Lupus gut microbiota transplants cause autoimmunity and inflammation

Lactobacillus rhamnosus LC-STH-13 ameliorates the progression of SLE in MRL/lpr mice by inhibiting the TLR9/NF-κB signaling pathway

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease often treated with glucocorticoids, which can lead to complications such as osteoporosis and an increased infection risk. Hence, identifying safe and effective treatment strategies is crucial. Lactobacillus has shown promise in improving immune disorders. We investigated Lactobacillus rhamnosus LC-STH-13 for its probiotic properties. Female MRL/lpr mice, prone to lupus, were used to assess its impact on SLE development. The results showed that the intervention with L. rhamnosus LC-STH-13 significantly reduced the level of circulating anti-autoantibodies (p < 0.05) and rebalanced Th17/Treg cells (p < 0.05). Kidney tissue analysis revealed reduced immune cell infiltration and immune complex deposition in glomeruli. L. rhamnosus LC-STH-13 mitigated kidney inflammation via the TLR9/NF-κB pathway (p < 0.05) and attenuated complement-induced renal damage (p < 0.05). Furthermore, 16S rRNA sequencing data analysis indicated that L. rhamnosus LC-STH-13 can restore intestinal microecological imbalance caused by the development of SLE. These findings suggested that L. rhamnosus LC-STH-13 improves the development of SLE by regulating the TLR9/NF-κB pathway and intestinal microbiota, offering a foundation for exploring safe and effective treatments.

Associations of gut microbiota with disease development, disease activity, and therapeutic effects in patients with systemic lupus erythematosus

Altered gut microbiota is linked to systemic lupus erythematosus (SLE), but its association with disease development, disease activity, and post-intervention changes remains unclear. We compared new-onset SLE (NOSLE, n = 25), SLE in remission (RemSLE, n = 30), and healthy controls (HC, n = 30) cross-sectionally and conducted the first longitudinal analysis of NOSLE patients (n = 22) from pre-intervention to remission over 12 months. Significant β-diversity differences were observed in both NOSLE and RemSLE compared to HC, but not between NOSLE and RemSLE. Only four operational taxonomic units (OTUs) were enriched in NOSLE versus HC. However, 26 OTUs, including butyrate-producing bacteria (BPB), were depleted, and seven (including five BPBs) remained depleted in RemSLE compared to HC. OTUs positively and negatively correlated with disease activity were also identified. Longitudinal analysis revealed a reversal of several OTUs altered at onset and an increase in Streptococci, unrelated to the disease. Significant β-diversity differences were observed in patients with anti-SSA or anti-RNP antibodies and those with complement reduction compared to their counterparts. Our study identified gut microbiota alterations, including BPB depletion, in SLE regardless of onset or remission status, bacteria linked to disease activity, and a reversal of disease-associated bacteria along with the enrichment of Streptococci through intervention.

The role of gut microbiota in different murine models of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by immune system dysfunction that can lead to serious health issues and mortality. Recent investigations highlight the role of gut microbiota alterations in modulating inflammation and disease severity in SLE. This review specifically summaries the variations in gut microbiota composition across various murine models of lupus. By focusing on these differences, we aim to elucidate the intricate relationship between gut microbiota dysbiosis and the development and progression of SLE in preclinical settings.

Fecal microbiota transplantation for the treatment of chronic inflammatory skin diseases

The regulation of immune functions and the maintenance of homeostasis in the internal environment are both integral to human gut microbiota (GM). If GM is disturbed, it can result in a range of autoimmune diseases, including chronic inflammatory skin conditions. Chronic inflammatory skin diseases driven by T or B-cell-mediated immune reactions are complex, including the most prevalent diseases and some rare diseases. Expanding knowledge of GM dysbiosis in chronic inflammatory skin diseases has emerged. The GM has some causal roles in the pathogenesis of these skin conditions. Targeting microbiota treatment, particularly fecal microbiota transplantation (FMT), is considered to be a promising strategy. FMT was commonly used in intestinal diseases by reshaping and balancing GM, serving as a reasonable administration in these skin inflammatory diseases. This paper summarizes the existing knowledge of GM dysbiosis in chronic inflammatory skin diseases and the research data on FMT treatment for such conditions.

