Dysbiosis in Functional Bowel Disorders

Factors underlying the long-term efficacy of faecal microbiota transplantation for patients with irritable bowel syndrome

The long-term effects of the transplant dose, its administration route and repeated faecal microbiota transplantation (FMT) on the outcomes of FMT for patients with irritable bowel syndrome (IBS) are unknown. This study included 171 patients (125 females and 46 males): 90 g of donor feces was administered into the large intestine (LI) in 58, into the small intestine (SI) in 57, and into the SI twice (repeated SI) in 56. The patients provided a fecal sample and completed five questionnaires at the baseline and at 2 years after FMT. Fecal bacteria and the dysbiosis index were analyzed using 16S rRNA gene PCR DNA amplification/probe. The response rates at 2 years after FMT were 47.2%, 80.9%, and 76.6% in the LI, SI, and repeated-SI groups, respectively. The response rate was significantly higher in the SI and repeated SI groups than in the LI group. IBS symptoms at 2 years after FMT were less severe in the SI and repeated-SI groups than in the LI group. Fluorescent signals of several bacteria were significantly correlated with IBS symptoms and fatigue after FMT. No long-term adverse events were observed. In conclusion, administering the transplant to the SI increased the long-term response rate and reduced IBS symptom severity compared with administering it to the LI, and led to the long-term colonization of beneficial bacteria. There was no long-term difference between one and two FMT procedures (www.clinicaltrials.gov: NCT04236843).

Study on the Therapeutic Effects and Mechanisms of Gintonin in Irritable Bowel Syndrome and Its Relationship with TRPV1, TRPV4, and NaV1.5

Irritable bowel syndrome (IBS) is a gastrointestinal (GI) disease accompanied by changes in bowel habits without any specific cause. Gintonin is a newly isolated glycoprotein from ginseng that is a lysophosphatidic acid (LPA) receptor ligand. To investigate the efficacy and mechanisms of action of gintonin in IBS, we developed a zymosan-induced IBS murine model. In addition, electrophysiological experiments were conducted to confirm the relevance of various ion channels. In mice, gintonin restored colon length and weight to normal and decreased stool scores, whilst food intake remained constant. Colon mucosal thickness and inflammation-related tumor necrosis factor-α levels were decreased by gintonin, along with a reduction in pain-related behaviors. In addition, the fecal microbiota from gintonin-treated mice had relatively more Lactobacillaceae and Lachnospiraceae and less Bacteroidaceae than microbiota from the control mice. Moreover, gintonin inhibited transient receptor potential vanilloid (TRPV) 1 and TRPV4 associated with visceral hypersensitivity and voltage-gated Na+ 1.5 channels associated with GI function. These results suggest that gintonin may be one of the effective components in the treatment of IBS.

Irritable Bowel Syndrome in the Elderly Population: A Comprehensive Review

Irritable bowel syndrome (IBS) is a fairly common functional digestive disorder; it occurs at any age but it is more common in adults and older adults. Patients experience a series of symptoms in which abdominal pain and changes in bowel movements stand out; some studies have revealed a possible association between IBS and psychological problems, such as anxiety and depression. Recent findings point to disorders of gut-brain interaction, disruption and alteration of gut microbiota and dysbiosis as key factors in the etiopathogenesis of IBS; aging is also one the factors involved. Most patients diagnosed with IBS required pharmacotherapy, greater caution needs to be considered when treating older patients because of the risk-benefit profile in the elderly. In this scenario, probiotics and non-pharmacological treatments appear as safe and accessible options. Clinicians must take into consideration the unique biopsychosocial factors in older adults when treating IBS. We aim to review critically recent literature on the topic of IBS as there is a need for consolidated guidelines.

Gut microbial signatures of patients with diarrhea-predominant irritable bowel syndrome and their healthy relatives

AIMS

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder, encompassing diarrhea-predominant irritable bowel syndrome (IBS-D). Here, we utilized 16S rDNA gene sequencing to identify potential microbial drivers of IBS-D.

METHODS AND RESULTS

A total of 30 healthy relatives and 27 patients with IBS-D were recruited. Clinical data and fecal samples were collected from patients and controls. 16S rDNA gene sequencing was performed to obtain fecal bacterial data. Differences in community composition were evaluated utilizing analysis of similarity (ANOSIM) using Bray-Curtis dissimilarity. The Wilcoxon rank sum test was used to compare differences in taxa and functional pathways. Finally, the key gut microbiota was identified using the random forest algorithm. Gut microbiota diversity, estimated through the Observe, Chao1, and abundance-based coverage estimator (ACE) indices, was significantly lower in the IBS-D patients than in the healthy relatives. ANOSIM analysis further confirmed significant differences in the composition of the gut microbiota between IBS-D patients and healthy relatives, with an R value of 0.106 and a P-value of 0.005. Notably, the IBS-D patients exhibited a significant enrichment of specific bacterial genera, including Fusicatenibacter, Streptococcus, and Klebsiella, which may possess potential pathogenic properties. In particular, the bacterial genus Klebsiella demonstrated a positive correlation with irritable bowel syndrome severity scoring system scores. Conversely, healthy subjects showed enrichment of bacterial genera such as Alistipes, Akkermansia, and Dialister, which may be beneficial bacteria in IBS-D. Utilizing the random forest model, we developed a discriminative model for IBS-D based on differential bacterial genera. This model exhibited impressive performance, with an area under the curve value of 0.90. Additionally, our analysis did not reveal any gender-specific differences in the microbiota community composition among IBS-D patients.

CONCLUSIONS

Our findings offer preliminary insights into the potential relationship between intestinal microbiota and IBS-D. The identification model for IBS-D, grounded in gut microbiota, holds promising prospects for improving early diagnosis of IBS-D.

Increasing the transplant dose and repeating faecal microbiota transplantation results in the responses of male patients with IBS reaching those of females

BACKGROUND

Faecal microbiota transplantation (FMT) performed with a proper protocol is a safe treatment for IBS that has high efficacy and durable effects. Females have been reported to respond better than males to FMT. The present study aimed at determining whether increasing the transplant dose or repeating FMT improve the responses of males to FMT.

