Excretion Of Fatty Acids Research Articles

Effects of the Cell Wall ofKluyveromyces marxianusYIT 8292 on the Plasma Cholesterol and Fecal Sterol Excretion in Rats Fed on a High-Cholesterol Diet

The cellular components involved in the hypocholesterolemic activity of Kluyveromyces marxianus YIT 8292 were examined in rats fed on a high-cholesterol diet. Whole cells (KM) were heated at 115 degrees C for 10 minutes and fractionated into water-soluble extract 1 and the insoluble residue (KM-CW). After mechanical disruption by glass beads, KM-CW was separated into the cell wall (KM-W) and water-soluble extract 2. Plasma total cholesterol was decreased by feeding KM-CW or KM-W, but was not changed by feeding extract 1 or extract 2. Feeding KM-CW and KM-W increased the fecal sterol excretion and concentration of short-chain fatty acids (SCFA) in the cecum. The hypocholesterolemic activity of KM-CW was completely abolished by the enzymatic degradation of alpha-mannan and beta-glucan. These results suggest that alpha-mannan and beta-glucan were the major active components of KM, and that its hypocholesterolemic activity may be attributable to the increasing fecal sterol excretion and/or production of SCFA.

Absence of an atheroprotective effect of the garlic powder printanor in APOE*3-Leiden transgenic mice

Numerous animal studies have reported that garlic can protect against atherosclerosis. However, a comparable number of studies do not support this observation. This contradiction may result from differences in study design, use of different animal models, and use of different garlic formulations and preparations. Here, we investigated the effect of the chemically well-characterized and production-controlled garlic powder printanor on atherosclerosis in the APOE*3-Leiden transgenic mouse, a mouse model well suited for evaluating anti-atherosclerotic properties of drugs and food components under human-like conditions. APOE*3-Leiden mice were fed a Western diet supplemented with either 5 or 50 g kg −1 printanor. As a reference, the commercially available fermented garlic kyolic was included (1.6 g kg −1 diet). Treatment with printanor demonstrated reduced body weight, coinciding with increased feces production and fecal fatty acids excretion. Printanor and kyolic treatment did not affect plasma lipids, markers of inflammation (serum amyloid A, serum-soluble intercellular adhesion molecule-1, and blood-leukocytes tumor necrosis factor-α (TNFα) production) and vascular activation (plasma von Willebrand factor (vWF)). As analyzed after 28 weeks of treatment, printanor and kyolic did not affect atherosclerotic lesion type, area or composition. Under conditions relevant to the human situation, the well-characterized and production-controlled garlic powder printanor does not display hypolipidemic, anti-inflammatory or anti-atherosclerotic properties.

Dietary Effects of Porphyran from Porphyra yezoensis on Growth and Lipid Metabolism of Sprague-Dawley Rats

Effects of porphyran (POR), a sulfated galactan from an edible red alga Porphyra yezoensis (Susabinori), on growth and lipid metabolism were examined using Sprague-Dawley rats fed a cholesterol-free diet. Rats were divided into four dietary groups: those fed diets containing 5% cellulose (control), agar or two types of POR differing in sugar composition and sulfate content (low sulfate content, LS-POR and high sulfate content, HS-POR) for 3 weeks. Ingestion of the diets containing LS- and HS-POR resulted in a significant decrease in food intake and body weight gain relative to the control diet. Renal adipose tissue weight and serum cholesterol level were also significantly lower in the LS-POR group and the HS-POR group than in the other groups. In contrast, agar, which consists of the same sugar components as POR, had no effect on the above-mentioned growth and lipid parameters. Fecal excretion of neutral sterols was markedly enhanced by POR ingestion, suggesting that POR has a potent effect to interfere with the absorption of neutral sterols within the gastrointestinal tract. Fecal excretion of fatty acids and neutral sterols was significantly higher in the LS-POR group than in the HS-POR group, and it was suggested that the ability to interfere with the absorption of cholesterol and fatty acid within the gastrointesitinal tract depends on the sulfation rate of porphyan.

