Germinated Barley Foodstuff Exhibits Different Adsorption Properties for Hydrophilic versus Hydrophobic Bile Acids

Abstract

Background/Aims: Germinated barley foodstuff (GBF), a type of dietary fiber, exhibits therapeutic effects in ulcerative colitis (UC) patients. However, the precise mechanisms responsible for these effects are still under investigation. On the other hand, it has been suggested that bile salts in the gut lumen play an important role in the integrity of the intestinal mucosa. The aim of the present study was to investigate the ability of GBF to adsorb bile salts in vitro. Methods: The binding capacities of GBF, enzymatically digested GBF (GBF-fiber), and α-cellulose for unconjugated and conjugated bile salts were measured using Langmuir’s method. The morphology of these fibers was observed by light and fluorescence microscopy. Results: GBF adsorbed bile salts very strongly, especially hydrophobic bile salts. Even after enzymatic digestion, the GBF fiber still exhibited strong binding capacity, whereas α-cellulose exhibited very low binding capacity. Microscopically, GBF consists mainly of aleurone, a lattice-like cell wall with cytoplasm enclosed. After enzymatic digestion, the cytoplasm was also digested. Conclusion: GBF possesses a great capacity to adsorb bile salts. This may be part of the mechanism for the therapeutic effects of GBF in UC patients.

Increased apoptosis and decreased proliferation of colonic epithelium in dextran sulfate sodium-induced colitis in mice

“…In addition, even a certain dietary fiber can alter the intestinal microflora, produce short chain fatty acids, subsequently colitis improved in human and DSS-induced colitis (12)(13)(14)(15). Even probiotics have been reported to have therapeutic effects for both diseases (16).…”

The herbal medicine rikkunshito exhibits strong and differential adsorption properties for bile salts

“…We have studied the role of bile salts in the gut lumen when considering the pathogenesis and disease-promoting factors for experimental and clinical gastrointestinal diseases (25,26,(33)(34)(35)(36)(37). In the course of these investigations, it has been revealed that bile salts exhibit mainly cytotoxic but also certain stimulatory effects towards the intestinal epithelium (38).…”

“…In addition, α-cellulose was used in order to compare the binding capacity of rikkunshito with other types of fiber. The binding experiment was carried out according to our previous method (25). Briefly, 50 mg of rikkunshito or α-cellulose was placed into a glass-stoppered conical flask with 5 ml of water.…”

“…In the process of investigating the therapeutic mechanisms of GBF, we discovered that one of its major properties was its capacity to adsorb bile salts (25), thus eliminating bile salts from the gut lumen and ameliorating colitis. Therefore, the aim of the present study was to investigate whether rikkunshito is able to adsorb bile salts in vitro and, if so, to establish whether this capability contributes to its therapeutic effects in reducing the symptoms of patients with GERD and DGER.…”

Germinated barley foodstuff suppresses dextran sulfate experimental colitis in rats: The role of mast cells

“…We have previously reported that a certain kind of dietary fiber, germinated barley foodstuff (GBF), is the best generator of SCFAs in the gut lumen, and exerts strong therapeutic effects against experimental colitis in rats (6) and clinical UC patients (7,8). With respect to the mechanism of action of GBF, we discovered that GBF has glutamine-rich proteins, has a high binding capacity for cytotoxic bile acids (9), and a high capacity for SCFA production through the actions of Eubacterium and Bifidobacterium in the gut lumen, and that the levels of SCFA correlated to an amelioration of the colitis (6), and inactivated nuclear factor kappa B (NFκB) (10).…”