METHODS

This study included 186 IBS patients (131 females and 55 males) who were randomized at a 1:1:1 ratio to receive 90 g of donor faeces once into the large intestine, once into the small intestine or twice into the small intestine. Patients completed five questionnaires that assessed their symptoms and quality of life, and provided faecal samples at baseline and at 3, 6 and 12 months after FMT. The faecal bacterial profile and dysbiosis index were determined using 16S rRNA gene PCR DNA amplification covering variable genes V3-V9.

RESULTS

The response rates to FMT at all observation times did not differ significantly between females and males regardless of the transplant administration route or whether it was repeated. Faecal Alistipes levels were higher in females than in males at baseline and increased in both females and males after FMT. In the repeated group, the Alistipes levels did not differ between females and males after FMT.

CONCLUSIONS

Increasing the transplant dose and repeating FMT results in the responses of male IBS patients to FMT reaching those of females regardless of the administration route. Alistipes spp. levels appear to play a role in this improvement.www.clinicaltrials.gov (NCT04236843).

Factors affecting the outcome of fecal microbiota transplantation for patients with irritable bowel syndrome

BACKGROUND

A previous study that introduced a Fecal microbiota transplantation (FMT) protocol with a high efficacy applied a combination of favorable factors.

AIMS

The present study aimed to evaluate some of these factors.

METHODS

This study included 186 patients with IBS randomized 1:1:1 into transplant administered to the colon (single LI), to the duodenum (single SI), or to the duodenum twice with a 1-week interval (repeated SI). The patients provided a fecal sample and were asked to complete five questionnaires at baseline and at 3, 6, and 12 months after FMT. The fecal bacteria composition and dysbiosis index (DI) were analyzed using 16S rRNA gene PCR DNA amplification/probe hybridization covering regions V3-V9.

RESULTS

The response rate was significantly higher in single SI than in single LI at 12 months after FMT. Symptoms and quality of life improved in all the treated groups at all time intervals after FMT. The abdominal symptoms were significantly reduced and the quality of life improved for repeated SI compared with for single SI. DI significantly decreased in all the treated groups at all observation times after FMT. The bacterial profiles changed in all groups at all observation intervals. However, these changes differed between single LI and single SI/repeated SI.

CONCLUSION

Administrating transplant to the small intestine had a long-term higher response rate than that administrated to the large intestine, and led to long-term colonization of beneficial bacteria. Repeating FMT had more effect on symptoms and quality of life than a single FMT. (www.

CLINICALTRIALS

gov: NCT04236843).

Impacts of gut microbiota alteration on age-related chronic liver diseases

The gut microbiome and its metabolites are involved in developing and progressing liver disease. Various liver illnesses, such as non-alcoholic fatty liver disease, alcoholic liver disease, hepatitis C, and hepatocellular carcinoma, are made worse and have worse prognoses with aging. Dysbiosis, which occurs when the symbiosis between the microbiota and the host is disrupted, can significantly negatively impact health. Liver disease is linked to qualitative changes, such as an increase in hazardous bacteria and a decrease in good bacteria, as well as quantitative changes in the overall amount of bacteria (overgrowth). Intestinal gut microbiota and their metabolites may lead to chronic liver disease development through various mechanisms, such as increasing gut permeability, persistent systemic inflammation, production of SCFA, bile acids, and alteration in metabolism. Age-related gut dysbiosis can disrupt the communication between gut microbiota and the host, impacting the host's health and lifespan. With aging, a gradual loss of the ability to maintain homeostasis because of structural alteration and gut dysbiosis leads to the disease progression in end-stage liver disease. Recently chronic liver disease has been identified as a global problem. A large number of patients are receiving liver transplants yearly. Thereby gut microbiome ecology is changing in the patients of the gut due to the changes in pathophysiology during the preoperative stage. The present review summarises the age-associated dysbiosis of gut microbial composition and its contribution to chronic liver disease. This review also provides information about the impact of liver transplant on the gut microbiome and possible disadvantageous effects of alteration in gut microbiota.

Intestinal bacteria associated with irritable bowel syndrome and chronic fatigue

The etiology of irritable bowel syndrome (IBS) is unknown. Abnormal intestinal bacterial profiles and low bacterial diversity appear to play important roles in the pathophysiology of IBS. This narrative review was designed to present recent observations made relating to fecal microbiota transplantation (FMT), which implicate possible roles of 11 intestinal bacteria in the pathophysiology of IBS. The intestinal abundances of nine of these bacteria increased after FMT in patients with IBS, and these increases were inversely correlated with IBS symptoms and fatigue severity. These bacteria were Alistipes spp., Faecalibacterium prausnitzii, Eubacterium biforme, Holdemanella biformis, Prevotella spp., Bacteroides stercoris, Parabacteroides johnsonii, Bacteroides zoogleoformans, and Lactobacillus spp. The intestinal abundances of two bacteria were decreased in patients with IBS after FMT and were correlated with the severity of IBS symptoms and fatigue (Streptococcus thermophilus and Coprobacillus cateniformis). Ten of these bacteria are anaerobic and one (Streptococcus thermophilus) is facultative anaerobic. Several of these bacteria produce short-chain fatty acids, especially butyrate, which is used as an energy source by large intestine epithelial cells. Moreover, it modulates the immune response and hypersensitivity of the large intestine and decreases intestinal cell permeability and intestinal motility. These bacteria could be used as probiotics to improve these conditions. Protein-rich diets could increase the intestinal abundance of Alistipes, and plant-rich diet could increase the intestinal abundance of Prevotella spp., and consequently improve IBS and fatigue.

The Association between Dysbiosis and Neurological Conditions Often Manifesting with Chronic Pain

The prevalence of neurological conditions which manifest with chronic pain is increasing globally, where the World Health Organisation has now classified chronic pain as a risk factor for death by suicide. While many chronic pain conditions have a definitive underlying aetiology, non-somatic conditions represent difficult-to-diagnose and difficult-to-treat public health issues. The interaction of the immune system and nervous system has become an important area in understanding the occurrence of neuroinflammation, nociception, peripheral and central sensitisation seen in chronic pain. More recently, however, the role of the resident microbial species in the human gastrointestinal tract has become evident. Dysbiosis, an alteration in the microbial species present in favour of non-beneficial and pathogenic species has emerged as important in many chronic pain conditions, including functional somatic syndromes, autoimmune disease and neurological diseases. In particular, a decreased abundance of small chain fatty acid, e.g., butyrate-producing bacteria, including Faecalibacterium, Firmicutes and some Bacteroides spp., is frequently evident in morbidities associated with long-term pain. Microbes involved in the production of neurotransmitters serotonin, GABA, glutamate and dopamine, which mediate the gut-brain, axis are also important. This review outlines the dysbiosis present in many disease states manifesting with chronic pain, where an overlap in morbidities is also frequently present in patients.

