Influence of three different fiber-supplemented enteral diets on bowel function and short-chain fatty acid production

Soy and Gastrointestinal Health: A Review

Soybean is the most economically important legume globally, providing a major source of plant protein for millions of people; it offers a high-quality, cost-competitive and versatile base-protein ingredient for plant-based meat alternatives. The health benefits of soybean and its constituents have largely been attributed to the actions of phytoestrogens, which are present at high levels. Additionally, consumption of soy-based foods may also modulate gastrointestinal (GI) health, in particular colorectal cancer risk, via effects on the composition and metabolic activity of the GI microbiome. The aim of this narrative review was to critically evaluate the emerging evidence from clinical trials, observational studies and animal trials relating to the effects of consuming soybeans, soy-based products and the key constituents of soybeans (isoflavones, soy proteins and oligosaccharides) on measures of GI health. Our review suggests that there are consistent favourable changes in measures of GI health for some soy foods, such as fermented rather than unfermented soy milk, and for those individuals with a microbiome that can metabolise equol. However, as consumption of foods containing soy protein isolates and textured soy proteins increases, further clinical evidence is needed to understand whether these foods elicit similar or additional functional effects on GI health.

Effects of Whole Brown Bean and Its Isolated Fiber Fraction on Plasma Lipid Profile, Atherosclerosis, Gut Microbiota, and Microbiota-Dependent Metabolites in Apoe-/- Mice

The health benefits of bean consumption are widely recognized and are largely attributed to the dietary fiber content. This study investigated and compared the effects of whole brown beans and an isolated bean dietary fiber fraction on the plasma lipid profile, atherosclerotic plaque amount, gut microbiota, and microbiota-dependent metabolites (cecal short-chain fatty acids (SCFAs) and plasma methylamines) in Apoe^−/− mice fed high fat diets for 10.5 weeks. The results showed that both whole bean and the isolated fiber fraction had a tendency to lower atherosclerotic plaque amount, but not plasma lipid concentration. The whole bean diet led to a significantly higher diversity of gut microbiota compared with the high fat diet. Both bean diets resulted in a lower Firmicutes/Bacteroidetes ratio, higher relative abundance of unclassified S24-7, Prevotella, Bifidobacterium, and unclassified Clostridiales, and lower abundance of Lactobacillus. Both bean diets resulted in higher formation of all cecal SCFAs (higher proportion of propionic acid and lower proportion of acetic acid) and higher plasma trimethylamine N-oxide concentrations compared with the high fat diet. Whole beans and the isolated fiber fraction exerted similar positive effects on atherosclerotic plaque amount, gut microbiota, and cecal SCFAs in Apoe^−/− mice compared with the control diets.

Soybean Protein Extraction by Alcalase and Flavourzyme, Combining Thermal Pretreatment for Enteral Feeding Product

Soybean is one of the essential ingredients when formulating a tube feeding formula. In this study, we initially focused on determining which enzyme is suitable for hydrolyzing soy and comparing the soy protein enzymatic hydrolysis of three different enzymes at the same enzyme content: Flavourzyme, Protamex, and Alcalase. The result showed that Flavourzyme attained the highest soluble protein recovery efficiency (SPRE). Secondly, the study determined the effect of thermal treatment conditions such as thermal treatment duration, and then it showed that when combining the thermal treatment and enzymatic hydrolysis, the yield reached (61.44 ± 0.22)%, which was much higher than only using enzymatic hydrolysis (52.57 ± 0.27)%. Next, optimizing the enzymatic hydrolysis (combining thermal treatment) using Flavourzyme and Alcalase, Flavourzyme achieved (62.47 ± 0.12)%, while Alcalase attained (41.32 ± 0.13)%. The soy hydrolyzate using Flavourzyme achieved an average molecular size of 3.19 kDa at the following optimizing conditions: enzyme concentration, 16.09 U·g−1; pH, 7.02; temperature, 45.8 °C; and beans/water ratio, 1:3. In contrast, when using Alcalase, the soy hydrolyzate achieved an average molecular size of 1.52 kDa at the following optimizing conditions: enzyme concentration, 28.01 U·g−1; pH, 7.2; temperature, 56.5 °C; beans/water ratio, 1:4.6. Soy protein hydrolyzate of suitable viscosity and particle size flow through the inhaler with branched-chain amino acids achieved a BCAA (Branched Amino Acid) ratio of 2:1:1 for Alcalase and 4:1:1 for Flavourzyme. Soybean hydrolyzate using both enzymes attained a high SPRE and was suitable for the digestive ability of patients recovering from surgery. Soy protein is divided into amino acids, di- and tri-amino acids, and peptides to create a soluble protein source that helps feed patients with a sonde tube easily. In addition, the molecular weight of peptides will reduce viscosity significantly when passing through a sonde tube, preventing tube congestion.

