Dietary Supplementation of Vitamin B12 to Rats Fed High-Amylose Cornstarch Normalizes Propionate Fermentation in the Colon.

Since propionate exerts several physiological effects, maintenance of its normal colonic fermentation is essential. To investigate whether vitamin B12 (VB12) is essential for normal propionate fermentation by colonic bacteria, via the succinate pathway, we examined if high-amylose cornstarch (HACS) feeding activated such a pathway, if high HACS feeding impaired propionate fermentation, and if oral VB12 supplementation normalized propionate fermentation. Male rats were given control, 20% HACS or 3% fucose diets (Expt. 1); a VB12-free control diet or one supplemented with 5-30% HACS (Expt. 2); and the 20% HACS diet supplemented with 0.025-25 mg/kg of VB12 (Expt. 3), for 14 d. HACS feeding significantly increased cecal succinate concentration, activating the succinate pathway (Expt. 1). Cecal cobalamin concentration in 20% and 30% HACS groups was about 75% of that in the control group (Expt. 2). Cecal succinate and propionate concentrations significantly increased and decreased in 30% HACS groups, respectively, compared with the control group. Although HACS group supplemented with 0.025 mg/kg of VB12 had a low concentration of cecal propionate, adding high amounts of VB12 to HACS diets provided sufficient amounts of VB12 to rat ceca and increased cecal propionate concentration (Expt. 3). Compared with the non-HACS group, the relative abundance of Akkermansia muciniphila, but not Bacteroides/Phocaeicola, was lower in the HACS counterpart and showed improvement with increased VB12 doses. To summarize, feeding high HACS decreased and increased cecal VB12 and succinate concentrations, respectively. Furthermore, colonic delivery of sufficient amounts of VB12 to rats likely reduced accumulation of succinate and normalized propionate fermentation.

High Amylose Wheat Bread at Breakfast Increases Plasma Propionate Concentrations and Reduces the Postprandial Insulin Response to the Following Meal in Overweight Adults.

BACKGROUND: High amylose starchy foods modulate the postprandial metabolic response in humans. However, the mechanisms of their metabolic benefits and their impact on the subsequent meal have not been fully elucidated. OBJECTIVE: We aimed to evaluate whether glucose and insulin responses to a standard lunch are influenced by the consumption of amylose-rich bread at breakfast in overweight adults and whether changes in plasma short chain fatty acids (SCFAs) concentrations contribute to their metabolic effects. METHODS: Using a randomized crossover design, 11 men and 9 women, BMI 30 ± 3 kg/m2, 48 ± 19 y, consumed at breakfast 2 breads made with high amylose flour (HAF): 85%-HAF (180 g) and 75%-HAF (170 g), and control bread (120 g) containing 100% conventional flour. Plasma samples were collected at fasting, 4 h after breakfast, and 2 h after a standard lunch to measure glucose, insulin, and SCFA concentrations. ANOVA posthoc analyses were used for comparisons. RESULTS: Postprandial plasma glucose responses were 27% and 39% lower after breakfasts with 85%- and 70%-HAF breads than control bread (P = 0.026 and P = 0.003, respectively), with no difference after lunch. Insulin responses were not different between the 3 breakfasts, whereas there was a 28% lower response after the lunch following breakfast with 85%-HAF bread than the control (P = 0.049). Propionate concentrations increased from fasting by 9% and 12% 6 h after breakfasts with 85%- and 70%-HAF breads and decreased by 11% with control bread (P < 0.05). At 6 h after breakfast with 70%-HAF bread, plasma propionate and insulin were inversely correlated (r = -0.566; P = 0.044). CONCLUSIONS: Amylose-rich bread reduces the postprandial glucose response after breakfast and insulin concentrations after the subsequent lunch in overweight adults. This second meal effect may be mediated by the elevation of plasma propionate due to intestinal fermentation of resistant starch. High amylose products could be a promising tool in a dietary prevention strategy for type 2 diabetes. THIS TRIAL WAS REGISTERED AT CLINICAL TRIAL REGISTRY AS: NCT03899974 (https://www. CLINICALTRIALS: gov/ct2/show/NCT03899974).