Efficacy of Fecal Microbiota Transplantation for Patients With Irritable Bowel Syndrome at 3 Years After Transplantation

BACKGROUND & AIMS

The long-term efficacy and possible adverse events of fecal microbiota transplantation (FMT) for irritable bowel syndrome (IBS) are unknown. This study performed a 3-year follow-up of the patients in our previous clinical trial to clarify these aspects.

METHODS

This study included 125 patients (104 females, and 21 males): 38 in a placebo group, 42 who received 30 g of donor feces, and 45 who received 60 g of donor feces. Feces was administered to the duodenum. The patients provided a fecal sample and completed 5 questionnaires at baseline and at 2 and 3 years after FMT. Fecal bacteria and dysbiosis index were analyzed using 16S ribosomal RNA gene polymerase chain reaction DNA amplification/probe hybridization covering the V3 to V9 regions.

RESULTS

Response rates were 26.3%, 69.1%, and 77.8% in the placebo, 30-g, and 60-g groups, respectively, at 2 years after FMT, and 27.0%, 64.9%, and 71.8%, respectively, at 3 years after FMT. The response rates were significantly higher in the 30-g and 60-g groups than in the placebo group. Patients in the 30-g and 60-g groups had significantly fewer IBS symptoms and fatigue, and a greater quality of life both at 2 and 3 years after FMT. The dysbiosis index decreased only in the active treatment groups at 2 and 3 years after FMT. Fluorescent signals of 10 bacteria had significant correlations with IBS symptoms and fatigue after FMT in the 30-g and 60-g groups. No long-term adverse events were recorded.

CONCLUSIONS

FMT performed according to our protocol resulted in high response rates and long-standing effects with only few mild self-limited adverse events. This study was registered at www.

CLINICALTRIALS

gov (NCT03822299).

Irritable bowel syndrome patients who are not likely to respond to fecal microbiota transplantation

BACKGROUND

Fecal microbiota transplantation (FMT) interventions have recently been advocated to not succeed in every irritable bowel syndrome (IBS) patient, since the outcome of FMT varies with the IBS subset. This study investigated the factors potentially affecting FMT response using the same patient cohort used in our previous study.

METHODS

This study included 109 patients who received allogenic FMT. Patients completed five questionnaires that assessed their symptoms and quality of life at baseline and at 2 weeks, 1 month, and 3 months after FMT. Patients also provided fecal samples at baseline and 1 month after FMT. The fecal bacterial profile and dysbiosis index (DI) were determined using 16S rRNA gene PCR DNA amplification covering variable genes V3-V9. Response to FMT was defined as a decrease of ≥50 points in the total IBS-SSS score after FMT.

RESULTS

An IBS patient's response or nonresponse to FMT was not determined by age, IBS duration, IBS subtype, IBS symptoms, fatigue, quality of life, or DI. There were more male nonresponders than responders, and the fluorescence signals of Alistipes were lower in nonresponders than in responders.

CONCLUSIONS

We concluded that IBS patients who are male and/or have low fecal Alistipes levels are most likely to not respond to FMT treatment. Whether low fecal Alistipes levels could be used as a marker for predicting the outcome of FMT remains to be determined. www.

CLINICALTRIALS

gov (NCT03822299).

The fecal microbiota transplantation response differs between patients with severe and moderate irritable bowel symptoms

OBJECTIVES

Fecal microbiota transplantation (FMT) is a promising intervention for patients with irritable bowel syndrome (IBS). The present study aimed to identify any differences in FMT response between patients with severe and moderate IBS symptoms.

MATERIALS AND METHOD

The study included the 164 patients who participated in our previous study, of which 96 (58.5%) and 68 (41.5%) had severe (S-IBS-S) and moderate (Mo-IBS-S) IBS, respectively. The patients were randomly divided into a placebo group (own feces) and 30-g and 60-g (donor feces) FMT groups. Patients completed three questionnaires that assessed their symptoms and quality of life at baseline and at 2 weeks, 1 month, and 3 months after FMT, and provided fecal samples before and 1 month after FMT. The fecal bacteria were analyzed using the 16S rRNA gene in PCR DNA amplification covering the V3-V9 variable genes.

RESULTS

Response rates of the placebo group did not differ between S-IBS-S and Mo-IBS-S patients at 2 weeks, 1 month and 3 months after FMT. The response rates in the active treatment group were higher in S-IBS-S patients than in Mo-IBS-S patients at each observation time. FMT reduced abdominal symptoms and fatigue and improved the quality of life in patients with both severe and moderate IBS. Patients with S-IBS-S had higher levels of Eubacterium siraeum, and lower levels of Eubacterium rectale than Mo-IBS-S, after FMT.

CONCLUSION

Patients with S-IBS-S have a higher response rate to FMT and a marked improvement in fatigue and in quality of life compared with those with Mo-IBS-S. The clinical trial registration number is NCT03822299 and is available at www.clinicaltrials.gov.

The microbiome of patients with irritable bowel syndrome: pathophysiology and applied aspects

Irritable bowel syndrome is a clinically and socially significant disease. The pathophysiology, the clinical manifestations of this disease and the  prognosis for  the patient are closely related to dysbiotic disorders of  the intestine. This review summarizes the ideas about changes in the intestinal microbiome in patients with irritable bowel syndrome. The pathogenetically substantiated approaches to the correction of dysbiosis that improving treatment outcomes are also considered. The results of the FLORAVIE clinical trial, which were discussed at the Expert Council “Identification of indications for prescribing probiotics in patients with irritable bowel syndrome” on March 18, 2022, are presented. Members of the Expert Council, Russian and international clinical guidelines emphasize the relevance of targeted probiotics administration. It was noticed that only strain specificity allows predicting a positive clinical response and has a certain evidence base. In this regard, the FLORAVIE study, conducted in real clinical practice in patients with predominantly severe forms of irritable bowel syndrome, is clinically relevant. It has been demonstrated that 30-day administration of the B. longum 35624 probiotic has reduced the severity of irritable bowel syndrome and has improved the quality of life in all subgroups of patients, especially in those with the most severe form of the disease. The data presented indicate that the inclusion of probiotic strains with proven mechanism of action in the complex therapy of irritable bowel syndrome can lead to the transformation of the course of the disease and improve the quality of life of patients. The high level of evidence made it possible to introduce the probiotic strain Bifidobacterium longum 35624 into a number of domestic and foreign guidelines.

