Chronic inflammation plays a central role in the pathophysiology of various non-communicable diseases. Dietary interventions can reduce inflammation, in part due to their effect on the gut microbiome. This systematic review aims to determine the effect of dietary interventions, specifically fiber intake, on chronic inflammatory diseases and the microbiome. It aims to form hypotheses on the potential mediating effects of the microbiome on disease outcomes after dietary changes. Included were clinical trials which performed a dietary intervention with a whole diet change or fiber supplement (>5 g/day) and investigated the gut microbiome in patients diagnosed with chronic inflammatory diseases such as cardiovascular disease (CVD), type 2 diabetes (T2DM), and autoimmune diseases (e.g., rheumatoid arthritis (RA), inflammatory bowel disease (IBD)). The 30 articles which met the inclusion criteria had an overall moderate to high risk of bias and were too heterogeneous to perform a meta-analysis. Dietary interventions were stratified based on fiber intake: low fiber, high fiber, and supplemental fiber. Overall, but most pronounced in patients with T2DM, high-fiber plant-based dietary interventions were consistently more effective at reducing disease-specific outcomes and pathogenic bacteria, as well as increasing microbiome alpha diversity and short-chain fatty acid (SCFA)-producing bacteria, compared to other diets and fiber supplements.

Cine-MRI of the abdomen is a non-invasive imaging technique allowing assessment of small intestinal motility. This is valuable for the evaluation of gastrointestinal disorders. While 2D cine-MRI is increasingly used for this purpose in both clinical practice and in research settings, the potential of 3D cine-MRI has been largely underexplored. In the absence of image analysis tools enabling investigation of the intestines as 3D structures, the assessment of motility in 3D cine-images is generally limited to the evaluation of movement in separate 2D slices. Furthermore, while a segmentation map of the small intestine would be required for a number of automatic analysis tasks, deep learning based segmentation of the small intestine generally performs poorly due to the large variety in shapes, sizes and locations in the abdomen among different patients. Using a data set of 3D cine-MRI scans from 14 healthy volunteers, we developed a multi-task method that automatically tracks individual segments of the small intestine in a time-point from 3D cine-MRI scans, using a stochastic tracker built on top of a CNN-based orientation classifier. The method additionally performs segmentation, conditioned on the locations of intestinal centerlines. We demonstrate the benefit of our stochastic tracking strategy and we show that our proposed segmentation method performs significantly better than an identical network without centerline conditioning. Furthermore, we assess the robustness of the method through evaluation on a set of patients with severe bowel disease. In terms of centerline tracking, our method achieves a recall of 0.74±0.07, a precision of 0.80±0.06 and an F1 score of 0.77±0.05 in the set of healthy volunteers. In the set of patients, it achieves a recall of 0.76±0.12, a precision of 0.86±0.11 and an F1 score of 0.80±0.08. Segmentation achieves a Dice coefficient of 0.88±0.03 in the set of healthy volunteers and 0.79±0.09 in the set of patients. By extracting a structural representation of the small intestine, the presented method provides a major first step towards automatic detailed quantitative assessment of small intestinal motility in abdominal 3D cine-MRI.

Objective:Dynamic imaging of small intestinal motility is an increasingly common research method to examine bowel physiology in health and disease. However, limited data exists to guide imaging protocols with respect to quantitative analysis. The purpose of this study is to define the required temporal resolution and scan duration in dynamic MRI for small bowel motility assessment.Methods:6 healthy volunteers underwent motility imaging with MR enterography using breath-hold protocol. A coronal 2D bFFE sequence was used to acquire dynamic data at high temporal resolution of 10fps. Motility was quantified by generating a registration derived motility index for local and global regions of bowel. To evaluate temporal resolution and scan duration the data was undersampled and the scan length was varied to determine the impact on motility index.Results:The mean motility index stabilizes at a temporal resolution of 1fps (median absolute percentage change 1.4% for global and 1.9% for local ROIs). The mean motilit...

Background: Chronic intestinal pseudo‐obstruction (CIPO) is a severe intestinal motility disorder of which the pathophysiology is largely unknown. This study aimed at gaining insight in fasted and fed small bowel motility in CIPO patients using cine‐MRI with caloric stimulation.Methods: Eight adult patients with manometrically confirmed CIPO were prospectively included. Patients underwent a cine‐MRI protocol after an overnight fast, comprising fasting‐state scans and scans after ingestion of a meal (Nutridrink, 300 kcal). Small bowel motility was quantified resulting in a motility score in arbitrary units (AU) and visually assessed by three radiologists. Findings were compared with those in 16 healthy volunteers.Key Results: Motility scores (median, IQR) in CIPO patients were 0.21 (0.15–0.30) in the fasting state and 0.23 (0.15–0.27) directly postprandially. In healthy volunteers, corresponding motility scores were 0.15 (0.13–0.18) and 0.22 (0.19–0.25), respectively. The postprandial change in motility score was +1% (−19 to +21%) in CIPO and +39% (+23 to +50%) in healthy volunteers (p = 0.001*). Visual analysis revealed increased small bowel contractility in four, normal in two, and decreased in two CIPO patients.Conclusions & Inferences: Surprisingly, we found hyperactive small bowel motility in half of the CIPO patients, suggestive of uncoordinated motility. A wide variation in motility patterns was observed, both higher, lower, and comparable contractility compared with healthy subjects. No clear postprandial activation was seen in patients. Cine‐MRI helps to gain insight in this complex disease and can potentially impact treatment decisions in the future.