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Magnetic resonance elastography (MRE) is a reliable noninvasive method for assessment of hepatic stiffness. Liver stiffness is known to be affected by elevated postprandial portal blood flow in patients with chronic liver disease. The goal of this study was to determine whether food intake affects liver stiffness in the absence of known liver disease. We evaluated 100 volunteers (35 men and 65 women) who met inclusion criteria. The subjects had two MRE examinations, first while fasting and then 30 min after a test meal. Fourteen subjects also had two additional MRE exams 1 h 30 min and 2 h 30 min after the meal. Liver stiffness was measured by placing the largest possible polygon ROIs on the four widest liver slices and calculated as a mean of stiffness values from each slice. The correlation of liver stiffness values before and after the meal was assessed using a paired t-test. To evaluate the relationship between the change in postprandial liver stiffness and fasting liver stiffness values, linear regression was performed. The liver stiffness values in the fasting state ranged from 1.84 to 2.82 kPa, with a mean of 2.30 ± 0.23 kPa (95% CI 2.25–2.34). At 30 min after the meal, liver stiffness values ranged from 2.12 to 3.50 kPa, with a mean of 2.70 ± 0.28 kPa (95% CI 2.64–2.75), demonstrating a systematic postprandial increase by 0.40 ± 0.23 kPa (17.7 ± 3.5%). Meal intake significantly increases liver stiffness in healthy individuals, which persists for at least 2 h 30 min. Patients should fast for 3–4 h before MRE examinations to avoid fibrosis overstaging due to postprandial liver stiffness augmentation.

Iron overload is a relatively common clinical condition resulting from disorders such as hereditary hemochromatosis, thalassemia, sickle cell disease, and myelodysplasia that can lead to progressive fibrosis and eventually cirrhosis of the liver. Therefore, it is essential to recognize the disease process at the earliest stage. Liver biopsy is the reference test for the assessment of liver fibrosis. It also allows for quantifying liver iron concentration (LIC) in patients. However, this is an invasive method with significant limitations and possible risks. Magnetic resonance imaging (MRI) and evaluation of the R2* relaxation rate can be an alternative to biopsy for assessing LIC. However, it causes a need for accurate R2* data corresponding to standard value for further comparison with examined patients. This study aimed to assess the normative values of liver R2* in healthy individuals. A total of 100 volunteers that met established criteria were enrolled in the study: 36 (36%) men and 64 (64%) women. The mean age was 22.9 years (range 20 to 32 years). R2* was estimated by an MRI exam with a 1.5 T clinical magnetic resonance scanner. Images for measuring the LIC and liver fat concentration were obtained using the IDEAL-IQ technique for liver imaging. The Mean (SD) liver R2* was 28.34 (2.25) s−1 (95% CI, 27.78–28.90, range 23.67–33.00 s−1) in females, 29.57 (3.20) s−1 (95% CI, 28.49–30.66, range 23.93–37.77 s−1) in males, and 28.72 (2.69) s−1 (range 23.67–37.77 s−1) in the whole group. R2* value in this particular population with a high proportion of young women did not exceed 38 s−1. In the absence of fibrosis or steatosis, liver stiffness and fat fraction did not show any relationship with R2*.

The gastrointestinal mucus layer represents the last barrier between ingested food or orally administered pharmaceuticals and the mucosal epithelium. This complex gel structure plays an important role in the process of small intestinal absorption. It provides protection against hazardous particles such as bacteria but allows the passage of nutrients and drug molecules towards the intestinal epithelium. In scientific research, mucus from animal sources is usually used to simulate difficult-to-obtain human small intestinal mucus for investigating the intramucus transport of drug delivery systems or food nanoparticles. However, there is a lack of evidence the human mucus can be reliably substituted by animal counterparts for human-relevant transport models. In this report, a procedure for collecting human mucus has been described. More importantly, the permeability characteristics of human and porcine small intestinal mucus secretions to sub-micron sized particles have been compared under simulated intestinal conditions. Negatively charged, 500 nm latex beads were used in multiple-particle tracking experiments to examine the heterogeneity and penetrability of mucus from different sources. Diffusion of the probe particles in adult human ileal mucus and adult pig jejunal and ileal mucus revealed no significant differences in microstructural organisation or microviscosity between the three mucus types (P > 0.05). In contrast to this interspecies similarity, the intraspecies comparison of particle diffusivity in the mucus obtained from adult pigs vs. 2-week old piglets showed better penetrability of the piglet mucus. The mean Stokes–Einstein viscosity of the piglet jejunal mucus was approx. two times lower than the viscosity of the pig jejunal mucus (P