Therapeutic Potential of Various Plant-Based Fibers to Improve Energy Homeostasis via the Gut Microbiota.

Obesity is due in part to increased consumption of a Western diet that is low in dietary fiber. Conversely, an increase in fiber supplementation to a diet can have various beneficial effects on metabolic homeostasis including weight loss and reduced adiposity. Fibers are extremely diverse in source and composition, such as high-amylose maize, ß-glucan, wheat fiber, pectin, inulin-type fructans, and soluble corn fiber. Despite the heterogeneity of dietary fiber, most have been shown to play a role in alleviating obesity-related health issues, mainly by targeting and utilizing the properties of the gut microbiome. Reductions in body weight, adiposity, food intake, and markers of inflammation have all been reported with the consumption of various fibers, making them a promising treatment option for the obesity epidemic. This review will highlight the current findings on different plant-based fibers as a therapeutic dietary supplement to improve energy homeostasis via mechanisms of gut microbiota.

Frozen Autoclaved Sorghum Enhanced Colonic Fermentation and Lower Visceral Fat Accumulation in Rats.

As raw sorghum is not able to influence considerable colonic fermentation despite its higher resistant starch (RS) content, our study aimed to investigate the effects of frozen autoclaved sorghum on colonic fermentation. Fischer 344 rats were fed frozen cooked refined (S-Rf) and whole (S-Wh) sorghum diets and were compared against α-corn starch (CON) and high amylose starch (HAS) fed rats for zoometric parameters, cecal biochemical and microbiological parameters. Sorghum fed rats exhibited significantly lower feed intake and visceral adipose tissue mass compared to CON. Bacterial alpha diversity was significantly higher in the sorghum fed rats compared to HAS and the two sorghum fed groups clustered together, separately from HAS and CON in the beta diversity plot. Serum non-High Density Lipoprotein cholesterol and total cholesterol in S-Rf group were significantly lower compared to CON, while total fecal bile excretion was also significantly higher in the two sorghum fed groups. Lower visceral adiposity was correlated with lower feed intake, RS content ingested and cecal short chain fatty acid (SCFA) contents. Thus, higher RS inflow to the colon via frozen autoclaved sorghum might have influenced colonic fermentation of RS and the resultant SCFA might have influenced lower adiposity as manifested by the lower body weight gain.

Resistant Starch Has No Effect on Appetite and Food Intake in Individuals with Prediabetes.

BACKGROUND: Type 2 resistant starch (RS2) has been shown to improve metabolic health outcomes and may increase satiety and suppress appetite and food intake in humans. OBJECTIVE: This study assessed whether 12 weeks of daily RS2 supplementation could influence appetite perception, food intake, and appetite-related gut hormones in adults with prediabetes, relative to the control (CTL) group. DESIGN: The study was a randomized controlled trial and analysis of secondary study end points. PARTICIPANTS/SETTING: Sixty-eight adults (body mass index ≥27) aged 35 to 75 years with prediabetes were enrolled in the study at Pennington Biomedical Research Center (2012 to 2016). Fifty-nine subjects were included in the analysis. INTERVENTION: Participants were randomized to consume 45 g/day of high-amylose maize (RS2) or an isocaloric amount of the rapidly digestible starch amylopectin (CTL) for 12 weeks. MAIN OUTCOME MEASURES: Subjective appetite measures were assessed via visual analogue scale and the Eating Inventory; appetite-related gut hormones (glucagon-like peptide 1, peptide YY, and ghrelin) were measured during a standard mixed-meal test; and energy and macronutrient intake were assessed by a laboratory food intake (buffet) test, the Remote Food Photography Method, and SmartIntake app. STATISTICAL ANALYSES PERFORMED: Data were analyzed using linear mixed models, adjusting for treatment group and time as fixed effects, with a significance level of α=.05. RESULTS: RS2 had no effect on subjective measures of appetite, as assessed by visual analogue scale (P>0.05) and the Eating Inventory (P≥0.24), relative to the CTL group. There were no effects of RS2 supplementation on appetite-related gut hormones, including glucagon-like peptide 1 (P=0.61), peptide YY (P=0.34), and both total (P=0.26) and active (P=0.47) ghrelin compared with the CTL. RS2 had no effect on total energy (P=0.30), carbohydrate (P=0.11), protein (P=0.64), or fat (P=0.37) consumption in response to a buffet meal test, relative to the CTL. In addition, total energy (P=0.40), carbohydrate (P=0.15), protein (P=0.46), and fat (P=0.53) intake, as quantified by the Remote Food Photography Method, were also unaffected by RS2, relative to the CTL. CONCLUSIONS: RS2 supplementation did not increase satiety or reduce appetite and food intake in adults with prediabetes.