Moderately high-protein enteral formula improved retinol-binding protein in tube-fed patients: A multicentre open study

Background:

Long-term inadequate dietary consumption may increase the possibility of malnutrition, morbidity and mortality. Enteral nutrition (EN) is a beneficial support that could help to maintain nutritional status and gut function.

Aim:

Our aim was to evaluate the effect of moderately high-protein enteral formula containing fibre on nutritional status, and its safety.

Method:

A total of 23 tube-feeding-dependent adult patients were included in this multicentre, open-label study. The patients were fed with the study formula for 7–12 days or equal to the required nutritional support period, during which we performed physical examinations and assessed nutritional status. The primary endpoint was the statistical difference in nutritional status after the treatment, and the secondary outcome was the desirable safety profile.

Results:

A significant improvement in cumulative energy balance after intervention was observed (p = 0.008). However, the differences in nutritional status, weight and BMI before and after the intervention do not reach statistical significance. Retinol-binding protein (RBP), a marker for nutritional status, increased from baseline levels. Few cases of diarrhoea and constipation had been reported during the study as a safety concern.

Conclusions:

This study investigated the efficacy and safety of an enteral feed formulation containing fibre. The patients were nourished with the studied formulation via tube feeding for a short period without serious adverse events. After the intervention, the significant increase in cumulative energy balance was observed. However, an extended period of the intervention may be required to attain the significance in other indicators for nutritional status.

Toxicological evaluation of alpha-galacto-oligosaccharides shows no adverse effects over a 90-day study in rats

AlphaGOS®, an alpha-galacto-oligosaccharides product, is a mixture of bi-, tri- and tetrasaccharides derived from oligosaccharides in the raffinose family of oligosaccharides (RFOs), naturally occurring plant-derived sugars. RFOs are alpha α-1,6-linked chains of D-galactose attached to the 6-position of D-glucose and differ from the currently commercially available beta-galacto-oligosaccharides products in the chirality and glyosidic bonds. In order to determine the safety of AlphaGOS, rats were given 2000 mg AlphaGOS/kg/day daily via gavage over 90 days. Daily assessments of the animals showed no adverse clinical signs. No adverse treatment-related changes in feed consumption, body weight, clinical chemistry or hematology were noted. There were no adverse treatment-related changes in organ weights, gross or histopathology. Given these findings, it can be concluded that the no observed adverse effect level for AlphaGOS is greater than 2000 mg/kg/day.

The effects of oats on the function of gut microflora in children with coeliac disease

BACKGROUND

Faecal short chain fatty acids (SCFAs) are produced by the gut microflora. We have previously reported high faecal SCFA levels in children with coeliac disease (CD), indicating alteration in gut microfloral metabolism. Data accumulated over recent decades by us and others suggest that wheat-free oats can safely be included in a gluten-free diet (GFD). However, concerns have been raised with respect to the safety of oats in a subset of coeliacs.

AIM

To describe faecal SCFA patterns in children with newly diagnosed CD treated for 1 year with a GFD with or without oats.

METHODS

This report is part of a randomised, double-blind study on the effect of a GFD containing oats (GFD-oats) vs. a standard GFD (GFD-std). Faecal samples were received from 34 children in the GFD-oats group and 37 in the GFD-std group at initial diagnosis and/or after 1 year on a GFD. Faecal SCFAs were analysed.