 

Involvement of toll-like receptor 5 in mouse model of colonic hypersensitivity induced by neonatal maternal separation

BACKGROUND

Chronic abdominal pain is the most common cause for gastroenterology consultation and is frequently associated with functional gastrointestinal disorders including irritable bowel syndrome and inflammatory bowel disease. These disorders present similar brain/gut/microbiota trialogue alterations, associated with abnormal intestinal permeability, intestinal dysbiosis and colonic hypersensitivity (CHS). Intestinal dysbiosis can alter colon homeostasis leading to abnormal activation of the innate immunity that promotes CHS, perhaps involving the toll-like receptors (TLRs), which play a central role in innate immunity.

AIM

To understand the mechanisms between early life event paradigm on intestinal permeability, fecal microbiota composition and CHS development in mice with TLRs expression in colonocytes.

METHODS

Maternal separation model (NMS) CHS model, which mimics deleterious events in childhood that can induce a wide range of chronic disorders during adulthood were used. Colonic sensitivity of NMS mice was evaluated by colorectal distension (CRD) coupled with intracolonic pressure variation (IPV) measurement. Fecal microbiota composition was analyzed by 16S rRNA sequencing from weaning to CRD periods. TLR mRNA expression was evaluated in colonocytes. Additionally, the effect of acute intrarectal instillation of the TLR5 agonist flagellin (FliC) on CHS in adult naive wildtype mice was analyzed.

RESULTS

Around 50% of NMS mice exhibited increased intestinal permeability and CHS associated with intestinal dysbiosis, characterized by a significant decrease of species richness, an alteration of the core fecal microbiota and a specific increased relative abundance of flagellated bacteria. Only TLR5 mRNA expression was increased in colonocytes of NMS mice with CHS. Acute intrarectal instillation of FliC induced transient increase of IPV, reflecting transient CHS appearance.

CONCLUSION

Altogether, these data suggest a pathophysiological continuum between intestinal dysbiosis and CHS, with a role for TLR5.

Non-pharmacological management of pediatric functional abdominal pain disorders: Current evidence and future perspectives

Functional abdominal pain disorders (FAPDs) are an important and prevalent cause of functional gastrointestinal disorders among children, encompassing the diagnoses of functional dyspepsia, irritable bowel syndrome, abdominal migraine, and the one not previously present in Rome III, functional abdominal pain not otherwise specified. In the absence of sufficiently effective and safe pharmacological treatments for this public problem, non-pharmacological therapies emerge as a viable means of treating these patients, avoiding not only possible side effects, but also unnecessary prescription, since many of the pharmacological treatments prescribed do not have good efficacy when compared to placebo. Thus, the present study provides a review of current and relevant evidence on non-pharmacological management of FAPDs, covering the most commonly indicated treatments, from cognitive behavioral therapy to meditation, acupuncture, yoga, massage, spinal manipulation, moxibustion, and physical activities. In addition, this article also analyzes the quality of publications in the area, assessing whether it is possible to state if non-pharmacological therapies are viable, safe, and sufficiently well-based for an appropriate and effective prescription of these treatments. Finally, it is possible to observe an increase not only in the number of publications on the non-pharmacological treatments for FAPDs in recent years, but also an increase in the quality of these publications. Finally, the sample selection of satisfactory age groups in these studies enables the formulation of specific guidelines for this age group, thus avoiding the need for adaptation of prescriptions initially made for adults, but for children use.

Long-term effects of fecal microbiota transplantation (FMT) in patients with irritable bowel syndrome

BACKGROUND

We recently found fecal microbiota transplantation (FMT) in irritable bowel syndrome (IBS) patients to be an effective and safe treatment after 3 months. The present follow-up study investigated the efficacy and safety of FMT at 1 year after treatment.

METHODS

This study included 77 of the 91 IBS patients who had responded to FMT in our previous study. Patients provided a fecal sample and completed five questionnaires to assess their symptoms and quality of life at 1 year after FMT. The dysbiosis index (DI) and fecal bacterial profile were analyzed using a 16S rRNA gene-based DNA probe hybridization. The levels of fecal short-chain fatty acids (SCFAs) were determined by gas chromatography.

RESULTS

There was a persistent response to FMT at 1 year after treatment in 32 (86.5%) and 35 (87.5%) patients who received 30-g and 60-g FMT, respectively. In the 30-g FMT group, 12 (32.4%) and 8 (21.6%) patients showed complete remission at 1 year and 3 months, respectively; the corresponding numbers in the 60-g FMT group were 18 (45%) and 11 (27.5%), respectively. Abdominal symptoms and the quality of life were improved at 1 year compared with after 3 months. These findings were accompanied by comprehensive changes in the fecal bacterial profile and SCFAs.

CONCLUSIONS

Most of the IBS patients maintained a response at 1 year after FMT. Moreover, the improvements in symptoms and quality of life increased over time. Changes in DI, fecal bacterial profile and SCFAs were more comprehensive at 1 year than after 3 months. www.clinicaltrials.gov (NCT03822299).

Current status of fecal microbiota transplantation for irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal functional disorder. Although IBS is a benign condition, it reduces the quality of life considerably. While there is currently no effective treatment for this disorder, fecal microbiota transplantation (FMT) seems to be promising.

PURPOSE

The aim of this review was to analysis possible factors affecting the success or failure of the randomized controlled trials (RCTs) of FMT for IBS and highlighting the gaps in our knowledge that need to be filled and of sketching a possible model for successful FMT in IBS patients.

METHODS

A systematic search was conducted of literature published in English from January 2015 to December 2020 using the keywords: fecal microbiota transplantation, randomized trials, and IBS.

KEY RESULTS

Seven randomized controlled trials (RCTs) on the efficacy of FMT for IBS were found in the literature. Four of the seven RCTs found various positive effects, while the other three did not find any effect.