Effects of dietary amylose/amylopectin ratio and amylase on growth performance, energy and starch digestibility, and digestive enzymes in broilers.

This study was conducted to investigate the effects of dietary amylose/amylopectin (AM/AP) ratio and amylase on growth performance, apparent digestibility of energy and starch, serum biochemical index, and digestive enzymes. The experiment used a 4 × 3 factor design, and 960 one-day-old Arbor Acres (AA) broilers were randomly divided into 12 groups fed diets containing different AM/AP ratio of 0.11, 0.23, 0.35 and 0.47 and combined with 0, 3,000 and 6,000 U/kg amylase. Results showed that 0.23-0.35 AM/AP ratio increased growth performance, while dietary addition of 6,000 U/kg amylase significantly reduced average daily weight gain in broilers. The energy digestibility was significantly reduced along with the increase of dietary AM/AP ratio and in the 6,000 U/Kg amylase-supplemented groups. The digestibility of starch also decreased significantly with the increase of dietary AM/AP ratio, but high dose (6,000 U/Kg) of amylase increased. High AM/AP diet reduced serum insulin concentration, which was increased in amylase-supplemented groups. Furthermore, exogenous amylase increased amylase activity in the jejunal chyme. In conclusion, dietary 0.23-0.35 AM/AP ratio was suggested to maintain a higher growth performance in broilers and high AM/AP ratio diets reduced energy and starch digestibility and serum insulin concentration, which was reversed by dietary amylase.

Sexually Dimorphic Response of Increasing Dietary Intake of High Amylose Wheat on Metabolic and Reproductive Outcomes in Male and Female Mice.

High amylose wheat (HAW) has a higher resistant starch content and lower glycaemic index than standard amylose wheat (SAW), which may be associated with health benefits. This study aimed to determine the effects of replacing SAW with HAW on metabolic and reproductive parameters in male and female mice. Male and female C57BL/6 mice were randomly divided into groups (n = 8/group/sex) and fed either a SAW65 (65% SAW w/w; control), HAW35 (35% HAW w/w), HAW50 (50% HAW w/w) or HAW65 (65% HAW w/w) diet for eight weeks. In male but not female, the HAW65 group had a lower abdominal circumference, relative total fat mass, relative gonadal fat mass and plasma leptin concentration compared to the HAW35 group. There were no differences in fasting blood glucose concentrations or plasma concentrations of cholesterol, triglycerides or non-esterified fatty acids between groups in either males or females. The HAW-fed males had a higher testicular weight and HAW-fed females spent less time in diestrus and a longer time in metestrus compared to the SAW-fed mice. Higher dietary intake of HAW appears to reduce abdominal fat deposition compared to the lower level of HAW in a sexually dimorphic manner. The impacts on reproductive parameters in the HAW-fed mice require further investigation.

High-Amylose Wheat Lowers the Postprandial Glycemic Response to Bread in Healthy Adults: A Randomized Controlled Crossover Trial.

