Key words: intestinal health, aging, intestinal microbiota, nutrition, synbiotics, dietary fibre

"Role of nutritional interventions and aging in intestinal health"

Healthy nutrition and good intestinal health contribute to healthy ageing. This dissertation focuses on the impact of aging and nutritional interventions on the intestinal barrier function and intestinal microbiota. In the literature was found that some functions of the gastrointestinal tract and the intestinal microbiota are different in the elderly compared to adults, and especially associated with a reduced health condition. An own study extensively demonstrated that the intestinal barrier function is maintained in aging. Three nutrition intervention studies were also carried out. Two weeks intake of a synbiotic (combination of probiotics and dietary fibres) increased the relief frequency in healthy adults, but had no effect on intestinal barrier function. The second study found that intestinal barrier function and intestinal microbiota were not affected by four weeks of dietary fibre intake in healthy adults and healthy elderly. Finally, it was shown that pre-vulnerable elderly compared to healthy adults had fewer bifidobacteria in the faeces. In addition, four weeks of dietary fibre intake led to an increase in these bifidobacteria, but did not affect immune system function.