CONCLUSIONS AND INFERENCES

The efficacy of FMT for IBS appears to be donor-dependent. The effective (super) donor would need to have a favorable microbiota signature, and 11 clinical criteria that are known to be associated with a favorable microbiota have been suggested for selecting FMT donors for IBS. Comparing the microbiota of the effective donors with those of healthy subjects would reveal the favorable microbiota signature required for a super-donor. However, the studies reviewed were not designed to compare efficacy of different donor types. The dose of the fecal transplant is also an important factor influencing the outcome of FMT for IBS. However, further studies designed to test the effect of fecal transplant dose are needed to answer this question. Administering the fecal transplant to either the small or large intestine seems to be effective, but the optimal route of administration remains to be determined. Moreover, whether single or repeated FMT is more effective is also still unclear. A 1-year follow-up of IBS patients who received FMT showed that adverse events of abdominal pain, diarrhea, and constipation were both mild and self-limiting.

Fecal microbiota transplantation for irritable bowel syndrome: An intervention for the 21st century

Irritable bowel syndrome (IBS) affects about 12% of the global population. Although IBS does not develop into a serious disease or increase mortality, it results in a considerable reduction in the quality of life. The etiology of IBS is not known, but the intestinal microbiota appears to play a pivotal role in its pathophysiology. There is no effective treatment for IBS, and so the applied treatments clinically focus on symptom relief. Fecal microbiota transplantation (FMT), an old Chinese treatment, has been applied to IBS patients in seven randomized controlled trials (RCTs). Positive effects on IBS symptoms in various degrees were obtained in four of these RCTs, while there was no effect in the remaining three. Across the seven RCTs there were marked differences in the selection processes for the donor and treated patients, the transplant dose, the route of administration, and the methods used to measure how the patients responded to FMT. The present frontier discusses these differences and proposes: (1) criteria for selecting an effective donor (superdonor); (2) selection criteria for patients that are suitable for FMT; (3) the optimal FMT dose; and (4) the route of transplant administration. FMT appears to be safe, with only mild, self-limiting side effects of abdominal pain, cramping, tenderness, diarrhea, and constipation. Although it is early to speculate about the mechanisms underlying the effects of FMT, the available data suggest that changes in the intestinal bacteria accompanied by changes in fermentation patterns and fermentation products (specifically short-chain fatty acids) play an important role in improving the IBS symptoms seen after FMT. FMT appears to be a promising treatment for IBS, but further studies are needed before it can be applied in everyday clinical practice.

Responses to faecal microbiota transplantation in female and male patients with irritable bowel syndrome

BACKGROUND

Faecal microbiota transplantation (FMT) seems to be a promising treatment for irritable bowel syndrome (IBS) patients. In Western countries (United States and Europe), there is a female predominance in IBS. A sex difference in the response to FMT has been reported recently in IBS patients.

AIM

To investigate whether there was a sex difference in the response to FMT in the IBS patients who were included in our previous randomized controlled trial of the efficacy of FMT.

METHODS

The study included 164 IBS patients who participated in our previous randomized controlled trial. These patients had moderate-to-severe IBS symptoms belonging to the IBS-D (diarrhoea-predominant), IBS-C (constipation-predominant) and IBS-M (mixed) subtypes, and had not responded to the National Institute for Health and Care Excellence (NICE)-modified diet. They belonged in three groups: placebo (own faeces), and active treated group (30-g or 60-g superdonor faeces). The patients completed the IBS severity scoring system (IBS-SSS), Fatigue Assessment Scale (FAS) and the IBS quality of life scale (IBS-QoL) questionnaires at the baseline and 2 wk, 1 mo and 3 mo after FMT. They also provided faecal samples at the baseline and 1 mo after FMT. The faecal bacteria profile and dysbiosis were determined using the 16S rRNA gene polymerase chain reaction DNA amplification covering V3-V9; probe labelling by single nucleotide extension and signal detection. The levels of short-chain fatty acids (SCFAs) were determined by gas chromatography and flame ionization.

RESULTS

There was no sex difference in the response to FMT either in the placebo group or active treated group. There was no difference between females and males in either the placebo group or actively treated groups in the total score on the IBS-SSS, FAS or IBS-QoL, in dysbiosis, or in the faecal bacteria or SCFA level. However, the response rate was significantly higher in females with diarrhoea-predominant (IBS-D) than that of males at 1 mo, and 3 mo after FMT. Moreover, IBS-SSS total score was significantly lower in female patients with IBS-D than that of male patients both 1 mo and 3 mo after FMT.

CONCLUSION

There was no sex difference in the response to FMT among IBS patients with moderate-to-severe symptoms who had previously not responded to NICE-modified diet. However, female patients with IBS-D respond better and have higher reduction of symptoms than males after FMT.

The Natural History of Chronic Unexplained Gastrointestinal Disorders and Gastroesophageal Reflux During 20 Years: A US Population-Based Study

OBJECTIVE

To explore the natural history of chronic unexplained gastrointestinal (GI) symptoms and to determine the longitudinal trends of prevalence during a 20-year period in a single US community.

METHODS

Between January 1, 1990, and December 31, 2009, valid self-report questionnaires of GI symptoms were mailed to randomly selected cohorts of a community. The study used respondents who answered questions on 1 or more of 3 surveys (initial, 1990-1992; second, 2003-2004; and third, 2008-2009). The trends of prevalence of GI symptoms over time were analyzed in responders who completed 3 surveys, and the natural history or transition was evaluated.

RESULTS

The overall prevalence of major symptom groupings including gastroesophageal reflux disease was consistent among residents in a community on 3 survey time points (1990-1992, 2003-2004, and 2008-2009). The transitions of GI symptoms were common in 228 patients who responded to all 3 surveys; only 29% had the same symptom category in 3 surveys; otherwise, symptoms changed over time, resolving, recurring, or transitioning to another disorder. Observed proportions of symptom transitions were significantly different from expected during 20 years (P<.001). Higher non-GI somatic symptom scores were significantly associated with both symptom transitions (odds ratio, 3.9; 95% CI, 1.38 to 10.77) and having sustained symptoms (odds ratio, 12.7; 95% CI, 4.62 to 34.90).

CONCLUSION

The overall population prevalence of chronic unexplained GI symptoms is stable, but in individuals, transitions seem to be the rule. As these various GI syndromes appear to be so intimately interconnected, the common underlying pathogenesis may account for a major subgroup of chronic unexplained GI disorders.