Effects of soybean beta-conglycinin on hepatic lipid metabolism and fecal lipid excretion in normal adult rats.

beta-Conglycinin decreased blood triacylglycerol (TAG) levels in male Wistar adult rats. Liver mitochondrial carnitine palmitoyltransferase activity in the beta-conglycinin-fed group significantly increased as against the casein-fed group. Hepatic fatty acid synthase activity in the beta-conglycinin group significantly decreased as against that of the casein-fed group. Fecal fatty acid excretion in the beta-conglycinin group was significantly higher than in the casein group.

Biochemical Functions ofBacillus licheniformisin Gnotobiotic Mice

A probiotic bacterial strain, Bacillus licheniformis NCTC 13123, has been mono-associated with germ-free mice. After colonization, the following biochemical microflora-associated characteristics (MACs) were analyzed in the large intestinal contents: excretion of short-chain fatty acids (SCFAs), inactivation of tryptic activity, degradation of β -aspartylglycine, breakdown of mucin, conversion of cholesterol to coprostanol and transformation of bilirubin to urobilins. An additional MAC, b-glucuronidase activity, was tested in vitro. β -Glucuronidase activity was not expressed by the bacterium. The amount of total SCFAs was lower than that previously found in germ-free mice. Utilization of individual SCFAs rather than production by the strain may be assumed. The other MACs remained similar to the basal values in germfree mice. We conclude that B. licheniformis NCTC 13123 is not able to alter any of the microbial functions investigated in vitro or in the gastrointestinal tract of germ-free mice. Whether and to what extent the strain has the capability to interfere with these functions in the presence of other micro-organisms remains to be investigated. Key wordis : Bacillus licheniforms , probiotics, microflora-associated characteristics, germ-free mice.

Effects of fermented, ropy, non-dairy, oat-based products on serum lipids and the faecal excretion of cholesterol and short chain fatty acids in germfree and conventional rats

Three fermented, ropy, non-dairy, oat-based products were evaluated for their effect on serum lipids, faecal cholesterol and faecal short chain fatty acids in germfree and conventional rats. Three different exopolysaccharide (EPS) producing lactic acid bacteria strains were used to ferment the non-dairy oat-base (Adavena ® G40) (Ceba Foods AB, Lund, Sweden). Two commercial non-dairy products based on oats (Mill Milk™) (Ceba Foods AB, Lund, Sweden) and rice (Rice Dream ®) (Imagine Foods, London, UK) were used as non-ropy and unfermented controls. All the standardized feeds were sterilized before being fed to the animals. Adult, germfree and conventional AGUS rats, were fed the above sterile diets ad libitum for 21 days. Blood samples and faecal samples were collected and the animals’ weight gain was monitored throughout the study. No significant change in serum lipids or faecal excretion of cholesterol was observed between the groups on the different diets. A difference in faecal SCFA pattern was observed in conventional rats fed on the oat-based diets in comparison to the group fed on the rice-based diet. More evidence is needed to support the effect of fermented, ropy, oat-based products and their potential effect on serum lipids, faecal cholesterol/coprostanol levels and amounts of short chain fatty acids.

Association of dietary fatty acids with urinary oxalate excretion in calcium oxalate stone-formers in their fourth decade.

To examine the influence of the dietary intake of fatty acid on urinary oxalate excretion in calcium oxalate stone-formers in their fourth decade, as previous reports show that animal fat intake is associated with urinary oxalate excretion. The dietary intake of 58 idiopathic stone-formers in their fourth decade was recorded using the dietary-record method. The patients collected 24-h urine samples at home and their urinary oxalate excretion was measured in a clinical biochemistry laboratory. The results were used to determine the relationship between the dietary intake of fatty acids and urinary oxalate excretion. Associations between urinary oxalate excretion and dietary contents of animal fat, animal protein and various fatty acids were assessed using Spearman's correlation coefficient and multiple regression. The dietary content of arachidonic acid was positively correlated with urinary oxalate excretion, as assessed by univariate and multivariate analysis. The association between arachidonic acid and oxalate excretion suggests that arachidonic acid increases the intestinal absorption of oxalate and increases the clearance of oxalate in the kidneys.

Diet, length of gestation, and fecal short chain fatty acids in healthy premature neonates.