The influence and therapeutic effect of microbiota in systemic lupus erythematosus

Systemic erythematosus lupus (SLE) is an autoimmune disease involving multiple organs that poses a serious risk to the health and life of patients. A growing number of studies have shown that commensals from different parts of the body and exogenous pathogens are involved in SLE progression, causing barrier disruption and immune dysregulation through multiple mechanisms. However, they sometimes alleviate the symptoms of SLE. Many factors, such as genetic susceptibility, metabolism, impaired barriers, food, and sex hormones, are involved in SLE, and the microbiota drives the development of SLE either by depending on or interacting with these factors. Among these, the crosstalk between genetic susceptibility, metabolism, and microbiota is a hot topic of research and is expected to lay the groundwork for the amelioration of the mechanism, diagnosis, and treatment of SLE. Furthermore, the microbiota has great potential for the treatment of SLE. Ideally, personalised therapeutic approaches should be developed in combination with more specific diagnostic methods. Herein, we provide a comprehensive overview of the role and mechanism of microbiota in lupus of the intestine, oral cavity, skin, and kidney, as well as the therapeutic potential of the microbiota.

A Scoping Review of the Positive and Negative Bacteria Associated With the Gut Microbiomes of Systemic Lupus Erythematosus Patients

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple systems of the body. Recent research on the gut microbiota dysbiosis associated with SLE patients has gained traction and warranted further exploration. It has not been determined whether the change in the gut microbiota is a cause of SLE or a symptom of SLE. However, based on the physiological and pathophysiological role of the bacteria in the gut microbiome, as levels of the bacteria rise or fall, symptomatology in SLE patients could be affected. This review analyzes the recent studies that examined the changes in the gut microbiota of SLE patients and highlights the correlations between gut dysbiosis and the clinical manifestations of SLE. A systematic search strategy was developed by combining the terms "SLE," "systemic lupus erythematosus," and "gut microbiome." Biomedical Reference Collection, CINAHL, Medline ProQuest, and PubMed Central databases were searched by combining the appropriate keywords with "AND." Only full-text, English-language articles were searched. The articles were restricted from 2013 to 2023. Only peer-reviewed controlled studies with both human and animal trials were included in this scoping review. Review articles, non-English articles, editorials, case studies, and duplicate articles from the four databases were excluded. Various species of bacteria were found to be positively or negatively associated with SLE gut microbiomes. Among the bacterial species increased were Clostridium, Lactobacilli, Streptococcus, Enterobacter, and Klebsiella. The bacterial species that decreased were Bifidobacteria, Prevotella, and the Firmicutes/Bacteroidetes ratio. Literature shows that Clostridium is one of several bacteria found in abundance, from pre-disease to the diseased state of SLE. Lachnospiraceae and Ruminococcaceae are both part of the family of butyrate-producing anaerobes that are known for their role in strengthening the skin barrier function and, therefore, may explain the cutaneous manifestations of SLE patients. Studies have also shown that the Firmicutes/Bacteroidetes ratio is significantly depressed, which may lead to appetite changes and weight loss seen in SLE patients. Based on the established role of these bacteria within the gut microbiome, the disruption in the gut ecosystem could explain the symptomatology common in SLE patients. By addressing these changes, our scoping review encourages further research to establish a true causal relationship between the bacterial changes in SLE patients as well as furthering the scope of microbiota changes in other systems and autoimmune diseases.

Asiaticoside ameliorates DSS-induced colitis in mice by inhibiting inflammatory response, protecting intestinal barrier and regulating intestinal microecology

