Application And Mechanism Of Soluble Dietary Fibers In Enteral Nutrition Preparations

In recent years,with the change of dietary structure,the content of dietary fiber in people's diet is becoming less and less.Diseases caused by overnutrition or malnutrition seriously affect human health,so functional foods which can promote health,prevent diseases and regulate human physiological function have been widely concerned.Dietary fiber has obvious health function,such as defecation,weight loss,blood sugar,blood lipid and cardiovascular disease,and most dietary fiber can help prevent the occurrence of colon cancer.At present,dietary fiber has become a hot topic in food science,nutrition and epidemiology.With the refinement of dietary structure,the types and contents of dietary fibers in food have decreased significantly,which has led to a series of health problems.There are few studies on the mechanism of dietary fibers.The effects of dietary fibers on gastrointestinal function are mostly focused on osmotic pressure regulation.There are few reports on whether dietary fibers have other mechanisms.In addition,there are few studies on the regulation of immune function by dietary fibers.Since dietary fiber is an important component of functional food,it is of great value to study the mechanism of different kinds of dietary fiber on gastrointestinal tract.In this study,the effect of soluble dietary fiber on gastrointestinal movement and its mechanism were discussed from the perspective of in vitro and overall by using the method of in vitro intestinal tube and small intestine propulsion.1.Experiments on isolated intestinal smooth muscle:Under normal physiological conditions,polydextrose?PDX?from 1 mg/ml to 40 mg/ml,fructooligosaccharide?FOS?from 1 mg/ml to 20 mg/ml,and isomaltose oligosaccharide?IMO?from 0.1mg/ml to 5 mg/ml all increased the baseline of the contraction curve,increased the tension,and positively correlated with the dose.There was a significant difference between the experimental group and the control group?P<0.01?.When PDX exceeded 100 mg/ml,FOS exceeded 50 mg/ml and IMO exceeded 20 mg/ml,the contraction curve decreased obviously.After adding atropine,the tension of small intestinal smooth muscle was?0.76±0.06?g,?0.56±0.52?g and?0.76±0.33?g,respectively.Compared with the blank group?1.21±0.21?g),the tension of small intestinal smooth muscle was significantly decreased?P<0.01?.When adrenaline hydrochloride was added,the tension of small intestinal smooth muscle was?1.02±0.22g?,?1.05±0.52?g,?1.05±0.03?g,which was significantly lower than that of the blank group?1.21±0.21?g?P<0.01?.When verapamil was added,the tension of small intestinal smooth muscle was?1.05±0.15?g,?1.01±0.15?g,?1.05±0.12?g?P<0.01?,which was significantly lower than that of the blank group?1.21±0.21?g?P<0.01?.On this basis,PDX,FOS,IMO and atropine groups were added respectively.The tension increased?2.02±0.55?g,?3.06±0.25?g,?2.35±0.56?g,with significant difference?P<0.01?.The tension increased?2.35±0.32?g,?3.45±0.32?g,?2.26±0.32?g in the adrenaline group,with significant difference?P<0.01?,and there was no significant change in the tension of verapamil group,with no significant difference?P<0.01?.?1.06±0.52?g,?0.92±0.32?g,?1.05±0.26?g,compared with the blank group?1.21±0.21?g,the difference was not significant?P>0.05?.2.Small intestinal propulsion test in mice:The results showed that PDX,FOSand IMO could significantly increase the degree of small intestinal propulsion.Compared with the blank group,the small intestinal propulsion rates in the low,middle and high concentration groups of PDX were 44.01%,47.41%and 53.83%respectively,which were significantly different from those in the blank group?44.83%??P<0.01?.The propulsion rates in the FOS group were 50.25%,54.33%and 69.91%,which were significantly different from those in the blank group?P<0.01?.The propulsive rate of IMO group was 55.41%,67.62%and 60.47%,which was significantly different from that of blank group?P<0.01?.After atropine injection,the propulsive rate was 42.01%.After continuous administration of PDX,FOS and IMO,the propulsive rate was47.41%,50.25%and 55.41%respectively,which was significantly different from the blank group?P<0.01?.After injection of adrenaline,the propulsive rate was 27.89%.After continuous administration of PDX,FOS and IMO,the propulsive rate was49.63%,52.31%and 50.65%,respectively,which was significantly different from the blank group?P<0.01?.After verapamil injection,the propulsive rate was 45.05%?P>0.05?,with no significant difference.3.Conclusion:The small intestine smooth muscle is the target tissue of PDX,FOS and IMO.The dosage of PDX,FOS and IMO can enhance the contractile tension of isolated small intestine in a certain range,and can inhibit the contractile strength of small intestine when the dosage exceeds this range,which indicates that PDX,FOS and IMO have bidirectional regulating effects on the motility of small intestine.The mechanism of gastrointestinal motility is not related to cholinergic M receptor and beta-adrenergic receptor,but may be related to Ca²⁺influx mediated by L-type Ca²⁺channel.In vivo and in vitro experiments showed that the effects of PDX,FOS and IMO were different at the same dose.IMO>FOS>PDX may be due to the different affinity of their structures to calcium channel receptors.The receptors of their effects need to be further studied.