Synbiotic yogurt consumption by healthy adults and the elderly: the fate of bifidobacteria and LGG probiotic strain.

Synbiotic dietary supplements are used to modulate the intestinal microbiota in adults; however, studies regarding elderly people are limited. The aim of this work is to determine the effect of regular consumption of yogurt containing Lactobacillus rhamnosus GG (LGG) and the fructooligosaccharide (FOS) Actilight(®) both in healthy adults and the elderly suffering from constipation. Yogurt was administered daily for 4 weeks; faecal samples were collected before starting, after 4-week administration and a 15-day wash out period, and analyzed for LGG and bifidobacteria counts. Constipation status in the elderly was recorded by a standardized questionnaire. Bifidobacteria did not increase in either groups; at the end of the intervention trial, LGG was detected in significantly different amount in the faeces of the elderly and adults, being higher in adults (95% vs. 30%). An increased evacuation number in the elderly was evidenced, probably due to the presence of FOS in yogurt.