GUT MICROBIOTA, PREBIOTICS, PROBIOTICS, AND SYNBIOTICS IN GASTROINTESTINAL AND LIVER DISEASES: PROCEEDINGS OF A JOINT MEETING OF THE BRAZILIAN SOCIETY OF HEPATOLOGY (SBH), BRAZILIAN NUCLEUS FOR THE STUDY OF HELICOBACTER PYLORI AND MICROBIOTA (NBEHPM), AND BRAZILIAN FEDERATION OF GASTROENTEROLOGY (FBG)

Over the last years, there is growing evidence that microorganisms are involved in the maintenance of our health and are related to various diseases, both intestinal and extraintestinal. Changes in the gut microbiota appears to be a key element in the pathogenesis of hepatic and gastrointestinal disorders, including non-alcoholic fatty liver disease, alcoholic liver disease, liver cirrhosis, inflammatory bowel disease, irritable bowel syndrome, and Clostridium difficile - associated diarrhea. In 2019, the Brazilian Society of Hepatology (SBH) in cooperation with the Brazilian Nucleus for the Study of Helicobacter Pylori and Microbiota (NBEHPM), and Brazilian Federation of Gastroenterology (FBG) sponsored a joint meeting on gut microbiota and the use of prebiotics, probiotics, and synbiotics in gastrointestinal and liver diseases. This paper summarizes the proceedings of the aforementioned meeting. It is intended to provide practical information about this topic, addressing the latest discoveries and indicating areas for future studies.

Clinical Management of Gastrointestinal Disease in the Common Marmoset (Callithrix jacchus)

Gastrointestinal disease is a frequently encountered problem among captive common marmoset (Callithrix jacchus) colonies. Management can be challenging due to the number of etiologies responsible for gastrointestinal disease in this species, limitations on diagnostic capabilities, and lack of effective treatments. Understanding commonly described GI diseases in the captive marmoset can provide insight on the impact these diseases have on research studies and aid in the development of appropriate management strategies. A review of commonly encountered GI disease processes as well as routinely implicated causes of GI disease in the common marmoset are provided. Current strategies in clinical management of GI disease in the common marmoset, including approaches to colony health, diagnostic testing, and commonly employed treatments are discussed.

Innovative Animal Model of DSS-Induced Ulcerative Colitis in Pseudo Germ-Free Mice

The aim of this study was to investigate the use of a standardized animal model subjected to antibiotic treatment, and the effects of this treatment on the course of dextran sodium sulphate (DSS)-induced colitis in mice. By decontamination with selective antibiotics and observation of pathogenesis of ulcerative colitis (UC) induced chemically by exposure of mice to various concentrations of DSS, we obtained an optimum animal PGF model of acute UC manifested by mucin depletion, epithelial degeneration and necrosis, leading to the disappearance of epithelial cells, infiltration of lamina propria and submucosa with neutrophils, cryptitis, and accompanied by decreased viability of intestinal microbiota, loss of body weight, dehydration, moderate rectal bleeding, and a decrease in the selected markers of cellular proliferation and apoptosis. The obtained PGF model did not exhibit changes that could contribute to inflammation by means of alteration of the metabolic status and the induced dysbiosis did not serve as a bearer of pathogenic microorganisms participating in development of ulcerative colitis. The inflammatory process was induced particularly by exposure to DSS and its toxic action on compactness and integrity of mucosal barrier in the large intestine. This offers new possibilities of the use of this animal model in studies with or without participation of pathogenic microbiota in IBD pathogenesis.

Paediatric functional abdominal pain disorders

Paediatric functional abdominal pain disorders, currently referred to as disorders of gut-brain interaction, comprise irritable bowel syndrome, functional dyspepsia, abdominal migraine and functional abdominal pain not otherwise specified, as defined by the Rome IV diagnostic criteria. Functional abdominal pain disorders are common disorders with a prevalence of 3-16% depending on country, age and sex. A greater understanding of aetiopathogenesis and pathophysiology is emerging and includes intestinal components (inflammation, motility and the microbiota), central factors (psychological aspects, sensitization and/or differences in connectivity or activity of certain brain regions) as well as extrinsic factors (infections). In particular, the timing of disruption of the microbiota-gut-brain axis seems to be important. Diagnosis is challenging but is primarily based on clinical symptoms and exclusion of other organic causes, with an emphasis on avoiding unnecessary invasive diagnostic procedures. The available pharmacological interventions are limited in children and, therefore, management has focused on combined approaches, including mind-targeted interventions (hypnotherapy and cognitive behavioural therapy), diet (probiotics) and percutaneous electrical nerve field stimulation. The evidence for their clinical efficacy, although limited, is favourable, with positive impacts on symptoms and overall quality of life. The coming decades hold promise for improved understanding and management of these enigmatic disorders.

The trace aminergic system: a gender-sensitive therapeutic target for IBS?

Due to a lack of specific or sensitive biomarkers, drug discovery advances have been limited for individuals suffering from irritable bowel syndrome (IBS). While current therapies provide symptomatic relief, inflammation itself is relatively neglected, despite the presence of chronic immune activation and innate immune system dysfunction. Moreover, considering the microgenderome concept, gender is a significant aetiological risk factor. We believe that we have pinpointed a "missing link" that connects gender, dysbiosis, diet, and inflammation in the context of IBS, which may be manipulated as therapeutic target. The trace aminergic system is conveniently positioned at the interface of the gut microbiome, dietary nutrients and by-products, and mucosal immunity. Almost all leukocyte populations express trace amine associated receptors and significant amounts of trace amines originate from both food and the gut microbiota. Additionally, although IBS-specific data are sparse, existing data supports an interpretation in favour of a gender dependence in trace aminergic signalling. As such, trace aminergic signalling may be altered by fluctuations of especially female reproductive hormones. Utilizing a multidisciplinary approach, this review discusses potential mechanisms of actions, which include hyperreactivity of the immune system and aberrant serotonin signalling, and links outcomes to the symptomology clinically prevalent in IBS. Taken together, it is feasible that the additional level of regulation by the trace aminergic system in IBS has been overlooked, until now. As such, we suggest that components of the trace aminergic system be considered targets for future therapeutic action, with the specific focus of reducing oxidative stress and inflammation.