Ulcerative colitis (UC) is one of the most prevalent inflammatory bowel diseases and poses a serious threat to human health. Currently, safe and effective preventive measures are unavailable. In this study, the protective effects of asiaticoside (AS) on dextran sodium sulfate (DSS)-induced colitis in mice and the underlying molecular mechanism were investigated. In this experiment, colitis was induced in mice with DSS. Subsequently, the role of AS in colitis and its underlying mechanisms were examined using H&E staining, immunofluorescence staining, western blot, Elisa, FMT, and other assays. The results showed that AS significantly attenuated the related symptoms of DSS-induced colitis in mice. In addition, AS inhibited the activation of signaling pathways TLR4/NF-κB and MAPK reduced the release of inflammatory factors, thereby attenuating the inflammatory response in mice. AS administration also restored the permeability of the intestinal barrier by increasing the levels of tight junction-associated proteins (claudin-3, occludin, and ZO-1). In addition, AS rebalanced the intestinal flora of DSS-treated mice by increasing the diversity of the flora. AS can alleviate DSS-induced ulcerative colitis in mice by maintaining the intestinal barrier, thus inhibiting the signaling pathways TLR4/NF-κB and MAPK activation, reducing the release of inflammatory factors, and regulating intestinal microecology.

Microbiome dynamics in rheumatic diseases

PURPOSE OF REVIEW

Rheumatic disease are characterized by their autoimmune nature, frequently affecting joints, bones, muscles, blood vessels, and connective tissues. The onset of these conditions typically unfolds gradually and subtly. It is noteworthy that individuals with rheumatic diseases often experience shifts in their microbiome, specifically on mucosal surfaces. The purpose of this review is to delve into the intricate interplay between the microbiome, encompassing bacteria, viruses and fungi, and its role in the development and aggravation of various rheumatic diseases. Additionally, it aims to offer insights into microbiome-centered therapeutic approaches for patients in the field of rheumatology.

RECENT FINDINGS

The advent of next-generation sequencing has significantly improved our understanding of microbiome changes. Numerous studies have consistently revealed a strong link between rheumatism and the microbiome, especially in the oral and gut microbiota.

SUMMARY

A deeper comprehension of the microbiome's connection to rheumatism holds potential for enhancing disease diagnosis and treatment. Targeted therapeutic approaches, including probiotics, fecal microbiota transplantation, and combination therapies with medications, offer promising avenues for disease management.

The gut microbiome in systemic lupus erythematosus: lessons from rheumatic fever

For more than a century, certain bacterial infections that can breach the skin and mucosal barriers have been implicated as common triggers of autoimmune syndromes, especially post-infection autoimmune diseases that include rheumatic fever and post-streptococcal glomerulonephritis. However, only in the past few years has the importance of imbalances within our own commensal microbiota communities, and within the gut, in the absence of infection, in promoting autoimmune pathogenesis become fully appreciated. A diversity of species and mechanisms have been implicated, including disruption of the gut barrier. Emerging data suggest that expansions (or blooms) of pathobiont species are involved in autoimmune pathogenesis and stimulate clonal expansion of T cells and B cells that recognize microbial antigens. This Review discusses the relationship between the gut microbiome and the immune system, and the potential consequence of disrupting the community balance in terms of autoimmune development, focusing on systemic lupus erythematosus. Notably, inter-relationships between expansions of certain members within gut microbiota communities and concurrent autoimmune responses bear features reminiscent of classical post-infection autoimmune disease. From such insights, new therapeutic opportunities are being considered to restore the balance within microbiota communities or re-establishing the gut-barrier integrity to reinforce immune homeostasis in the host.

A double-edged sword: interactions of CX3CL1/CX3CR1 and gut microbiota in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a systemic chronic disease initiated by an abnormal immune response to self and can affect multiple organs. SLE is characterized by the production of autoantibodies and the deposition of immune complexes. In regard to the clinical observations assessed by rheumatologists, several chemokines and cytokines also contribute to disease progression. One such chemokine and adhesion molecule is CX3CL1 (otherwise known as fractalkine). CX3CL1 is involved in cell trafficking and inflammation through recognition by its receptor, CX3CR1. The CX3CL1 protein consists of a chemokine domain and a mucin-like stalk that allows it to function both as a chemoattractant and as an adhesion molecule. In inflammation and specifically lupus, the literature displays contradictory evidence for the functions of CX3CL1/CX3CR1 interactions. In addition, the gut microbiota has been shown to play an important role in the pathogenesis of SLE. This review highlights current studies that illustrate the interactions of the gut microbiota and CX3CR1 in SLE.

