many natural environments there are examples of phenotypically dormant, non-growing cells that do not replicate immediately and that are phenotypically 'nonculturable' on media that normally admit their growth. They thereby evade detection by conventional culture-based methods. Such dormant cells may also be observed in laboratory cultures and in clinical microbiology. They are usually more tolerant to stresses such as antibiotics, and in clinical microbiology they are typically referred to as 'persisters'. Bacterial cultures necessarily share a great deal of relatedness, and inclusive fitness theory implies that there are conceptual evolutionary advantages in trading a variation in growth rate against its mean, equivalent to hedging one's bets. There is much evidence that bacteria exploit this strategy widely. We here bring together data that show the commonality of these phenomena across environmental, laboratory and clinical microbiology. Considerable evidence, using methods similar to those common in environmental microbiology, now suggests that many supposedly non-communicable, chronic and inflammatory diseases are exacerbated (if not indeed largely caused) by the presence of dormant or persistent bacteria (the ability of whose components to cause inflammation is well known). This dormancy (and resuscitation therefrom) often reflects the extent of the availability of free iron. Together, these phenomena can provide a ready explanation for the continuing inflammation common to such chronic diseases and its correlation with iron dysregulation. This implies that measures designed to assess and to inhibit or remove such organisms (or their access to iron) might be of much therapeutic benefit.

Rheumatoid arthritis is caused by a Proteus urinary tract infection

Genetic, molecular and biological studies indicate that rheumatoid arthritis (RA), a severe arthritic disorder affecting approximately 1% of the population in developed countries, is caused by an upper urinary tract infection by the microbe, Proteus mirabilis. Elevated levels of specific antibodies against Proteus bacteria have been reported from 16 different countries. The pathogenetic mechanism involves six stages triggered by cross-reactive autoantibodies evoked by Proteus infection. The causative amino acid sequences of Proteus namely, ESRRAL and IRRET, contain arginine doublets which can be acted upon by peptidyl arginine deiminase thereby explaining the early appearance of anti-citrullinated protein antibodies in patients with RA. Consequently, RA patients should be treated early with anti-Proteus antibiotics as well as biological agents to avoid irreversible joint damages.

Microbial Infection and Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a complex autoimmune disease affecting 1–2% of general worldwide population. The etiopathogenesis of RA involves the interplay of multiple genetic risk factors and environmental triggers. Microbial infections are believed to play an important role in the initiation and perpetuation of RA. Recent clinical studies have shown the association of microbial infections with RA. Accumulated studies using animal models have also found that microbial infections can induce and/or exaggerate the symptoms of experimental arthritis. In this review, we have identified the most common microbial infections associated with RA in the literature and summarized the current evidence supporting their pathogenic role in RA. We also discussed the potential mechanisms whereby infection may promote the development of RA, such as generation of neo-autoantigens, induction of loss of tolerance by molecular mimicry, and bystander activation of the immune system.

