The increasing prevalence of allergic diseases in affluent societies has been associated with changes in microbial exposure early in life and a less diverse gut flora. The objective of this thesis was to assess the development of allergic sensitisation and symptoms during the first four years of life in a non-selected birth cohort in relation to environmental factors, family history, gut microbiota and salivary IgA antibodies. The cohort comprised all 1,228 infants living in a Swedish county who were born over a one-year period. The parents replied to questionnaires, and 817 children (67 %) were skin prick tested both at 1 and 4 years of age. Saliva (n=279), faecal (n=139) and blood (n=253) samples were collected at 1 year of age from children with a positive skin prick test at 1 year and from a sample of children with a negative skin prick test. Faecal samples were also obtained from 53 children at 4 years of age. Dog keeping during infancy was associated with a decreased risk of sensitisation to pollen and late-onset wheezing at age 4, and the reduced odds ratios persisted after adjustment for heredity and avoidance measures, OR 0.3, 95% CI 0.1-0.9 and OR 0.5, 95% CI 0.2-1.0, respectively. In contrast, early dog keeping was associated with an increased risk of earlyonset transient wheezing but only in children with parental asthma (OR 2,8, 95% CI 1.3-6.4). Levels of short chain fatty acids (SCFAs) in faeces were assessed both at 1 and 4 years of age and related to the development of sensitisation and symptoms. The levels of acetic (p<.01) and propionic (p<.01) acids decreased from one to four years of age, whereas valeric acid (p<.001) increased which is in line with a more complex gut microbiota with age. Allergic children, compared with non-allergic children, had lower levels of i-butyric, i-valeric and valeric acid in faeces both at 1 and 4 years of age. Low levels of secretory IgA (SIgA) in saliva were associated with wheezing but only in sensitised children. In children with positive SPT to at least one allergen both at 1 and 4 years of age and in children with circulating IgE antibodies to egg or cat at one year of age, those who developed late-onset wheezing had lower levels of SIgA than those who did not, p=.04 and p=.02 respectively. Of 9 children with levels of SIgA in the upper quartile and persistent sensitisation, none developed wheezing, compared with 10/20 children with lower levels, (p=. 01). Having older siblings, more than three infections during infancy, at least one smoking parent and male gender were all associated with high levels (in the upper quartile) of total IgA and SIgA. The findings in this thesis indicate that the microbial load early in life could affect the development of allergy. A functional assessment of the gut flora demonstrated differences between allergic and non-allergic children both at 1 and 4 years of age. Salivary IgA was associated with infections during infancy, and high levels of secretory IgA protected from symptoms in sensitised children. Finally, dog keeping in infancy may offer protection from allergy, but the mechanism is uncertain.

This thesis examined effects of dietary supplementations (0.75%) of the prebiotics of retrograded resistant cornstarch, fibersol-2 and inulin, and oat β-glucan in replacing feed antibiotics on growth performance, plasma urea concentrations, total tract dry matter (DM) and lactose digestibility, fecal scores, proximal jejunal and serum alkaline phosphatase (AP) kinetics and large intestinal fermentation in weanling pigs fed corn and soybean meal-based diets. There were no differences (P > 0.05) in the growth performance, plasma urea concentrations, DM and lactose digestibility and the volatile short-chain fatty acid concentrations in the cecal and fecal samples among the treatment diets. Dietary lactose was completely digested in the weanling pigs. Supplementations of fibersol-2, inulin and β-glucan significantly affected some of the jejunal and serum AP kinetics. In conclusion, lactose was a highly digestible carbohydrate and dietary supplementations of the three prebiotic and β-glucan at 0.75% had little effects on growth performance and plasma urea concentration but might affect gut and the whole body health status via influencing the AP detoxification kinetics in the weanling pigs. / Ontario Pork, Ontario Ministry of Agriculture, Agriculture Adaptation Council

No description available.