Fecal microbiota transplantation for the management of autoimmune diseases: Potential mechanisms and challenges

Autoimmune diseases (AIDs) are a series of immune-mediated lethal diseases featured by over-activated immune cells attacking healthy self-tissues and organs due to the loss of immune tolerance, which always causes severe irreversible systematical organ damage and threatens human health heavily. To date, there are still no definitive cures for the treatment of AIDs due to their pathogenesis has not been clearly understood. Besides, the current clinical treatments of AIDs majorly rely on glucocorticoids and immune suppressors, which can lead to serious side effects. In the past years, there are increasing studies demonstrating that an imbalance of gut microbiota is intimately related to the pathogenesis of various AIDs, shedding light on the development of therapeutics by targeting the gut microbiota for the management of AIDs. Among all the approaches targeting the gut microbiota, fecal microbiota transplantation (FMT) has attracted increasing interest, and it has been proposed as a possible strategy to intervene in the homeostasis of gut microbiota for the treatment of various diseases. However, despite the reported good curative effects and clinical studies conducted on FMT, the detailed mechanisms of FMT for the effective treatment of those diseases have not been figured out. To fully understand the mechanisms of the therapeutic effects of FMT on AIDs and improve the therapeutic efficacy of FMT treatment, a systematic review of this topic is necessary. Hence, in this review paper, the potential mechanisms of FMT for the treatment of various AIDs were summarized, including promotion, shaping, activation, or inhibition of the host immune system via the interactions between the microorganisms and the gut immune system, gut-brain, gut-liver, gut-kidney axis, and so on. Then, applications of FMT for the treatment of various AIDs were detailed presented. Finally, the current challenges and potential solutions for the development of FMT formulations and FMT therapeutics were comprehensively discussed.

The gut ecosystem and immune tolerance

The gastrointestinal tract is home to the largest microbial population in the human body. The gut microbiota plays significant roles in the development of the gut immune system and has a substantial impact on the maintenance of immune tolerance beginning in early life. These microbes interact with the immune system in a dynamic and interdependent manner. They generate immune signals by presenting a vast repertoire of antigenic determinants and microbial metabolites that influence the development, maturation and maintenance of immunological function and homeostasis. At the same time, both the innate and adaptive immune systems are involved in modulating a stable microbial ecosystem between the commensal and pathogenic microorganisms. Hence, the gut microbial population and the host immune system work together to maintain immune homeostasis synergistically. In susceptible hosts, disruption of such a harmonious state can greatly affect human health and lead to various auto-inflammatory and autoimmune disorders. In this review, we discuss our current understanding of the interactions between the gut microbiota and immunity with an emphasis on: a) important players of gut innate and adaptive immunity; b) the contribution of gut microbial metabolites; and c) the effect of disruption of innate and adaptive immunity as well as alteration of gut microbiome on the molecular mechanisms driving autoimmunity in various autoimmune diseases.

Possible Role of Dysbiosis of the Gut Microbiome in SLE

PURPOSE OF REVIEW

The resident gut microbiota serves as a double-edged sword that aids the host in multiple ways to preserve a healthy equilibrium and serve as early companions and boosters for the gradual evolution of our immune defensive layers; nevertheless, the perturbation of the symbiotic resident intestinal communities has a profound impact on autoimmunity induction, particularly in systemic lupus erythematosus (SLE). Herein, we seek to critically evaluate the microbiome research in SLE with a focus on intestinal dysbiosis.

RECENT FINDINGS

SLE is a complex and heterogeneous disorder with self-attack due to loss of tolerance, and there is aberrant excessive immune system activation. There is mounting evidence suggesting that intestinal flora disturbances may accelerate the formation and progression of SLE, presumably through a variety of mechanisms, including intestinal barrier dysfunction and leaky gut, molecular mimicry, bystander activation, epitope spreading, gender bias, and biofilms. Gut microbiome plays a critical role in SLE pathogenesis, and additional studies are warranted to properly define the impact of gut microbiome in SLE, which can eventually lead to new and potentially safer management approaches for this debilitating disease.

