Browsing by Author "Hodgkinson SM"

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    Comparison of True Ileal Amino Acid Digestibility between Adult Humans and Growing Pigs
    (Oxford University Press on behalf of the American Society for Nutrition, 2022-07) Hodgkinson SM; Stroebinger N; van der Wielen N; Mensink M; Montoya C; Hendriks WH; de Vries S; Stein HH; Moughan PJ
    BACKGROUND: It is not feasible to determine the true ileal amino acid (AA) digestibility of protein sources in humans on a routine basis, and the growing pig has been recommended as an animal model for this purpose but requires further validation. OBJECTIVES: To determine and compare true ileal AA digestibility between adult human ileostomates and growing cannulated pigs for a range of food proteins. METHODS: Seven protein sources (black beans, bread, collagen, pigeon peas, wheat bran, whey protein isolate, and zein) that spanned the range of digestibilities typically seen in foods were evaluated. Six female growing pigs received each of the protein sources, as well as a protein-free diet, and digesta were collected via ileal T-cannula. Adult human ileostomates consumed the same protein sources (5-8 ileostomates, depending on the protein source), as well as a protein-free diet, and digesta were collected. Titanium dioxide and celite were included in the diets as indigestible markers. True ileal AA digestibility coefficients were determined. RESULTS: There was a significant effect of protein source (P ≤ 0.001) for all AAs. The effect of species was not significant (P > 0.05) except for total lysine (but not for available lysine). When analyzed within diets, the statistically significant species effect for true lysine digestibility was found for black beans only. Pig and human digestibility values were generally highly and significantly (P ≤ 0.05) correlated. A linear regression equation derived for true ileal AA digestibility (given as coefficients) determined in the human and pig for the overall mean of all AAs was (y = human, x = pig) y = 1.00x - 0.010, with the slope not statistically significant (P > 0.05) from unity and the intercept not different (P > 0.05) from zero. CONCLUSIONS: True ileal AA digestibility values determined in the growing pig can be directly used for predicting digestibility in adult humans.
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    Cooked Rice-Based and Wheat-Based Food Structure Influenced Digestion Kinetics and Glycemic Response in Growing Pigs
    (Elsevier Inc on behalf of American Society for Nutrition, 2023-05-03) Nadia J; Olenskyj AG; Stroebinger N; Hodgkinson SM; Estevez TG; Subramanian P; Singh H; Singh RP; Bornhorst GM
    BACKGROUND: How starch-based food structure can affect the rate and extent of digestion in the small intestine and resulting glycemic response is not properly understood. One possible explanation is that food structure influences gastric digestion, which subsequently determines digestion kinetics in the small intestine and glucose absorption. However, this possibility has not been investigated in detail. OBJECTIVES: Using growing pigs as a digestion model for adult humans, this study aimed to investigate how physical structure of starch-rich foods affects small intestinal digestion and glycemic response. METHODS: Male growing pigs (21.7 ± 1.8 kg, Large White × Landrace) were fed one of the 6 cooked diets (250-g starch equivalent) with varying initial structures (rice grain, semolina porridge, wheat or rice couscous, or wheat or rice noodle). The glycemic response, small intestinal content particle size and hydrolyzed starch content, ileal starch digestibility, and portal vein plasma glucose were measured. Glycemic response was measured as plasma glucose concentration collected from an in-dwelling jugular vein catheter for up to 390 min postprandial. Portal vein blood samples and small intestinal content were measured after sedation and euthanasia of the pigs at 30, 60, 120, or 240 min postprandial. Data were analyzed with a mixed-model ANOVA. RESULTS: The plasma glucose Δmaxoverall and iAUCoverall for couscous and porridge diets (smaller-sized diets) were higher than that of intact grain and noodle diets (larger-sized diets): 29.0 ± 3.2 compared with 21.7 ± 2.6 mg/dL and 5659 ± 727 compared with 2704 ± 521 mg/dL⋅min, for the smaller-sized and larger-sized diets, respectively (P < 0.05). Ileal starch digestibility was not significantly different between the diets (P ≥ 0.05). The iAUCoverall was inversely related to the starch gastric emptying half-time of the diets (r = -0.90, P = 0.015). CONCLUSIONS: Starch-based food structure affected the glycemic response and starch digestion kinetics in the small intestine of growing pigs.
