Background: Modifying the gut microbiota through the administration of probiotics during high fat feeding has been shown to attenuate weight gain and body fat accretion while improving insulin sensitivity in animal models. Objective: Our objective was to determine the effects of the probiotic VSL#3 on body weightand composition, skeletal muscle substrate oxidation, and insulin sensitivity and during 4 weeks of high-fat, hypercaloric feeding. We hypothesized that the probiotic would attenuate the body weight and fat gain and adverse changes in insulin sensitivity and substrate oxidation following high fat, hypercaloric feeding in young, non-obese males. Methods: Twenty non-obese males (18-30 y) volunteered to participate in the present study. Following a 2-week eucaloric control diet, subjects underwent a dual x-ray absorptiometry (DXA) to determine body composition, an intravenous glucose tolerance test (IVGTT) to determine insulin sensitivity, a skeletal muscle biopsy for measurement of substrate oxidation. Serum endotoxin was also measured. Subsequently, subjects were randomized to receive either VSL#3 (2 satchets) or placebo during 4 weeks of consuming a high fat (55% fat), hypercaloric diet (+1,000 kcal/day). Macronutrient composition of the high fat diet was 55% fat, 30% carbohydrate, and 15% protein. Results: There were no differences between the groups in subject characteristics or in the dependent variables at baseline. Body weight and fat mass increased less (P<0.045) following the high fat diet with VSL#3 compared to placebo. Insulin sensitivity (and other IVGTT variables) and both glucose and fat oxidation did not change significantly with time or VSL#3 treatment. Serum endotoxin concentration was not different between groups following the high-fat diet. Conclusions: VSL#3, a multi-strain probiotic, attenuated body weight and fat gain following a 4-week high fat, hypercaloric diet compared with a placebo. There were no differences between the VSL and control in circulating endotoxin, insulin sensitivity (and other IVGTT variables) or in skeletal muscle substrate oxidation. / Ph. D.

The composition and metabolic activity of the microbiome affect many aspects of health, and there is current interest in dietary constituents that may affect this system. The purpose of this study was to evaluate the effects of a mix of probiotics, a mix of prebiotics and a bioactive protein fraction on the microbiome, when fed to mice individually and in combination. Mice were fed the total western diet (TWD) supplemented with prebiotics, probiotics, and Tri-Factor (bioactive proteins) individually and in combination for four weeks. Subsequently, effects on the composition of gut microbiome, gut short chain fatty acids (SCFAs) concentration, gut inflammation and integrity of the mucosal barrier were analyzed. Ruminococcus gnavus was increased in mice gut microbiome after feeding prebiotics. Bifidobacterium longum was increased after feeding probiotics. Probiotic was associated with higher level of Clostridium neonatale. The treatments affected beta-diversity with exception of Tri-Factor, but not alpha diversity of microbiome. All treatments were associated with lower plasma zonulin, compared to the control group, indicating an effect on gut permeability. There were no treatment effects on cecal or fecal SCFAs, and the treatments did not affect gut inflammation as measured by fecal calprotectin.

No description available.

As the international poultry industry searches for antibiotic alternatives, dietary probiotic supplementation has exhibited the ability to decrease FCR, increase live weight gain, and regulate inflammatory responses within the gut of broiler chickens. The in ovo (or in egg) supplementation of probiotics has the potential for promoting early colonization of probiotic bacteria in the gastrointestinal tract and providing enhanced protection against pathogens in the hatchery and grow-out facilities. In the present studies, the in ovo injection of either L. animalis + E. faecium combination or L. animalis + B. licheniformis combination on d 18 of incubation does not negatively affect the chick’s ability to hatch out of the egg. These combinations also influence post-hatch performance, where FCR, gastrointestinal tissue weights, and immune-physiological parameters were impacted under non-challenged and coccidiosis-challenged grow-out conditions. These results indicate the physiological and immunomodulatory role that beneficial bacteria may have on a developing chick.

No description available.