Quatro experimentos foram realizados para estudar o desempenho, produção de metano e metabolismo ruminal em ovinos alimentados com dietas contendo nitrato de cálcio (NC). Experimento 1: Cinquenta borregas foram utilizadas, em delineamento em blocos completos casualizados, para avaliar o desempenho, as características de carcaça e a produção de CH4. As dietas continham teores crescentes (0, 1, 2, 3 ou 4% na MS) de NC. Houve efeito quadrático para consumo de MS, peso final, ganho médio diário e eficiência alimentar. O aumento do consumo de NC promoveu redução da produção de CH4. O peso ao abate, peso da carcaça quente e fria e espessura da parede corporal reduziram linearmente. Houve efeito quadrático para a espessura de gordura, área de olho de lombo e para a luminosidade. A inclusão de NC reduz a produção de metano, no entanto, em teores a partir de 2%, reduz o consumo, o ganho médio diário e a eficiência alimentar. Em teores de até 4% de NC não alterou os valores de NaNO3 e NaNO2 na carne fresca. Experimento 2: Cinco ovinos canulados no rúmen, distribuídos em delineamento em quadrado latino, foram utilizados para avaliar o metabolismo ruminal, digestibilidade e balanço de N. As dietas continham teores crescentes (0, 1, 2, 3 ou 4% na MS) de NC encapsulado. Houve efeito quadrático para o consumo de MS, consumo de água/kg MS e N retido. Houve efeito linear crescente para a digestibilidade da MO, da FDN e da PB. Houve efeito linear decrescente para o N fecal. Houve efeito quadrático para a concentração de AGCC total e para a proporção molar de ácido valérico. Houve efeito linear crescente para a proporção de ácido acético, butírico e isobutírico. Houve efeito quadrático para o N-NH3 e aumento linear para o pH ruminal. O NC encapsulado até teores de 4% para ovinos aumenta a digestibilidade dos nutrientes e da fibra insolúvel em detergente neutro, o pH ruminal e a proporção de ácido acético em relação a concentração de AGCC. No entanto o consumo é reduzido quando o NCE é adicionado em teores de 4%. Experimentos 3 e 4: foram realizados em delineamento em blocos completos casualizados para avaliar dietas contendo diferentes fontes de nitrogênio: farelo de soja (controle), ureia, nitrato de cálcio encapsulado (NCE) e nitrato de cálcio não encapsulado (NCNE). Em ambos os experimentos analisou-se os contrastes: controle vs nitrogênio nãoproteico (ureia, NCE e NCNE), ureia vs nitrato de cálcio (NCE e NCNE) e NCE vs NCNE. No experimento 3 foram utilizados 44 cordeiros para determinar os efeitos de diferentes fontes de nitrogênio nas características de desempenho e de carcaça. O peso final, o ganho médio diário e a eficiência alimentar foram maiores no controle em relação ao NNP. No experimento 4 foram utilizados 20 ovinos machos castrados, canulados no rúmen, para avaliar o metabolismo ruminal e a digestibilidade dos nutrientes. A digestibilidade da FDN foi maior nas dietas contendo NNP em relação à dieta controle. O pH ruminal foi maior nas dietas com NNP em relação ao controle; e maior no NC em relação a dieta com ureia. O ácido acético foi maior nas dietas com NC em relação a dieta com ureia. O ácido propiônico foi maior com NNP comparados à dieta controle e menor nas dietas com NC comparada à dieta com ureia. A relação acetato: propionato foi maior no NC em relação à ureia. A inclusão de 2% do íon nitrato, tanto na forma de NCE como NCNE para ovinos, permite que o desempenho e características de carcaça sejam similares a dieta com inclusão de 1,1% de ureia. O NC influencia no aumento da digestibilidade da fibra em detergente neutro, do pH ruminal, da proporção de acetato em relação a concentração de AGCC total e da relação Ac:Pr. / Four experiments were conducted to study the performance, methane production and ruminal metabolism in sheep fed diets containing calcium nitrate (CN). Experiment 1: Fifty ewe lambs were used, in a randomized complete block design, to determine the performance, carcass characteristics and methane production. Diets contained increasing levels (0, 1, 2, 3 or 4%, DM basis) of CN. There was a quadratic effect on dry matter intake, final body weight, average daily gain and feed efficiency. Increased CN intake promoted reduction in methane production. Slaughter weight, hot carcass weight and chilled carcass weight reduced linearly. There were a quadratic effect on the fat thickness, rib eye area and for brightness. Increased CN reduces the production of methane, however, in amounts from 2% reduces intake, average daily gain and feed efficiency. In amounts of up to 4% did not change NaNO3 and NaNO2 in fresh meat. Experiment 2: Five sheep, cannulated in the rumen, distributed in a Latin Square design, were used to determine ruminal metabolism and digestibility. There was a quadratic effect for DM intake, water intake/kg DM and N retained. There was a linear increase for the digestibility of OM, NDF and CP, while fecal N decreased linearly. There was a quadratic effect on the concentration of the total SCFA and the molar proportion of valeric acid. There was a linear effect on the proportion of acetic acid, butyric acid and isobutyric acid. There was a quadratic effect for N-NH3 while ruminal pH increased linearly. The encapsulated CN up to 4% in sheep increases the digestibility of the nutrients and insoluble in neutral detergent fiber, ruminal pH and the proportion of acetic acid relative concentration of SCFA. However intake is reduced when the encapsulated CN is added at 4%. Experiments 3 and 4: were conducted in a randomized complete block design to evaluate diets containing different nitrogen sources: soybean meal (control), urea, encapsulated calcium nitrate (ECN) and nonencapsulated calcium nitrate (NECN). In both experiments were analyzed the following contrasts: control vs non-protein nitrogen (urea, ECN and NECN), urea vs calcium nitrate (ECN and NECN) and ECN vs NECN. In Experiment 3, 44 ram lambs were used to determine the effects of different nitrogen sources on performance and carcass traits. The final weight, average daily gain and feed efficiency were greater in the control diet compared to the NPN. In the experiment 4, 20 wethers, cannulated in the rumen, were used to assess the rumen metabolism and diets digestibility. The NDF digestibility was greater in diets containing NPN compared to the control. The ruminal pH was higher in the NPN diets compared to the control; and greater in the diets with NC than those with urea. The acetic acid was higher in diets with CN than the urea diet. The propionic acid was higher in the NPN diets compared to the control and lower in CN compared to the urea diet. The acetate: propionate ratio was higher for diets with CN compared to the urea diet. CN influences the increased digestibility of neutral detergent fiber, ruminal pH, the proportion of acetate relative to the total SCFA concentration and the relationship Ac: Pr.

