Microbiome, antibiotics and irritable bowel syndrome

Therapeutic potential of probiotics in gut microbial homeostasis and Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation and joint damage. Existing treatment options primarily focus on managing symptoms and slowing disease progression, often with side effects and limitations. The gut microbiome, a vast community of microorganisms present in the gastrointestinal tract, plays a crucial role in health and disease. Recent research suggests a bidirectional relationship between the gut microbiome and RA, highlighting its potential as a therapeutic option. This review focuses on the interaction between the gut microbiome and RA development, by discussing how dysbiosis, an imbalance in gut bacteria, can contribute to RA through multiple mechanisms such as molecular mimicry, leaky gut, and metabolic dysregulation. Probiotics, live microorganisms with health benefits, are emerging as promising tools for managing RA. They can prevent the negative effects of dysbiosis by displacing harmful bacteria, producing anti-inflammatory metabolites like short-chain fatty acids (SCFA), Directly influencing immune cells, and modifying host metabolism. animal and clinical studies demonstrate the potential of probiotics in improving RA symptoms and disease outcomes. However, further research is needed to optimize probiotic strains, dosages, and treatment protocols for personalized and effective management of RA. This review summarizes the current understanding of the gut microbiome and its role in RA and discusses future research directions. In addition to the established role of gut dysbiosis in RA, emerging strategies like fecal microbiota transplantation, prebiotics, and postbiotics offer exciting possibilities. However, individual variations in gut composition necessitate personalized treatment plans. Long-term effects and clear regulations need to be established. Future research focusing on metagenomic analysis, combination therapies, and mechanistic understanding will unlock the full potential of gut microbiome modulation for effective RA management.

Investigation of intestinal microbiome in chronic spontaneous urticaria patients

BACKGROUND

Chronic urticaria is a disorder characterized by itchy erythematous plaques with edema lasting 6 weeks or more. The prevalence is 1%, and two thirds of these cases are "chronic spontaneous urticaria (CSU)." Drugs, food, infections, and systemic diseases may be etiologic factors for CSU, although it may be idiopathic.

OBJECTIVES

The aim of this study was to compare the diversity and distribution of the intestinal microbiome in CSU patients with that of healthy individuals. The hypothesis was to determine the probable association of intestinal microbiome with CSU.

METHODS

This study was conducted in Sakarya University Training and Research Hospital, Department of Dermatology. In this study, 20 CSU patients and 10 healthy volunteers were included. Stool samples were collected from all participants. 16S RNA sequencing and bioinformatic analysis were performed after isolation of DNA isolation from all samples.

RESULTS

Diversity in microorganisms, stool pH averages, Bristol scores, and the ratio of Firmicutes/Bacteroidetes were the significant changes between the two groups.

LIMITATIONS

Due to high cost involved in microbiota studies, only a limited number of patients and volunteers participated.

CONCLUSION

The alteration in the intestinal microbiota (dysbiosis) may be an essential factor for CSU development and may explain idiopathic cases.

Increasing Guideline-Concordant Durations of Antibiotic Therapy for Acute Otitis Media

OBJECTIVE

To compare the effectiveness of 2 interventions in improving prescribing of guideline-concordant durations of therapy for acute otitis media (AOM).

STUDY DESIGN

This was a quasi-experimental mixed methods analysis that compared a bundled quality improvement intervention consisting of individualized audit and feedback, education, and electronic health record (EHR) changes to an EHR-only intervention. The bundle was implemented in 3 pediatric clinics from January to August 2020 and an EHR-only intervention was implemented in 6 family medicine clinics. The primary outcome measure was prescription of an institutional guideline-concordant 5-day duration of therapy for children ≥2 years of age with uncomplicated AOM. Propensity score matching and differences-in-differences analysis weighted with inverse probability of treatment were completed. Implementation outcomes were assessed using the Reach, Effectiveness, Adoption, Implementation, Maintenance Framework. Balance measures included treatment failure and recurrence.

RESULTS

In total, 1017 encounters for AOM were included from February 2019 to August 2020. Guideline-concordant prescribing increased from 14.4% to 63.8% (difference = 49.4%) in clinics that received the EHR-only intervention and from 10.6% to 85.2% (difference = 74.6%) in clinics that received the bundled intervention. In the adjusted analysis, the bundled intervention improved guideline-concordant durations by an additional 26.4% (P < .01) compared with the EHR-only intervention. Providers identified EHR-prescription field changes as the most helpful components. There were no differences in treatment failure or recurrence rates between baseline and either intervention.