RESULTS

The GFD-std group had a significantly lower total faecal SCFA concentration at 12 months compared with 0 months (P < 0.05). In contrast, total SCFA in the GFD-oats group remained high after 1 year on the GFD. The children in the GFD-oats group had significantly higher acetic acid (P < 0.05), n-butyric acid (P < 0.05) and total SCFA concentration (P < 0.01) after 1-year diet treatment compared to the GFD-std group.

CONCLUSIONS

Our results indicate that oats do affect the gut microflora function, and that some coeliac children receiving oats may develop gut mucosal inflammation, that may present a risk for future complications.

Assessment of patient-reported measures of bowel function before and after pelvic radiotherapy: an ancillary study of the North Central Cancer Treatment Group study N00CA

PURPOSE

The Bowel Function Questionnaire (BFQ) has been used in clinical trials to assess symptoms during and after pelvic radiotherapy (RT). This study evaluated the importance of symptoms in the BFQ from a patient perspective.

METHODS

Patients reported presence or absence of symptoms and rated importance of symptoms at baseline, 4 weeks after completion of pelvic RT, and 12 and 24 months after RT. The BFQ measured overall quality of life (QOL) and symptoms of nocturnal bowel movements, incontinence, clustering, need for protective clothing, inability to differentiate stool from gas, liquid bowel movements, urgency, cramping, and bleeding. Bowel movement frequency also was recorded. A content validity questionnaire (CVQ) was used to rate symptoms as "not very important," "moderately unimportant," "neutral," "moderately important," or "very important."

RESULTS

Most of the 125 participating patients rated all symptoms as moderately or very important. Generally, patients gave similar ratings for symptom importance at all study points, and ratings were independent of whether the patient experienced the symptom. Measures of greatest importance (moderately or very important) at baseline were ability to control bowel movements (94 %), not having to wear protective clothing (90 %), and not having rectal bleeding (94 %). With the exception of need for protective clothing, the presence of a symptom at 4 weeks was associated with significantly worse QOL (P < .01 for all).

CONCLUSIONS

The BFQ has excellent content validity. Patients rated most symptoms as moderately or very important, indicating the BFQ is an appropriate tool for symptom assessment during and after pelvic RT.

Tolerance of an enteral formula with insoluble and prebiotic fiber in children with compromised gastrointestinal function

The effects of adding fiber to the tolerance of a peptide-based formula have not been studied. The objective of this study was to evaluate the tolerance of a peptide-based formula with insoluble and prebiotic fiber in children with compromised gut function. During January 2005 to June 2006, a 6-week randomized, double-blind, cross-over clinical study was conducted to compare stool frequency, stool consistency, and tolerance (abdominal pain, abdominal distension, vomiting, weight gain, and intake) between a formula with or without 3.5 g fructo-oligosaccharides and 3.8 g insoluble fiber/L. Fourteen children with gastrointestinal dysmotility (n=9), Crohn's disease (n=3), or mild short bowel syndrome (n=2) were randomized to receive one of two formulas for 2 weeks followed by a 5-day washout period and then the second diet for another 2 weeks. Means and standard deviations of daily stool frequency and consistency were calculated and compared using intent-to-treat analysis. Linear mixed models were applied to each outcome variable. Stool frequency did not differ by formula. Stool consistency did differ with more soft "mushy" stools (less hard stools) occurring with use of fiber (P<0.001) and more watery stools occurring with control formula (P<0.01). The extremes of stool consistency were normalized with the fiber formula. No significant differences were observed in vomiting, abdominal pain, feeding intakes, or weight gain between the two formulas. This study showed that a peptide-based formula containing fiber was as well-tolerated as a fiber-free formula in a small population of children with gastrointestinal impairments. Longer-term effects of the fiber formula need to be studied.

Fructo-oligosaccharides and fibre in enteral nutrition has a beneficial influence on microbiota and gastrointestinal quality of life

OBJECTIVE

Intestinal microbiota is important in health and disease. The aim of this study was to evaluate the effect of fructo-oligosaccharides (FOS) and fibre-enriched tube feeding on quality of life and intestinal microbiota (faecal Bifidobacteria).

