Projects / Programmes
NUTRITION AND ECOLOGY OF GASTROINTESTINAL TRACT
January 1, 2004
- December 31, 2008
| Code |
Science |
Field |
Subfield |
| 4.02.00 |
Biotechnical sciences |
Animal production |
|
| 4.06.00 |
Biotechnical sciences |
Biotechnology |
|
| Code |
Science |
Field |
| B420 |
Biomedical sciences |
Nutrition |
nutrition, feed, environment, functional food, health, oxidative stress, probiotics, prebiotics, microbiology, bacteriocins, gastrointestinal tract, selection criteria, markers, identification, classification, biotechnology
Researchers (43)
Organisations (2)
Abstract
Nutrition is an important factor in maintaining organism in good health condition. A new concept in searching for optimal food was introduced designated as functional food. Original definition stating "Food can be labeled as functional when its beneficial effect on one or more target function in the body, beyond satisfying traditional nutrient requirements can be sufficiently demonstrated by evidence", requires establishement of new objectives of research and developmental nature. Study of mechanisms and searching for appropriate markers on molecular and immunological level which enable satisfactory measurement of effects of food or feed, are basic approaches in progress of this new scientific area.
Reasons for development of modern civilisation diseases which can be defined from nutrition-medical point of view can be classified into two groups, the first comprising energetically and compositionally non-equilibrated nutrition, and the latter resulting in disturbed microbial balance of the gut. Normal gut microflora has at least three important roles: it reduces the possibility of infections with pathogenic bacteria, it stimulates maturation of gut mucosal immunological system and development of immune tolerance to ubiquitous antigens. Discovering roles of microorganisms in interactions with host organisms and host itself, is one of the key steps towards understanding the function of the human and/or animal gastrointestinal tract ecosystems. Different in vitro, ex vivo and in vivo methods and different animal models will be applied to carry out the proposed research. Nutrition studies will be performed on domestic and laboratory animals, via monitoring of feed intake and quantitative excrement of substances with urine and faeces, via monitoring of metabolic parameters and investigating of nutritional factors by different markers such as malonaldehyde (MDA) in plasma, in urine, in feeed, in animal products and food (HPLC), via level of DNA damage in the cells (comet test), concentration of E-vitamine (alpha-, beta plus gama-, delta- tocopherol/HPLC), overall antioxidative status of blood serum and glutathion peroxidase activity in enterocytes. In addition to conventional analysis of feed and food, determination of macro- and micro-minerals concentration (atomic absorption spectrometry) and in sacco method for determination of feed digestibility by using fistulated animals, the conditions and microbial fermentation in particular parts of the gut will be studied by determination of concentrations of short chain fatty acids (gas chromatography), ATP, ammonia, of intestinal content viscosity and fermentability (in vitro gas-tests). Besides traditional microbiological methods for isolation and cultivation of microaerophilic and strictly anaerobic bacteria in anaerobic chambers, a wide range of molecular and genetic methods will be used to study structure and population dynamics of microbial community.
Objectives: study of mechanisms and new approaches in feeding, enabling the production of functional food of animal origin, finding out the effects of alternative feed additives (plant extracts, fibrinolytic enzymes) and selected probiotics and prebiotics on the composition of microbial population in the gut of domestic animals or humans and in the systems simulating these ecosystems, selection of markers for measurement of influences of feed, nutrients, pre-, probiotics and other bioactive substances in organism and development of toxicological, genotoxicological and immunological methods for tracing of their positive and negative effects.