Excretion of fecal short-chain fatty acids (SCFAs) may indicate changes in colonic or colonocyte metabolism. The aim of this study was to detect the influence of gestational age and feeding practices on SCFA concentrations and profiles in healthy preterm infants. A total of 198 fecal samples (28 infants) were collected from 8 to 21 days of age from 3 groups of preterm infants born at 33 to 37 weeks of gestation and fed either breast milk (group I) or Nutramigen, a lactose-free formula (group II), and extremely preterm infants born before 33 weeks of gestation and fed breast milk (group III). Total SCFA concentrations and SCFA profiles were analyzed using a gas chromographic (GC) procedure. Total fecal SCFA excretion did not differ significantly between group I (mean, 24.0 micromol/g; range, 1.3 to 118.8 micromol/g) and group II (mean, 23.0 micromol/g; range, 3.0 to 73.3 micromol/g). Conversely, differences occurred between SCFA profiles and became significant after day 17. The main differences were a significant increase in the butyric acid concentration (12% versus 30%) with group II. Compared with group I, fecal SCFA concentrations were 3.2-fold lower (7.4 micromol/g; range, 0.3 to 37.4 micromol/g) in group III with no significant changes in the profiles. Fecal SCFA excretion may vary in absence of any digestive disease. During this study, in terms of gestational age, total SCFA concentrations were significantly lower in extremely premature infants compared with infants born less premature, despite their known higher deficiency in intestinal lactase activity. In terms of diet, the absence of lactose did not lead to a decrease in colonic fermentation and induced changes in SCFA patterns. These new baseline data may offer clues to further development of milk formulas.

Coarse Brown Rice Increases Fecal and Large Bowel Short-Chain Fatty Acids and Starch but Lowers Calcium in the Large Bowel of Pigs

Young male pigs were fed a diet formulated from human foods including either boiled white rice plus rice bran or heat-stabilized brown rice at equivalent levels of fiber for 3 wk. Stool and starch excretion were low in pigs fed white rice during the first 2 wk of the experiment. In pigs fed brown rice, their excretion was high during wk 1 but declined in wk 2 while short-chain fatty acid (SCFA) excretion was higher at both times. Large bowel digesta mass, measured during wk 3, was higher in pigs fed brown rice but only in the proximal colon. Large bowel and fecal starch concentrations were higher in pigs fed brown rice but the difference was insufficient to explain the increase in large bowel digesta mass. In pigs with a cecal cannula, digesta starch concentrations were equally higher when white or brown rice was fed compared with the corresponding rice which had been finely milled, indicating that particle size was a determinant of ileal digestibility. Concentrations and pools of total and individual SCFA were higher in all regions of the colon but not the cecum of pigs fed brown rice. Large bowel Ca(2+) concentrations were lower in pigs fed brown rice, suggesting greater absorption. The data confirm earlier findings that brown rice raises large bowel digesta mass and SCFA through greater fermentation of starch but show that starch itself makes a relatively small contribution to digesta and stool mass. Apparently, the rate of passage of digesta is a determinant of the concentrations and pools of SCFA in the distal colon and in feces.

Cholesterol and short-chain fatty acids in diets for Atlantic salmonSalmo salar(L.): effects on growth, organ indices, macronutrient digestibility, and fatty acid composition