Gut microbiota and metabolome in sporadic Creutzfeldt-Jakob disease

BACKGROUND

Gut dysbiosis and the resulting changes in the metabolites have been associated with neurological diseases. However, the relationship between the gut microbiota and sporadic Creutzfeldt-Jakob disease (sCJD) need to be clarified. The aim of this study was to evaluate the changes in the composition of gut microbiota and metabolome accompanying sCJD, and determine their correlation with disease severity.

METHODS

Fecal samples were collected from 25 sCJD patients and 23 healthy controls. The composition of the fecal microbiota and metabolites was respectively analyzed by 16S ribosomal RNA sequencing and untargeted metabolomics. The correlation of gut microbiota and metabolites with MMSE, MoCA and MRC scores was analyzed.

RESULTS

The sCJD patients showed significant differences in the composition of gut microbiota and metabolites relative to the healthy controls. Several bacteria taxa in sCJD patients were increased at genus level, such as Turicibacter, norank_f_Christensenellaceae, Eisenbergiella, Bilophila and Holdemania. A total of 547 differential metabolites were identified between these two groups (VIP > 1, FDR p < 0.05). As per KEGG analysis, the metabolites related to the biosynthesis of phenylpropanoids, especially biochanin A, showed the most obvious decrease in the sCJD group. In addition, most metabolites involved in the pathways related to linoleic acid metabolism and steroid hormone biosynthesis were associated with MRC scale.

CONCLUSION

Our findings provide new insights into the relationship between gut microbiota and metabolites and sCJD. Some compounds, especially those related to the biosynthesis of phenylpropanoids were significantly altered in patients with sCJD, and those related to linoleic acid metabolism and steroid hormone biosynthesis might be biomarkers of evaluating disease severity.

The Evolving Landscape of Fecal Microbial Transplantation

The human gastrointestinal tract houses an enormous microbial ecosystem. Recent studies have shown that the gut microbiota plays significant physiological roles and maintains immune homeostasis in the human body. Dysbiosis, an imbalanced gut microbiome, can be associated with various disease states, as observed in infectious diseases, inflammatory diseases, autoimmune diseases, and cancer. Modulation of the gut microbiome has become a therapeutic target in treating these disorders. Fecal microbiota transplantation (FMT) from a healthy donor restores the normal gut microbiota homeostasis in the diseased host. Ample evidence has demonstrated the efficacy of FMT in recurrent Clostridioides difficile infection (rCDI). The application of FMT in other human diseases is gaining attention. This review aims to increase our understanding of the mechanisms of FMT and its efficacies in human diseases. We discuss the application, route of administration, limitations, safety, efficacies, and suggested mechanisms of FMT in rCDI, autoimmune diseases, and cancer. Finally, we address the future perspectives of FMT in human medicine.

Prevention and treatment of rheumatoid arthritis through traditional Chinese medicine: role of the gut microbiota

Recently, despite the increasing availability of treatments for Rheumatoid arthritis (RA), the incidence of RA and associated disability-adjusted life years have been on the rise globally in the late decades. At present, accumulating evidence has been advanced that RA is related to the gut microbiota, therefore, the therapeutic approaches for RA by regulating the gut microbiota are anticipated to become a new means of treatment. Traditional Chinese medicine (TCM) can regulate immunity, reduce inflammation and improve quality of life in various ways. Moreover, it can treat diseases by affecting the gut microbiota, which is a good way to treat RA. In this review, we mainly explore the relationship between TCM and gut microbiota regarding the perspective of treating RA. Moreover, we comprehensively summarize the roles of gut microbiota in the onset, development, progression, and prognosis of RA. Additionally, we elucidate the mechanism of TCM prevention and treatment of RA by the role of microbiota. Finally, we provide an evidence-based rationale for further investigation of microbiota-targeted intervention by TCM.

