Effects of fecal microbiota transplant on DNA methylation in subjects with metabolic syndrome

Accumulating evidence shows that microbes with their theater of activity residing within the human intestinal tract (i.e., the gut microbiome) influence host metabolism. Some of the strongest results come from recent fecal microbial transplant (FMT) studies that relate changes in intestinal microbiota to various markers of metabolism as well as the pathophysiology of insulin resistance. Despite these developments, there is still a limited understanding of the multitude of effects associated with FMT on the general physiology of the host, beyond changes in gut microbiome composition. We examined the effect of either allogenic (lean donor) or autologous FMTs on the gut microbiome, plasma metabolome, and epigenomic (DNA methylation) reprogramming in peripheral blood mononuclear cells in individuals with metabolic syndrome measured at baseline (pre-FMT) and after 6 weeks (post-FMT). Insulin sensitivity was determined with a stable isotope-based 2 step hyperinsulinemic clamp and multivariate machine learning methodology was used to uncover discriminative microbes, metabolites, and DNA methylation loci. A larger gut microbiota shift was associated with an allogenic than with autologous FMT. Furthemore, the data results of the the allogenic FMT group data indicates that the introduction of new species can potentially modulate the plasma metabolome and (as a result) the epigenome. Most notably, the introduction of Prevotella ASVs directly correlated with methylation of AFAP1, a gene involved in mitochondrial function, insulin sensitivity, and peripheral insulin resistance (Rd, rate of glucose disappearance). FMT was found to have notable effects on the gut microbiome but also on the host plasma metabolome and the epigenome of immune cells providing new avenues of inquiry in the context of metabolic syndrome treatment for the manipulation of host physiology to achieve improved insulin sensitivity.

Faster recovery of gastrointestinal transit after laparoscopy and fast-track care in patients undergoing colonic surgery

BACKGROUND & AIMS

Postoperative ileus is characterized by delayed gastrointestinal (GI) transit and is a major determinant of recovery after colorectal surgery. Both laparoscopic surgery and fast-track multimodal perioperative care have been reported to improve clinical recovery. However, objective measures supporting faster GI recovery are lacking. Therefore, GI transit was measured following open and laparoscopic colorectal surgery with or without fast-track care.

METHODS

Patients (n = 93) requiring elective colonic surgery were randomized to laparoscopic or conventional surgery with fast-track multimodal management or standard care, resulting in 4 treatment arms. Gastric emptying and colonic transit were scintigraphically assessed from days 1 to 3 in 78 patients and compared with clinical parameters such as time to tolerance of solid food and/or bowel movement and time until (ready for) discharge.

RESULTS

A total of 71 patients without mechanical bowel obstructions or surgical complications requiring intervention were available for analysis. No differences in gastric emptying 24 hours after surgery between the different groups were observed (P = .61). However, the median colonic transit of patients undergoing laparoscopic/fast-track care was significantly faster compared with the laparoscopic/standard, open/fast-track, and open/standard care groups. Multiple linear regression analysis showed that both laparoscopic surgery and fast-track care were significant independent predictive factors of improved colonic transit. Both were associated with significantly faster clinical recovery and shorter time until tolerance of solid food and first bowel movement.

CONCLUSIONS

Colonic transit recovers significantly faster after laparoscopic surgery and the fast-track program; laparoscopy and fast-track care lead to faster recovery of GI motility and improve clinical recovery.

In vivo evaluation of 111In-labeled T-lymphocyte homing in experimental colitis

Blockade of lymphocyte recruitment to the intestinal mucosa is considered a useful therapy for inflammatory bowel disease (IBD) and anti-alpha4 antibodies have clinical benefit in patients with active Crohn's disease. The aim of this study was to evaluate a scintigraphic technique to assess lymphocyte homing to the colon in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced experimental colitis (TNBS colitis) in vivo.

METHODS

TNBS-sensitized and nonsensitized murine total lymphocytes or CD4+ lymphocytes were radiolabeled with 111In-oxinate. Cells were injected into control mice (n = 5) or mice with TNBS colitis (n = 5). Specific abdominal radioactive uptake was determined by SPECT using a dedicated pinhole system 48 h after cell transfer. Radioactive colon uptake was correlated with histology and colon weight as parameters of inflammation.

RESULTS

The radioactive colon uptake was most evident in mice with TNBS colitis that received sensitized lymphocytes (uptake ratio [mean +/- SEM], 0.51 +/- 0.03 vs. 0.22 +/- 0.04; P = 0.004). The sensitized 111In-labeled lymphocytes exacerbated colitis compared with nonsensitized lymphocytes. The colon uptake correlated well with both colon weight and histologic score (R2 = 0.836 and 0.933, respectively). The use of purified 111In labeled CD4+ lymphocytes resulted in a similar scintigraphic pattern. Administration of an anti-alpha4 antibody decreased radioactivity colon uptake of the (111)In-labeled cells compared with the control antibody in mice with TNBS colitis (uptake ratio, 0.72 +/- 0.14 to 0.33 +/- 0.03; P = 0.012).

CONCLUSION

Animal pinhole SPECT can be applied for temporal and spatial analysis of the lymphocyte homing process in experimental colitis. This technique makes possible the in vivo evaluation of therapeutic efficacy of new drugs that interfere with lymphocyte migration. Moreover, colon uptake of radioactivity can be used as a parameter of disease activity in experimental colitis.