The epidemic of Clostridium difficile infection fueled by new virulent strains of the organism has led to increased use of fecal microbiota transplantation (FMT). The procedure is effective for even ...the most desperate cases after failure of multiple courses of antibiotics. The approach recognizes microbiota to be integral to normal human physiology, and microbiota being used in FMT represents a new class of therapeutics. Imbalance in the composition and altered activity of the microbiota are associated with many diseases. Consequently, there is growing interest in applying FMT to non– C difficile indications. However, this may succeed only if microbiota therapeutics are developed systematically, based on mechanistic understanding, and applying up-to-date principles of microbial ecology. We discuss 2 pathways in the development of this new therapeutic class: whole microbial communities separated from donor stool and an assembly of specific fecal microorganisms grown in vitro.
Fecal microbiota transplantation: in perspective Gupta, Shaan; Allen-Vercoe, Emma; Petrof, Elaine O.
Therapeutic Advances in Gastroenterology,
03/2016, Letnik:
9, Številka:
2
Book Review, Journal Article
Recenzirano
Odprti dostop
There has been increasing interest in understanding the role of the human gut microbiome to elucidate the therapeutic potential of its manipulation. Fecal microbiota transplantation (FMT) is the ...administration of a solution of fecal matter from a donor into the intestinal tract of a recipient in order to directly change the recipient’s gut microbial composition and confer a health benefit. FMT has been used to successfully treat recurrent Clostridium difficile infection. There are preliminary indications to suggest that it may also carry therapeutic potential for other conditions such as inflammatory bowel disease, obesity, metabolic syndrome, and functional gastrointestinal disorders.
Vitamin D and the vitamin D receptor (VDR) appear to be important immunological regulators of inflammatory bowel diseases (IBD). Defective autophagy has also been implicated in IBD, where ...interestingly, polymorphisms of genes such as ATG16L1 have been associated with increased risk. Although vitamin D, the microbiome and autophagy are all involved in pathogenesis of IBD, it remains unclear whether these processes are related or function independently.
We investigated the effects and mechanisms of intestinal epithelial VDR in healthy and inflamed states using cell culture models, a conditional VDR knockout mouse model (VDR(ΔIEC)), colitis models and human samples.
Absence of intestinal epithelial VDR affects microbial assemblage and increases susceptibility to dextran sulfate sodium-induced colitis. Intestinal epithelial VDR downregulates expressions of ATG16L1 and lysozyme, and impairs antimicrobial function of Paneth cells. Gain and loss-of-function assays showed that VDR levels regulate ATG16L1 and lysozyme at the transcriptional and translational levels. Moreover, low levels of intestinal epithelial VDR correlated with reduced ATG16L1 and representation by intestinal Bacteroides in patients with IBD. Administration of the butyrate (a fermentation product of gut microbes) increases intestinal VDR expression and suppresses inflammation in a colitis model.
Our study demonstrates fundamental relationship between VDR, autophagy and gut microbial assemblage that is essential for maintaining intestinal homeostasis, but also in contributing to the pathophysiology of IBD. These insights can be leveraged to define therapeutic targets for restoring VDR expression and function.
Neonatal necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of preterm infants. Increased intestinal epithelium permeability is an early event in NEC pathogenesis. Autophagy ...and apoptosis are induced by multiple stress pathways which may impact the intestinal barrier, and they have been associated with pathogenesis of diverse gastrointestinal diseases including inflammatory bowel disease. Using both in vitro and in vivo models, this study investigates autophagy and apoptosis under experimental NEC stresses. Furthermore this study evaluates the effect of erythropoietin (Epo), a component of breast milk previously shown to decrease the incidence of NEC and to preserve intestinal barrier function, on intestinal autophagy and apoptosis. It was found that autophagy and apoptosis are both rapidly up regulated in NEC in vivo as indicated by increased expression of the autophagy markers Beclin 1 and LC3II, and by evidence of apoptosis by TUNEL and cleaved caspase-3 staining. In the rat NEC experimental model, autophagy preceded the onset of apoptosis in intestine. In vitro studies suggested that Epo supplementation significantly decreased both autophagy and apoptosis via the Akt/mTOR signaling pathway and the MAPK/ERK pathway respectively. These results suggest that Epo protects intestinal epithelium from excessive autophagy and apoptosis in experimental NEC.
