Digestion characteristics and kinetic analysis of bio-molecules in a simulated human intestinal system

Abstract

We designed and assembled a simulated human intestinal system (SHIS) consisting of a stomach and a small intestine. Each reactor vessel has several ports such as the input and output of medium, a sampler of liquid phase, a pH electrode, a pH control (acid and base), and a thermometer. The SHIS was kept at body temperature (37°C) by pumping water into the space between the jacket and the inside walls. The stomach chamber was initially filled with gas fluids and then digested for 2 hr. After the stomach digestion, the residuals was delivered from stomach chamber into the small intestine chamber by secreting intestinal fluid for 4 hr, followed by secretion of 0.3M NaHCO 3 , 0.1M NaHCO 3 , 4% bile salt, and 2% bile salt for 1, 3, 0.5, and 3.5 hrs, respectively. In order to prepare the alginate/chitosan capsule as a delivery system for bioactive agents, the microencapsulation system was assembled with a control unit, a electrical, a pneumatic systems, and a reaction vessel. After digestion of alginate capsules, the content of total sugar was 7.47% and 60.82% in the stomach and small intestine (simulated human intestinal system, SHIS), respectively. However, in case of alginate/chitosan capsule and alginate/chitosan capsule coated with polyacryl emulsion (alginate/chitosan-PAE), the total sugar content were 3.12 and 4.62% in the stomach model and 43.46 and 42.09% in the small intestine model, respectively. There were no difference on the degree of digestion in the alginate capsule and alginate/polyethylene glycol (alginate/PEG) capsule prepared with 0.1-0.3% of PEG in the stomach model. As a result, the alginate matrix remained in a shrunken state due to conversion of sodium alginate into insoluble alginic acid, which acted as a barrier to chitosan microparticles. And it was effective for digesting by intestinal fluid and releasing of the sugar.

Optimal conditions for the encapsulation of Weissella cibaria JW15 using alginate and chicory root and evaluation of capsule stability in a simulated gastrointestinal system

“…The alginate concentration strongly affects capsule integrity and fluid viscosity influenced by the surface tension of the stirred CaCl 2 solution. A good alternative was achieved with alginate concentrations between 1% and 2.5% (Choi et al., ). Stable calcium alginate capsules were obtained with CaCl 2 concentrations greater than 0.05 M (Keita & Imai, ), whereas a high Ca 2+ concentration (16 g/100 mL) in the solution used for formulating capsules may decrease the viability of the probiotic (Shori, ).…”

“…The level of capsule degradation was confirmed by analyzing the level of total carbohydrate (Choi et al., ). During the simulated GI reactions, 10 mL fluid samples were withdrawn from the stomach and small intestine vessels at 1 and 2 hr intervals, respectively.…”

UII/GPR14 is involved in NF-κB-mediated colonic inflammation in vivo and in vitro

“…In the present study, we used urantide, a special antagonist of GPR14, to block GPR14 and the results indicated that GPR14 inhibition alleviated DSS-induced colitis in mice evidenced by reduced rectal bleeding and histological injury, indicating a protective role of urantide in the colitis model. Pro-inflammatory cytokines and inflammation response in the gastrointestinal tract play a vital role in the progression of IBD (10,(22)(23)(24)(25). However, the effect of UII/GPR14 signaling on DSS-induced pro-inflammatory cytokine generation is not fully understood.…”

“…In the present study, NF-κB signaling was activated after DSS treatment in vivo and in vivo, while inhibition of the UII/ GPR14 signal via urantide or GPR14 siRNA transfection significantly inactivated NF-κB via reducing p65 phosphorylation. NF-κB activation requires IκBs, an inhibitory protein of NF-κB (25,26,29). The present data revealed that urantide markedly alleviated the inhibitory effect of DSS on IκBα.…”

Long-term effects of oral tea polyphenols and Lactobacillus brevis M8 on biochemical parameters, digestive enzymes, and cytokines expression in broilers

“…Bornhoeft et al (2012) reported that dietary 0.2% TP improved lipid metabolism in rats fed an atherogenic diet via mediating serum LDL-C and HDL-C concentrations. The mechanism may be that TP can regulate fatty acid synthesis and lipolysis-related genes, including carnitine palmitoyl transferase I, acyl-CoA oxidase 1, peroxisome proliferator-activated receptor-α (PPARα), adipose triglyceride lipase, and lipoprotein lipase (LPL) (Huang et al, 2013;Choi et al, 2015).…”