Project description:Colorectal cancer (CRC) is strongly affected by diet, with red and processed meat increasing risk. To understand the role of microbiome in this phenomenon and to identify specific microbiome/metabolomics profiles associated with CRC risk, will be studied: 1) healthy volunteers fed for 3 months with: a high-CRC risk diet (meat-based MBD), a normalized CRC risk diet (MBD plus alpha-tocopherol, MBD-T), a low-CRC risk diet (pesco-vegetarian, PVD). At the beginning and at the end of the intervention, gut microbiome profiles (metagenomics and metabolomics), and CRC biomarkers (genotoxicity, cytotoxicity, peroxidation in faecal water; lipid/glycemic indexes, inflammatory cytokines, oxidative stress), 2) Colon carcinogenesis: the same diets will be fed (3 months) to carcinogen-induced rats or to Pirc rats, mutated in Apc, the key gene in CRC; faecal microbiome profiles, will be correlated to carcinogenesis measuring preneoplastic lesions, colon tumours, and faecal and blood CRC biomarkers as in humans; 3) To further elucidate the mechanisms underlying the effect of different microbiomes in determining CRC risk, faeces from rats fed the experimental diets will be transplanted into carcinogen-induced germ-free rats, measuring how microbiome changes correlate with metabolome and disease outcomes. The results will provide fundamental insight in the role of microbiome in determining the effect of the diet, in particular red/processed meat intake, on CRC risk
Project description:Aging alters gastrointestinal morphology, microbiota, and functionality, and is associated with increased incidence of intestinal disease. The mechanisms that contribute to these changes are poorly described. Gene expression in dogs has been evaluated for a few select genes under pathogenic or varying dietary conditions, but global gene expression profiles of aged versus young adult dogs have not been compared previously. Thus, we used canine microarrays to compare gene expression profiles of colonic epithelial tissue from geriatric and young adult dogs fed 2 different diets. Colon tissue samples were collected from 6 geriatric (12 yr-old) and 6 young adult (1 yr-old) female beagles after being fed one of two diets (animal protein-based versus plant-protein based) for 12 months. RNA samples were hybridized to Affymetrix GeneChip Canine Genome Arrays. Statistical analyses indicated that age had the greatest impact on gene expression, with 212 genes differentially expressed in geriatric dogs. Although not as robust as age, diet affected mRNA abundance of 66 genes. The effect of age was most notable, with increased expression in genes related to inflammation, stress response, cellular metabolism and cell proliferation and decreased expression in genes associated with apoptosis and defense mechanism in senior dogs. The effect of diet on gene expression was not consistent, but appeared to have a greater response in senior dogs. Six geriatric (11.1 yr old) and 6 weanling (8 wk old) female beagles were used. Three dogs of each age were assigned to one of two dietary treatments and fed for 12 months. Diets tested in this experiment were previously shown to manipulate energy metabolism. One diet was an animal-protein based diet (APB) and was composed primarily of highly digestible ingredients and animal-derived protein and fat sources (brewer’s rice, poultry by-product meal, poultry fat) and was formulated to contain 28% protein, 23% fat, and 5% dietary fiber. The other diet was a plant-protein based diet (PPB) and was composed primarily of moderately digestible plant-derived ingredients (corn, soybean meal, wheat middlings, and meat and bone meal) and was formulated to contain 26% protein, 11% fat, and 15% dietary fiber. Although the two diets were very different in terms of ingredient and chemical composition, both were formulated to meet or exceed all nutrient requirements for canine growth according to the Association of American Feed Control Officials. Young dogs were fed ad libitum to allow for adequate growth, while geriatric dogs were fed to maintain baseline BW throughout the experiment. To produce the desired metabolic effects, the PPB diet was formulated to contain a lower caloric density (APB = 5.38 kcal/g; PPB = 4.75 kcal/g) and have a lower nutrient digestibility than the APB diet. Thus, dogs fed the PPB diet needed to consume a greater (P<0.05) quantity of food (237 g/d; 1123 kcal/d) than dogs fed the APB diet (166 g/d; 893 kcal/d) to grow (young) or maintain BW (geriatrics). Even though metabolic indices were altered, mean BW among dietary treatments was not different at any time over the course of the study for young or geriatric dogs. After 12 months on experiment, animals were fasted for 12 hr and then given a lethal dose (130 mg/kg BW) of sodium pentobarbital (Euthasol, Virbac Corp., Fort Worth, TX) intravenously into the left forearm. Death was confirmed by lack of respiration and a corneal reflex, and absence of a heartbeat detected with a stethoscope placed under the left elbow. Colon samples were collected immediately after death was confirmed, flash frozen using liquid nitrogen, and stored at -80oC. Frozen samples were placed in RNAlater-ICE until epithelial layer could be scraped off and used for microarray analysis.