Förekomsten av övervikt och fetma har ökat kraftigt de senaste åren över hela världen och i fetmans fotspår ökar även fetmarelaterade sjukdomar. Utvecklingen anses bero på en kombination av faktorer som större tillgång på energirik kost, miljömässiga, livsstilsrelaterade, genetiska och patologiska faktorer. Ny forskning har gett en ökad kuskap om tarmflorans betydelse för hälsa och studier på både obesa människor och djur visar att deras sammansättning i tarmfloran skiljer sig jämfört med normalviktiga individer. Detta har lett till ett ökat intresse hos forskare att titta närmare på kostens relation tilltarmfloran och dess sammansättning för att få klarhet i dess koppling till fetma och kunna använda denna kunskap för att förebygga och utveckla behandlingsmetoder mot fetma. Syftet med denna litteraturstudie var att analysera vetenskapliga artiklar och titta närmare på relationen mellan tarmfloran, kost och fetma. Resultaten visade att tarmflorans sammansättning är olika hos normalviktiga och obesa individer och att sammansättningen påverkar fermentationen av ej nedbrytningsbara kolhydrater i kolon. Studierna visade också att det finns en koppling mellan tarmfloran och inflammation som i sin tur också är en faktor relaterad till fetma. Ytterligare studier krävs för att besvara frågan ifall sammansättningen av tarmfloran är en orsakande faktor till utveckling av fetma, eller ett resultat av sjukdomen, samt vilka bakterier och grupper i den som genom bland annat kost går att påverka på ett positivt sätt mot fetma. / Obesity has increased dramatically during the past decades over the whole world, and has resulted in an increase of obesity-related diseases. The potential contributing factors to obesity are a combination of increase in the availability of energy-rich foods, environmental, lifestyle-related, genetic and pathological factors. New research has led to more knowledge about the gut microbiota and its role in health and studies show a difference in the microbial communities of lean vs. obese humans and animals. These findings have created an interest in research to understand gut microbiota composition and its relation to obesity so that the knowledge can be used in the prevention and treatment of obesity. The aim of this project was to analyse scentific articles and investigate the relation between the gut microbiota, diet and obesity. The studies showed differences in gut microbiota composition between lean vs. obese individuals, and that the composition affects the microbiotas ability to ferment non-digestible carbonhydrates in the colon. The studies also showed that the gut microbiota is related to inflammation, and inflammation is another factor that´s also related to obesity. There is a need for further studies to answer the question if the composition of the gut microbiota is the cause or the consequence of obesity, and which bacteria that for example through dietary modulation, can have a positive effect on obesity.