MATERIAL AND METHODS

Nineteen out of 59 home-living, tube-feeding-dependent, adult patients and matched healthy controls were included in this randomized, double-blind study. After a washout period, patients received either no residue tube feeding (non-FOS group) or FOS and fibre-enriched tube feeding (FOS group). Quality of life as defined by the Gastrointestinal Quality of Life Index (GIQLI) and quantification of faecal Bifidobacteria were determined.

RESULTS

At baseline, GIQLI scores in controls and patients were 88+/-12 and 67+/-14, respectively (p=0.001). Following 6 weeks' intervention, GIQLI scores remained stable (65+/-14 versus 67+/-17) in the FOS group, whereas the non-FOS group values decreased (68+/-17 versus 64+/-19). Baseline faecal samples contained 2. 1x 10(7)+/-3.5 x 10(7) and 2.1 x 10(6)+/-5.6 x10(6)Bifidobacteria (p=0.002) in controls and patients, respectively, with no differences between patient groups. During the intervention, this number remained stable in the FOS group (0.7 x 10(6)+/-1.3 x 10(6) versus 1.0 x 10(6)+/-1.3 x 10(6) baseline versus end-point), but decreased in the non-FOS group (3.6 x1 0(6)+/-8.0 x 10(6) versus 2.5 x 10(4)+/-4.0 x 10(4)). GIQLI scores were correlated with the number of faecal Bifidobacteria (r=0.41, p=0.007).

CONCLUSIONS

The GIQL score for the tube-fed patients increased with the number of faecal Bifidobacteria, although in a non-linear way, and addition of FOS increased the number of Bifidobacteria. This suggests that prebiotic tube feeding may lead to a change in intestinal microbiota that could induce an increased quality of life in these patients.

Systematic review and meta-analysis: the clinical and physiological effects of fibre-containing enteral formulae

BACKGROUND

Enteral nutrition can be associated with gastrointestinal side effects and fibre supplementation has been proposed as a means to normalize bowel function.

AIM

To evaluate systematically the effects of fibre supplementation of enteral feeds in healthy volunteers and patients both in the hospital and community settings.

METHODS

Electronic and manual bibliographic searches were conducted. Controlled studies in adults or children, comparing fibre-supplemented vs. fibre-free formulae given as the sole source of nutrition for at least 3 days, were included.

RESULTS

Fifty-one studies (including 43 randomized-controlled trials), enrolling 1762 subjects (1591 patients and 171 healthy volunteers) met the inclusion criteria. Fibre supplementation was generally well tolerated. In the hospital setting, the incidence of diarrhoea was reduced as a result of fibre administration (OR 0.68, 95% CI: 0.48-0.96; 13 randomized-controlled trials). Meta-regression showed a more pronounced effect when the baseline incidence of diarrhoea was high. In both patients and healthy subjects, fibre significantly reduced bowel frequency when baseline frequency was high and increased it when it was low, revealing a significant moderating effect of fibre.

CONCLUSIONS

The review indicates that the fibre-supplemented enteral formulae have important physiological effects and clinical benefits. There is a need to use a consistent approach to undertake more studies on this issue in the community setting.

Soyoligosaccharide increases fecal bifidobacteria counts, short-chain fatty acids, and fecal lipid concentrations in young Korean women

The effects of soyoligosaccharide intake on human fecal characteristics were investigated by measuring the fecal water content, bifidobacteria counts, pH, and concentrations of short-chain fatty acids (SCFAs) and lipids. Sixteen young women were randomly assigned to one of two groups: (1) 1.5 g/day soyoligosaccharide intake group [low soyoligosaccharide (LSO)] or (2) 3 g/day soyoligosaccharide intake group [high soyoligosaccharide (HSO)]. The experimental period was 30 days, and fecal samples were collected every 7 days. The number of bifidobacteria in feces was increased significantly in the HSO group. Of the fecal SCFAs, propionate and butyrate concentrations were significantly increased in the HSO group. The excretions of total lipids in feces were significantly increased in both the LSO and HSO groups. These results demonstrate that a soyoligosaccharide intake of 3 g/day increases fecal bifidobacteria counts, SCFA concentrations, and fecal lipid output in Korean young women.