The influence of dietary cholesterol (CHOL) and short-chain fatty acids (SCFA; sodium salts of acetic, propionic and butyric acid, 5:5:2 w/w/w) on growth, organ indices, macronutrient digestibility, and fatty acid composition of Atlantic salmon Salmo salar was investigated. Salmon (initial average weight 0.7 kg) held in seawater (7°C) for 175 days were fed one of six diets: 1, without CHOL/SCFA supplement; 2, with 0.5% SCFA; 3, with 2.0% SCFA; 4, with 1.0% CHOL; 5, with 1.0% CHOL and 0.5% SCFA; 6, with 1.0% CHOL and 2.0% SCFA. Neither SCFA nor CHOL supplements had any significant effects on specific growth rate (SGR), mortality, apparent digestibility coefficients (ADC) of macronutrients, total lipid content. Hepatosomatic index (HSI) was slightly increased in salmon fed the CHOL supplement (P < 0.05). Hepatic CHOL concentration, but not the hepatic CHOL pool, was significantly increased (P < 0.001) by dietary CHOL supplementation. The fatty acid compositions of fillet and gut tissues were not influenced by dietary treatment, while significant effects of CHOL supplements were observed in faeces and liver. Less saturated fatty acids and more mono- and poly-unsaturated fatty acids were excreted with faeces in salmon fed CHOL supplements. Salmon fed CHOL supplements significantly reduced the relative concentration of hepatic palmitic acid (C16 : 0), arachidonic acid (C20 : 4 n-6) and docosahexaenoic acid (C22 : 6 n-3), while the contents of oleic acid (C18 : 1 n-9) and eicosenoic acid (C20 : 1 n-9) were significantly increased. SCFA did not influence the observed effects of dietary CHOL. The present study shows that dietary CHOL supplements profoundly altered excretion and liver metabolism of individual fatty acids in salmon. The impact of this alteration on physiological performance has not been elucidated.

A High Dietary Lipid Intake during Pregnancy and Lactation Enhances Mammary Gland Lipid Uptake and Lipoprotein Lipase Activity in Rats

Rats fed a diet with high fat concentration produce larger amounts of milk with a higher lipid concentration than rats fed a lower fat diet. This investigation was designed to study the relationship between dietary fat intake, mammary gland lipid uptake and lipogenesis in rat dams fed, during pregnancy and lactation, one of two purified diets, with equal energy density, containing 2.5 (LL) or 20 g fat/100 g diet (HL). Milk lipid concentration and fatty acid composition were determined at d 14 of lactation. Mammary gland lipogenesis, lipoprotein lipase (LPL) activity and the uptake of [1-14C]triolein by the mammary gland and its transfer to the pups was measured. The intestinal absorption of oral 14C-lipid, 14CO2 production and the amount of 14C-lipid transferred to the pups (milk clot + pups carcass) were significantly higher in the HL group than in the LL group (P < 0.05). Mammary gland lipogenesis was 75% lower and LPL activity was 30% higher in the HL group (P < 0.05). Medium-chain fatty acids (C6–C14) excretion was 46% lower and that of long-chain fatty acids was 142% (P < 0.001) higher in the HL group than in the LL group. The higher milk lipid excretion in the rats fed a high-fat diet resulted from a larger uptake of dietary lipid by the mammary gland, indicated by a larger transfer of 14C-lipid to the pups and by a higher LPL activity in the mammary gland.

Characterization of hepatic cytochrome P450 isozyme composition in the transgenic rat expressing low level human growth hormone

1. The present authors have previously developed a transgenic rat carrying a chimeric gene of the mouse whey acidic protein promoter and the structural portion of human growth hormone (GH) gene. Among this (hGH-TG) rat, a line (low GH rat) missing a male-specific pulsatile GH secretary pattern due to suppression of endogenous GH secretion and having a continuous low GH (hGH and rat GH) level in the peripheral circulation was identified. The latter rat was also characterized as having severe obesity with age. This strain (low Gh rat) was used to correlate the sex-specific secretory pattern of GH with the sex-specific expression of cytochrome P450 (CYP) in rat. 2. Comparisons were made between the low GH rat and the non-transgenic rat as to the expression of liver microsomal CYP isozymes. The following enzyme activities were assessed: testosterone (T) hydroxylation and oxidation; ethoxyresorufin O-dealkylation (EROD); bunitrolol (BTL) 4-hydroxylation and T5 alpha-reduction. Protein expression of CYP1A, CYP2C11, CYP2D, CYP2E1, CYP3A2 and CYP4A1 were also assessed by Western blot analysis. 3. Enzyme activities and protein expression of CYP2C11 (T16 alpha and 2alpha-hydroxylase and 17-oxidase activities) and CYP3A2 (T6beta and 2beta-hydroxylase activities) levels, which are known to be higher in the male than in the female rat, were significantly lower in the adult male low GH rat than in the control male rat. In contrast, CYP2A1 (T7 alpha hydroxylase) and T5-alpha-reductase activities, which are known to be specifically elevated in the female, were significantly higher in the adult male low GH rat than in the control male rat. Thus, the loss of male-specific secretory pattern of GH results in feminization of the pattern of expression of CYP and T5 alpha-reductase activity in the liver. 4. In contrast to other GH-deficient models so far studied, an increase in CYP4A1 and a decrease in CYP2E1 protein expression were observed in the low GH rat. These trends are consistent with the characteristic phenotype of obesity in the transgenic rat because CYP4A1 and CYP2E1 enhance fatty acid excretion and glyconeogenesis from fatty acids respectively.

