Microbial monotherapy with Prevotella histicola for patients with multiple sclerosis

Fecal microbial biomarkers in older adults with autoimmune diseases

Aim: To analyze the alterations in the fecal microbiota of older adults with autoimmune disease and determine the diagnostic capabilities of microbial biomarkers. Methods: The raw data of fecal samples from 444 older adults from the publicly available American Gut Project database was analyzed. Results: It was found that there were no significant differences in the microbiota richness and evenness between older adults with autoimmune disease and healthy controls. However, significant differences were observed in the microbiota composition and structure. The subject operating characteristic curve of the eight key microbiota was obtained, and the area under curve value was 70.0%. Conclusion: Older adults with autoimmune disease showed changes in intestinal microbiota composition, which can be used as microbial biomarkers.

The Preventive Effects of Probiotic Prevotella histicola on the Bone Loss of Mice with Ovariectomy-Mediated Osteoporosis

It has been demonstrated that the disturbance of gut microbiota (GM) is closely related to the reduction of bone mass and incidence of osteoporosis (OP). The aim of this study is to investigate whether the supplementation of Prevotella histicola (Ph) can prevent the bone loss in mice with ovariectomy (OVX)-mediated OP, and further explore relevant mechanisms. Regular (once a day for 8 consecutive weeks) and quantitative (200 µL/d) perfusion of Ph (the bacteria that orally gavaged) was conducted starting from 1 week after the construction of mice models. Bone mass and bone microstructure were detected by Micro-computed tomography (Micro-CT). Expressions of intestinal permeability, pro-inflammatory cytokines, and osteogenic and osteoclastic activities of mice were analyzed by histological staining and immunohistochemistry (IHC). 16S rRNA high throughput sequencing technique was applied to analyze the alterations of composition, abundance, and diversity of collected feces. Regular and quantitative perfusion of Ph mitigated the bone loss in mice with OVX-mediated OP. Compared with OVX + PBS group, perfusion of Ph repressed osteoclastogenesis and promoted osteogenesis, reduced release of pro-inflammatory cytokine cytokines (interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)), and reversed expressions of tight junction proteins (zonula occludens protein 1 (ZO-1) and Occludin). Besides, the perfusion of Ph improved the composition, abundance, and diversity of GM. Collectively, this study revealed that regular and quantitative perfusion of Ph can improve the bone loss in mice with OVX-mediated OP by repairing intestinal mucosal barrier damage, optimizing intestinal permeability, inhibiting release of pro-osteoclastogenic cytokines, and improving disturbance of GM.

Advantages and limitations of experimental autoimmune encephalomyelitis in breaking down the role of the gut microbiome in multiple sclerosis

Since the first model of experimental autoimmune encephalomyelitis (EAE) was introduced almost a century ago, there has been an ongoing scientific debate about the risks and benefits of using EAE as a model of multiple sclerosis (MS). While there are notable limitations of translating EAE studies directly to human patients, EAE continues to be the most widely used model of MS, and EAE studies have contributed to multiple key breakthroughs in our understanding of MS pathogenesis and discovery of MS therapeutics. In addition, insights from EAE have led to a better understanding of modifiable environmental factors that can influence MS initiation and progression. In this review, we discuss how MS patient and EAE studies compare in our learning about the role of gut microbiome, diet, alcohol, probiotics, antibiotics, and fecal microbiome transplant in neuroinflammation. Ultimately, the combination of rigorous EAE animal studies, novel bioinformatic approaches, use of human cell lines, and implementation of well-powered, age- and sex-matched randomized controlled MS patient trials will be essential for improving MS patient outcomes and developing novel MS therapeutics to prevent and revert MS disease progression.