Fructooligosaccharides and fiber partially prevent the alterations in fecal microbiota and short-chain fatty acid concentrations caused by standard enteral formula in healthy humans

The intestinal microbiota are important during enteral tube feeding because they exert colonization resistance and produce SCFAs. However, the effect of the enteral formula composition on major bacterial groups of the microbiota has not been clearly defined. The aim of this study was to investigate the effect of enteral formulas with and without prebiotic fructooligosaccharides (FOS) and fiber on the fecal microbiota and SCFAs. Healthy subjects (n = 10; 4 men, 6 women) consumed both a standard enteral formula and one containing FOS (5.1 g/L) and fiber (8.9 g/L) as a sole source of nutrition for 14 d in a randomized, double-blind, crossover trial with a 6-wk washout phase. Fecal samples were collected at the start and end of each formula phase, and were analyzed for major bacterial groups and SCFA concentrations using fluorescent in situ hybridization and GLC, respectively. Although there were reductions in total fecal bacteria due to both formula treatments, concentrations were higher after the FOS/fiber formula period compared with the standard formula period (11.2 +/- 0.2 vs. 11.0 +/- 0.2 log(10) cells/g, P = 0.005). The FOS/fiber formula increased bifidobacteria (P = 0.004) and reduced clostridia (P = 0.006). Compared with the standard formula, the FOS/fiber formula resulted in higher concentrations of total SCFA (332.4 +/- 133.8 vs. 220.1 +/- 124.5 micromol/g, P = 0.022), acetate (219.6 +/- 96.3 vs. 136.8 +/- 74.5 micromol/g, P = 0.034) and propionate (58.4 +/- 37.4 vs. 35.6 +/- 25.5 micromol/g, P = 0.02). This study demonstrates that standard enteral formula leads to adverse alterations to the fecal microbiota and SCFA concentrations in healthy subjects, and these alterations are partially prevented by fortification of the formula with FOS and fiber.

Application of dietary fiber in clinical enteral nutrition: A meta-analysis of randomized controlled trials

AIM: To evaluate the effects of dietary fiber (DF) as a part of enteral nutrition (EN) formula on diarrhea, infection, and length of hospital stay.

METHODS: Following electronic databases were searched for randomized controlled trials about DF: Chinese Biomedicine Database (CBM), MEDLINE, EMBASE and Cochrane Controlled Trials Register. RevMan 4.1 was used for statistical analysis.

RESULTS: Seven randomized controlled trials with 400 pat-ients were included. The supplement of DF in EN was compared with standard enteral formula in five trials. Combined analysis did not show a significant reduction in occurrence of diarrhea, but there were valuable results for non-critically ill patients. Combined analysis of two trials observing the infection also did not show any valid evidence that DF could decrease the infection rate, though the length of hospital stay was reduced significantly.

CONCLUSION: Based on the current eligible randomized controlled trials, there is no evidence that the value of DF in the diarrhea can be proved. Though length of hospital stay was shortened by the use of DF, there is no available evidence in preventing infection by DF. Further studies are needed for evaluating the value of DF in EN.

Enteral feeding: the effect on faecal output, the faecal microflora and SCFA concentrations

Enteral tube feeding is common in both the hospital and community environment; however, patients can suffer alterations in faecal output that can have serious clinical sequelae. Problems associated with accurate characterisation of faecal output and definition of diarrhoea impede the comparison of research studies and prevent standardised assessment of therapeutic interventions in clinical practice. The colonic microflora may protect the patient against diarrhoea by preventing enteropathogenic infection and by producing SCFA that stimulate colonic water absorption. However, studies in healthy volunteers suggest that the composition of the enteral formula may have a negative impact on the microflora and SCFA concentrations. The addition of fructo-oligosaccharides to the enteral formula may partially prevent negative alterations to the microflora, although conclusive data from studies in patients are not yet available. Modification of the microflora with probiotics and prebiotics may hold potential in prophylaxis against diarrhoea during enteral tube feeding.