Fecal bacteriotherapy ('stool transplant') can be effective in treating recurrent Clostridium difficile infection, but concerns of donor infection transmission and patient acceptance limit its use. ...Here we describe the use of a stool substitute preparation, made from purified intestinal bacterial cultures derived from a single healthy donor, to treat recurrent C. difficile infection that had failed repeated standard antibiotics. Thirty-three isolates were recovered from a healthy donor stool sample. Two patients who had failed at least three courses of metronidazole or vancomycin underwent colonoscopy and the mixture was infused throughout the right and mid colon. Pre-treatment and post-treatment stool samples were analyzed by 16 S rRNA gene sequencing using the Ion Torrent platform.
Both patients were infected with the hyper virulent C. difficile strain, ribotype 078. Following stool substitute treatment, each patient reverted to their normal bowel pattern within 2 to 3 days and remained symptom-free at 6 months. The analysis demonstrated that rRNA sequences found in the stool substitute were rare in the pre-treatment stool samples but constituted over 25% of the sequences up to 6 months after treatment.
This proof-of-principle study demonstrates that a stool substitute mixture comprising a multi-species community of bacteria is capable of curing antibiotic-resistant C. difficile colitis. This benefit correlates with major changes in stool microbial profile and these changes reflect isolates from the synthetic mixture.
CinicalTrials.gov NCT01372943.
Clostridium difficile infection (CDI) is a major burden in health care and community settings. CDI recurrence is of particular concern because of limited treatment options and associated clinical and ...infection control issues. Fecal microbiota transplantation (FMT) is a promising, but not readily available, intervention.
To determine whether frozen-and-thawed (frozen, experimental) FMT is noninferior to fresh (standard) FMT in terms of clinical efficacy among patients with recurrent or refractory CDI and to assess the safety of both types of FMT.
Randomized, double-blind, noninferiority trial enrolling 232 adults with recurrent or refractory CDI, conducted between July 2012 and September 2014 at 6 academic medical centers in Canada.
Patients were randomly allocated to receive frozen (n = 114) or fresh (n = 118) FMT via enema.
The primary outcome measures were clinical resolution of diarrhea without relapse at 13 weeks and adverse events. Noninferiority margin was set at 15%.
A total of 219 patients (n = 108 in the frozen FMT group and n = 111 in the fresh FMT group) were included in the modified intention-to-treat (mITT) population and 178 (frozen FMT: n = 91, fresh FMT: n = 87) in the per-protocol population. In the per-protocol population, the proportion of patients with clinical resolution was 83.5% for the frozen FMT group and 85.1% for the fresh FMT group (difference, -1.6% 95% CI, -10.5% to ∞; P = .01 for noninferiority). In the mITT population the clinical resolution was 75.0% for the frozen FMT group and 70.3% for the fresh FMT group (difference, 4.7% 95% CI, -5.2% to ∞; P < .001 for noninferiority). There were no differences in the proportion of adverse or serious adverse events between the treatment groups.
Among adults with recurrent or refractory CDI, the use of frozen compared with fresh FMT did not result in worse proportion of clinical resolution of diarrhea. Given the potential advantages of providing frozen FMT, its use is a reasonable option in this setting.
clinicaltrials.gov Identifier:NCT01398969.
Development of the infant small intestine is influenced by bacterial colonization. To promote establishment of optimal microbial communities in preterm infants, knowledge of the beneficial functions ...of the early gut microbiota on intestinal development is needed. The purpose of this study was to investigate the impact of early preterm infant microbiota on host gut development using a gnotobiotic mouse model. Histological assessment of intestinal development was performed. The differentiation of four epithelial cell lineages (enterocytes, goblet cells, Paneth cells, enteroendocrine cells) and tight junction (TJ) formation was examined. Using weight gain as a surrogate marker for health, we found that early microbiota from a preterm infant with normal weight gain (MPI-H) induced increased villus height and crypt depth, increased cell proliferation, increased numbers of goblet cells and Paneth cells, and enhanced TJs compared with the changes induced by early microbiota from a poor weight gain preterm infant (MPI-L). Laser capture microdissection (LCM) plus qRT-PCR further revealed, in MPI-H mice, a higher expression of stem cell marker Lgr5 and Paneth cell markers Lyz1 and Cryptdin5 in crypt populations, along with higher expression of the goblet cell and mature enterocyte marker Muc3 in villus populations. In contrast, MPI-L microbiota failed to induce the aforementioned changes and presented intestinal characteristics comparable to a germ-free host. Our data demonstrate that microbial communities have differential effects on intestinal development. Future studies to identify pioneer settlers in neonatal microbial communities necessary to induce maturation may provide new insights for preterm infant microbial ecosystem therapeutics.