CONCLUSIONS

Both interventions resulted in improved prescribing of guideline-concordant durations of antibiotics. The bundled intervention improved prescribing more than an EHR-only intervention and was acceptable to providers.

Targeting the Gut Microbiota to Relieve the Symptoms of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common, chronic, functional disorder with a large impact on world population. Its pathophysiology is not completely revealed; however, it is certain that dysregulation of the bidirectional communications between the central nervous system (CNS) and the gut leads to motility disturbances, visceral hypersensitivity, and altered CNS processing characterized by differences in brain structure, connectivity and functional responsiveness. Emerging evidence suggests that gut microbiota exerts a marked influence on the host during health and disease. Gut microbiome disturbances can be also important for development of IBS symptoms and its modulation efficiently contributes to the therapy. In this work, we review the current knowledge about the IBS therapy, the role of gut microbiota in pathogenesis of IBS, and we discuss that its targeting may have significant impact on the effectiveness of IBS therapy.

Antibiotic use but not gastrointestinal infection frequently precedes first diagnosis of functional gastrointestinal disorders

INTRODUCTION

While the etiopathogenesis of functional gastrointestinal disorders (FGIDs) is not completely understood, alterations of the intestinal microbiome have been observed. Antibiotics can induce dysbiosis, but whether antibiotics are a risk factor for the onset of FGIDs is uncertain. Antibiotics have been reported as both a risk factor for new onset FGID but also as a therapy for existing FGID. This study aimed to estimate the fraction of cases where antibiotics provoked the onset of FGID.

METHOD

Electronic medical records were obtained from general practices (primary care) in the United Kingdom. Dates of antibiotic prescription (AP) were compared with first date of FGID diagnosis and contrasted across three prevalent FGIDs and controls without gastrointestinal disorders.

RESULTS

There were 10,926 GI healthy controls, 4326 IBS alone, 3477 FD alone, 340 chronic constipation and 4402 with overlap of multiple conditions. Both the prevalence of AP and rate were higher in FGID patients and increased with diagnosis of multiple FGIDs. 7%-14% of FGID patients were prescribed their first recorded antibiotic in the 12 months prior to their first FGID diagnosis and 20%-33% were prescribed an antibiotic in the same period. Differences between FGID groups were not accounted for by social deprivation and only rate of AP was moderated by social deprivation. In contrast, only 5%-10% of patients ever had a gastrointestinal infection recorded and only 1.5%-3.5% prior to their first FGID diagnosis.

CONCLUSION

These data indicate that antibiotics are prescribed prior to FGID diagnosis in a significant minority of care-seeking FGID patients, opening the potential for this medication to contribute to the pathophysiology. APs appears to mostly be for non-gastrointestinal conditions.

The gut-brain axis and beyond: Microbiome control of spinal cord injury pain in humans and rodents

Spinal cord injury (SCI) is a devastating injury to the central nervous system in which 60 to 80% of patients experience chronic pain. Unfortunately, this pain is notoriously difficult to treat, with few effective options currently available. Patients are also commonly faced with various compounding injuries and medical challenges, often requiring frequent hospitalization and antibiotic treatment. Change in the gut microbiome from the "normal" state to one of imbalance, referred to as gut dysbiosis, has been found in both patients and rodent models following SCI. Similarities exist in the bacterial changes observed after SCI and other diseases with chronic pain as an outcome. These changes cause a shift in the regulation of inflammation, causing immune cell activation and secretion of inflammatory mediators that likely contribute to the generation/maintenance of SCI pain. Therefore, correcting gut dysbiosis may be used as a tool towards providing patients with effective pain management and improved quality of life.

Effects of fecal microbiota transplantation in subjects with irritable bowel syndrome are mirrored by changes in gut microbiome

Irritable bowel syndrome (IBS) is a common disorder of the lower gastrointestinal tract. The pathophysiology is far from settled, but a gut microbial dysbiosis is hypothesized to be a contributing factor. We earlier published a randomized double-blind placebo-controlled clinical trial on fecal microbiota transplantation (FMT) for IBS - the REFIT trial. The present data set describes the engraftment and includes participants from the study who received active FMT; 14 participants with effect of FMT (Effect) and 8 without (No effect). Samples were collected at baseline, after 6 and 12 months. Samples from the transplants (Donor) served as a comparator. In total 66 recipient samples and 17 donor samples were subjected to deep metagenomic sequencing, and taxonomic and functional analyses were performed. Alpha diversity measures showed a significantly increased diversity and evenness in the IBS groups compared to the donors. Taxonomic profiles showed higher relative abundance of phylum Firmicutes, and lower relative abundance of phylum Bacteroidetes, compared to donors at baseline. This profile was shifted toward the donor profile following FMT. Imputed growth rates showed that the resulting growth pattern was a conglomerate of donor and recipient activity. Thirty-four functional subclasses showed distinct differences between baseline samples and donors, most of which were shifted toward a donor-like profile after FMT. All of these changes were less pronounced in the No effect group. We conclude that FMT induces long-term changes in gut microbiota, and these changes mirror the clinical effect of the treatment. The study was registered in ClinicalTrials.gov (NCT02154867).