Content of short-chain fatty acids in the hindgut of rats fed processed bean (Phaseolus vulgaris) flours varying in distribution and content of indigestible carbohydrates

Red kidney beans (Phaseolus vulgaris) processed to differ in distribution and content of indigestible carbohydrates were used to study hindgut fermentability and production of short-chain fatty acids (SCFA). Bean flours with low or high content of resistant starch (RS), mainly raw and physically-inaccessible starch, were obtained by milling the beans before or after boiling. Flours containing retrograded starch and with a high or low content of oligosaccharides were prepared by autoclaving followed by freeze-drying with or without the boiling water. Six diets were prepared from these flours yielding a total concentration of indigestible carbohydrates of 90 or 120 g/kg (dry weight basis). The total fermentability of the indigestible carbohydrates was high with all diets (80-87 %). Raw and physically-inaccessible starch was more readily fermented than retrograded starch (97-99 % v. 86-95 %; ). Non-starch glucans were fermented to a lesser extent than RS, but the fermentability was higher in the case of autoclaved (50-54 %) than boiled beans (37-41 %). The distribution between acetic, propionic and butyric acid in the caecum was similar for all diets, with a comparatively high percentage of butyric acid (approximately 18). However, with diets containing the high amounts of RS, the butyric acid concentration was significantly higher in the distal colon than in the proximal colon ( and for the high- and low-level diets respectively), whereas it remained constant, or decreased along the colon in the case of the other diets. Furthermore, the two diets richest in RS also promoted the highest percentages of butyric acid in the distal colon (24 and 17 v. 12 and 12-16 for the high- and low-level diets respectively).

Effect of bowel rehabilitative therapy on structural adaptation of remnant small intestine: animal experiment

AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel.

METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days. From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 d: TPNcon group, receiving TPN and enteral 20 g·L^-1 glycine perfusion; TPN + Gln group, receiving TPN and enteral 20 g·L^-1 glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g·L^-1 glycine; EN + Gln group, enteral nutrition fortified with 20 g·L^-1 glutamine; EN + Fib group, enteral nutrition and 2 g·L^-1 oral soybean fiber; EN + GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection.

RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 µm ± 29 µm in TPNcon vs 330 µm ± 54 µm in TPN + Gln, ileal villus height 260 µm ± 28 µm in TPNcon vs 330 µm ± 22 µm in TPN + Gln, P < 0.05) and mucosa thickness (jejunal mucosa thickness 360 µm ± 32 µm in TPNcon vs 460 µm ± 65 µm in TPN +Gln, ileal mucosa thickness 400 µm ± 25 µm in TPNcon vs 490 µm ± 11 µm in TPN + Gln, P < 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g ± 3.6 g in EN + Fib, 265.7 g ± 3.3 g in EN + GH, vs 257 g ± 3.3 g in ENcon, P < 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 µg·L^-1± 52 µg·L^-1 in EN + Fib, 1200 µg·L^-1± 96 µg·L^-1 in EN ± GH, vs 620 µg·L^-1± 43 µg·L^-1 in ENcon, P < 0.05), and increased the villus height (jejunum 560 µm ± 44 µm in EN ± Fib, 530 µm ± 30 µm in EN ± GH, vs 450 µm ± 44 µm in ENcon, ileum 400 µm ± 30 µm in EN + Fib, 380 µm ± 49 µm in EN ± GH, vs 320 µm ± 16 µm in ENcon, P < 0.05) and the mucosa thickness (jejunum 740 µm ± 66 µm in EN ± Fib, 705 µm ± 27 µm in ENGH, vs 608 µm ± 58 µm in ENcon, ileum 570 µm ± 27 µm in EN ± Fib, 560 µm ± 56 µm in EN ± GH, vs 480 µm ± 40 µm in ENcon, P < 0.05) in remnant jejunum and ileum. Glutamine-enriched EN produced little effect in body mass, plasma IGF-I level, and remnant small bowel mucosal structure. The ENint group had greater body mass (280 g ± 2.2 g), plasma IGF-I level (1450 µg·L^-1± 137 µg·L^-1), and villus height (jejunum 620 µm ± 56 µm, ileum 450 µm ± 31 µm) and mucosal thickness (jejunum 800 µm ± 52 µm, ileum 633 µm ± 33 µm) than those in ENcon, EN + Gln (jejunum villus height and mucosa thickness 450 µm ± 47 µm and 610 µm ± 63 µm, ileum villus height and mucosa thickness 330 µm ± 39 µm and 500 µm ± 52 µm), EN + GH groups (P < 0.05), and than those in EN + Fib group although no statistical significance was attained.

