A randomised crossover study investigating the effects of galacto-oligosaccharides on the faecal microbiota in men and women over 50 years of age

Abstract

Faecal microbial changes associated with ageing include reduced bifidobacteria numbers. These changes coincide with an increased risk of disease development. Prebiotics have been observed to increase bifidobacteria numbers within humans. The present study aimed to determine if prebiotic galacto-oligosaccharides (GOS) could benefit a population of men and women of 50 years and above, through modulation of faecal microbiota, fermentation characteristics and faecal water genotoxicity. A total of thirty-seven volunteers completed this randomised, double-blind, placebo-controlled crossover trial. The treatments -juice containing 4 g GOS and placebo -were consumed twice daily for 3 weeks, preceded by 3-week washout periods. To study the effect of GOS on different large bowel regions, three-stage continuous culture systems were conducted in parallel using faecal inocula from three volunteers. Faecal samples were microbially enumerated by quantitative PCR. In vivo, following GOS intervention, bifidobacteria were significantly more compared to post-placebo (P¼0·02). Accordingly, GOS supplementation had a bifidogenic effect in all in vitro system vessels. Furthermore, in vessel 1 (similar to the proximal colon), GOS fermentation led to more lactobacilli and increased butyrate. No changes in faecal water genotoxicity were observed. To conclude, GOS supplementation significantly increased bifidobacteria numbers in vivo and in vitro. Increased butyrate production and elevated bifidobacteria numbers may constitute beneficial modulation of the gut microbiota in a maturing population.

Prebiotics in infant formula

“…24 There is also a report on GOS supplementation and its effect on bifido numbers in vivo and in vitro in women and men over 50 y old. 26 In conclusion: prebiotic oligosaccharides stimulate the development of bifidobacteria.…”

Nutrition and the gut microbiome in the elderly

“…C. difficile, Enterococcus faecium, Clostridium perfringens or Campylobacter) and enterobacteria. Regarding the prebiotic approach, the use of galacto-oligossaccharides has been successful in correcting microbiota changes and for improving the immunological state associated with the elderly 106,107 (Table 2), however intervention studies with alternative prebiotics (pectin, xilo-oligosaccharides, malto-oligosaccharides, etc) are lacking. Synbiotics have been also recently tested to improve age-related changes in the gut microbiota, with some positive effects on specific intestinal microbial populations ( Table 2).…”

Human gut microbiota: does diet matter?

“…Changes in some selected bacterial groups have been observed due to controlled changes to the normal diet e.g. high-protein diet (118,119) , prebiotics (97,(120)(121)(122) , probiotics (123)(124)(125) , weight-loss diet (20,126,127) and berries (128) . More specifically, changes in the type and quantity of non-digestible carbohydrates in the human diet influence both the metabolic products formed in the lower regions of the GI tract and levels of bacterial populations detected in faeces (129) .…”

“…The best sources of naturally occurring prebiotics may be found in vegetables such as artichokes, onions, chicory, garlic and leeks (167) . There are numerous studies in which the bifidogenic properties of prebiotics are shown (121,122,166,(168)(169)(170)(171) . In addition, increase in abundance of lactobacilli (121,122) and F. prausnitzii (170,172) has been shown.…”

“…There are numerous studies in which the bifidogenic properties of prebiotics are shown (121,122,166,(168)(169)(170)(171) . In addition, increase in abundance of lactobacilli (121,122) and F. prausnitzii (170,172) has been shown. Moreover, in infant formulas, galactooligosaccharides + FOS supplementation of cow's milkbased formula has led to a bifidobacterial population which resembled more that of breast-fed infants than purely formula-fed infants (173) .…”