Chronic oxidation linked diseases are on a rise and are one of the leading causes of death globally. Epidemiological evidence increasingly points towards consumption of fruits and vegetables as a preventive way to manage early stages of chronic oxidation linked diseases. Oxidation linked diseases are caused by excessive reactive oxygen species (ROS) generated by a disruption in cellular antioxidant homeostasis due to an overload of calories combined with stress, no excerise and a diet low in antioxidants. Phenolic compounds can not only act as antioxidants but also stimulate the activities of antioxidants enzyme through protective pathways which can help modulate cellular protection. The aim of this dissertation was to use probiotic fermentation to enhance the phenolic and antioxidant compounds in fruit systems which can form the basis of functional food design. The potential of these food systems for disease prevention was investigated in eukaryotic systems through understanding the role of critical metabolic pathways involed in prevention of oxidation linked chronic diseases. Based on structure-function rationale, antioxidant, anti-hyperglycemia and anti-hypertensive potential of phenolic compounds in tea and the effect of extraction time and different degrees of fermentation were investigated in in vitro models. Results indicated that the most fermented teas and a longer extraction time had the highest potential. Further these extracts also had higher H. pylori inhibition potential. Probiotic fermentation of fruit juices with L. helveticus was used to mobilize phenolics and improve biological functionality by maintaining a consistent phytochemical profile. Results indicated that total phenolic and antioxidant potential decreased with feremnetation. However α-glucosidase inhibitory activity and H. pylori inhibitory potential increased with fermentation. Investigation into the mechanism of H. pylori inhibition with fermented cherry extracts revealed inhibition of proline dehydrogenase as the likely mode of action. The potential of fermented apple extracts was further investigated as a phytochemical elicitor in eliciting phenolic and antioxidant response in germinating fava bean. The results indicated a stimulation of phenolic and antioxidant response likely through the stimulation of carbon flux through glycolytic pathways. In yeast, fermented apple extracts accelerated cell death in the presence of peroxide stress in pretreatment model whereas it provided protection against oxidative stress and prevented cell death in concurrent model. Chitosan oligosachharide treatment was investigated as a potential replacement of cancer causing diphenylamine treatment for scald reduction in Cortland apples. Although the treatment did not have any effect on scald reduction, it provides better protection in storage by stimulating phenolic and antioxidant response which related to better health relevant functionality.

This study aimed to isolate and characterize in-vitro and under simulated colonic conditions, probiotic candidates isolated from food environment producing γ-aminobutyric acid (GABA), a major inhibitory neuromediator of the enteric nervous system with a potential role in modulating the immune system in many health disorders. Several lactic acid bacteria were isolated and detected for the presence of the gadB gene using PCR and GAD enzymatic assay. The most active strains with high and fast production kinetics were identified, characterized, and included Streptococcus thermophilus, Lactiplantibacillus plantarum, and Lactobacillus delbrueckii subsp. bulgaricus. The biological safety (i.e., sensitivity to antibiotics and the presence of virulence factors) and probiotic potential (i.e., resistance to gastrointestinal conditions and whole-genome sequencing) of identified bioactive strains was also confirmed in vitro. The growth, GABA production, and competitiveness of selected probiotic candidates (B. animalis, S. thermophilus, and L. bulgaricus) were investigated in the presence of human gut microbiota ex vivo in a model of a proximal colon mimicking physiological and microbiological conditions of the human large intestine. Supplementation with GABA-producing probiotic candidates did not affect the overall gut microbiota diversity over 48 h of treatment. However, we observed modulation of the microbiome composition, especially change of Bacteroides population, a key gut microbe associated with anti-depressive and anti-inflammatory activities. The level of microbiota-generated butyrate within 12 h of treatment was significantly increased compared to control. Results from this study demonstrated the probiotic potential of tested GABA-producing bacteria and their impact on gut microbiota structure and metabolism, suggesting their suitability for gut health-promoting application.