Limosilactobacillus reuteri in immunomodulation: molecular mechanisms and potential applications

Frequent use of hormones and drugs may be associated with side-effects. Recent studies have shown that probiotics have effects on the prevention and treatment of immune-related diseases. Limosilactobacillus reuteri (L. reuteri) had regulatory effects on intestinal microbiota, host epithelial cells, immune cells, cytokines, antibodies (Ab), toll-like receptors (TLRs), tryptophan (Try) metabolism, antioxidant enzymes, and expression of related genes, and exhibits antibacterial and anti-inflammatory effects, leading to alleviation of disease symptoms. Although the specific composition of the cell-free supernatant (CFS) of L. reuteri has not been clarified, its efficacy in animal models has drawn increased attention to its potential use. This review summarizes the effects of L. reuteri on intestinal flora and immune regulation, and discusses the feasibility of its application in atopic dermatitis (AD), asthma, necrotizing enterocolitis (NEC), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS), and provides insights for the prevention and treatment of immune-related diseases.

Gut microbiota: a newly identified environmental factor in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that predominantly affects women of childbearing age and is characterized by the damage to multiple target organs. The pathogenesis of SLE is complex, and its etiology mainly involves genetic and environmental factors. At present, there is still a lack of effective means to cure SLE. In recent years, growing evidence has shown that gut microbiota, as an environmental factor, triggers autoimmunity through potential mechanisms including translocation and molecular mimicry, leads to immune dysregulation, and contributes to the development of SLE. Dietary intervention, drug therapy, probiotics supplement, fecal microbiome transplantation and other ways to modulate gut microbiota appear to be a potential treatment for SLE. In this review, the dysbiosis of gut microbiota in SLE, potential mechanisms linking gut microbiota and SLE, and immune dysregulation associated with gut microbiota in SLE are summarized.

Gut microbiota mediated the effects of high relative humidity on lupus in female MRL/lpr mice

INTRODUCTION

The relationship between humidity and systemic lupus erythematosus (SLE) has yielded inconsistent results in prior research, while the effects of humidity on lupus in animal experiments and its underlying mechanism remain inadequately explored.

METHODS

The present study aimed to investigate the impact of high humidity (80 ± 5%) on lupus using female and male MRL/lpr mice, with a particular focus on elucidating the role of gut microbiota in this process. To this end, fecal microbiota transplantation (FMT) was employed to transfer the gut microbiota of MRL/lpr mice under high humidity to blank MRL/lpr mice under normal humidity (50 ± 5%), allowing for an assessment of the effect of FMT on lupus.

RESULTS

The study revealed that high humidity exacerbated lupus indices (serum anti-dsDNA, ANA, IL-6, and IFN- g, and renal pathology) in female MRL/lpr mice but had no significant effect on male MRL/lpr mice. The aggravation of lupus caused by high humidity may be attributed to the increased abundances of the Rikenella, Romboutsia, Turicibacter, and Escherichia-Shigella genera in female MRL/lpr mice. Furthermore, FMT also exacerbated lupus in female MRL/lpr mice but not in male MRL/lpr mice.

CONCLUSION

In summary, this study has demonstrated that high humidity exacerbated lupus by modulating gut microbiota in female MRL/lpr mice. The findings underscore the importance of considering environmental factors and gut microbiota in the development and progression of lupus, particularly among female patients.

Effects of Spermidine on Mouse Gut Morphology, Metabolites, and Microbial Diversity

Spermidine is a class of biologically active organic small molecules that play an important role in maintaining intestinal homeostasis. The specific objective of this study was to explore the effects of spermidine on intestinal morphology, metabolites, and microbial diversity in mice. We showed that 0.3 mmol/L of spermidine significantly promoted the growth of ileal villi (p < 0.05), and 3.0 mmol/L of spermidine significantly increased the body weight of mice and promoted the growth of jejunum villi (p < 0.05). The 16S rDNA sequencing results indicated that 3.0 mmol/L of spermidine affected the balance of the intestinal flora by increasing the abundance of intestinal Lactic acid bacteria and reducing the abundance of harmful bacteria (Turicibacter and Alistipes). Additionally, spermidine affects the levels of microbial metabolites such as succinic acid and Pantetheine. In summary, spermidine affects intestinal morphology and regulates intestinal flora and metabolites, and this study has provided a new understanding of spermidine's effects on the intestinal tract.

