From bugs to drugs

Published on 9 July 2011 in Food, health and wellbeing

Key Challenges

The dramatic increase in the incidence and prevalence of chronic inflammatory diseases in Westernised countries, and the heightened allergy risk associated with urban (not rural) lifestyles, are now recognised to be linked to variations in microbial diversity within these environments. Current research dealing with the nitty-gritty of microbe-gut interactions is clearly demonstrating that bugs play a critical role in directing appropriate immune development and function.

Key Benefits

Research on human gut bacteria is often packaged and presented under the umbrella term ‘Probiotics’. Traditionally, probiotics have been linked with numerous human health benefits most of which have been driven by billion dollar marketing campaigns and based on limited scientific evidence. As a result the scientific literature is awash with contradictory reports regarding the efficacy of these probiotics and the failed attempts to obtain European Food Safety Authority (EFSA) regulatory approval, further fuels the notion that probiotics are products of hype and no substance.

Probiotic research in its broadest sense is now mistakenly regarded as mature science. The implication being that we have discovered all there is to know about probiotics, bugs and human health. This is emphatically not the case.

Research undertaken contributed to significant advances in understanding of how human gut microbes influence gut health and inflammatory bowel disease.

The challenge is to ensure that the scientific breakthroughs and advances in our understanding of how gut bugs positively influence the human immune system and human health are successfully harnessed and translated into tangible health benefits.

Although much is known about how pathogenic bacteria invade the host and influence immune defence mechanisms, at the time the research featured in this story was undertaken, little was known about the interactions between the normal gut bacteria and the human gut immune system.  In particular how the diverse and numerically dense microbiota could co-exist with the host gut in the absence of any sign of inflammation was completely unknown.  Subsequent ground-breaking research demonstrated the mechanism whereby Bacteroides thetaiotaomicron actively reduced the inflammation in the gut and identified a potentially new bacterial-derived therapeutic protein with anti-inflammatory activity.

In analysing both microbial diversity and immune development in early life (hygiene hypothesis) we have provided the first data showing that environmental exposure is a critical factor determining diversity in adult life.  We have also shown that a highly diverse microbiota correlated with different patterns of immune development and shed some light on how the immune system distinguishes pathogenic from normal gut micro-organisms.

This work has significant impact for human and animal health as through the manipulation of the microbiota it may be possible to alleviate many of the symptoms associated with chronic inflammatory diseases.

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