Impacts of Gut Microbiota on the Immune System and Fecal Microbiota Transplantation as a Re-Emerging Therapy for Autoimmune Diseases

The enormous and diverse population of microorganisms residing in the digestive tracts of humans and animals influence the development, regulation, and function of the immune system. Recently, the understanding of the association between autoimmune diseases and gut microbiota has been improved due to the innovation of high-throughput sequencing technologies with high resolutions. Several studies have reported perturbation of gut microbiota as one of the factors playing a role in the pathogenesis of many diseases, such as inflammatory bowel disease, recurrent diarrhea due to Clostridioides difficile infections. Restoration of healthy gut microbiota by transferring fecal material from a healthy donor to a sick recipient, called fecal microbiota transplantation (FMT), has resolved or improved symptoms of autoimmune diseases. This (re)emerging therapy was approved for the treatment of drug-resistant recurrent C. difficile infections in 2013 by the U.S. Food and Drug Administration. Numerous human and animal studies have demonstrated FMT has the potential as the next generation therapy to control autoimmune and other health problems. Alas, this new therapeutic method has limitations, including the risk of transferring antibiotic-resistant pathogens or transmission of genes from donors to recipients and/or exacerbating the conditions in some patients. Therefore, continued research is needed to elucidate the mechanisms by which gut microbiota is involved in the pathogenesis of autoimmune diseases and to improve the efficacy and optimize the preparation of FMT for different disease conditions, and to tailor FMT to meet the needs in both humans and animals. The prospect of FMT therapy includes shifting from the current practice of using the whole fecal materials to the more aesthetic transfer of selective microbial consortia assembled in vitro or using their metabolic products.

Morais L. Convergent pathways of the gut microbiota-brain axis and neurodegenerative disorders

Recent research has been uncovering the role of the gut microbiota for brain health and disease. These studies highlight the role of gut microbiota on regulating brain function and behavior through immune, metabolic, and neuronal pathways. In this review we provide an overview of the gut microbiota axis pathways to lay the groundwork for upcoming sessions on the links between the gut microbiota and neurogenerative disorders. We also discuss how the gut microbiota may act as an intermediate factor between the host and the environment to mediate disease onset and neuropathology. Based on the current literature, we further examine the potential for different microbiota-based therapeutic strategies to prevent, to modify, or to halt the progress of neurodegeneration.

Bacterial variation in the oral microbiota in multiple sclerosis patients

BACKGROUND

Microorganisms in oral cavity are called oral microbiota, while microbiome consists of total genome content of microorganisms in a host. Interaction between host and microorganisms is important in nervous system development and nervous diseases such as Autism, Alzheimer, Parkinson and Multiple Sclerosis (MS). Bacterial infections, as an environmental factor in MS pathogenesis play role in T helper 17(Th17) increase and it enhancing the production of pro-inflammatory cytokines such as Interlukin-21(IL-21), IL-17 and IL -22. Oral microbiota consists diverse populations of cultivable and uncultivable bacterial species. Denaturing gradient gel electrophoresis (DGGE) is an acceptable method for identification of uncultivable bacteria. In this study, we compared the bacterial population diversity in the oral cavity between MS and healthy people.

METHODS

From October to March 2019, samples were taken at Kermanshah University of Medical Sciences' MS patients center. A total of 30 samples were taken from MS patients and another 30 samples were taken from healthy people. Phenotypic tests were used to identify bacteria after pure cultures were obtained. DNA was extracted from 1 mL of saliva, and PCR products produced with primers were electrophoresed on polyacrylamide gels.

RESULTS

The genera Staphylococcus, Actinomyces, Fusobacterium, Bacteroides, Porphyromonas, Prevotella, Veillonella, Propionibacterium and uncultivable bacteria with accession number MW880919-25, JQ477416.1, KF074888.1 and several other un-culturable strains were significantly more abundant in the MS group while Lactobacillus and Peptostreptococcus were more prevalent in the normal healthy group according to logistic regression method.

CONCLUSION

Oral micro-organisms may alleviate or exacerbate inflammatory condition which impact MS disease pathogenesis. It may be assumed that controlling oral infections may result in reduction of MS disease progression.