The Role of Diet in Influencing the Diversity of Gut Microbiome Related to Lupus Disease Activities: A Systematic Review

Gut microbiome dysbiosis can affect the host immune system. The balance and activity of the gut microbiome, which are influenced by daily diet, might be associated with disease activity in systemic lupus erythematosus (SLE). Therefore, we conducted a systematic review based on the PRISMA guideline to explore the role and types of diet that affects the gut microbiome related to changes in SLE disease activity. All original and full-text English articles in the last ten years were included using predefined keywords according to PEO (population, exposure, and outcome) design in PubMed. The study subjects were carefully analyzed, including lupus-susceptible mice and humans with SLE on various diets. Children and pregnant women populations were excluded. Of 134 studies found, only seven full-text articles had met the inclusion criteria of which only one study conducted in human. This human study showed that dietary polyphenol as dihydrochalcones and flavanones affected the gut microbiome and ameliorated lupus disease activity. On the contrary, dietary flavones increased Blautia (family: Lachnospiraceae), and that often found in active lupus diseases. Furthermore, six studies in lupus-prone mice models showed that resistant starch (RS), retinoic acid (RA) or all-trans retinoic acid (tRA), and acidic water (AW) had influenced the gut microbiome, leading to an improved lupus development. Conversely, the 2018 commercial rodent diet, vitamin A-retinoic acid (VARA), neutral water (NW), and high tryptophan diet had impacted various microbiomes, resulting in increased lupus activity. Interestingly, several diets have the effect of either increasing or decreasing lupus disease activity depending on the microbiome they affect, such as AW associated with Turicibacter spp., which is frequently found in active lupus disease, and tRA in Bacteroidetes associated with renal pathology. To conclude, diet can influence the gut microbiome, which is related to the disease activity process of SLE.

Let’s review the gut microbiota in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic, immune-mediated disease associated with significant morbidity and mortality. New evidence suggests that diet, gut microbiota, intestinal permeability, and endotoxemia may modulate chronic inflammation and disease activity in SLE. This review focus on what is known about the gut microbiota in lupus mouse models and SLE patients and the possible mechanisms that connect the gut microbiota with SLE. It included 29 studies (12 animal studies, 15 human studies, and 2 included data on both), with variable results regarding alpha and beta-diversity and gut microbiota composition between lupus-mouse models and SLE patients. Ruminococcus (R.) gnavus was significantly increased in lupus nephritis (LN) in one study, but this was not corroborated by others. Despite the different results, mechanistic lupus mouse model studies have shown that gut microbiota can modulate disease activity. Interestingly, pathobiont translocation in monocolonized and autoimmune-prone mice induced autoantibodies and caused mortality, which could be prevented by a vaccine targeting the pathobiont. Moreover, studies on fecal transplants and diet on different lupus mouse models showed an effect on disease activity. In SLE patients, a higher adherence to the Mediterranean diet was associated with lower disease activity, which may be explained by the connection between diet and gut microbiota. Although gut dysbiosis has been observed in SLE patients and lupus mouse models, it remains to clarify if it is a cause or a consequence of the disease or its treatments. Further studies with larger and well-characterized populations will undoubtedly contribute to deciphering the role of gut microbiota in SLE development, progression, and outcome.

Gut Dysbiosis and Fecal Microbiota Transplantation in Autoimmune Diseases

Gut microbiota dysbiosis has recently been reported in a number of clinical states, including neurological, psychiatric, cardiovascular, metabolic and autoimmune disorders. Yet, it is not completely understood how colonizing microorganisms are implicated in their pathophysiology and molecular pathways. There are a number of suggested mechanisms of how gut microbiota dysbiosis triggers or sustains extraintestinal diseases; however, none of these have been widely accepted as part of the disease pathogenesis. Recent studies have proposed that gut microbiota and its metabolites could play a pivotal role in the modulation of immune system responses and the development of autoimmunity in diseases such as rheumatoid arthritis, multiple sclerosis or type 1 diabetes. Fecal microbiota transplantation (FMT) is a valuable tool for uncovering the role of gut microbiota in the pathological processes. This review aims to summarize the current knowledge about gut microbiota dysbiosis and the potential of FMT in studying the pathogeneses and therapies of autoimmune diseases. Herein, we discuss the extraintestinal autoimmune pathologies with at least one published or ongoing FMT study in human or animal models.