Project description:The liver is the central organ in the regulation of nutrient metabolism, xenobiotic metabolism, and detoxification. Aging leads to a marked change in liver structure and function, characterized by a decline in weight, blood flow, regeneration rate, and detoxification. However, the mechanisms that contribute to these changes are poorly described. Global gene expression profiles of aged versus young adult dogs have not been compared previously. Thus, we used canine microarrays to compare gene expression profiles of liver tissue from geriatric and young adult dogs fed 2 different diets. Liver tissue samples were collected from 6 geriatric (12 yr-old) and 6 young adult (1 yr-old) female beagles after being fed one of two diets (animal protein-based versus plant-protein based) for 12 months. RNA samples were hybridized to Affymetrix GeneChip Canine Genome Arrays. Statistical analyses indicated that age had the greatest impact on gene expression, with 234 gene transcripts differentially expressed in geriatric dogs. Although not as robust as age, diet affected mRNA abundance of 137 gene transcripts. The effect of age was most notable, with increased expression in genes related to inflammation, oxidative stress, and glycolysis and decreased expression in genes associated with regeneration, xenobiotic metabolism, and cholesterol trafficking in senior dogs. The effect of diet on gene expression was not consistent, but led to more changes in young adult dogs. Six geriatric (11.1 yr old) and 6 weanling (8 wk old) female beagles were used. Three dogs of each age were assigned to one of two dietary treatments and fed for 12 months. Diets tested in this experiment were previously shown to manipulate energy metabolism. One diet was an animal-protein based diet (APB) and was composed primarily of highly digestible ingredients and animal-derived protein and fat sources (brewer’s rice, poultry by-product meal, poultry fat) and was formulated to contain 28% protein, 23% fat, and 5% dietary fiber. The other diet was a plant-protein based diet (PPB) and was composed primarily of moderately digestible plant-derived ingredients (corn, soybean meal, wheat middlings, and meat and bone meal) and was formulated to contain 26% protein, 11% fat, and 15% dietary fiber. Although the two diets were very different in terms of ingredient and chemical composition, both were formulated to meet or exceed all nutrient requirements for canine growth according to the Association of American Feed Control Officials. Young dogs were fed ad libitum to allow for adequate growth, while geriatric dogs were fed to maintain baseline BW throughout the experiment. To produce the desired metabolic effects, the PPB diet was formulated to contain a lower caloric density (APB = 5.38 kcal/g; PPB = 4.75 kcal/g) and have a lower nutrient digestibility than the APB diet. Thus, dogs fed the PPB diet needed to consume a greater (P<0.05) quantity of food (237 g/d; 1123 kcal/d) than dogs fed the APB diet (166 g/d; 893 kcal/d) to grow (young) or maintain BW (geriatrics). Even though metabolic indices were altered, mean BW among dietary treatments was not different at any time over the course of the study for young or geriatric dogs. After 12 months on experiment, animals were fasted for 12 hr and then given a lethal dose (130 mg/kg BW) of sodium pentobarbital (Euthasol, Virbac Corp., Fort Worth, TX) intravenously into the left forearm. Death was confirmed by lack of respiration and a corneal reflex, and absence of a heartbeat detected with a stethoscope placed under the left elbow. Liver samples were collected immediately after death was confirmed, flash frozen using liquid nitrogen, and stored at -80oC until further analysis.
Project description:Peripheral blood mononuclear cell (PBMC) gene expression profiling is a low-invasive tool used in human diet intervention studies. In dogs this technique has been used to investigate disease states but not to examine the effect of diet. We tested the hypothesis that diet alters dog systemic immune cell gene expression profiles by comparing PBMC gene expression in dogs fed either a premium kibbled diet or a raw red meat diet for 9 weeks. Our results showed that diet shifted the dogs’ PBMC gene expression profile and these alterations corresponded with changes in plasma IgA levels. This illustrates that PBMC microarrays are a useful tool that may be applied to study the long-term effects of diet on health outcomes for the dog.