Influence of a High-Impact Multidimensional Rehabilitation Program on the Gut Microbiota of Patients with Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative inflammatory condition mediated by autoreactive immune processes. Due to its potential to influence host immunity and gut-brain communication, the gut microbiota has been suggested to be involved in the onset and progression of MS. To date, there is no definitive cure for MS, and rehabilitation programs are of the utmost importance, especially in the later stages. However, only a few people generally participate due to poor support, knowledge, and motivation, and no information is available on gut microbiota changes. Herein we evaluated the potential of a brief high-impact multidimensional rehabilitation program (B-HIPE) in a leisure environment to affect the gut microbiota, mitigate MS symptoms and improve quality of life. B-HIPE resulted in modulation of the MS-typical dysbiosis, with reduced levels of pathobionts and the replenishment of beneficial short-chain fatty acid producers. This partial recovery of a eubiotic profile could help counteract the inflammatory tone typically observed in MS, as supported by reduced circulating lipopolysaccharide levels and decreased populations of pro-inflammatory lymphocytes. Improved physical performance and fatigue relief were also found. Our findings pave the way for integrating clinical practice with holistic approaches to mitigate MS symptoms and improve patients’ quality of life.

Influence of immunomodulatory drugs on the gut microbiota

Immunomodulatory medications are a mainstay of treatment for autoimmune diseases and malignancies. In addition to their direct effects on immune cells, these medications also impact the gut microbiota. Drug-induced shifts in commensal microbes can lead to indirect but important changes in the immune response. We performed a comprehensive literature search focusing on immunotherapy/microbe interactions. Immunotherapies were categorized into 5 subtypes based on their mechanisms of action: cell trafficking inhibitors, immune checkpoint inhibitors, immunomodulators, antiproliferative drugs, and inflammatory cytokine inhibitors. Although no consistent relationships were observed between types of immunotherapy and microbiota, most immunotherapies were associated with shifts in specific colonizing bacterial taxa. The relationships between colonizing microbes and drug efficacy were not well-studied for autoimmune diseases. In contrast, the efficacy of immune checkpoint inhibitors for cancer was tied to the baseline composition of the gut microbiota. There was a paucity of high-quality data; existing data were generated using heterogeneous sampling and analytic techniques, and most studies involved small numbers of participants. Further work is needed to elucidate the extent and clinical significance of immunotherapy effects on the human microbiome.

Unravelling the potential of gut microbiota in sustaining brain health and their current prospective towards development of neurotherapeutics

Increasing incidences of neurological disorders, such as Parkinson's disease (PD), multiple sclerosis (MS), Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS) are being reported, but an insight into their pathology remains elusive. Findings have suggested that gut microbiota play a major role in regulating brain functions through the gut-brain axis. A unique bidirectional communication between gut microbiota and maintenance of brain health could play a pivotal role in regulating incidences of neurodegenerative diseases. Contrarily, the present life style with changing food habits and disturbed circadian rhythm may contribute to gut homeostatic imbalance and dysbiosis leading to progression of several neurological disorders. Therefore, dysbiosis, as a primary factor behind intestinal disorders, may also augment inflammation, intestinal and blood-brain barrier permeability through microbiota-gut-brain axis. This review primarily focuses on the gut-brain axis functions, specific gut microbial population, metabolites produced by gut microbiota, their role in regulating various metabolic processes and role of gut microbiota towards development of neurodegenerative diseases. However, several studies have reported a decrease in abundance of a specific gut microbial population and a corresponding increase in other microbial family, with few findings revealing some contradictions. Reports also showed that colonization of gut microbiota isolated from patients suffering from neurodegenerative disease leads to the development of enhance pathological outcomes in animal models. Hence, a systematic understanding of the dominant role of specific gut microbiome towards development of different neurodegenerative diseases could possibly provide novel insight into the use of probiotics and microbial transplantation as a substitute approach for treating/preventing such health maladies.