Perturbing gut microbiota early in life can lead to the development of autoimmunity. We are just beginning to unravel how early immune programming by microbiota may have long-term effects on noncommunicable diseases. In this thesis, we lay groundwork for programming of the immune system by commensal bacteria early in life through our studies on the induction of early endogenous neonatal IgA, and we evaluate Limosilactobacillus reuteri's characteristics as an inducer. Garnering attention for use a probiotic, L. reuteri has many proven health promoting benefits, such as IgA induction, but emerging evidence also links specific strains to autoimmune disease. "Super-induction" of neonatal IgA can be achieved through cross-fostering immunocompetent pups on immunocompromised dams. We found that this phenomenon was categorically due to transferal of microbes from dam to offspring. By comparing strain CF48-3A to the non-gastric-related organism L. oris, we discovered that L. reuteri is a microorganism that can enhance early neonatal IgA induction. Further investigations revealed that the ability to induce neonatal IgA is not ubiquitous in all L. reuteri strains, as ATCC PTA 6475 did not significantly elevate IgA. We discovered that 6475 has the antigenic ability to stimulate B cell differentiation and IgA production, but it is suppressed by a mechanism related to differences in surface architecture of this strain. L. reuteri strains also vary in their potency of aryl hydrocarbon receptor (AhR) stimulation. In mice, activation of AhR during gestation by a potent prototypical ligand, TCDD, leads to development of autoimmunity offspring. We found that TCDD exacerbated autoimmunity in adult mice using a strain of mice with similar AhR affinity to humans. Further investigations can clarify whether differential AhR ligand expression between L. reuteri strains contributes to the relationship between L. reuteri and autoimmunity. Overall, we conclude that differences between strains of L. reuteri have profoundly different immunological consequences that contribute to our understanding of the linkage between strains and autoimmunity. / Doctor of Philosophy / Differences in microbes transferred to infants through maternal routes shapes the early development of the immune system. In general, transferred microbes are healthy for the infant, and studies suggest that disruption of healthy microbes in the infant gut is linked to long-term health consequences, like autoimmune diseases. We found that a particular difference in maternally transferred microbes increases the early appearance of immunoglobulin A (IgA, a gut-related antibody) in neonatal mice, which is an antibody important for protecting against gut-related infections. We were able to link this early IgA production to a probiotic species Limosilactobacillus reuteri. Within the species classification as L. reuteri, several genetically different strains are health-promoting and broadly marketed over-the-counter for use in probiotic supplements for infants, children, and pregnant and nursing mothers. Emerging scientific evidence also points to a potential connection between other L. reuteri strains and autoimmune disease. Secreted products of genetically different L. reuteri strains have been discovered to activate aryl hydrocarbon receptor (AhR) with various potency. We used a prototypical AhR ligand and found exacerbation of autoimmune disease in adult mice. Thus, we have concluded that different strains of L. reuteri have broadly different effects on immune system development, and strain variability may explain the different effects on autoimmunity that have been observed.