BACKGROUND: Conventional wheat-based foods contain high concentrations of readily digestible starch that commonly give these foods a high postprandial glycemic response and may contribute to the development of type 2 diabetes and cardiovascular disease. OBJECTIVES: The aim of this study was to determine if bread made from high-amylose wheat (HAW) and enriched in resistant starch dampens postprandial glycemia compared with bread made from conventional low-amylose wheat (LAW). METHODS: This single-center, randomized, double-blinded, crossover controlled study involved 7 consecutive weekly visits. On separate mornings, 20 healthy nondiabetic men and women (mean age 30 ± 3 y; body mass index 23 ± 0.7 kg/m2) consumed a glucose beverage or 4 different breads (each 121 g); LAW-R (refined), LAW-W (wholemeal), HAW-R, or HAW-W. The starch contents of the LAW and HAW breads were 24% and 74% amylose, respectively. Venous blood samples were collected at regular intervals before and for 3 h after the breakfast meal to measure plasma glucose, insulin, ghrelin, and incretin hormone concentrations, and the incremental area under the curve (AUC) was calculated (mmol/L × 3 h). Satiety and cravings were also measured at 30-min intervals during the postprandial period. RESULTS: HAW breads had a glycemic response (AUC) that was 39% less than that achieved with conventional wheat breads (HAW 39 ± 5 mmol/L × 3 h; LAW 64 ± 5 mmol/L × 3 h; P < 0.0001). Insulinemic and incretin responses were 24-30% less for HAW breads than for LAW breads (P < 0.05). Processing of the flour (wholemeal or refined) did not affect the glycemic, insulinemic, or incretin response. The HAW breads did not influence plasma ghrelin, or subjective measures of satiety or cravings during the postprandial period. CONCLUSIONS: Replacing LAW with HAW flour may be an effective strategy for lowering postprandial glycemic and insulinemic responses to bread in healthy men and women, but further research is warranted. This trial was registered at the Australian and New Zealand Clinical Trials Registry as ACTRN12616001289404.

Effects of dietary amylose and amylopectin ratio on growth performance, meat quality, postmortem glycolysis and muscle fibre type transformation of finishing pigs.

The present study was conducted to investigate the effects of dietary amylose and amylopectin ratio on growth performance, meat quality, postmortem glycolysis and muscle fibre type transformation of finishing pigs. Twenty-four barrows (Duroc × Landrace × Yorkshire) with an average initial body weight of 61.7 ± 2.01 kg were randomly assigned to four dietary treatments with amylose: amylopectin ratios of 1:1 (HD), 1:2 (MD), 1:3 (CD) and 1:4 (LD). The results showed that the average daily weight gain of finishing pigs tended to reduce with the ratio of amylose and amylopectin decreased (p = 0.09). Diet LD increased the pH24h value and decreased the shear force in longissimus dorsi (LM) compared with diet HD (p < 0.05). Diet LD decreased the lactate content and the HK-2 mRNA abundance and increased the mRNA abundance of ATP5B in LM compared with diet HD (p < 0.05). Higher mRNA abundance of MyHC I and lesser abundance of MyHC IIb in LM were found in pigs fed diet CD and LD than those fed diet HD (p < 0.05). Furthermore, pigs fed diet LD had higher mRNA abundances of PGC-1α and PPAR δ in LM than other groups (p < 0.05). These results suggested that diet with low amylose and amylopectin ratio could improve meat quality of finishing pigs via delaying muscle glycolysis capacity and shifting muscle fibre types.

Long-term ingestion of low amylose/amylopectin ratio diet affects aspects of meat quality by changing muscle fibre characteristics in growing-finishing pigs.

Amylose plays important role in body health. It is controversial whether changing dietary amylose/amylopectin ratio (DAR) will improve meat quality in growing-finishing pigs. A total of 48 Duroc × Landrace × Large White castrated male pigs (initial body weight 49.8 ± 2.8 kg) were randomly allotted to two treatments, and fed ad libitum either with a low DAR diet (LR, amylose/amylopectin: 12/88) or a high DAR diet (HR, amylose/amylopectin: 30/70) for 68 days. Feed intake was recorded every day, body weight was weighed at 46th and 68th day to calculate average daily gain (ADG), average daily feed intake (ADFI) and Feed:gain ratio. Blood was collected at -30 min (fasting 12 hr), 60, 90, 120, 180 min postprandial at 64th day and then serum was obtained by centrifugation of blood at 1,500× g at 4°C. After pigs were slaughtered, samples such as longissimus dorsi, iliopsoas and semitendinosus were collected. Density, diameter and types of muscle fibres were analysed. Results showed that ADG, ADFI, Feed:Gain ratio, cross-sectional area of longissimus dorsi muscle, backfat thickness, colour scores were not affected by DAR. Ingestion of LR diet increased the fasting glucose (p < 0.05) and insulin (p < 0.05) concentrations in serum. The drip loss and firmness were decreased significantly in LR vs. HR animals (p < 0.05). Densities of muscle fibre in longissimus dorsi, iliopsoas and semitendinosus were greater in LR pigs (p < 0.05). Moreover, ingestion of LR diet significantly increased myosin heavy chain (MyHC) IIa mRNA level and decreased MyHC IIb gene expression in longissimus dorsi muscle (LM) (p < 0.05). Therefore, intake of diet low in amylose/amylopectin ratio induces a better meat quality (lower drip loss and lower firmness), which could attribute to smaller myofibres, a shift to slower and/or more oxidative fibres.