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    Heat treatment and homogenization of bovine milk loosened gastric curd structure and increased gastric emptying in growing pigs
    (Elsevier Ltd, 2023-04) Ahlborn NG; Montoya CA; Hodgkinson SM; Dave A; Ye A; Samuelsson LM; Roy NC; McNabb WC
    During gastric digestion, bovine milk forms a curd, which consists largely of proteins and lipids. However, it is unknown how processing-induced changes to curd structure affects the gastric emptying of milk proteins and lipids. This study aimed to determine the impact of heat treatment and homogenization on gastric curd formation, and gastric emptying of dry matter (DM), proteins and lipids from bovine milk fed to pigs as a human model. Growing pigs (n = 180, mean ± standard error of the mean (SEM) bodyweight 22.4 ± 0.13 kg) consumed raw, or pasteurized non-homogenized (PNH), or pasteurized homogenized (PH), or ultra-high temperature treated homogenized (UHT) milk diets. A protein-lipid-free lactose (PLFL) solution was also fed as a test diet. At 0, 20, 60, 120, 180 and 300 min postprandially the entire gastrointestinal tract was dissected out. The gastric chyme (curd and liquid) fractions were collected after separation using a mesh screen. The DM, protein, and lipid contents of these fractions were quantified. Confocal, transmission electron microscopy, cryo-scanning electron microscopy and rheological analyses were conducted to determine the micro- and macrostructure of the curd. Overall, both heat treatment and homogenization influenced the in vivo gastric curd structure formed of bovine milk, although to different extents. The gastric emptying of DM, proteins, and lipids increased with the extent of processing. Gastric emptying rates of DM and proteins followed the pattern UHT > PH > PNH = raw, while emptying rates of lipid also differed between PNH and raw milk. Curd structure was the main gastric parameter affected in PNH milk.
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    In vitro digestibility of dietary proteins and in vitro DIAAS analytical workflow based on the INFOGEST static protocol and its validation with in vivo data
    (Elsevier Ltd, 2023-03-15) Sousa R; Recio I; Heimo D; Dubois S; Moughan PJ; Hodgkinson SM; Portmann R; Egger L
    The FAO recommends the digestible indispensable amino acid score (DIAAS) to determine protein quality in foods, preferably tested in vivo. Here, the INFOGESTin vitrodigestion protocol was applied and supplemented with an analytical workflow allowing the assessment of protein digestibility and DIAAS calculation. The protocol was applied to selected samples WPI, zein, collagen, black beans, pigeon peas, All-Bran®, and peanuts. The total protein digestibility, digestibility of individual amino acids (AA), and DIAAS values were established and compared with in vivo data for the same substrates. Total protein digestibility (total Nitrogen, r = 0.7, P < 0.05; primary amines (OPA), r = 0.6, P < 0.02; total AA, r = 0.6, P < 0.02) and digestibility of individual AA (r = 0.6, P < 0.0001) were in good agreement, between in vitro and in vivo, with a mean difference of 1.2 %. In vitro DIAAS was highly correlated with DIAAS obtained from in vivo true ileal digestibility values (r = 0.96, R2 = 0.89, P < 0.0001) with a mean difference of 0.1 %.
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    In Vitro Ileal Fermentation is Affected More by the Fiber Source Fermented than the Ileal Microbial Composition in Growing Pigs
    (Elsevier Inc. on behalf of American Society for Nutrition, 2023-05) Hoogeveen AM; Moughan PJ; Hodgkinson SM; Stroebinger N; Yu W; Rettedal EA; McNabb WC; Montoya CA
    BACKGROUND: The fermentation of undigested material in the ileum is quantitatively important. However, the respective contributions of the microbial composition and the substrate to ileal fermentation are unclear. OBJECTIVE: This aim was to investigate the contribution of microbial composition and fiber source to in vitro ileal fermentation outcomes. METHODS: Thirteen ileal cannulated female pigs (Landrace/Large White; 9-wk-old; 30.5 kg body weight) were given diets containing black beans, wheat bread, chickpeas, peanuts, pigeon peas, sorghum, or wheat bran as the sole protein source for 7 d (100 g protein/kg dry matter diet). On day 7, ileal digesta were collected and stored at -80°C for microbial analysis and in vitro fermentation. For each diet, a pooled ileal inoculum was prepared to ferment different fiber sources (cellulose, pectin, arabinogalactan, inulin, fructooligosaccharides, and resistant starch) for 2 h at 37°C. Organic matter fermentability and organic acid production were determined following in vitro fermentation. Data were analyzed using a 2-way ANOVA (inoculum × fiber). RESULTS: Forty-five percent of the identified genera in the digesta differed across diets. For instance, the number of Lactococcus was 115-fold greater (P ≤ 0.05) in the digesta of pigs fed the pigeon pea diet than for pigs fed the wheat bran diet. For both in vitro organic matter fermentability and organic acid production, there were significant (P ≤ 0.05) interactions between the inoculum and the fiber source. For instance, pectin and resistant starch resulted in 1.6- to 31-fold more (P ≤ 0.05) lactic acid production when fermented by the pigeon pea inoculum than other inocula. For specific fiber sources, statistically significant correlations were found between the number of bacteria from certain members of the ileal microbial community and fermentation outcomes. CONCLUSIONS: Both the fiber source fermented and the ileal microbial composition of the growing pig affected in vitro fermentation; however, the effect of the fiber source was predominant.Curr Dev Nutr 2023;x:xx.