With World Health Organization estimation of population increase to over 9 billion by 2050, malnutrition and food insecurity are predicated to be two of the main challenges facing the world in the future. Fish is a source of protein that can have a significant contribution for solving the global food crisis. Fish for human consumption is provided by both the aquaculture industry and the capture fisheries, however, the flat-lined production of seafood from capture fisheries means aquaculture production should double in number to provide enough protein by 2050. Culturing fish at higher densities is being used as a way to increase the global aquaculture production. Modern aquaculture intensified practices expose the fish to various stressors that can negatively impact their welfare. Good nutrition can improve the health status of aquacultured fish while accumulation of specific nutrient can add value to the fillet. In line with that, the studies described in this dissertation aimed to examine the vital role of fish in human health and evaluate strategies to improve the sustainable aquaculture production of fish using novel aquafeeds. This was completed by conducting a survey of the essential minerals and heavy metals of commercially available catfish, salmon, and tilapia fillets in the United States marketplace and three fish nutritional trials to evaluate the impacts of novel aquafeeds on production and health of fish and the food quality of their respective fillets. Selenium with the established health benefit for human and fish was the trace mineral of interest in this dissertation. This element is the main component of a group of selenium containing proteins called selenoproteins that are antioxidant and maintain oxidative homeostasis of fish and human. Additionally, selenium is an antagonist for many heavy metals such as mercury. The market study revealed that catfish, salmon and tilapia samples available in United States marketplace are good source of selenium, zinc and phosphorous. The concentration of heavy metals in all the samples were lower than safety standards. Nile tilapia (Oreochromis niloticus) and rainbow trout (Oncorhynchus mykiss), which are two economically important aquacultured fish, were used as animal models in the fish nutritional trials. Different forms of selenium supplemented to Nile tilapia diet. The form of Dietary Se form did not have any significant (p>0.05) effect on growth, and plasma and hepatic GPX activity of Nile tilapia. However, organic selenium supplement showed significantly (p<0.05) higher bioavailability and accumulated in the fillets at the significantly higher concentration. In the second fish trial selenoneine, a novel selenium containing compound, was supplemented at various concentrations to rainbow trout diet. Other than growth parameters multiple other health biomarkers (lysozyme, glutathione peroxidase, superoxide dismutase activities) were examined to determine whether selenoneine supplementation had a positive impact on fish health. Selenoneine enriched diet significantly(p<0.05) increased the weight gain, lysozyme and oxidative enzymes activities of rainbow trout. Lastly rainbow trout feed was supplemented with commercially available probiotic (Actisaf®), prebiotic (Safmmann®), and their mixture (synbiotic). These dietary supplements did not have any significant effect on fish production but led to a significant increase in activity of oxidative enzymes in plasma when compared to control diet. These results suggest that feed supplements used in this dissertation can be used to promote the fish health raised in recirculating aquaculture systems and support an economically and environmentally sustainable aquaculture. / PHD / Fish contributes significantly to human’s diet in terms of high quality, easily digestible animal protein that helps fight malnutrition and food insecurity. More than half of the fish for human consumption is produced by the aquaculture industry and the growth of the industry is very critical for meeting the future needs for protein. Other than production of high-quality protein the aquaculture industry has made a great contribution to people’s livelihood, poverty alleviation, income generation, employment and, trade globally. To continue contributing effectively to global food security aquaculture industry should overcome various obstacles such as disease and sustainable production of high-quality feed. In this dissertation, important roles of fish in human diet was examined by measuring the mineral composition of commercially available catfish, salmon and tilapia in the United States market place. Also diets of Nile tilapia and rainbow trout were supplemented with various forms of selenium, prebiotics, and/or probiotics which have positive effect on health of both human and fish. These supplementations led to production of valued-added fish fillets enriched in selenium and improved the fish growth and health.

Master of Science / Food Science Institute -- Animal Science & Industry / Karen A. Schmidt / Yogurt starter and probiotic bacteria have been reported to confer health benefits to the consumer; however, to confer these health benefits yogurt and probiotic bacteria should be live and present at the recommended concentration of 6 to 8 log cfu g-1. Cegemett® Fresh (Cognis Nutrition & Health, Monheim, Germany) is a plant extract that possesses antioxidant properties. This research was divided into two experiments. The objective of experiment-I was to investigate the effect of plant extract supplementation on the redox potential (Eh) and the viability of starter cultures (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) in nonfat yogurt. Five yogurt samples [non-supplemented, supplemented with 0.5 or 1.0% (w/v) plant extract, or supplemented with 0.014 or 0.028% (w/w) L-cysteine.HCl] were prepared, stored at 5ºC for 50 days and analyzed weekly. L. bulgaricus counts in supplemented yogurts were > 6 log cfu mL-1 for additional 7 to 21 days compared with non-supplemented yogurt; however, S. thermophilus counts in all yogurts were > 6 log cfu mL-1 throughout the storage. Overall, Eh of plant extract supplemented yogurts were similar to non-supplemented yogurt during storage; therefore the improvement in L. bulgaricus viability cannot be attributed to the Eh alone. The objective of experiment-II was to investigate the effect of plant extract supplementation on the buffering ability of the yogurt mix, and on the viability of starter and probiotic (Bifidobacterium animalis ssp. animalis and Lactobacillus acidophilus) cultures in nonfat yogurt stored at 5ºC for 50 days. Nine yogurt samples were prepared with 0.5% (w/v) plant extract, 0.25% (w/v) sodium acetate or no supplement, fermented with starter cultures and B. animalis, L. acidophilus or both probiotics, and analyzed weekly. The plant extract and sodium acetate supplemented yogurt mixes had greater buffering capacities compared with non-supplemented yogurt mix. L. bulgaricus and L. acidophilus counts in supplemented yogurts were > 6 log cfu mL-1 for additional 7 to 35 days compared with non-supplemented yogurts. S. thermophilus and B. animalis counts were not affected by supplementation. These results suggested that greater buffering capacity could improve the viability of L. bulgaricus and L. acidophilus in yogurt during storage.