Comparison of a sports-hydration drink containing high amylose starch with usual hydration practice in Australian rules footballers during intense summer training.

BACKGROUND: Fluid deficits exceeding 1.6% can lead to physical and cognitive impairment in athletes. Sport drinks used by athletes are often hyper-osmolar but this is known to be suboptimal for rehydration in medical settings and does not utilize colonic absorptive capacity. Colonic absorption can be enhanced by fermentative production of short chain fatty acids (SCFA) from substrates such as high amylose maize starch (HAMS). This study therefore compared, in elite Australian Football League (AFL) players at the height of outdoor summer training, a novel dual-action sports oral rehydration strategy that contained HAMS as well as glucose, to their usual rehydration practices (Control). The primary outcome markers of hydration were hematocrit and body weight. METHODS: A randomized single-blind crossover study was undertaken in thirty-one AFL players; twenty-seven completed the study which was conducted on four days (two days in the Intervention arm and two in Control arm). The Intervention arm was comprised a 50-100 g evening preload of an acetylated HAMS (Ingredion Pty Ltd) followed by consumption of a specially formulated sports oral rehydration solution (SpORS) drink during intense training and recovery. Players followed their usual hydration routine in the Control arm. Quantitative assessments of body weight, hematocrit and urine specific gravity were made at three time-points on each day of training: pre-training, post-training (90 min), and at end of recovery (30-60 min later). GPS tracking monitored player exertion. RESULTS: Across the three time-points, hematocrit was significantly lower and body weight significantly higher in Intervention compared to Control arms (p < 0.02 and p = 0.001 respectively, mixed effects model). Weights were significantly heavier at all three assessment points for Intervention compared to Control arms (Δ = 0.30 ± 0.13, p = 0.02 pre-training; Δ = 0.43 ± 0.14, p = 0.002 post training; and Δ = 0.68 ± 0.14, p < 0.001 for recovery). Between the pre-training and end-of-recovery assessments, the Control arm lost 0.80 kg overall compared with 0.12 kg in the Intervention arm, an 85% lower reduction of bodyweight across the assessment period. CONCLUSION: The combination of the significantly lower hematocrit and increased body weight in the Intervention arm represents better hydration not only at the end of training as well as following a recovery period but also at its commencement. The magnitude of the benefit seems sufficient to have an impact on performance and further studies to test this possibility are now indicated. TRIAL REGISTRATION: Trial is listed on the Australian New Zealand Clinical Trials Registry ( ACTRN 12613001373763 ).

High amylose cornstarch preloads stabilized postprandial blood glucose but failed to reduce satiety or food intake in healthy women.

High fiber diets promote satiety and sustain normal blood glucose by delaying digestion and slowing glucose absorption, but their longer-term impact on body weight loss is thought to be due primarily to their lower energy density. Starches that are digested slowly in the small intestine, resistant starches (RS), contribute to a diet's fiber load. The worldwide epidemic of obesity has supported the incorporation of RS in commercial food products to curtail body weight gain. AIM: The present study explored whether consumption of a beverage containing RS, from high amylose cornstarch (Amylose), will lead to higher satiety and lower energy intake (EI). METHODS: Preload beverages containing 75 gm Amylose, Glucose, or a Glucose-Amylose mixture were administered to young healthy females after an overnight fast and blood glucose and appetite measurements were taken at 0, 15, 30, 45, 60, 90, 120, 180 and 240 min. Calorie intake was assessed at a pizza meal at 2 h (Experiment 1) or 4 h (Experiment 2). RESULTS: The glycemic responses were lower with Amylose: Glucose > Glucose-Amylose > Amylose = water Control (p < 0.0001). Appetite was not affected by the treatments (p > 0.05). EI was lower only after Glucose at 2 h, but unaffected by treatment after 4 h. CONCLUSION: As high amylose cornstarch improves postprandial blood glucose response but has no effect on satiety and EI, a more careful analysis of its benefits for body weight loss is needed. The research was funded by the Research Office of Kuwait University, Grant # FF01/16. STUDY REGISTRATION: TCTR20180815005.

