Project description:Necrotizing enterocolitis (NEC) is an acute and life-threatening gastrointestinal disorder afflicting preterm infants, which is currently unpreventable. Fecal microbiota transplantation (FMT) is a promising preventative therapy, but potential bacterial infection raise concern. Removal of bacteria from donor feces may reduce this risk while maintaining the NEC-preventive effects. We aimed to assess preclinical efficacy and safety of bacteria-free fecal filtrate transfer (FFT). Using fecal material from healthy suckling piglets, we administered FMT rectally, or cognate FFT either rectally or oro-gastrically to formula-fed preterm, cesarean-delivered piglets as a model for preterm infants, We compared gut pathology and related safety parameters with saline controls, and analyzed ileal mucosal transcriptome to gauge the host e response to FMT and FFT treatments relative to control. Results showed that oro-gastric FFT prevented NEC, whereas FMT did not perform better than control. Moreover, FFT but not FMT reduced intestinal permeability, whereas FMT animals had reduced body weight increase and intestinal growth. Global gene expression of host mucosa responded to FMT but not FFT with increased and decreased bacterial and viral defense mechanisms, respectively. In conclusion, as preterm infants are extremely vulnerable to enteric bacterial infections, rational NEC-preventive strategies need incontestable safety profiles. Here we show in a clinically relevant animal model that FFT, as opposed to FMT, efficiently prevents NEC without any recognizable side effects. If translatable to preterm infants, this could lead to a change of practice and in turn a reduction in NEC burden.
Project description:Purpose: To determine whether previously observed behavioral differences in alcoholic human patients after fecal microbiota transplantation (FMT) could be transferred to mice. Methods: Fecal microbiota samples from a previously published phase 1, double-blind, randomized clinical trial of AUD-related cirrhosis patients were used to colonize germ-free mice. Fecal material was transferred to 10-15-week-old GF C57BL/6 male mice by daily gavage for 3 day. The mice were housed in sterile individually filtered cages for 15 days after which stool was collected and then they underwent the alcohol preference experiment using 2-bottle choice drinking (water and 20% ethanol v/v). Microbial DNA was isolated from stool samples by sequencing the V1 and V2 variable regions of the bacterial 16S rRNA gene were sequenced using Multitag fusion primers and sequenced on an Ion Torrent PGM next-generation sequencer. Intestinal mucosa, liver, and prefrontal cortex tissue was collected from mice at time of sacrifice. RNAseq was used to measure gene expression in pre-FMT and post-FMT samples. RNAseq data were aligned to the mouse genome (GRCm39) using STAR (version 2.7.9a) and counts were generated with HTSeq (version 0.13.5). Genes with very low counts across the study (defined as fewer than 10 counts in more than 2 samples) were eliminated before differential expression analysis. Low count genes were determined separately for each tissue type. The DESeq2 package for R was then used to measure differential expression between pre-FMT and post-FMT mice in the intestine, liver, and PFC. Benjamini and Hochberg False Discovery Rate (FDR) was used to correct for multiple testing with FDR ≤ 0.2 considered significant. Results: Mice colonized with post-FMT stool significantly reduced ethanol acceptance, intake and preference versus pre-FMT colonized mice. Microbial taxa that were higher in post-FMT humans were also associated with lower alcohol intake and preference in mice. RNAseq further showed that differential gene expression, post-FMT, occurred in the intestine rather than the liver and prefrontal cortex. Conclusions: FMT leads to significant change in gut microbiome population, which in turn alters gene expression in the intestine. FMT also significantly affects alcohol consumption. The microbiotal-intestinal interface may alter gut-liver-brain axis and reduce alcohol consumption in humans.
Project description:We performed a phase I clinical trial to assess the safety and feasibility of fecal microbiota transplantation (FMT) and re-induction of anti-PD-1 immunotherapy in patients with anti-PD-1-refractory metastatic melanoma. FMT donors were two metastatic melanoma patients who achieved a durable complete response. FMT recipient patients were metastatic melanoma patients who failed at least one anti-PD-1 line of treatment. Each recipient patient received FMT implants from only one of the two donors. FMT was conducted by both colonoscopy and oral ingestion of stool capsules, followed by anti-PD-1 re-treatment (Nivolumab, BMS). Recipient patients underwent pre- and post-treatment stool sampling, tissue biopsy of both gut and tumor, and total body imaging. Clinical responses were observed in three patients, including two partial responses and one complete response. Notably, treatment with FMT was associated with favorable changes in immune cell infiltrates and gene expression profiles in both the gut lamina propria and the tumor microenvironment.
Project description:Advanced age is associated with chronic low-grade inflammation, which is usually referred to as inflammaging. Elderly are also known to have an altered gut microbiota composition. However, whether inflammaging is a cause or consequence of an altered gut microbiota composition is not clear. In this study gut microbiota from young or old conventional mice was transferred to young germ-free mice. Four weeks after gut microbiota transfer immune cell populations in spleen, Peyer’s patches, and mesenteric lymph nodes from conventionalized germ-free mice were analyzed by flow cytometry. In addition, whole-genome gene expression in the ileum was analyzed by microarray. Gut microbiota composition of donor and recipient mice was analyzed with 16S rDNA sequencing. Here we show by transferring aged microbiota to young germ-free mice that certain bacterial species within the aged microbiota promote inflammaging. This effect was associated with lower levels of Akkermansia and higher levels of TM7 bacteria and Proteobacteria in the aged microbiota after transfer. The aged microbiota promoted inflammation in the small intestine in the germ-free mice and enhanced leakage of inflammatory bacterial components into the circulation was observed. Moreover, the aged microbiota promoted increased T cell activation in the systemic compartment. In conclusion, these data indicate that the gut microbiota from old mice contributes to inflammaging after transfer to young germ-free mice.
Project description:This study aimed to analyze changes in gut microbiota composition in mice after transplantation of fecal microbiota (FMT, N = 6) from the feces of NSCLC patients by analyzing fecal content using 16S rRNA sequencing, 10 days after transplantation. Specific-pathogen-free (SPF) mice were used for each experiments (N=4) as controls.
Project description:Transplantation of differential microbiota in young germ-free donors show distinct metabolic signatures. We used microarrays to understand pathway level changes in the livers and small intestines of differential-microbiota conventionalized young recipeint mice.