ABSTRACT

CONTENTS Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 The Microflora of the Large Intestine in the Elderly . . . . . . . . . . . . . . . . . . . . . . . . 406

Nutritional Approaches: Modification of Gut Microflora by Probiotics and Prebiotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408

Diarrhea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409 Constipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410 Irritable Bowel Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 Colorectal Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 Immune Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415

Increased life expectancy and lower rates of fertility have resulted in the phenomenon of population ageing, characterized by an increase in proportion of older people and a decreased proportion of children and young adults. This is most apparent in the developed countries of the world; for example, in the UK, the proportion of people over 50 years old is expected to increase from 19.8 million in 2002 to 27 million by 2031, while the proportion of those over 85 will rise from approximately 2% to 3.8% over the same period (National Statistics, 2004). Within the EU, it is estimated that, between 2000 and 2010, the numbers

of people in the 80+ age group will rise by 35% and that, by 2010, there will be twice as many older people as in 1960 (69 million versus 34 million) (Eurostat, 2002).