The effect of dietary amylose/amylopectin ratio on serum and hepatic lipid content and its molecular mechanisms in growing-finishing pigs.

This study was conducted to investigate the effects of dietary amylose/amylopectin ratio (DAR) on serum and hepatic lipid content, luminal short-chain fatty acid (SCFA) concentrations, and the expression of host genes involved in fat and glucose metabolism in liver and mucosa in growing-finishing pigs. Forty-eight Duroc × Landrace × Large White pigs (49.8 ± 2.8 kg) were randomly allocated to low amylose/amylopectin ratio (LR) and high amylose/amylopectin ratio (HR) groups, each group consisting of six replicates (pen) with four pigs per pen. The DAR was 12/88 for LR and 30/70 for HR. Experiment lasted for 67 days. Results showed that, compared with HR group, ingestion of LR significantly increased the liver total lipid and cholesterol concentration (p < .05) and decreased the serum LDL-C concentration (p < .05). The concentration of propionate, butyrate and total SCFAs in caecum digesta was significantly lower in LR group than in HR group (p < .05). We observed a significant increase in glucose transporter 2 (GLUT2), sodium-dependent glucose transporter 1 (SGLT1) gene expression in LR-fed pigs in the jejunum mucosa (p < .01). A decrease in Na+-coupled monocarboxylate transporter (SMCT1) and free fatty acid receptor 3 (FFAR3) expression was found in the ileum mucosa with LR group (p < .05). Ingestion of LR diet significantly decreased the hexokinase (p < .01) and tend to decrease the pyruvate kinase (p = .050) activities in the liver. Meanwhile, the present results indicated that ingestion of LR diet significantly increased the transcription of gluconeogenesis and lipogenic genes such as forkhead box O1 (FOXO1), fatty acid synthetase3 (FAS3) (p < .05). These findings demonstrated that high amylopectin has harmful effects on hepatic lipid deposit through the modulation of the liver Foxo1 signalling and should be avoided from one's diet.

Transplantation of High Hydrogen-Producing Microbiota Leads to Generation of Large Amounts of Colonic Hydrogen in Recipient Rats Fed High Amylose Maize Starch.

The hydrogen molecule (H2), which has low redox potential, is produced by colonic fermentation. We examined whether increased hydrogen (H2) concentration in the portal vein in rats fed high amylose maize starch (HAS) helped alleviate oxidative stress, and whether the transplantation of rat colonic microbiota with high H2 production can shift low H2-generating rats (LG) to high H2-generating rats (HG). Rats were fed a 20% HAS diet for 10 days and 13 days in experiments 1 and 2, respectively. After 10 days (experiment 1), rats underwent a hepatic ischemia-reperfusion (IR) operation. Rats were then categorized into quintiles of portal H2 concentration. Plasma alanine aminotransferase activity and hepatic oxidized glutathione concentration were significantly lower as portal H2 concentration increased. In experiment 2, microbiota derived from HG (the transplantation group) or saline (the control group) were orally inoculated into LG on days 3 and 4. On day 13, portal H2 concentration in the transplantation group was significantly higher compared with the control group, and positively correlated with genera Bifidobacterium, Allobaculum, and Parabacteroides, and negatively correlated with genera Bacteroides, Ruminococcus, and Escherichia. In conclusion, the transplantation of microbiota derived from HG leads to stable, high H2 production in LG, with the resultant high production of H2 contributing to the alleviation of oxidative stress.

Whole-Grain Starch and Fiber Composition Modifies Ileal Flow of Nutrients and Nutrient Availability in the Hindgut, Shifting Fecal Microbial Profiles in Pigs.