Fecal short-chain fatty acids predict digestive disorders in premature infants.

Excretion of fecal short-chain volatile fatty acids (SCFAs) may indicate changes in colonic or colonocyte metabolism. The aim of this study was to detect the existence of an average fecal SCFA profile and to define which changes were associated with clinical events that occurred during the survey period. SCFA profiles of 185 stool samples collected from 46 fed preterm neonates (mean birth weight, 1920 g; mean gestational age, 32.8 weeks) were evaluated and their association with digestive disorders or therapy was explored. Total SCFA concentration increased from 0 to 80 micromol/g feces wet weight over the first 20 days of life. A basic SCFA profile revealed the existence of a highly sensitive period between the second and the third week of life. In the absence of any digestive problem (n = 15), the butyric acid (C4) ratio increased from 7% to 24%. Phototherapy (n = 13) enhanced the SCFA concentration but decreased the ratios of C4 and minor acids. Digestive disorders reported included abdominal distention (n = 6) or bleeding (n = 8). Only in the case of bleeding was the SCFA profile changed by an enhancement of C4 by >50%. Antibiotic therapy (n = 3) suppressed SCFA production. This study supports a hypothesis that changes in the SCFA profile could offer a noninvasive method to anticipate functional modifications of the gastrointestinal tract before the first clinical signs of pathologic events, including necrotizing enterocolitis.

Effects of high-lipase pancreatin on fecal fat, neutral sterol, bile acid, and short-chain fatty acid excretion in patients with pancreatic insufficiency resulting from chronic pancreatitis.

Steatorrhea was almost completely stopped and malabsorption of neutral sterols and short-chain fatty acids was reduced by treatment of high-lipase pancreatin in Japanese patients with pancreatic insufficiency whose dietary fat consumption is low. Fifteen patients with chronic pancreatitis complicated by steatorrhea who consumed an average of 48 g of dietary fats a day were selected as subjects and given 3 g of high-lipase pancreatin (lipase, 379,800 USP U/g), at each meal (total daily dose is 9 g) for a mean duration of 28.5 d. Fecal output and fecal fat neutral sterol, bile acid, and short-chain fatty acid excretion were determined before and after the course of pancreatin therapy. Pancreatin administration resulted in significant reductions (P < 0.01) in fecal output (from 243.2 to 149.1 g), excretion of fecal fat, (from 12.3 to 3.9 g), animal sterols (from 816.3 to 604.6 mg), and short-chain fatty acids (from 52.6 to 18.5 mM). In contrast, no marked changes were recorded in fecal excretion of beta-sitosterol (a plant sterol), bile acids, or the hydroxy fatty acid fraction. Fecal fat and short-chain fatty-acid excretion showed strong correlations with fecal output.

Effects of resistant starch on the colon in healthy volunteers: possible implications for cancer prevention

Recent evidence suggests that resistant starch (RS) is the single most important substrate for bacterial carbohydrate fermentation in the human colon. During two 4-wk periods. 12 healthy volunteers consumed a controlled basal diet enriched with either amylomaize starch (55.2 +/- 3.5 g RS/d; high-RS diet) or available cornstarch (7.7 +/- 0.3 g RS/d; low-RS diet). Approximately 90% of the RS consumed disappeared during intestinal passage; increased fermentation was verified by elevated breath-hydrogen excretion. During the high-RS diet, fecal wet and dry weight increased 49% and 56%, respectively (P < or = 0.005), whereas stool water content did not change significantly. Fecal concentrations and daily excretion of short-chain fatty acids were not different in the two study periods. During the high-RS diet, bacterial beta-glucosidase activity decreased by 26% (P < or = 0.05). Fecal concentrations of total and secondary bile acids were significantly lower during the high-RS than during the low-RS period [a decrease of 30% (P < or = 0.05) and 32% (P < or = 0.01), respectively, in total and secondary bile acids] whereas concentrations of primary bile acids were unaffected by RS consumption. During the high-RS diet, fecal concentrations of total neutral sterols decreased by 30% (P < or = 0.005) and fecal concentrations of 4-cholesten-3-one decreased by 36% (P < or = 0.05). These data suggest that RS has potentially important effects on bacterial metabolism in the human colon that may be relevant for cancer prevention.