Project description:Mechanisms contributing to age-related cognitive decline are poorly defined. Thus, we used canine microarrays to compare gene expression profiles of brain tissue from geriatric and young adult dogs. Cerebral cortex samples were collected from 6 geriatric (12 yr-old) and 6 young adult (1 yr-old) female beagles after being fed one of two diets (animal protein-based versus plant-protein based) for 12 months. RNA samples were hybridized to Affymetrix GeneChip Canine Genome Arrays. Statistical analyses indicated that the age had the greatest impact on gene expression, with 963 transcripts differentially expressed in geriatric dogs. Although not as robust as age, diet affected mRNA abundance of 140 transcripts. As demonstrated in aged rodents and humans, geriatric dogs had increased expression of genes associated with inflammation, stress response, and calcium homeostasis and decreased expression of genes associated with neuropeptide signaling and synaptic transmission. In addition to its existing strengths, availability of gene sequence information and commercial microarrays make the canine a powerful model for studying the effects of aging on cognitive function. Keywords: age; diet Six geriatric (11.1 yr old) and 6 weanling (8 wk old) female beagles were used. Three dogs of each age were assigned to one of two dietary treatments and fed for 12 months. Diets tested in this experiment were previously shown to manipulate energy metabolism. One diet was an animal-protein based diet (APB) and was composed primarily of highly digestible ingredients and animal-derived protein and fat sources (brewer’s rice, poultry by-product meal, poultry fat) and was formulated to contain 28% protein, 23% fat, and 5% dietary fiber. The other diet was a plant-protein based diet (PPB) and was composed primarily of moderately digestible plant-derived ingredients (corn, soybean meal, wheat middlings, and meat and bone meal) and was formulated to contain 26% protein, 11% fat, and 15% dietary fiber. Although the two diets were very different in terms of ingredient and chemical composition, both were formulated to meet or exceed all nutrient requirements for canine growth according to the Association of American Feed Control Officials. Young dogs were fed ad libitum to allow for adequate growth, while geriatric dogs were fed to maintain baseline BW throughout the experiment. To produce the desired metabolic effects, the PPB diet was formulated to contain a lower caloric density (APB = 5.38 kcal/g; PPB = 4.75 kcal/g) and have a lower nutrient digestibility than the APB diet. Thus, dogs fed the PPB diet needed to consume a greater (P<0.05) quantity of food (237 g/d; 1123 kcal/d) than dogs fed the APB diet (166 g/d; 893 kcal/d) to grow (young) or maintain BW (geriatrics). Even though metabolic indices were altered, mean BW among dietary treatments was not different at any time over the course of the study for young or geriatric dogs. After 12 months on experiment, animals were fasted for 12 hr and then given a lethal dose (130 mg/kg BW) of sodium pentobarbital (Euthasol, Virbac Corp., Fort Worth, TX) intravenously into the left forearm. Death was confirmed by lack of respiration and a corneal reflex, and absence of a heartbeat detected with a stethoscope placed under the left elbow. Cerebral cortex samples were collected immediately after death was confirmed, flash frozen using liquid nitrogen, and stored at -80oC until further analysis.
Project description:The typical human diet differs substantially in a number of ways from that of other primates. For instance, although many humans consume meat on a regular basis, non-human primate diets are typically dominated by plant foods. In addition, most human populations cook the majority of their foods, whereas all other free-living primate species eat exclusively raw diets. Such differences in food substrates and food processing are hypothesized to exert a large influence on metabolism. If maintained over evolutionary timescales, dietary differences may have contributed to shaping important human-specific features. To index the effect of food substrate and food preparation on metabolism we measured liver gene expression in mice fed diets of meat or tubers served either raw or cooked.
Project description:Aging animals display a decline in a multitude of physical and physiological functions, including muscle function and strength. Muscle gene expression in dogs has been evaluated for a few select genes under pathogenic or varying dietary conditions, but global gene expression profiles of aged animals has not been performed. Because the mechanisms contributing to age-related decline in muscle function are poorly defined, we used canine microarrays to compare gene expression profiles of muscle tissue from geriatric and young adult dogs. Skeletal muscle (biceps femoris) samples were collected from 6 geriatric (12 yr-old) and 6 young adult (1 yr-old) female beagles after being fed one of two diets (animal protein-based versus plant-protein based) for 12 months. RNA samples were hybridized to Affymetrix GeneChip Canine Genome Arrays. Statistical analyses indicated that age had the greatest impact on gene expression, with 262 genes differentially expressed in geriatric dogs. Although not as robust as age, diet affected mRNA abundance of 22 genes. The effect of age was most notable in genes related to metabolism, cell cycle and cell development, and transcription function, with all of these functional groups being predominantly down-regulated in older animals. The effect of diet on gene expression was mostly limited to the geriatric animals, but interactions between age and diet do not allow for a clear-cut pattern of gene expression to be observed. Keywords: age; diet Six geriatric (11.1 yr old) and 