Antibiotic-induced changes in the human gut microbiota for the most commonly prescribed antibiotics in primary care in the UK: a systematic review

OBJECTIVE

The gut microbiota influences many aspects of human health. We investigated the magnitude and duration of changes in gut microbiota in response to antibiotics commonly prescribed in UK primary care.

METHODS

We searched MEDLINE, EMBASE and AMED, all years up to May 2020 including all study designs, collecting and analysing data on the effect of antibiotics prescribed for respiratory and urinary tract infections. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane standard methods. Risk of bias was evaluated using the Critical Appraisal Skills Programme. Narrative synthesis was used to report the themes emerging from the data.

MAIN OUTCOME MEASURES

Primary outcomes were antibiotic-induced changes in the composition and/or diversity of the gut microbiota. Secondary outcome was the time for the microbiota to return to baseline.

RESULTS

Thirty-one articles with low or unclear risk of bias showed that antibiotics impact the gut microbiota by causing rapid and diminished levels of bacterial diversity and changes in relative abundances. After cessation of treatment, gut bacteria recover, in most individuals, to their baseline state within a few weeks. Some studies suggested longer term effects from 2 to 6 months. Considerable heterogeneity in methodology makes the studies prone to biases and other confounding factors. Doxycycline was associated with a marked short-term decrease in Bifidobacterium diversity. Clarithromycin decreased the populations of Enterobacteria, and the anaerobic bacteria Bifidobacterium sp and Lactobacillus sp in numbers and diversity for up to 5 weeks. Phenoxymethylpenicillin, nitrofurantoin and amoxicillin had very little effect on the gut microbiome.

CONCLUSIONS

Despite substantial heterogeneity of the studies and small sample sizes, there is evidence that antibiotics commonly used in primary care influence the composition of the gastrointestinal microbiota. Larger population-based studies are needed to fully understand how antibiotics modulate the microbiota, and to determine if these are associated with (longer term) health consequences.

PROSPERO REGISTRATION NUMBER

CRD42017073750.

The Skin and Gut Microbiome and Its Role in Common Dermatologic Conditions

Microorganisms inhabit various areas of the body, including the gut and skin, and are important in maintaining homeostasis. Changes to the normal microflora due to genetic or environmental factors can contribute to the development of various disease states. In this review, we will discuss the relationship between the gut and skin microbiome and various dermatological diseases including acne, psoriasis, rosacea, and atopic dermatitis. In addition, we will discuss the impact of treatment on the microbiome and the role of probiotics.

Successful Fecal Microbiota Transplantation in a Patient Suffering From Irritable Bowel Syndrome and Recurrent Urinary Tract Infections

Background

Irritable bowel syndrome (IBS) is a chronic and debilitating functional gastrointestinal disorder affecting 9%-23% of the population across the world. The relative efficacy of fecal microbiota transplantation (FMT) on IBS symptoms was demonstrated in a double-blind, randomized study.

Methods

We describe the case of a 73-year-old woman suffering from IBS (abdominal pain, bloating, and abundant and disabling diarrhea, with 10-15 stools a day) and repetitive urinary tract infection (UTI; 5 episodes in 6 months, including 3 the last 2 months) for several years, generating an impaired quality of life. She received an FMT with 400 mL of fecal infusion from a healthy donor via a nasogastric tube after bowel lavage. Her digestive microbiota was analyzed using culturomic and metagenomic targeting 16S rRNA sequencing methods.

Results

Eight months after transplantation, we observed a significant reduction in frequency and improvement in stool consistency (3-4 molded stools a day against 10-15 before the transplant) and no recurrence of urinary infection (as previously reported). Using culturomics, we found 12 bacteria present in the fecal infusion and post-transplant stool; these were absent pretransplant. Three of them (Intestinimonas massiliensis, Oscillibacter massiliensis, and Provencibacter massiliensis) were previously discovered and cultivated in our laboratory using culturomics. Using metagenomics, we also observed 12 bacteria, different from those observed during culture, that could have been transferred to the patient by FMT.