Pulses (i.e. beans, lentils, and chickpeas) are enriched in plant-based proteins and non-digestible carbohydrates (e.g. fibre) that may beneficially impact intestinal and metabolic health. The objectives of this thesis were to determine if i) consumption of diet supplemented with kidney beans would improve biomarkers of intestinal and metabolic health, ii) dark-colored beans would provide additional health benefits compared to light-colored beans, and iii) background diet composition would impact the health effects of kidney bean consumption. Study 1: 5-week-old male C57Bl/6 mice were fed either a basal diet (BD; 20% casein, wt/wt), or isocaloric diets supplemented with 15% cooked white kidney beans or dark red kidney beans for 9 weeks (n=12/group); Study 2: 5-week-old male C57Bl/6 mice were fed either a high-fat diet (HF; 60% kcals from fat) or HF diet supplemented with 15% cooked white kidney beans or dark red kidney beans. In both studies, consumption of diets supplemented with beans improved microbiota community structure and activity, as indicated by increased abundance of short-chain fatty acid (SCFA) producing bacteria (Prevotella and S24-7) and intestinal SCFA concentrations, with dark kidney beans inducing the greatest effects. Furthermore, biomarkers of colonic inflammation, barrier integrity, and metabolic health were beneficially impacted by kidney bean consumption, however, the effects were greater in mice consuming low-fat vs. high-fat diets. In conclusion, this thesis demonstrated that while kidney bean consumption led to improvements in intestinal and metabolic health, the results were influenced by seed coat color and the nutrient composition of the background diet.

Short-chain fatty acids (SCFAs) and the tricarboxylic acid (TCA) cycle metabolites aresmall hydrophilic compounds that play crucial roles in biological species ranging fromenergy metabolism, immune homeostasis to cellular signalling. There is a need for reliableand precise quantification of these metabolites in biological matrices as they can providecrucial information of metabolic status and potentially be used as diagnostic biomarkersfor different pathological and physiological conditions. However, their retention andseparation in traditional reversed-phase system, without chemical derivatization, is oftenproblematic due to their volatile and hydrophilic characteristics. The aim of this studywas to implement a facile and effective derivatization method for the simultaneousquantitation of SCFAs and TCA cycle metabolites by LC-qToF-MS in negative ion mode. Inthis work, 3-nitrophenylhydrazine (3-NPH) was employed for preanalyticalderivatization to convert the compounds to their respective 3-nitrophenylhydrazones.Analytical standards and faecal samples were used to assess the linearity, matrix effect,accuracy, extraction efficiency, precision, retention-time shift and short-term stability.The compounds were successfully separated within 6 minutes on a reverse-phase C18column. All the compounds showed good linearity (R2≥ 0.97) in both solvent-only andfaecal samples. The matrix effect was minimal and did not affect the compoundsquantitation. The extraction efficiency ranged from 80% to 110% (CV≤9.7%, n = 6). Theaccuracy of quantitation was determined to be between 82.8% to 113.8% (CV≤9.0%, n =6). The intra-day (CV%) demonstrated good precision for all analytes, the inter-day (%)were more variable due to the derivatives’ chemical instability. However, most of thederivatives were chemical stable up to 5 days in the autosampler (10°C). The method wasalso applied to explore the levels of these metabolites in human faecal samples and mousebrain samples.

