Designer Oligosaccharides

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Prebiotics towards a mechanistic understanding
Chair Bob Rastall University of Reading
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Workshop programme
G. Falony Cross-feeding between Bifidobacterium
longum BB536 and acetate-converting,
butyrate-producing colon bacteria during growth
on oligofructose A. Belenguer Alternative
mechanisms of metabolic cross-feeding between
human gut bacteria D. Bosscher Dietary inulin and
oligofructose attenuate plaque formation in an
animal model of atherosclerosis R.A. Rastall
Effect of glycosidic linkage and molecular weight
on fermentation selectivity in vitro Panel
discussion
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Discussion questions

• 1) Given the huge complexity of the colonic
  microbiota, is it reasonable to think that we can
  achieve a mechanistic understanding?
• The group felt that, whilst it will take a long
  time and new experimental approaches to achieve,
  a mechanistic understanding should be possible
• Several groups have already started to map out
  the nutritional and ecological interactions
  between members of the gut flora

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Discussion questions

• 2) What is the relevance of the data generated
  from in vitro studies for the actual situation in
  humans?
• Whilst all model systems are a compromise, in
  vitro studies are essential to achieve a
  mechanistic understanding
• The molecular tools to investigate both the
  structure and the function of the colonic
  microbiota are evolving steadily
• Human trials need to be more sophisticated with
  respect to the analyses carried out and this will
  correlate more with in vitro data

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Discussion questions

• 3) Given the high degree of individual variation
  in the colonic microbiota, what will be the
  optimum strategy to improve health?
• Whilst individuals vary considerably, similar
  trends are frequently seen with respect to
  responses to prebiotic consumption
• Most prebiotic studies focus on specific
  organisms
• Range of organisms considered as desirable will
  increase as our knowledge expands
• A mechanistic understanding will depend on
  studying as wide a range of organisms as possible

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Discussion questions

• 3) Given the high degree of individual variation
  in the colonic microbiota, what will be the
  optimum strategy to improve health?
• The goal should be to achieve optimum
  preventative nutrition targeted at the healthy
  population
• This does not exclude targeted application at
  specific disease states where our knowledge
  allows
• Within the medical community the focus is very
  firmly on gut health

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Discussion questions

• 4) What is the potential for use of mechanistic
  knowledge to generate novel functional food
  ingredients?
• There is considerable potential to combine
  understanding in chemistry, biotechnology and gut
  microbiology to generate new prebiotics
• These may be targeted at organisms yet to be
  identified as desirable to health
• Synbiotics are frequently seen to be much more
  effective that prebiotics alone and there is
  potential to develop enhanced synbiotics

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Overall conclusions

• New tools to characterise the functional
  interactions between members of the colonic
  microbiota are being/will be developed
• This knowledge will provide the basis for the
  mechanistic understanding of prebiotic effects
• The mechanisms underlying health promotion are
  equally important to those for fermentation
  selectivity
• Synergy between different groups using different
  approaches should be maximised

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The bottom line?
We need more research
and hence more money!