Fecal Numbers of Bifidobacteria Are Higher in Pigs Fed Bifidobacterium longum with a High Amylose Cornstarch Than with a Low Amylose Cornstarch ,

Twelve young male pigs consumed a purified diet containing wheat bran as fiber source. Starch provided 50% of total daily energy either as a low amylose cornstarch or as a high amylose (amylomaize) starch. The pigs were given a supplement of a freeze-dried probiotic organism (Bifidobacterium longum CSCC 1941). A block crossover design was used so that at any one time two groups of three pigs consumed either the high or low amylose cornstarch without probiotic and a further two groups of three pigs consumed either high or low amylose cornstarch with probiotic. Neither food intake nor body weight gain was affected by diet. Fecal output was higher when pigs were fed the high amylose cornstarch, but moisture content was unaffected. Fecal concentrations and excretion of total volatile fatty acids were higher when pigs were fed the high amylose cornstarch. Concentrations of acetate were unaffected by dietary starch, but those of propionate and butyrate were higher when the high amylose cornstarch was consumed. Fecal excretion of all three acids was higher during high amylose cornstarch feeding. Bifidobacteria were detected in the feces only when pigs were fed Bifidobacterium longum. Fecal bifidobacteria counts (expressed per gram of wet feces) and their daily fecal excretion were higher when pigs were fed high amylose cornstarch. Feeding the probiotic did not alter fecal starch or volatile fatty acids. None of the variables studied was affected by the order of feeding of starch or probiotic. The data show that a high amylose starch acts as a prebiotic in promoting the fecal excretion of probiotic organisms.

ABSORPTION AND LYMPHATIC TRANSPORT OF INTERESTERIFIED OR MIXED FATS RICH IN SATURATED FATTY ACIDS AND THEIR EFFECT ON TISSUE LIPIDS IN RATS

Interesterification of fully hydrogenated plant oils with liquid oils has been used as an alternative to partial hydrogenation to produce a zero-trans solid fat due to recent reports of unfavorable effects of dietary trans fatty acids on serum cholesterol levels. Present study was carried out to examine absorption of saturated fatty acids derived from mixed and interesterified fats and their effects on concentration of serum cholesterol. Dietary fats consisted of tripalmitin or tristearin: high oleic safflower oil: safflower oil ratios of 44.4:35.3:20.3 or their interesterified products; a melting point of the interesterified fat was lower than that of the corresponding mixed fats. When rats were fed these-fat containing diets for three wks, absorption rate estimated by excretion of fatty acids into feces was higher in interesterified fat-fed rats than in the corresponding mixed fat-fed rats. This improved absorption was accompanied by an increased concentration of liver triacylglycerols and an increased proportion of stearic acid in the adipose tissue and an increased proportion of oleic acid in serum and liver. Dietary fats exerted no significant effect on the liver or serum cholesterol concentration or the excretion of neutral or acidic steroids into feces. In contrast to dietary fat absorption, administration of the mixed and interesterified fats, emulsified with taurocholate and albumin, into stomach of rats cannulated with thoracic lymph duct resulted in lymphatic triacylglycerols with a comparable transport rate and with a similar fatty acid composition at each position of triacylglycerols. These results demonstrate that interesterification improves absorption of dietary fats, possibly by facilitating emulsification of saturated fats, but seems not to exert any adverse effects on the concentration of serum and liver cholesterol. © 1997 Elsevier Science Inc.

The energy value of short-chain fatty acids infused into the caecum of pigs.