Background: Changes in whole-grain chemical composition can affect the site of nutrient digestion, which may alter substrate availability and gut microbiota composition.Objective: This study elucidated the function of whole-grain fermentable fiber composition on ileal substrate flow, hindgut substrate availability, and subsequent gut microbial profiles in pigs.Methods: Five whole grains-1) high-fermentability, high-ß-glucan hull-less barley (HFB); 2) high-fermentability, high-amylose hull-less barley (HFA); 3) moderate-fermentability hull-less barley (MFB); 4) low-fermentability hulled barley (LFB); or 5) low-fermentability hard red spring wheat (LFW)-were included at 800 g/kg into diets fed to ileal-cannulated growing pigs for 9 d in a 6 (periods) × 5 (diets) Youden square. Digesta were analyzed for nutrient flow and microbial composition via 16S ribosomal RNA gene sequencing.Results: The consumption of fermentable whole grains, HFB, and HFA increased (P < 0.05) ileal starch flow by 69% and dry matter flow by 37% compared with LFB and LFW intakes. The consumption of HFB and HFA increased (P < 0.05) fecal Firmicutes phylum abundance by 26% and 21% compared with LFB intake and increased (P < 0.05) fecal Dialister genus abundance, on average, by 98% compared with LFB and LFW intakes. Fecal Sharpea and Ruminococcus genera abundances increased (P < 0.05) with HFB intake compared with LFB and LFW intakes. In contrast, the consumption of LFB increased (P < 0.05) fecal Bacteroidetes phylum abundance by 43% compared with MFB intake. Ileal starch flow and fecal Firmicutes abundance were positively correlated and determined by using principal components analysis.Conclusions: Increasing dietary fermentable fiber from whole grains can increase ileal substrate flow and hindgut substrate availability, shifting the fecal microbiota toward Firmicutes phylum members. Thus, digesta substrate flow is important to shape gut microbial profiles in pigs, which indicates that the manipulation of substrate flow should be considered as a tool to modulate gut microbiota composition.

Dietary starch types affect liver nutrient metabolism of finishing pigs.

This study aimed to evaluate the effect of different starch types on liver nutrient metabolism of finishing pigs. In all ninety barrows were randomly allocated to three diets with five replicates of six pigs, containing purified waxy maize starch (WMS), non-waxy maize starch (NMS) and pea starch (PS) (the amylose to amylopectin ratios were 0·07, 0·19 and 0·28, respectively). After 28 d of treatments, two per pen (close to the average body weight of the pen) were weighed individually, slaughtered and liver samples were collected. Compared with the WMS diet, the PS diet decreased the activities of glycogen phosphorylase, phosphoenolpyruvate carboxykinase and the expression of phosphoenolpyruvate carboxykinase 1 in liver (P0·05). Compared with the WMS diet, the PS diet reduced the expressions of glutamate dehydrogenase and carbamoyl phosphate synthetase 1 in liver (P<0·05). PS diet decreased the expression of the insulin receptor, and increased the expressions of mammalian target of rapamycin complex 1 and ribosomal protein S6 kinase ß-1 in liver compared with the WMS diet (P<0·05). These findings indicated that the diet with higher amylose content could down-regulate gluconeogenesis, and cause less fat deposition and more protein deposition by affecting the insulin/PI3K/protein kinase B signalling pathway in liver of finishing pigs.

Effects of dietary starch types on growth performance, meat quality and myofibre type of finishing pigs.

To investigate the effects of dietary starch types on growth performance and meat quality of finishing pigs, ninety barrows (68.0±2.0kg) were randomly allotted to three experimental diets with five replicates of six pigs, containing pure waxy maize starch (WMS), nonwaxy maize starch (NMS) and pea starch (PS) (amylose/amylopectin were 0.07, 0.19 and 0.28 respectively). Compared with WMS diet, PS diet increased the average daily gain, loin eye area, pH45 value, NMR transverse relaxation (T2)2 peak area ratio and sarcoplasmic protein solubility, decreased the feed to gain ratio, back fat, drip loss, cooking loss and T23 peak area ratio (P<0.05). Moreover, PS diet increased the myosin heavy-chain (MyHC)-I and IIa levels, decreased the MyHC-IIb level, decreased the miR23a level and increased its target gene level, increased the miR499 level and decreased its target gene level (P<0.05). Diet with high amylose content might be beneficial to the growth performance and meat quality of finishing pigs.