CONCLUSION: Both dietary fiber and GH when used separately can enhance the postresectional small bowel structural adaptation. Simultaneous use of these two gut-trophic factors can produce synergistic effects on small bowel structural adaptation. Enteral glutamine perfusion is beneficial in preserving small bowel mucosal structure during TPN, but has little beneficial effect during EN.

The effect of a polymeric enteral formula supplemented with a mixture of six fibres on normal human bowel function and colonic motility

BACKGROUND AND AIMS

Fibres with varying fermentability may improve bowel function during enteral feeding. Two studies in healthy volunteers aimed to 1) investigate effects of Nutrison Multi Fibre (NMF) on gastrointestinal function, and 2) compare effects of NMF administered orally and nasogastrically on distal colonic motor activity.

METHODS

(1) Ten subjects were randomly assigned to 3x7 days self-selected diet (SSD), 2 litres Nutrison Standard (NS), or 2 l NMF. Objective and subjective indices were measured. (2) Two groups (n=6) received 2x250 ml boluses of NMF 2 hourly either nasogastrically or orally. Distal colonic motility was measured for 8 h (3 pre/5 post) first bolus.

RESULTS

Whole gut transit time was prolonged during NS (P<0.05) compared with SSD or NMF. Stool wet weight was higher during SSD (P<0.05) than during NS or NMF. Bowel frequencies were comparable. NMF was well tolerated. 2. Colonic activity index was maintained after oral administration with no associated diarrhoea. Activity index decreased after nasogastric bolus (P<0.05), but recovered to higher than fasting levels (P<0.05). 5 subjects had watery stools.

CONCLUSIONS

Oral NMF is well tolerated, normalises whole gut transit time and maintains colonic motility. Recovery of colonic activity after nasogastric bolus suggests a putative protective effect of NMF over a longer period of feeding.

How do fiber-supplemented formulas affect antroduodenal motility during enteral nutrition? A comparative study between mixed and insoluble fibers

BACKGROUND

Fiber supplementation during enteral nutrition has been recommended, but the effect of soluble compared with insoluble fiber supplements on antroduodenal motility is unknown.

OBJECTIVE

The objective of this study was to compare antroduodenal motor patterns in 8 healthy volunteers during and after gastric infusion of 3 different diets: a fiber-free diet, an insoluble-fiber diet, and a mixed-fiber diet (50% soluble fiber and 50% insoluble fiber).

DESIGN

Manometric studies with the 3 different diets (2100 kJ) were performed in random order. Antroduodenal motility was monitored continuously for 6 h by using a pneumohydraulic system to calculate the number, amplitude, and duration of the pressure waves; the area under the curve (AUC); and the percentage of time occupied by motor activity before, during, and after each type of infusion. Variations in antral areas were measured by ultrasonography.

RESULTS

The gastric motor response was significantly higher, whatever the diet, in the distal antral recording site than in the 2 more proximal sites. In the proximal but not the distal antrum, the number of waves, the AUC, and the percentage of time occupied by motor activity were higher (P: < 0.04) with the mixed-fiber than with the insoluble-fiber diet. No significant differences in variations of antral area were observed among the 3 diets. In the duodenum, motor variables were not significantly different among the 3 diets.

CONCLUSIONS

A gastric infusion induced a greater motor response in the distal than in the proximal antrum. A mixed-fiber diet was associated with significantly greater proximal antral motility than was an insoluble-fiber diet. There was no significant difference among the 3 formulas in duodenal motor variables or in variations in antral area as measured by ultrasound.

