This Masters thesis was written as a part of PreTerm project and presents the results of analysed faeces samples of individuals who took part in the research. The purpose of the thesis was to compare the state of metabolites and the environmental parameters in faeces of participants born prematurely contrasted with the state in those born on time. The research was conducted on 34 participants aged between 18-24, among which there were 20 born prematurely and 14 born on time. In the testing period tests in hypoxia as well as normoxia were carried out, each type of test executed both during rest and physical activity. Faeces samples were collected 3 days prior and subsequent to each test and tested later. Physical-chemical parameters and the content of metabolites using the 1H-NMR analysis were identified. Both the results of physical-chemical parameters (water and sterol content, faeces hardness according to Bristol stool chart, piercing weight, pH, conductivity, SR, E2:E3, TSOC and RS) as well as metabolites results obtained by NMR analysis bring us to identic conclusion, i. e. that it is not possible to dismiss the set hypothesis stating that there will be no differences in the state of metabolites between both researched groups before and after the physical strain tests. The influence of various experimental parameters on data dispersion was also checked and it was determined that none of the chosen parameters (sampling day, test type, researched group, sampling time according to the test, age, height and weight of participants at the beginning of testing as well as their gestational height and weight) had significantly influenced the end results. The results were mostly influenced by the successive number of the sample meaning the samples were different among themselves. It can be concluded that human body and therefore its digestive tract is a highly complex and stable environment which must maintain its function and activity even in stressful situations. Consequently it is not possible to change its structure and function with minor environmental influences.