The total removal of antibiotic growth promoters (AGP) from poultry feed is underway in the United States. Feed additive strategies will be utilized to maintain the efficient growth, health, and economic value found with current commercial broiler production. Experiment 1 investigated the effects of feeding an encapsulated butyric acid and zinc product (EBAZ) at 3 inclusions on d 0- 49 Ross x Ross 708 male and female broiler performance, blood chemistry, and cecal short-chain fatty acid content. These data suggest that EBAZ can be safely included at 0.5 g/kg and at 2.5 g/kg into diets for Ross x Ross 708 male and female broilers. The objective of the second experiment was to examine the efficacy of 2 commercially available carbohydrases in commercial diets on d 0-57 male broiler performance and processing. The resulting data demonstrates that the inclusion of xylanase (CE2) improved broiler performance thus, increased potential gross profits.

Current practices support the use of probiotic and prebiotic supplementation to improve chronic gastrointestinal distress (GID). The aim of this study was to determine the tolerance and benefits of GlutenShield (GS), a prebiotic, probiotic, and enzyme supplement, on adults with GID. Subjects (n=20) took either GS or the placebo for 30 days and completed a pre-treatment FFQ as well as a pre- and post-treatment GID questionnaire, blood draw, and stool sample. Participants consumed more total and saturated fat, and less fiber and whole grains compared to the recommended intake. A significant reduction in IgG2 was observed in the GS group (p=0.008) as well as a significant reduction in self-reported bloating (p=0.038) with no change observed to cytokines or SCFAs (p>0.05). GS was well tolerated and perceived to be beneficial; however, further research is needed to identify the specific population of GID patients who could most benefit from GS supplementation.

Objectives: This study aimed to evaluate physiological and microbiome differences in a murine model consuming a Mediterranean (M) v. Western (W) diet. Methods Study design: To investigate the potential of diets in modifying the fecal microbiota, we used 16 ICR mice per diet split evenly between males and females. Mice were acclimated for 5 weeks, consuming regular chow, before switching to M or W diets. Four same sex mice were housed per cage and randomly assigned M or W diets with 2 cages of male and female mice/diet. All animals were weighed weekly, and stool samples were collected, freeze-dried, and ground. An aliquot was analyzed for short-chain fatty acid (SCFA) to determine the fecal fermentation profile (FFP). Diets: All animals were acclimated to their surroundings while consuming the standard mouse chow diet for 5 wks. Experimental diets were from Envigo for 10 wks. M v.. W diets were 24.2v. 17.3% protein, 42.3 v. 48.5% carbohydrate, 13 v. 21.2 % fat, 9 v. 5% fiber, and energy density of 3.6 v. 4.5 kcal/g, and were offered ad libitum. Fecal Fermentation Profile: Fecal samples had SCFA extracted and analyzed using a modified Schwiertz et al. method via gas chromatography. The resulting SCFA profiles were used to determine differences between diets. Statistical Model: General linear models examined main effects of diet, sex, and week while accounting for baseline value and a random effect for cage (SCFA) or mouse (weight). Results: Diet effects for M v. W diets for SCFA were Acetate 50.12 v. 38.45% (p< 0.01), Propionate 14.19 v. 7.98% (p< 0.01), Butyrate 8.37 v. 17.27% (p< 0.01), Caproate 16.19 v. 23.68% (p< 0.01), and Caprillic 0.44 v. 0.68% (p< 0.01). Sex comparisons showed higher percentages of Butyrate (p< 0.05) for males and higher percentages of Isobutyrate (p< 0.01), Isovalerate (p< 0.01), and Propionate (p=0.02) for female mice. On the Mediterranean diet, male mice gained more weight than female mice, 4.96g v. 2.86g compared to baseline (p<0.01). Animals on a Western diet approached significance by gaining more weight (p<0.0871).