Lactobacillus reuteri DSM 17938 alleviates d-galactosamine-induced liver failure in rats

Liver failure is a serious hepatic dysfunction with high mortality. This work aimed to investigate the effect of a famous probiotic and drug, Lactobacillus reuteri DSM 17938, on liver failure in rats. Sprague-Dawley rats were gavaged with 3 × 109 CFU of DSM 17938 for 7 days. d-galactosamine was intraperitoneally injected to induce acute liver failure on the eighth day. Samples were collected to determine the liver function, serum cytokines levels, terminal ileum and liver histology, gut microbiota, metabolome and transcriptome. Our results showed that pretreatment with DSM 17938 not only reduced the elevation in serum alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, IL-1α, IL-2, IL-18, M-CSF, and MIP-3α levels but also alleviated histological abnormalities of both the terminal ileum and liver induced by d-galactosamine. Additionally, DSM 17938 reduced d-galactosamine-induced enrichment of some taxa of gut Actinobacteria or Firmicutes, including abundant pathogens such as Actinomycetales, Coriobacteriaceae, Staphylococcaceae and Enterococcaceae. Furthermore, DSM 17938 reduced the d-galactosamine-induced increase in not only fecal metabolites such as trisaminol and lithocholic acid but also the transcription of liver inflammatory genes, such as Ccl2, Ccl7, Ccl11, Ccl12, Il6, Il11, Il20rb, Mmp3 and Mmp10. Downregulation of retinol metabolism and PPAR signaling pathway as well as upregulation of viral protein interaction with cytokine and cytokine receptor and central carbon metabolism in cancer signaling pathway were involved in the mechanism of L. reuteri DSM 17938 alleviating liver failure. Our findings suggested that DSM 17938 is a potential probiotic for the prevention or treatment of liver failure.

Nutritional Status and the Influence of the Vegan Diet on the Gut Microbiota and Human Health

The human gut microbiota is considered a well-known complex ecosystem composed of distinct microbial populations, playing a significant role in most aspects of human health and wellness. Several factors such as infant transitions, dietary habits, age, consumption of probiotics and prebiotics, use of antibiotics, intestinal comorbidities, and even metabolic diseases may continously alter microbiota diversity and function. The study of vegan diet-microbiota interactions is a rapidly evolving field, since plenty of research has been focused on the potential effects of plant-based dietary patterns on the human gut microbiota. It has been reported that well-planned vegan diets and their associated components affect both the bacterial composition and metabolic pathways of gut microbiota. Certain benefits associated with medical disorders but also limitations (including nutritional deficiencies) have been documented. Although the vegan diet may be inadequate in calorific value, it is rich in dietary fiber, polyphenols, and antioxidant vitamins. The aim of the present study was to provide an update of the existing knowledge on nutritional status of vegan diets and the influence of their food components on the human gut microbiota and health.

Inhibitory milieu at the multiple sclerosis lesion site and the challenges for remyelination

Regeneration of myelin, following injury, can occur within the central nervous system to reinstate proper axonal conductance and provide trophic support. Failure to do so renders the axons vulnerable, leading to eventual degeneration, and neuronal loss. Thus, it is essential to understand the mechanisms by which remyelination or failure to remyelinate occur, particularly in the context of demyelinating and neurodegenerative disorders. In multiple sclerosis, oligodendrocyte progenitor cells (OPCs) migrate to lesion sites to repair myelin. However, during disease progression, the ability of OPCs to participate in remyelination diminishes coincident with worsening of the symptoms. Remyelination is affected by a broad range of cues from intrinsic programming of OPCs and extrinsic local factors to the immune system and other systemic elements including diet and exercise. Here we review the literature on these diverse inhibitory factors and the challenges they pose to remyelination. Results spanning several disciplines from fundamental preclinical studies to knowledge gained in the clinic will be discussed.