Dietary compounds that induce cancer preventive phase 2 enzymes activate apoptosis at comparable doses in HT29 colon carcinoma cells

Dietary agents that induce glutathione S-transferases and related detoxification systems (Phase 2 enzyme inducers) are thought to prevent cancer by enhancing elimination of chemical carcinogens. The present study shows that compounds of this group (benzyl isothiocyanate, allyl sulfide, dimethyl fumarate, butylated hydroxyanisole) activated apoptosis in human colon carcinoma (HT29) cells in culture over the same concentration ranges that elicited increases in enzyme activity (5-25, 25-100, 10-100, 15-60 micromol/L, respectively). Pretreatment of cells with sodium butyrate, an agent that induces HT29 cell differentiation, resulted in parallel increases in Phase 2 enzyme activities and induction of apoptosis in response to the inducers. Cell death characteristics included apoptotic morphological changes, appearance of cells at sub-G1 phase on flow cytometry, caspase activation, DNA fragmentation and TUNEL-positive staining. The results suggest that dietary Phase 2 inducers may protect against cancer by a mechanism distinct from and in addition to that associated with enhanced elimination of carcinogens. If this occurs in vivo, diets high in such compounds could eliminate precancerous cells by apoptosis at time points well after initial exposure to chemical mutagens and carcinogens.

Formulation of enteral diets

The number of enteral diets has increased from a handful in the 1970s to over 100 at present. These can be classified as polymeric, chemically defined, disease-specific, and specialized diets, as well as oral dietary supplements. The properties, indications, pros and cons for the use of these diets are outlined in an effort to assist clinicians in their selection.

Enteral feeding techniques

Major technical advances in enteral nutrition include the use of erythromycin or magnetic guidance for the placement of the feeding tube into the duodenum, the development of new enteral tubes, and bedside methods to control the tube position. Percutaneous endoscopic jejunostomy is becoming a safe procedure with a high success rate. Specialized diets offer little or no clinical advantages when compared with standard polymeric diets.

Short chain fatty acids inhibit human (SW1116) colon cancer cell invasion by reducing urokinase plasminogen activator activity and stimulating TIMP-1 and TIMP-2 activities, rather than via MMP modulation

BACKGROUND

Short chain fatty acids derived from dietary fiber may protect against invasive colon cancer by modulating degradative matrix metalloproteinases (MMPs) and protective tissue inhibitor matrix metalloproteinases (TIMPs). Since invasion depends on the MMP/TIMP ratio, we hypothesized that short chain fatty acids inhibit colon cancer invasion by inhibiting MMPs and stimulating TIMPs.

MATERIALS AND METHODS

SW1116 colon cancer cells were seeded onto Matrigel-coated Boyden chambers and treated with unsupplemented media or media containing 10 mM acetate, propionate, or butyrate. SW1116 invasion was quantitated by light microscopy and conditioned media were assayed by ELISA for MMP-1,2,3,9; TIMP-1,2; MMP/TIMP complex; and urokinase plasminogen activator (uPA). All data are expressed as mean percentage of control +/- SE (n > 6).

RESULTS

Although all three short chain fatty acids inhibited invasion, butyrate was more potent than either acetate or propionate, inhibiting SW1116 invasion by 35 +/- 1% of control (n = 18, P < .0001) vs. 18 +/- 9% (n = 7, P < .05) for acetate and 10 +/- 6% (n = 7, P < .05) for propionate. MMP-2 was not modulated by any of the short chain fatty acids while MMP-1 was modulated only by butyrate and MMP-3 by propionate. Acetate did not modulate MMPs, TIMP-1, or uPA, but stimulated TIMP-2. In contrast, propionate and butyrate stimulated MMP-9 and TIMP-2 by 119-233% and both inhibited uPA by 8-16%. TIMP-1 was stimulated only by butyrate and actually inhibited by propionate. Only butyrate stimulated both TIMP-1 and TIMP-2.

CONCLUSIONS

These data suggest that dietary fiber may protect against invasive colon cancer through stimulation of TIMP and inhibition of uPA activities, rather than through short chain fatty acids effects on the activities of the MMPs studied.