Conclusions

In this case report, IBS symptoms and UTI frequency decreased after FMT UTI. Further studies involving more patients would be relevant to confirm this work and develop bacteriotherapy.

A Unified Conceptual Framework for Metabolic Phenotyping in Diagnosis and Prognosis

Understanding metabotype (multicomponent metabolic characteristics) variation can help to generate new diagnostic and prognostic biomarkers, as well as models, with potential to impact on patient management. We present a suite of conceptual approaches for the generation, analysis, and understanding of metabotypes from body fluids and tissues. We describe and exemplify four fundamental approaches to the generation and utilization of metabotype data via multiparametric measurement of (i) metabolite levels, (ii) metabolic trajectories, (iii) metabolic entropies, and (iv) metabolic networks and correlations in space and time. This conceptual framework can underpin metabotyping in the scenario of personalized medicine, with the aim of improving clinical outcomes for patients, but the framework will have value and utility in areas of metabolic profiling well beyond this exemplar.

Antibiotic therapy in neonates and impact on gut microbiota and antibiotic resistance development: a systematic review

Objectives

To systematically review the impact of antibiotic therapy in the neonatal period on changes in the gut microbiota and/or antibiotic resistance development.

Methods

Data sources were PubMed, Embase, Medline and the Cochrane Database, supplemented by manual searches of reference lists. Randomized controlled trials (RCTs) and observational studies were included if they provided data on different categories of antibiotic treatment (yes versus no, long versus short duration and/or broad- versus narrow-spectrum regimens) and subsequent changes in the gut microbiota and/or antibiotic resistance development. We evaluated risk of bias using the Cochrane Handbook, adapted to include observational studies. When appropriate, we used the vote-counting method to perform semi-quantitative meta-analyses. We applied the Grades of Recommendation, Assessment, Development and Evaluation approach to rate the quality of evidence (QoE). Study protocol registration: PROSPERO CRD42015026743.

Results

We included 48 studies, comprising 3 RCTs and 45 observational studies. Prolonged antibiotic treatment was associated with reduced gut microbial diversity in all three studies investigating this outcome (very low QoE). Antibiotic treatment was associated with reduced colonization rates of protective commensal anaerobic bacteria in four of five studies (very low QoE). However, all three categories of antibiotic treatment were associated with an increased risk of antibiotic resistance development, in particular MDR in Gram-negative bacteria, and we graded the QoE for these outcomes as moderate.

Conclusions

We are moderately confident that antibiotic treatment leads to antibiotic resistance development in neonates and it may also induce potentially disease-promoting gut microbiota alterations. Our findings emphasize the need to reduce unnecessary antibiotic treatment in neonates.

Variability in Antibiotic Prescribing for Upper Respiratory Illnesses by Provider Specialty

OBJECTIVE

To evaluate variation in antibiotic prescribing between pediatric and nonpediatric providers for common upper respiratory illnesses.

STUDY DESIGN

Patient encounters for children aged <18 years from a regional health care system were identified. Electronic medical records from 2011 to 2016 were extracted for diagnoses of upper respiratory infection, pharyngitis, acute otitis media, and sinusitis. Encounters with competing medical diagnoses, recent hospitalization, and antibiotic prescriptions within 30 days were excluded. Adherence to antibiotic guidelines was assessed by provider training (pediatric, nonpediatric physicians, and advance practice providers). Additional factors assessed were calendar year, and patient's age, sex, insurance status, and number of sick visits in the prior year.

RESULTS

Across 6 years, 141 361 visits were examined: 43 914 for upper respiratory infection, 43 701 for pharyngitis, 43 925 for acute otitis media, and 9821 for sinusitis. Pediatricians were more likely than Advanced practice providers (APP) and nonpediatric providers to have guideline-concordant prescribing for pharyngitis (pediatricians, 66.7% [95% CI, 54.5-77.0]; nonpediatricians, 49.1% [95% CI, 36.3-62.0], APPs, 52.2% [95% CI, 39.4-64.7]; P < .0001) and sinusitis (pediatricians, 70.8% [95% CI, 53.8-83.4], nonpediatricians, 63.3% [95% CI, 46.8-77.2], APPs, 62.1% [95% CI, 45.1-76.5]; P = .48) and to withhold antibiotics for upper respiratory infection than APPs and nonpediatric providers (pediatricians, 86.6% [95% CI, 81.2-90.6], nonpediatricians, 80.8% [95% CI, 73.0-86.8], APPs, 76.8% [95% CI, 68.4-83.5]; P < .0001). Pediatricians were less likely to prescribe antibiotics for pharyngitis without a positive test for group A Streptococcus than APPs and nonpediatric providers (pediatricians, 15.1% [95% CI, 10.4-21.6], nonpediatricians, 29.4% [95% CI, 20.8-39.6], APPs, 27.2% [95% CI, 19.3-36.9]; P < .0001). First-line antibiotic prescribing for acute otitis media did not differ between provider specialties. A trend toward more guideline-concordant prescribing was seen for pharyngitis and sinusitis over the study period.