Low expression of vitamin D receptor (VDR) and dysfunction of vitamin D/VDR signaling are reported in patients with inflammatory bowel disease (IBD); therefore, restoration of VDR function to control ...inflammation in IBD is desirable. Probiotics have been used in the treatment of IBD. However, the role of probiotics in the modulation of VDR signaling to effectively reduce inflammation is unknown. We identified a novel role of probiotics in activating VDR activity, thus inhibiting inflammation, using cell models and VDR knockout mice. We found that the probiotics Lactobacillus rhamnosus strain GG (LGG) and Lactobacillus plantarum (LP) increased VDR protein expression in both mouse and human intestinal epithelial cells. Using the VDR luciferase reporter vector, we detected increased transcriptional activity of VDR after probiotic treatment. Probiotics increased the expression of the VDR target genes, such as antimicrobial peptide cathelicidin, at the transcriptional level. Furthermore, the role of probiotics in regulating VDR signaling was tested in vivo using a Salmonella-colitis model in VDR knockout mice. Probiotic treatment conferred physiological and histologic protection from Salmonella-induced colitis in VDR(+/+) mice, whereas probiotics had no effects in the VDR(-/-) mice. Probiotic treatment also enhanced numbers of Paneth cells, which secrete AMPs for host defense. These data indicate that the VDR pathway is required for probiotic protection in colitis. Understanding how probiotics enhance VDR signaling and inhibit inflammation will allow probiotics to be used effectively, resulting in innovative approaches to the prevention and treatment of chronic inflammation.
Faecal microbiota transplant (FMT) effectively treats recurrent
infection (rCDI), but its mechanisms of action remain poorly defined. Certain bile acids affect
germination or vegetative growth. We ...hypothesised that loss of gut microbiota-derived bile salt hydrolases (BSHs) predisposes to CDI by perturbing gut bile metabolism, and that BSH restitution is a key mediator of FMT's efficacy in treating the condition.
Using stool collected from patients and donors pre-FMT/post-FMT for rCDI, we performed 16S rRNA gene sequencing, ultra performance liquid chromatography mass spectrometry (UPLC-MS) bile acid profiling, BSH activity measurement, and qPCR of
/
CD genes involved in bile metabolism. Human data were validated in
batch cultures and a C57BL/6 mouse model of rCDI.
From metataxonomics, pre-FMT stool demonstrated a reduced proportion of BSH-producing bacterial species compared with donors/post-FMT. Pre-FMT stool was enriched in taurocholic acid (TCA, a potent
germinant); TCA levels negatively correlated with key bacterial genera containing BSH-producing organisms. Post-FMT samples demonstrated recovered BSH activity and
/
CD gene copy number compared with pretreatment (p<0.05). In batch cultures, supernatant from engineered
-expressing
and naturally BSH-producing organisms (
and
) reduced TCA-mediated
germination relative to culture supernatant of wild-type (BSH-negative)
total viable counts were ~70% reduced in an rCDI mouse model after administration of
expressing highly active BSH relative to mice administered BSH-negative
(p<0.05).
Restoration of gut BSH functionality contributes to the efficacy of FMT in treating rCDI.
The human gut microbiome is a complex ecosystem of fundamental importance to human health. Our increased understanding of gut microbial composition and functional interactions in health and disease ...states has spurred research efforts examining the gut microbiome as a valuable target for therapeutic intervention. This review provides updated insight into the state of the gut microbiome in recurrent Clostridium difficile infection (CDI), ulcerative colitis (UC), and obesity while addressing the rationale for the modulation of the gut microbiome using fecal microbiota transplant (FMT)-based therapies. Current microbiome-based therapeutics in pre-clinical or clinical development are discussed. We end by putting this within the context of the current regulatory framework surrounding FMT and related therapies.
•There is an increased understanding of gut microbial composition and functional interactions in health and disease states.•FMT is effective for rCDI and has led to the development of fecal microbiota-based therapeutics for other indications.•For stool-substitute therapies to enter mainstream medicine, further mechanistic studies, RCTs and regulations are needed.
PDF