Rheumatoid arthritis, Proteus, anti-CCP antibodies and Karl Popper

Rheumatoid arthritis (RA) is a crippling joint disease affecting over 20 million people worldwide. The cause of RA is most probably linked to the triad of microbial trigger, genetic association and autoimmunity and can be explained using the philosophical method of Karl Popper or Popperian sequences. Ten "Popper sequences" have been identified which point to the urinary microbe Proteus mirabilis as the cause of RA: Popper sequence 1 establishes that HLA-DR4 lymphocytes injected into a rabbit evoke specific antibodies against Proteus bacteria. Popper sequence 2 establishes that antibodies to Proteus bacteria are present in RA patients from 14 different countries. Popper sequence 3 establishes that antibodies to Proteus bacteria in RA patients are disease specific since no such antibodies are found in other conditions. Popper sequence 4 establishes that when RA patients have high titres of antibodies to Proteus such bacteria are found in urinary cultures. Popper sequence 5 establishes that only Proteus bacteria and no other microbes evoke significantly elevated antibodies in RA patients. Popper sequence 6 establishes that the "shared epitope" EQR(K)RAA shows "molecular mimicry" with the sequence ESRRAL found in Proteus haemolysin. Popper sequence 7 establishes that Proteus urease contains a sequence IRRET which has "molecular mimicry" with LRREI found in collagen XI of hyaline cartilage. Popper sequence 8 establishes that sera obtained from RA patients have cytopathic properties against sheep red cells coated with the cross-reacting EQR(K)RAA and LRREI self-antigen peptides. Popper sequence 9 establishes that Proteus sequences in haemolysin and urease as well as the self antigens, HLA-DR1/4 and collagen XI, each contain an arginine doublet, thereby providing a substrate for peptidyl arginine deiminase (PAD) to give rise to citrulline, which is the main antigenic component of CCP, antibodies to which are found in early cases of RA. Popper sequence 10 establishes that antibodies to Proteus come not only from sequences crossreacting to self antigens but also from non-crossreacting sequences, thereby indicating that active RA patients have been exposed to infection by Proteus. The ten Popper sequences establish that RA is most probably caused by Proteus upper urinary tract infections, which can possibly be treated with anti-Proteus therapy.

Rheumatoid arthritis is an autoimmune disease triggered by Proteus urinary tract infection

Rheumatoid arthritis (RA) is a chronic and disabling polyarthritic disease, which affects mainly women in middle and old age. Extensive evidence based on the results of various microbial, immunological and molecular studies from different parts of the world, shows that a strong link exists between Proteus mirabilis microbes and RA. We propose that sub-clinical Proteus urinary tract infections are the main triggering factors and that the presence of molecular mimicry and cross-reactivity between these bacteria and RA-targeted tissue antigens assists in the perpetuation of the disease process through production of cytopathic auto-antibodies. Patients with RA especially during the early stages of the disease could benefit from Proteus anti-bacterial measures involving the use of antibiotics, vegetarian diets and high intake of water and fruit juices such as cranberry juice in addition to the currently employed treatments.

Diet and rheumatoid arthritis: a review of the literature

INTRODUCTION

Rheumatoid arthritis is a common inflammatory condition. A large number of patients seek alternative or complementary therapies of which diet is an important component. This article reviews the evidence for diet in rheumatoid arthritis along with the associated concept of oral tolerization.

METHODS

References were taken from Medline from 1966 to September 2004. The keywords, rheumatoid arthritis, diet, n-3 fatty acids, vitamins, and oral tolerization, were used.

RESULTS

Randomized controlled trials (RCTs) indicate that dietary supplementation with n-3 fatty acids provides modest symptomatic benefit in groups of patients with rheumatoid arthritis. Epidemiological studies and RCTs show cardiovascular benefits in the broader population and patients with ischemic heart disease. A number of mechanisms through which n-3 fats may reduce inflammation have been identified. In a small number of patients with rheumatoid arthritis, other dietary manipulation such as fasting, vegan, and elimination diets may have some benefit. However, many of these diets are impractical or difficult to sustain long term.

CONCLUSIONS

Dietary manipulation provides a means by which patients can a regain a sense of control over their disease. Dietary n-3 supplementation is practical and can be easily achieved with encapsulated or, less expensively, bottled fish oil.

Genetic diversity in Proteus mirabilis isolates found in the urinary tract of rheumatoid arthritis patients

OBJECTIVE

Elevated levels of anti-Proteus antibodies but not antibodies to E. coli have been reported in patients with rheumatoid arthritis (RA). The suggestion has been made that P. mirabilis may have a role in the aetiopathogenesis of rheumatoid arthritis. The aim of this study was to determine whether there are differences at the genetic level inisolates of P. mirabilis obtained from controls and RA patients.

METHODS

A blind study was performed whereby P. mirabilis isolates obtained from urinary cultures of RA patients and controls were analysed using RAPD PCR. Isolates were then grouped on the basis of their DNA band profile after agarose gel electrophoresis, thereby allowing the composition of the Proteus population in the urinary tract to be analysed at the genetic level.