Gut microbiota in systemic lupus erythematosus: A fuse and a solution

Gut commensals help shape and mold host immune system and deeply influence human health. The disease spectrum of mankind that gut microbiome may associate with is ever-growing, but the mechanisms are still enigmas. Characterized by loss of self-tolerance and sustained self-attack, systemic lupus erythematosus (SLE) is labeled with chronic inflammation, production of autoantibodies and multisystem injury, which so far are mostly incurable. Gut microbiota and their metabolites, now known as important environmental triggers of local/systemic immune responses, have been proposed to be involved in SLE development and progression probably through the following mechanisms: translocation beyond their niches; molecular mimicry to cross-activate immune response targeting self-antigens; epitope spreading to expand autoantibodies spectrum; and bystander activation to promote systemic inflammation. Gut microbiota which varies between individuals may also influence the metabolism and bio-transformation of disease-modifying anti-rheumatic drugs, thus associated with the efficacy and toxicity of these drugs, adding another explanation for heterogenic therapeutic responses. Modulation of gut microbiota via diet, probiotics/prebiotics, antibiotics/phages, fecal microbiota transplantation, or helminth to restore immune tolerance and homeostasis is expected to be a promising neoadjuvant therapy for SLE. We reviewed the advances in this territory and discussed the application prospect of modulating gut microbiota in controlling SLE.

Gut Barrier Damage and Gut Translocation of Pathogen Molecules in Lupus, an Impact of Innate Immunity (Macrophages and Neutrophils) in Autoimmune Disease

The gut barrier is a single cell layer that separates gut micro-organisms from the host, and gut permeability defects result in the translocation of microbial molecules from the gut into the blood. Despite the silent clinical manifestation, gut translocation of microbial molecules can induce systemic inflammation that might be an endogenous exacerbating factor of systemic lupus erythematosus. In contrast, circulatory immune-complex deposition and the effect of medications on the gut, an organ with an extremely large surface area, of patients with active lupus might cause gut translocation of microbial molecules, which worsens lupus severity. Likewise, the imbalance of gut microbiota may initiate lupus and/or interfere with gut integrity which results in microbial translocation and lupus exacerbation. Moreover, immune hyper-responsiveness of innate immune cells (macrophages and neutrophils) is demonstrated in a lupus model from the loss of inhibitory Fc gamma receptor IIb (FcgRIIb), which induces prominent responses through the cross-link between activating-FcgRs and innate immune receptors. The immune hyper-responsiveness can cause cell death, especially apoptosis and neutrophil extracellular traps (NETosis), which possibly exacerbates lupus, partly through the enhanced exposure of the self-antigens. Leaky gut monitoring and treatments (such as probiotics) might be beneficial in lupus. Here, we discuss the current information on leaky gut in lupus.

Gut microbiota in various childhood disorders: Implication and indications

Gut microbiota has a significant role in gut development, maturation, and immune system differentiation. It exerts considerable effects on the child's physical and mental development. The gut microbiota composition and structure depend on many host and microbial factors. The host factors include age, genetic pool, general health, dietary factors, medication use, the intestine's pH, peristalsis, and transit time, mucus secretions, mucous immunoglobulin, and tissue oxidation-reduction potentials. The microbial factors include nutrient availability, bacterial cooperation or antagonism, and bacterial adhesion. Each part of the gut has its microbiota due to its specific characteristics. The gut microbiota interacts with different body parts, affecting the pathogenesis of many local and systemic diseases. Dysbiosis is a common finding in many childhood disorders such as autism, failure to thrive, nutritional disorders, coeliac disease, Necrotizing Enterocolitis, helicobacter pylori infection, functional gastrointestinal disorders of childhood, inflammatory bowel diseases, and many other gastrointestinal disorders. Dysbiosis is also observed in allergic conditions like atopic dermatitis, allergic rhinitis, and asthma. Dysbiosis can also impact the development and the progression of immune disorders and cardiac disorders, including heart failure. Probiotic supplements could provide some help in managing these disorders. However, we are still in need of more studies. In this narrative review, we will shed some light on the role of microbiota in the development and management of common childhood disorders.