Efficacy of faecal microbiota transplantation for patients with irritable bowel syndrome in a randomised, double-blind, placebo-controlled study

OBJECTIVE

Faecal microbiota transplantation (FMT) from healthy donors to patients with irritable bowel syndrome (IBS) has been attempted in two previous double-blind, placebo-controlled studies. While one of those studies found improvement of the IBS symptoms, the other found no effect. The present study was conducted to clarify these contradictory findings.

DESIGN

This randomised, double-blind, placebo-controlled study randomised 165 patients with IBS to placebo (own faeces), 30 g FMT or 60 g FMT at a ratio of 1:1:1. The material for FMT was obtained from one healthy, well-characterised donor, frozen and administered via gastroscope. The primary outcome was a reduction in the IBS symptoms at 3 months after FMT (response). A response was defined as a decrease of 50 or more points in the total IBS symptom score. The secondary outcome was a reduction in the dysbiosis index (DI) and a change in the intestinal bacterial profile, analysed by 16S rRNA gene sequencing, at 1 month following FMT.

RESULTS

Responses occurred in 23.6%, 76.9% (p<0.0001) and 89.1% (p<00.0001) of the patients who received placebo, 30 g FMT and 60 g FMT, respectively. These were accompanied by significant improvements in fatigue and the quality of life in patients who received FMT. The intestinal bacterial profiles changed also significantly in the groups received FMT. The FMT adverse events were mild self-limiting gastrointestinal symptoms.

CONCLUSIONS

FMT is an effective treatment for patients with IBS. Utilising a well-defined donor with a normal DI and favourable specific microbial signature is essential for successful FMT. The response to FMT increases with the dose. Trial registration www.clinicaltrials.gov (NCT03822299) and www.cristin.no (ID657402).

Intestinal epithelial barrier and neuromuscular compartment in health and disease

A number of digestive and extra-digestive disorders, including inflammatory bowel diseases, irritable bowel syndrome, intestinal infections, metabolic syndrome and neuropsychiatric disorders, share a set of clinical features at gastrointestinal level, such as infrequent bowel movements, abdominal distension, constipation and secretory dysfunctions. Several lines of evidence indicate that morphological and molecular changes in intestinal epithelial barrier and enteric neuromuscular compartment contribute to alterations of both bowel motor and secretory functions in digestive and extra-digestive diseases. The present review has been conceived to provide a comprehensive and critical overview of the available knowledge on the morphological and molecular changes occurring in intestinal epithelial barrier and enteric neuromuscular compartment in both digestive and extra-digestive diseases. In addition, our intent was to highlight whether these morphological and molecular alterations could represent a common path (or share some common features) driving the pathophysiology of bowel motor dysfunctions and related symptoms associated with digestive and extra-digestive disorders. This assessment might help to identify novel targets of potential usefulness to develop original pharmacological approaches for the therapeutic management of such disturbances.

Possible role of intestinal stem cells in the pathophysiology of irritable bowel syndrome

The pathophysiology of irritable bowel syndrome (IBS) is not completely understood. However, several factors are known to play a role in pathophysiology of IBS such as genetics, diet, gut microbiota, gut endocrine cells, stress and low-grade inflammation. Understanding the pathophysiology of IBS may open the way for new treatment approaches. Low density of intestinal stem cells and low differentiation toward enteroendocrine cells has been reported recently in patients with IBS. These abnormalities are believed to be the cause of the low density of enteroendocrine cells seen in patients with IBS. Enteroendocrine cells regulate gastrointestinal motility, secretion, absorption and visceral sensitivity. Gastrointestinal dysmotility, abnormal absorption/secretion and visceral hypersensitivity are all seen in patients with IBS and haven been attributed to the low density the intestinal enteroendocrine cells in these patients. The present review conducted a literature search in Medline (PubMed) covering the last ten years until November 2019, where articles in English were included. Articles about the intestinal stem cells and their possible role in the pathophysiology of IBS are discussed in the present review. The present review discusses the assumption that intestinal stem cells play a central role in the pathophysiology of IBS and that the other factors known to contribute to the pathophysiology of IBS such as genetics, diet gut microbiota, stress, and low-grade inflammation exert their effects through affecting the intestinal stem cells. It reports further the data that support this assumption on genetics, diet, gut microbiota, stress with depletion of glutamine, and inflammation.

Germ-Free Swiss Webster Mice on a High-Fat Diet Develop Obesity, Hyperglycemia, and Dyslipidemia

A calorie-dense diet is a well-established risk factor for obesity and metabolic syndrome (MetS), whereas the role of the intestinal microbiota (IMB) in the development of diet-induced obesity (DIO) is not completely understood. To test the hypothesis that Swiss Webster (Tac:SW) mice can develop characteristics of DIO and MetS in the absence of the IMB, we fed conventional (CV) and germ-free (GF) male Tac:SW mice either a low-fat diet (LFD; 10% fat derived calories) or a high-fat diet (HFD; 60% fat derived calories) for 10 weeks. The HFD increased feed conversion and body weight in GF mice independent of the increase associated with the microbiota in CV mice. In contrast to CV mice, GF mice did not decrease feed intake on the HFD and possessed heavier fat pads. The HFD caused hyperglycemia, hyperinsulinemia, and impaired glucose absorption in GF mice independent of the increase associated with the microbiota in CV mice. A HFD also elevated plasma LDL-cholesterol and increased hepatic triacylglycerol, free fatty acids, and ceramides in all mice, whereas hypertriglyceridemia and increased hepatic medium and long-chain acylcarnitines were only observed in CV mice. Therefore, GF male Tac:SW mice developed several detrimental effects of obesity and MetS from a high-fat, calorie dense diet.

Risk Factors for Gastrointestinal Symptoms Following Successful Eradication of Clostridium difficile by Fecal Microbiota Transplantation (FMT)

BACKGROUND

Fecal microbiota transplantation (FMT) is a promising therapy for recurrent Clostridioides difficile infection (CDI). Many patients report altered bowel habits including constipation, bloating, gas and loose stool post-FMT despite resolution of CDI, and the etiology remains unclear.

METHODS

This was a prospective cohort study of adult patients with recurrent CDI who underwent FMT (1) via colonoscopy with patient-selected donor stool, (2) via colonoscopy from a universal stool bank donor, or (3) via capsules from a universal stool bank. Reassessment occurred 8 weeks post-FMT. Those cured were assessed for gastrointestinal symptoms (bloating, loose stools, constipation). Multivariate logistic regression was performed to assess predictors of post-FMT gastrointestinal symptoms.