RESULTS

Fourteen different DNA band profiles were obtained from the 93 isolates tested: 70% of these isolates fell into only five of the 14 groups and approximately 25% of all isolates fell into one group. No differences were observed in the frequency of isolates from either control or RA subjects.

CONCLUSIONS

There is genetic diversity in P. mirabilis populations found in the urinary tract, but there are no differences in the frequency of these bacteria between RA patients and controls.

Molecular mimicry between HLA-DR alleles associated with rheumatoid arthritis and Proteus mirabilis as the Aetiological basis for autoimmunity

Molecular mimicry is one of the pathological mechanisms proposed to explain the association between microorganisms and autoimmune diseases. This review deals with the association between bacteria and rheumatic diseases with a special emphasis on rheumatoid arthritis where upper urinary tract infection by Proteus mirabilis is the possible cause of this severe, arthritic condition. Prospective trials involving anti-Proteus therapy should be carried out.

Diets, dietary supplements, and nutritional therapies in rheumatic diseases

Rheumatoid arthritis and many other systemic rheumatic diseases remain illnesses of unknown cause for which current therapy is often inadequate. This leads patients to seek questionable remedies, prominent among which are dietary manipulations. Is there a role for dietary modifications in the routine therapy for patients with rheumatic diseases? This article discusses the relationships between diets, fasting, elemental nutrition, vitamins, minerals, and foods for rheumatic diseases. Known scientific-based evidence for the use, safety, and efficacy of diets and dietary-related practices subscribed by patients with rheumatic diseases are presented. Studies that link diet with arthritis offer the possibility of identifying new therapeutic approaches for selected patients and of developing new insights to disease pathogenesis. Dietary therapy for arthritis, however, is still being investigated.

Rheumatoid arthritis treated with vegetarian diets

The notion that dietary factors may influence rheumatoid arthritis (RA) has been a part of the folklore of the disease, but scientific support for this has been sparse. In a controlled, single-blind trial we tested the effect of fasting for 7-10 d, then consuming an individually adjusted, gluten-free, vegan diet for 3.5 mo, and then consuming an individually adjusted lactovegetarian diet for 9 mo on patients with RA. For all clinical variables and most laboratory variables measured, the 27 patients in the fasting and vegetarian diet groups improved significantly compared with the 26 patients in the control group who followed their usual omnivorous diet throughout the study period. One year after the patients completed the trial, they were reexamined. Compared with baseline, the improvements measured were significantly greater in the vegetarians who previously benefited from the diet (diet responders) than in diet nonresponders and omnivores. The beneficial effect could not be explained by patients' psychologic characteristics, antibody activity against food antigens, or changes in concentrations of prostaglandin and leukotriene precursors. However, the fecal flora differed significantly between samples collected at time points at which there was substantial clinical improvement and time points at which there were no or only minor improvements. In summary, the results show that some patients with RA can benefit from a fasting period followed by a vegetarian diet. Thus, dietary treatment may be a valuable adjunct to the ordinary therapeutic armamentarium for RA.

Cross-reactivity between the rheumatoid arthritis-associated motif EQKRAA and structurally related sequences found in Proteus mirabilis

Cross-reactivity or molecular mimicry may be one of the underlying mechanisms involved in the etiopathogenesis of rheumatoid arthritis (RA). Antiserum against the RA susceptibility sequence EQKRAA was shown to bind to a similar peptide ESRRAL present in the hemolysin of the gram-negative bacterium Proteus mirabilis, and an anti-ESRRAL serum reacted with EQKRAA. There was no reactivity with either anti-EQKRAA or anti-ESRRAL to a peptide containing the EDERAA sequence which is present in HLA-DRB1*0402, an allele not associated with RA. Furthermore, the EQKRAA and ESRRAL antisera bound to a mouse fibroblast transfectant cell line (Dap.3) expressing HLA-DRB1*0401 but not to DRB1*0402. However, peptide sequences structurally related to the RA susceptibility motif LEIEKDFTTYGEE (P. mirabilis urease), VEIRAEGNRFTY (collagen type II) and DELSPETSPYVKE (collagen type XI) did not bind significantly to cell lines expressing HLA-DRB1*0401 or HLA-DRB1*0402 compared to the control peptide YASGASGASGAS. It is suggested here that molecular mimicry between HLA alleles associated with RA and P. mirabilis may be relevant in the etiopathogenesis of the disease.