Significance for science
Problems related to the nutrition and health do not concern only medical service but also agricultural sector which is involved in the food production, as well as food processing industry. Nutrition studies aimed to identify foods which are due to specific nutritional-physiological effects a source of important nutrients or active compounds are therefore very up-to-date. One of the actual problems of modern nutrition are effects of the nutrition on the oxidative stress which may in the conditions of weak anti-oxidative protection in the body, lead toward the collapse of pro-oxidative/anti-oxidative equilibrium in the organism, and as a consequence the increased risk for the development of different diseases. Studies performed by our group contributed some new knowledge in this field. Results of animal studies confirmed lower oxidative stability of lipids in the pigs and chickens fed with high amounts of n-3 PUFA, and therefore higher need for antioxidants application. Addition of different antioxidants (sintetic and natural vitamine E, plant extracts reach with poliphenils, for ex. extracts from Calendula officinalis, cinnamon, cayenne pepper, tannin extracts from sweet chestnut tree) reduces or sometimes even prevents negative effects of oxidative stress. Since the anti-oxidative activity of studied extract has been known only in vitro, our studies present the first evidence of their activity also in vivo. Also the antioxidative activity of the tannin extracts from sweet chestnut tree, of extracts from the mixture of origano and cinnamon, as well as of extracts from Calendula officinalis have been described for the first time. Results show that all three extracts reduce the level of lipid oxidation (MDA, IPF2alfa) and diminish the DNA damages (comet test, 8-OHdG). Their effectiveness is comparable to or even better than vitamin E's. It is becoming evident that human and animal nutrition can not be optimally planned without considering the microbiota of gastrointestinal tract which plays an important role not only in the feed/food degradation but also in the protection and immune defence of the organism. For this reason we've paid much attention to the composition of microbiota and effects of different nutrients and supplements on the structural changes of the composition. Some results from this part of research are scientifically important. When we studied the effects of tannins from carob bean's flour on the composition of rabbits' caecum, we identified a new species belonging to the Metanobrevibacter genus of methanogenic arhea. The molecular and taxonomic description of this new species was carried out and metagenomic library of ribosomal genes of bacteria from rabbits' caecum was prepared. Bioinformatic analysis of obtained sequences showed that rabbit caecum contains several yet indescribed bacterial specia and genera, predominantly those from XIV. group Firmicutes. Two new wide-spectral bacteriocins produced by Lb. gasseri strains (K7 and LF221) were described, as well as a new phenomenon of cross homology of active and non-active subunits of K7 and LF221 bacteriocins with narrow-activity bacteriocin gassericin T.
Significance for the country
Several methods for measuring the effects of feed, nutrients, probiotics and other bioactive substances in vitro and in vivo in the organism were introduced. The researchers from our group developed a model of oxidative stress induction, which enables to test and compare antioxidative activities of sinthetic and natural antioxidants and toxins, in vivo and ex vivo. Methods for the measurements of oxidative stress on different levels of antioxidative defence were introduced. There are few research teams able to perform such studies which include such a wide spectrum of analysis, therefore considerable interest from the industry is not surprising. We have already established cooperation with some industrial partners (Chemoforma Ltd, Switzerland; Tanin Sevnica, Slovenija). The cooperation includes also studies required before the registration of individual feed supplements and their inclusion into the Register of feed supplements. Similar cooperation has been established also in the probiotic field, where we perform studies and control of probiotic products such as food, food supplements and OTC drugs. Our main partners in the probiotic field are Lek (Slovenia), Adria Medics (Bolgaria), LTH (Switzerland). Among the main objectives of this research program group is also support of the educational process at University, on the graduate as well as postgraduate level, in accordance to the mission of the organisation which we belong to. The realised research program contributed new knowledge in one of the priority thematic areas, i. e. production and supply of safe food, which is included in the first priority field: »genomics and biotechnology for health, quality and safety of food and sustainable development«. We believe that the results of our research will contribute to better knowledge of food, to the better nutrition and consequently better health of residents of RS. New findings and methods have already been introduced into the management of animal nutrition, of animal breeding and in the production of safe food and functional foods, by the mean of applicative projects. This presents considerable contribution to the assurance of safety, quality and competitiveness of Slovenian products and consequently of agriculture and agro-food industry.
Most important scientific results
Final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Final report,
complete report on dLib.si