Oxidized amylose with high carboxyl content: A promising solubilizer and carrier of linalool for antimicrobial activity.

The oxidized amyloses with different carboxyl content were prepared to include linalool for antimicrobial activity in aqueous environment. The results show that linalool can be effectively reserved from volatilization through encapsulation into amylose and oxidized amyloses. The inclusion ability of oxidized amyloses towards linalool is decreasing with the increase of oxidation level due to the depolymerization of amylose. However, the solubilization effect of oxidized amyloses to linalool is enhanced efficiently owning to the high water solubility of oxidized amyloses. It is interesting that the inclusion complexes have good antimicrobial activity in aqueous environment. Linalool solubilized by oxidized amyloses presents better antimicrobial performance than that solubilized by amylose, mainly resulting from that amylose-linalool inclusion complex would aggregate and retrograde fast in aqueous solution, which is disadvantageous for the release of linalool. The study suggests that oxidized amylose is a promising solubilizer and carrier of linalool for antimicrobial activity in aqueous environment.

A novel fiber composite ingredient incorporated into a beverage and bar blunts postprandial serum glucose and insulin responses: a randomized controlled trial.

Previous research supports that consumption of resistant starch and guar gum independently influences insulin-mediated glucose responses to meals. This research assessed a novel co-processed fiber composite (FC) ingredient comprising whole-grain high-amylose maize flour and viscous guar gum on glucose and insulin responses to co-consumed and subsequent meals in humans. It was hypothesized that a smoothie-type beverage or a cold-pressed snack bar containing the FC would blunt and sustain serum glucose and insulin postprandial responses compared with maltodextrin (MD). The beverage and bar were assessed in 2 separate studies using identical protocols. Young, nondiabetic, nonobese adults participated in 2 testing days (randomized crossover design) separated by at least 1 week for both food forms. On each testing day, the FC or MD product was consumed with a low-fiber standardized breakfast followed by a low-fiber standardized lunch (with no FC or MD) 4 hours later. Blood samples were collected at baseline and incrementally throughout the 8-hour testing day. One-tailed paired t tests were performed to compare treatment areas under the curve, and a doubly repeated-measures analysis of variance was performed to compare treatment responses at individual time points (P< .05, Bonferroni corrected). The FC blunted the postprandial glucose and insulin responses compared with MD, including a robust glucose and insulin response reduction after breakfast and a continued modest glycemic second-meal reduction after lunch in both the beverage and the bar. These findings support the use of this novel whole-grain FC ingredient in a beverage or bar for insulin-mediated glucose control in young healthy adults.

Preparation and Characterization of Amylose Inclusion Complexes for Drug Delivery Applications.

Amylose complexes with nimesulide (NMS) and praziquantel (PZQ) were prepared by a simple and low cost method, so that high yield (>57%) and drug content (up to 68.16%) were achieved. The influence of drug:polymer ratio, temperature, and presence of palmitic acid on the complexes properties was evaluated. Differential scanning calorimetry, X-ray diffraction, and nuclear magnetic resonance data evidenced the drug-polymer interaction and the formation of inclusion complexes with semi-crystalline structures related to type II complexes. The drug release rates from complexes were lowered in acid media (pH 1.2) and phosphate buffer (pH 6.9). The presence of pancreatin promoted a significant acceleration of the release rates of both drugs, evidencing the enzymatic degradability of these complexes. The highest enzymatic resistance of PZQ1:30PA60°C complex makes the release time longer and the full release of PZQ in phosphate buffer with pancreatin occurred at 240 min, whereas the complexes with NMS and PZQ1:5PA90°C did it in 60 min. According to the Weibull model, the drug release process in media without enzyme occurred by complex mechanisms involving diffusion, swelling, and erosion. In media containing pancreatin, generally, the better correlation was with the first order, evidencing the acceleration of the release rates of drugs in the early stages of the test, due to enzymatic degradation.