Food sensitivity and rheumatoid arthritis

The majority of double-blind placebo-controlled trials have shown that 30-40% of rheumatoid arthritis (RA) patients can improve substantially by using an elimination diet to identify foods that precipitate symptoms and the avoiding of these foods. Some such patients have discontinued drug treatment and remained well for 12 years or more. Prior to the elimination diet, most patients had not recognised diet as a trigger for their symptoms, because the offending foods were eaten daily. (Foods eaten infrequently can also provoke sensitivity, resulting in episodic arthritis.) Additionally, many RA patients are sensitive to several foods, making a rigorous elimination diet essential for diagnosis. The pattern of response to an elimination diet (30-40% of RA patients respond well; response occurs within 10-21 days; benefits are maintained if offending foods are avoided) is markedly different from the pattern of response to a fast (almost all RA patients respond well; response occurs within 3-5 days; benefits are lost rapidly when a normal diet is resumed). Clearly fasting and the elimination diet have different therapeutic mechanisms. The effect of fasting may be mediated by the absence of dietary fat, leading to a shortage of pro-inflammatory prostaglandins and leukotrienes. The mechanism by which food sensitivity is involved in rheumatoid arthritis remains unknown, but weight loss is definitely not responsible for the improvement seen on an elimination diet. Some evidence implicates the gut flora. Food-sensitive RA patients may also show changes in immune parameters during an elimination diet, but no consistent universal change has yet been found.

Molecular mimicry: the geographical distribution of immune responses to Klebsiella in ankylosing spondylitis and its relevance to therapy

The discovery that HLA-B27 is linked to ankylosing spondylitis (AS) and HLA-DR1/DR4 to rheumatoid arthritis (RA) has provided new approaches to the study of the possible causation of these diseases. Several theories have been proposed to explain these associations but only one, namely "molecular mimicry", has provided a specific aetiological agent for each of these diseases. Molecular mimicry between HLA-B27 and two molecules in Klebsiella microbes: nitrogenase and pullulanase D has been reported whilst in Proteus microbes, the haemolysin molecule shows sterochemical similarity to HLA-DR1/DR4. Elevated immune responses to Klebsiella microbes have been demonstrated in AS patients from 10 different countries and this wide geographical distribution suggests that the same aetiological agent is probably acting in producing this condition. Furthermore RA patients show similar immune responses to Proteus microbes. Whether AS or RA are caused by these bacteria can only be resolved by tissue typing all rheumatological patients early, in the course of their disease and then assessing their response to antibiotic chemotherapy in longitudinal studies involving double-blind crossover trials. It is possible that in the future, the course of AS or even RA could be modified by adequate antibiotic chemotherapy or even diets which affect the substrates on which these bacteria grow.

The specificity of the anti-Proteus antibody response in tissue-typed rheumatoid arthritis (RA) patients from Brest

Anti-Proteus mirabilis antibody titres were found to be elevated in 50 active tissue-typed French rheumatoid arthritis (RA) patients from Brest when compared to 49 healthy French controls using enzyme-linked immunosorbent assay (ELISA; P < 0.001) and indirect immunofluorescence assay (IIFA; P < 0.001). However, there was no significant elevation in antibody titres against Escherichia coli or Salmonella typhimurium in the RA patients compared to the controls when measured by ELISA. Serum levels of C-reactive protein (CRP) were also found to be significantly higher in RA patients when compared to healthy control subjects (P < 0.001). These results suggest that P. mirabilis may play an important and specific role in the triggering and persistence of RA.