RESULTS

A total of 150 subjects underwent FMT for recurrent CDI, of which 68.7% (103) were female, mean age was 61.5 years±18.1 and 31 patients (20.7%) had preexisting irritable bowel syndrome. Thirty-six had FMT via colonoscopy with a patient-selected donor, 67 via colonoscopy with stool bank donors, and 47 via FMT capsules from stool bank donors. Among those cured, 41 (31.2%) had gastrointestinal symptoms post-FMT. The factors associated with symptoms included younger age (57.2 vs. 64.1 y, P=0.03), a baseline history of irritable bowel syndrome (36.6% vs. 13.3%, P=0.002) and preexisting inflammatory bowel disease (31.7% vs. 10%, P=0.002). Small bowel exposure to donor stool was not related to symptoms (63.4% vs. 62.2%, P=0.89).

CONCLUSIONS

Altered bowel habits are a consequence of CDI and are common after FMT. This study suggests that donor type and FMT delivery modality are not related to the presence of irregular gastrointestinal symptoms after FMT.

Fecal microbiota transplantation in irritable bowel syndrome: A systematic review and meta-analysis

Background

Modulating gut microbiota is a potential treatment for irritable bowel syndrome (IBS). This meta-analysis explored whether fecal microbiota transplantation (FMT) is successful in treating IBS.

Methods

A systematic review was performed to find trials on FMT in IBS. Ratios and relative ratios (RR) of improvement for single-arm trials (SATs) and randomized controlled trials (RCTs) were calculated, respectively. Changes in IBS Severity Scoring System (IBS-SSS) and IBS Quality of Life (IBS-QOL) instrument compared to baseline in FMT versus placebo groups were pooled.

Results

In SATs, 59.5% (95% confidence interval (CI) 49.1-69.3) of IBS patients showed significant improvement. In RCTs, there were no differences between FMT and control in improvement (RR=0.93 (95% CI 0.50-1.75)) or changes in the IBS-SSS and IBS-QOL.

Conclusions

FMT was not effective in IBS. Variations in FMT methods and patient factors may contribute to the heterogeneous results of the trials.

Microbiota: a novel regulator of pain

Among the various regulators of the nervous system, the gut microbiota has been recently described to have the potential to modulate neuronal cells activation. While bacteria-derived products can induce aversive responses and influence pain perception, recent work suggests that "abnormal" microbiota is associated with neurological diseases such as Alzheimer's, Parkinson's disease or autism spectrum disorder (ASD). Here we review how the gut microbiota modulates afferent sensory neurons function and pain, highlighting the role of the microbiota/gut/brain axis in the control of behaviors and neurological diseases. We outline the changes in gut microbiota, known as dysbiosis, and their influence on painful gastrointestinal disorders. Furthermore, both direct host/microbiota interaction that implicates activation of "pain-sensing" neurons by metabolites, or indirect communication via immune activation is discussed. Finally, treatment options targeting the gut microbiota, including pre- or probiotics, will be proposed. Further studies on microbiota/nervous system interaction should lead to the identification of novel microbial ligands and host receptor-targeted drugs, which could ultimately improve chronic pain management and well-being.

Diet in Irritable Bowel Syndrome (IBS): Interaction with Gut Microbiota and Gut Hormones

Diet plays an important role not only in the pathophysiology of irritable bowel syndrome (IBS), but also as a tool that improves symptoms and quality of life. The effects of diet seem to be a result of an interaction with the gut bacteria and the gut endocrine cells. The density of gut endocrine cells is low in IBS patients, and it is believed that this abnormality is the direct cause of the symptoms seen in IBS patients. The low density of gut endocrine cells is probably caused by a low number of stem cells and low differentiation progeny toward endocrine cells. A low fermentable oligo-, di-, monosaccharide, and polyol (FODMAP) diet and fecal microbiota transplantation (FMT) restore the gut endocrine cells to the level of healthy subjects. It has been suggested that our diet acts as a prebiotic that favors the growth of a certain types of bacteria. Diet also acts as a substrate for gut bacteria fermentation, which results in several by-products. These by-products might act on the stem cells in such a way that the gut stem cells decrease, and consequently, endocrine cell numbers decrease. Changing to a low-FODMAP diet or changing the gut bacteria through FMT improves IBS symptoms and restores the density of endocrine cells.

Increasing the Dose and/or Repeating Faecal Microbiota Transplantation (FMT) Increases the Response in Patients with Irritable Bowel Syndrome (IBS)

BACKGROUND

Faecal microbiome transplantation (FMT) appears to be an effective method for treating irritable bowel syndrome (IBS) patients. However, it is not clear if a high transplant dose and/or repeating FMT are/is needed to ensure a response. The present study was undertaken to clarify this matter.

METHODS

Ten IBS patients who did not respond to a 30-g transplant subsequently received a 60-g transplant into the duodenum via a gastroscope. The patients provided faecal samples before and 1 month after FMT. They completed five questionnaires measuring symptoms, fatigue and quality of life at baseline and then at 2 weeks, 1 month and 3 months after FMT. The dysbiosis index (DI) was measured using the GA-map Dysbiosis Test®.

RESULTS

Seven patients (70%) responded to the 60-g transplant, with significant clinical improvements in the abdominal symptoms, fatigue and quality of life in 57%, 80% and 67% of these patients. The 60-g transplant also reduced the DI.

CONCLUSION

FMT is an effective treatment for IBS. A high-dose transplant and/or repeated FMT increase the response rate and the intensity of the effects of FMT.

Mucosal permeability and mast cells as targets for functional gastrointestinal disorders

The intestinal mucosa is constantly exposed to harmful luminal content, and uptake is closely controlled and regulated by neuro-immune factors. If control is broken, it might lead to ongoing enhanced mucosal permeability, potentially resulting in functional gastrointestinal disorders. The importance of mast cells in the regulation of the mucosal barrier has become obvious, and increased numbers and more activated mast cells have been observed in irritable bowel syndrome, functional dyspepsia and gastroesophageal reflux disease. To target the disturbed mucosal permeability, directly or via mast cells, is therefore currently of major interest. For example, administration of mast cell stabilizers and probiotics have shown promising effects in patients with functional gastrointestinal disorders.