6 weanling (8 wk old) female beagles were used. Three dogs of each age were assigned to one of two dietary treatments and fed for 12 months. Diets tested in this experiment were previously shown to manipulate energy metabolism. One diet was an animal-protein based diet (APB) and was composed primarily of highly digestible ingredients and animal-derived protein and fat sources (brewerâs rice, poultry by-product meal, poultry fat) and was formulated to contain 28% protein, 23% fat, and 5% dietary fiber. The other diet was a plant-protein based diet (PPB) and was composed primarily of moderately digestible plant-derived ingredients (corn, soybean meal, wheat middlings, and meat and bone meal) and was formulated to contain 26% protein, 11% fat, and 15% dietary fiber. Although the two diets were very different in terms of ingredient and chemical composition, both were formulated to meet or exceed all nutrient requirements for canine growth according to the Association of American Feed Control Officials. Young dogs were fed ad libitum to allow for adequate growth, while geriatric dogs were fed to maintain baseline BW throughout the experiment. To produce the desired metabolic effects, the PPB diet was formulated to contain a lower caloric density (APB = 5.38 kcal/g; PPB = 4.75 kcal/g) and have a lower nutrient digestibility than the APB diet. Thus, dogs fed the PPB diet needed to consume a greater (P<0.05) quantity of food (237 g/d; 1123 kcal/d) than dogs fed the APB diet (166 g/d; 893 kcal/d) to grow (young) or maintain BW (geriatrics). Even though metabolic indices were altered, mean BW among dietary treatments was not different at any time over the course of the study for young or geriatric dogs. After 12 months on experiment, animals were fasted for 12 hr and then given a lethal dose (130 mg/kg BW) of sodium pentobarbital (Euthasol, Virbac Corp., Fort Worth, TX) intravenously into the left forearm. Death was confirmed by lack of respiration and a corneal reflex, and absence of a heartbeat detected with a stethoscope placed under the left elbow. Skeletal muscle samples were collected immediately after death was confirmed, flash frozen using liquid nitrogen, and stored at -80oC until further analysis.
Project description:Compositional changes in the microbiota (dysbiosis) may be a basis for Irritable Bowel Syndrome (IBS) but biomarkers are currently unavailable to direct microbiota-directed therapy. We therefore examined whether changes in fecal β-defensin could be a marker of dysbiosis in a murine model. Experimental dysbiosis was induced using four interventions relevant to IBS: a mix of antimicrobials, westernized diets (high-fat/high-sugar and, high salt diets), or mild restraint stress. Fecal mouse β-defensin-3 and 16S rRNA-based microbiome profiles were assessed at baseline, during and following these interventions. Each intervention, except for mild restraint stress, altered compositional and diversity profiles of the microbiota. Exposure to antimicrobials or a high-fat/high-sugar diet, but not mild restraint stress, resulted in decreased fecal β-defensin-3 compared to baseline. In contrast, exposure to the high salt diet increased β-defensin-3 compared to baseline but this was not accompanied by discernible inflammatory changes in the host.
Project description:In this work, the effects of different sources of meat protein on liver metabolic enzymes were investigated. Rats were fed for 90 days with semisynthetic diets in which casein was fully replaced by isolated soybean, fish, chicken, pork, or beef proteins. Then, liver proteomics was performed using iTRAQ and LC−ESI−MS/MS. The results indicated that intake of meat protein diets significantly reduced the protein levels of CYP450s, GSTs, UGTs, and SULTs compared to those of the casein and soybean protein diet groups. The total antioxidant capacity and lipid peroxidation values did not differ between four meat protein diet groups and the casein diet group. However, GSH activity in the fish, chicken, and beef protein groups was significantly higher than those of the casein and soybean protein groups. The beef protein diet significantly upregulated the expression of immune-related proteins. The Keap1-Nrf2-ARE signaling pathway was suggested to involve the diet-mediated regulation of biotransformation, inflammation, and redox status.
Project description:Aging alters gastrointestinal morphology, microbiota, and functionality, and is associated with increased incidence of intestinal disease. The mechanisms that contribute to these changes are poorly described. Gene expression in dogs has been evaluated for a few select genes under pathogenic or varying dietary conditions, but global gene expression profiles of aged versus young adult dogs have not been compared previously. Thus, we used canine microarrays to compare gene expression profiles of colonic epithelial tissue from geriatric and young adult dogs fed 2 different diets. Colon tissue samples were collected from 6 geriatric (12 yr-old) and 6 young adult (1 yr-old) female beagles after being fed one of two diets (animal protein-based versus plant-protein based) for 12 months. RNA samples were hybridized to Affymetrix GeneChip Canine Genome Arrays. Statistical analyses indicated that age had the greatest impact on gene expression, with 212 genes differentially expressed in geriatric dogs. Although not as robust as age, diet affected mRNA abundance of 66 genes. The effect of age was most notable, with increased expression in genes related to inflammation, stress response, cellular metabolism and cell proliferation and decreased expression in genes associated with apoptosis and defense mechanism in senior dogs. The effect of diet on gene expression was not consistent, but appeared to have a greater response in senior dogs.