CONCLUSIONS

Pediatricians were more likely to adhere to guidelines for management of pediatric acute respiratory infections. Pediatric antibiotic stewardship efforts should also target nonpediatricians.

Saturated long-chain fatty acid-producing bacteria contribute to enhanced colonic motility in rats

BACKGROUND

The gut microbiota is closely associated with gastrointestinal (GI) motility disorder, but the mechanism(s) by which bacteria interact with and affect host GI motility remains unclear. In this study, through using metabolomic and metagenomic analyses, an animal model of neonatal maternal separation (NMS) characterized by accelerated colonic motility and gut dysbiosis was used to investigate the mechanism underlying microbiota-driven motility dysfunction.

RESULTS

An excess of intracolonic saturated long-chain fatty acids (SLCFAs) was associated with enhanced bowel motility in NMS rats. Heptadecanoic acid (C17:0) and stearic acid (C18:0), as the most abundant odd- and even-numbered carbon SLCFAs in the colon lumen, can promote rat colonic muscle contraction and increase stool frequency. Increase of SLCFAs was positively correlated with elevated abundances of Prevotella, Lactobacillus, and Alistipes. Functional annotation found that the level of bacterial LCFA biosynthesis was highly enriched in NMS group. Essential synthetic genes Fabs were largely identified from the genera Prevotella, Lactobacillus, and Alistipes. Pseudo germ-free (GF) rats receiving fecal microbiota from NMS donors exhibited increased defecation frequency and upregulated bacterial production of intracolonic SLCFAs. Modulation of gut dysbiosis by neomycin effectively attenuated GI motility and reduced bacterial SLCFA generation in the colon lumen of NMS rats.

CONCLUSIONS

These findings reveal a previously unknown relationship between gut bacteria, intracolonic SLCFAs, and host GI motility, suggesting the importance of SLCFA-producing bacteria in GI motility disorders. Further exploration of this relationship could lead to a precise medication targeting the gut microbiota for treating GI motility disorders.

Free fatty acid receptor 3 activation suppresses neurogenic motility in rat proximal colon

BACKGROUND

Short-chain fatty acids (SCFA) are microbial fermentation products absorbed by the colon. We recently reported that activation of the SCFA receptor termed free fatty acid receptor 3 (FFA3), expressed on cholinergic nerves, suppresses nicotinic acetylcholine receptor (nAChR)-mediated transepithelial anion secretion. This study aimed to clarify how activation of neurally expressed FFA3 affects colonic motor function.

METHODS

FFA3-expressing myenteric neurons were identified by immunostaining; contractions of isolated circular muscle strips obtained from rat proximal colon were measured by isometric transducers. The effect of FFA3 agonists on defecation in vivo was examined in an exogenous serotonin-induced defecation model.

KEY RESULTS

FFA3 immunoreactivity was located in nitrergic and cholinergic neurons in the myenteric plexus. In isolated circular muscle strips without mucosa and submucosa, the addition of nicotine (10 μM) or serotonin transiently relaxed the muscle through nitrergic neurons, whereas high concentrations of nicotine (100 μM) induced large-amplitude contractions that were mediated by cholinergic neurons. Pretreatment with FFA3 agonists inhibited nicotine- or serotonin-induced motility changes but had no effect on bethanechol-induced direct muscle contractions. The G_i/o inhibitor pertussis toxin reversed the inhibitory effect of an FFA3 agonist AR420626 on nicotine-evoked contractions, suggesting that FFA3 activation suppresses nAChR-mediated neural activity in myenteric neurons, consistent with an FFA3-mediated antisecretory effect. In conscious rats, exogenous serotonin increased the volume of fecal output, compared with the vehicle- or AR420626-treated groups. Pretreatment with AR420626 significantly suppressed serotonin-induced fecal output.