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    Protein and amino acid digestibility: definitions and conventional oro-ileal determination in humans
    (Frontiers Media S.A., 2024-06-20) Hodgkinson SM; Sergi D
    When assessing protein quality, a correction needs to be made to take into consideration the availability of the amino acids. This correction is based on the digestibility of the amino acids. It is recommended to use ileal (end of small intestine) digestibility as opposed to faecal digestibility. A correction needs to be made for endogenous (gut sourced as opposed to diet sourced) amino acids to give true digestibility as opposed to apparent digestibility. Also, this correction should be made by correcting the amino acid composition for individual amino acid digestibilities as opposed to correcting all amino acids for nitrogen digestibility. Determination of true ileal amino acid digestibility requires the collection of ileal digesta. In the human there are two methods that can be used; naso-ileal intubation and using the ileostomy model. Both are discussed in detail and it is concluded that both are appropriate methods to collect ileal digesta.
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    Structural changes in milk from different species during gastric digestion in piglets
    (Elsevier Inc and Fass Inc on behalf of the American Dairy Science Association, 2022-05) Roy D; Moughan PJ; Ye A; Hodgkinson SM; Stroebinger N; Li S; Dave AC; Montoya CA; Singh H
    This study investigated the structural and physicochemical changes that occur in milk, a naturally designed complex structured emulsion, during gastric digestion using the bottle-fed piglet as an animal model. The gastric digestions of cow, goat, and sheep milk were compared in male piglets euthanized at different postfeeding times to collect the stomach chyme. The cow and noncow milks separated into curd (aggregated caseins) and liquid (mostly soluble whey) phases in the piglet's stomach. For milk from all the species, the curd remained longer in the stomach because of its slow disintegration, whereas the liquid phase emptied readily. The majority of the fat globules were found to be entrapped within the protein network of the curd. The rate of release of fat globules was strongly dependent on the breakdown of the surrounding protein network of the curd. The consistency of the gastric curds changed as digestion progressed, with goat and sheep milk curds having relatively softer curd consistency and less fused protein networks, especially toward the end of digestion. This might have led to the lower protein and fat retention in the goat and sheep milk curds and relatively faster gastric emptying of these nutrients from goat and sheep milk in comparison to cow milk. This in vivo study provided new and enhanced understanding of the mechanisms of the gastric digestion of milk from different species. It may have implications for developing bioinspired structures for the controlled digestion and delivery of nutrients.
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    The kinetics of amino acid disappearance in the small intestine is related to the extent of amino acids absorbed in growing pigs
    (Cambridge University Press on behalf of The Nutrition Society, 2024-03-14) Montoya CA; van Bemmel M; Kreutz K; Hodgkinson SM; Stroebinger N; Moughan PJ
    This study evaluated the importance of a correction for amino acids (AA) released into the hindgut on a measure of AA absorption kinetics and tested whether AA absorption kinetics are related to the extent of AA absorption using the growing pig as a model for humans. Thirty-six nine-week-old pigs (22·3 kg) received a diet containing whey protein as the sole protein source for 8 d. Pigs received their last meal containing the indigestible marker titanium dioxide before being euthanised at 1, 2, 3, 4, 6 and 12 h post-feeding. The entire content of each gastrointestinal tract (GIT) region was collected to determine AA released into the hindgut, and the kinetics and extent of AA absorption (uncorrected and corrected for AA entering the hindgut). Amounts of AA released into the hindgut increased over time (e.g. 33 and 180 mg of Glu for 4 and 6 h post-feeding). The corrected apparent amount of each AA absorbed from the GIT lumen after 4 h post-feeding was generally lower (P ≤ 0·05) than the uncorrected counterpart. Differences in both the kinetics and extent of AA absorption were observed across AA. For example, the time to reach half of the apparent AA absorption (T50) was 1·5 and 3·4 h for Met and Arg, respectively, whereas their extent of apparent absorption was 93 and 73 %. Negative correlations between parameters related to kinetics and the extent of apparent absorption were observed (e.g. for T50 r = -0·81; P < 0·001). The kinetics of AA absorption is related to the extent of AA absorption.
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    The role of holistic nutritional properties of diets in the assessment of food system and dietary sustainability
    (Taylor and Francis Group, 2023) Dave LA; Hodgkinson SM; Roy NC; Smith NW; McNabb WC
    Advancing sustainable diets for nutrition security and sustainable development necessitates clear nutrition metrics for measuring nutritional quality of diets. Food composition, nutrient requirements, and dietary intake are among the most common nutrition metrics used in the current assessment of sustainable diets. Broadly, most studies in the area classify animal-source foods (ASF) as having a substantially higher environmental footprint in comparison to plant-source foods (PSF). As a result, much of the current dietary advice promulgates diets containing higher proportions of PSF. However, this generalization is misleading since most of these studies do not distinguish between the gross and bioavailable nutrient fractions in mixed human diets. The bioavailability of essential nutrients including β-carotene, vitamin B-12, iron, zinc, calcium, and indispensable amino acids varies greatly across different diets. The failure to consider bioavailability in sustainability measurements undermines the complementary role that ASF play in achieving nutrition security in vulnerable populations. This article critically reviews the scientific evidence on the holistic nutritional quality of diets and identifies methodological problems that exist in the way the nutritional quality of diets is measured. Finally, we discuss the importance of developing nutrient bioavailability as a requisite nutrition metric to contextualize the environmental impacts of different diets.