The present work was undertaken to study the energy value of a mixture of acetic, propionic and butyric acids (0.682:0.226:0.092) infused intracaecally in growing pigs. A basal diet low in fibre (42 g NSP/kg DM) was given at below the requirement for maximum weight gain. In six 2-week periods, N and energy balance measurements in eight growing pigs were carried out with and without infusion of short-chain fatty acids (SCFA). Heat production was measured using open-circuit chambers and the concentration of SCFA in faeces was determined. Less than 1% of the infused SCFA was excreted in faeces illustrating the capacity of the hind-gut to absorb and metabolize SCFA. Infusion of SCFA did not affect the digestibility of nutrients and energy. However, N retention increased demonstrating that SCFA are an energy source for protein gain when pigs are fed at below the requirement of energy. Increased CH4 production together with an increased excretion of branched-chain fatty acids in faeces suggested that there was a higher microbial activity in the hind-gut during infusion. The partial utilization of the infused energy in SCFA was 0.821. A small proportion of the infused energy in SCFA was retained in protein (0.099) and a considerable amount was retained as fat (0.722).

Digestion and physiological properties of resistant starch in the human large bowel

The digestion of four sources of resistant starch (RS) has been studied in twelve healthy volunteers who ate controlled diets for 15 d periods. RS from potato, banana, wheat and maize (17-30 g/d) was compared with a starch-free diet, a diet containing wheat starch that was fully digested in the small intestine, and with 18.4 g NSP from brand/d. RS increased stool wet weight by 1.6 g/d per g RS fed for potato, 1.7 for banana, 2.5 for wheat and 2.7 for maize, but this was significantly less than bran NSP at 4.9 g/g. RS was extensively digested in twenty-seven of thirty-four diet periods but five subjects were unable to break down one or two of the RS sources. Faecal N and energy excretion were increased. RS decreased NSP breakdown and RS2 (resistant starch granules) tended to prolong transit time. All forms of RS increased faecal total short-chain fatty acid excretion. RS2 (from potato and banana) gave greater proportions of acetate in faeces, and RS3 (retrograded starch from wheat and maize) more propionate. We have concluded that RS2 and RS3 are broken down in the human gut, probably in the colon although in 26% of cases this breakdown was impaired. RS exerts mild laxative properties, predominantly through stimulation of biomass excretion but also through some sparing of NSP breakdown.

Prospective evaluation of faecal fatty acid excretion in short bowel syndrome in newborns

Short bowel syndrome (SBS) in the newborn results in limited intestinal absorptive capacity, leading especially to fatty acid (FA) malabsorption. It is unknown whether adaptation occurs in time in FA absorption, and whether this adaptation is chain-length dependent. The aim of the present study was to prospectively evaluate FA absorption and excretion during SBS in the newborn. Twenty-one neonates who underwent small bowel resection (of variable length) for various reasons (necrotizing enterocolitis, intestinal atresia, meconium peritonitis, cloacal extrophy, etc) were studied. Eight neonates had SBS, defined as a small bowel remnant of less than 50% of the original small bowel length related to gestational age. The mean remaining small bowel length in the SBS group was 34% (24% to 42%). The non-SBS control group consisted of 13 neonates who had only minor small bowel resections. The mean remaining bowel length for the non-SBS group was 95% (70% to 100%). The results show that the total fractional excretion of FA (FE-FA) at 2 weeks and 1, 2, 3, and 4 months postsurgery was 51% ± 37%, 33% ± 24%, 51% ± 65%, 53% ± 27%, and 7% ± 2% in patients with SBS, versus 12% ± 8%, 24% ± 10%, 9% ± 3%, 8% ± 3% and 17% ± 14% in the non-SBS controls, respectively ( P < .05 by ANOVA). There appeared to be an amelioration in time in FA absorption, especially in the SBS group, after 3 months. FE-FA was chain-length related, being considerably less for C10 and C12 than for C14 and longer amounts. An amelioration of absorption occurred in the SBS patients, especially with the longer-chain FA. On the basis of the study data, the authors conclude that in the initial adaptation phase shorter chain lengths are better absorbed than longer chain lengths; however, in the latter FA group, substantial adaptation occurs with time.