CONCLUSION AND INFERENCES

FFA3 is a promising target for the treatment of neurogenic diarrheal disorders by suppressing nAChR-mediated neural pathways.

Gut dysbiosis and irritable bowel syndrome: The potential role of probiotics

OBJECTIVE

To discuss the role of gut dysbiosis in the development of irritable bowel syndrome (IBS) and the impact of probiotics as a potential therapeutic measure.

METHODS

PubMed was used to search for all of the studies published over the last 15 years using the key words: "irritable bowel syndrome" and "gut dysbiosis" or "probiotic". More than 800 articles were found, but only those published in English or providing evidence-based data were included in the evaluation.

RESULTS

IBS is a common disease for which no resolutive therapy is presently available. In recent years, strong evidence of a possible relationship between modifications of the gut microbiota composition and development of IBS has been collected. Moreover, the evidence showed that attempts to treat acute infectious and post-antibiotic gastroenteritis with some probiotics were significantly effective in a great number of patients, leading many experts to suggest the use of probiotics to address all of the clinical problems associated with IBS.

CONCLUSION

The available data are promising, but presently, a precise definition of which probiotic or which mixture of probiotics is effective cannot be made. Moreover, the dose and duration of treatment has not been established. Finally, we do not know whether probiotic treatment should be different according to the type of IBS. Further studies are needed before probiotics can be considered a reliable treatment for IBS.

A Novel Prebiotic Blend Product Prevents Irritable Bowel Syndrome in Mice by Improving Gut Microbiota and Modulating Immune Response

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder yet it still lacks effective prevention therapies. The aim of this study is to determine whether a novel prebiotic blend (PB) composed of fructo-oligosaccharide (FOS), galactooligosaccharide (GOS), inulin and anthocyanins could be effective in preventing the development of IBS. We explored the possible mechanisms both in animal and in cells. Post-infectious IBS models in C57BL/6 mice were established and were pretreated with the PB, PB and probiotic strains 8 weeks in advance of infection. Eight weeks after infection, intestinal tissues were collected for assessing histomorphology, visceral sensitivity, barrier function, pro-inflammatory cytokines expression and proteomics analysis. Fecal samples were also collected for microbiota analysis. The pro-inflammatory cytokines expression in Caco-2 cells were evaluated after co-incubation with PB and Salmonella typhimurium 14028. The results showed that PB significantly decreased the pro-inflammatory cytokines both in infected Caco-2 cells and PI-IBS models. The loss of body weight, decreased expression of tight junction protein Occludin (OCLN), and changes of the microbiota composition induced by infections could be greatly improved by PB intervention (p < 0.05). The proteomics analysis revealed that this function was associated with Peroxisome proliferator-activated receptor (PPAR)γ pathway.

[Therapeutic modulation of intestinal microbiota in irritable bowel syndrome. From probiotics to fecal microbiota therapy]

BACKGROUND

An abnormal intestinal microbiota (dysbiosis) plays a central role in the pathogenesis of the irritable bowel syndrome.

METHOD

An overview of four current options for the treatment of irritable bowel syndrome, which are characterized by modulation of intestinal microbiota, is given.

RESULTS AND CONCLUSIONS

Probiotics have very different effects on the individual symptoms of the irritable bowel. The choice of the appropriate preparation should therefore be based on the clinical symptomatology. The antibiotic rifaximin is effective in selected patients. Some patients also benefit from the repetition of this therapy. A FODMAP-reduced diet has shown significant alleviation of irritable bowel symptoms in studies. The fecal microbiota therapy (FMT) is a promising treatment option. At present, however, there are no such placebo-controlled studies to assess the effectiveness of this method.

Skin-gut axis: The relationship between intestinal bacteria and skin health

The gut microbiome is an emerging area of interest in medicine. Imbalances in the gut microbiome have been linked to a number of disease states such as obesity and type 2 diabetes. The relationship between normally residing intestinal bacteria (the gut microbiota) and their potential role in the pathogenesis of skin diseases is an area of research for which we are only beginning to understand. Small studies have demonstrated underlying changes in the gut microbiome of patients with certain dermatological diseases. Interestingly, studies suggest that probiotics may have a role in the treatment of atopic dermatitis. However, the concept of the “skin-gut axis” is a newly emerging and important avenue of investigation, still lacking in pathobiological explanations. This review will introduce and describe the intestinal microbiome as it relates to skin health in a complex communication network between the immune system, endocrine system, metabolic system, and nervous system.