**8. Manipulation of gut microbiota with pro- and prebiotics**

The diet plays a major role in stratifying the gut microbiota (Muegge, 2011). This gives promise for food related gut microbiota perturbations. Manipulation of the gut microbiota through the diet is an old concept, either through probiotic live bacteria, or through prebiotic oligosaccharides.

Even though there is a range of products on the marked, there have been challenges in documenting the effect of these products. Diagnostic products that will help in substantiating the potential health claims would be of great benefit to the food industry. A main reason for the lack of documentation could actually be the lack of proper tools to describe the microbiota, rather than that the products have no effect.

Given proper documentation, the marked for pro- and prebiotics is very large. In particular, documentation that can be used in marketing would have a high commercial value. New diagnostic approaches could also potentially enable the discovery of new pro- and prebiotic products.

diagnostics. These are diseases representing enormous burden and costs to society. If these diseases can be linked to some kind of gut microbiota disorders, then there may also be

Discomfort such as abdominal pain, flatulence and bloating affect our everyday life. It has recently been shown correlation between these discomforts and specific gut bacteria (Jalanka-Tuovinen et al., 2011). Although not life threatening, the quality of life can be severely reduced by these discomforts. Diagnosis of the gut microbiota could potentially

Although the severity of IBS is not pronounced, 10% - 20% of people in the Western world suffer from this (Maxion-Bergemann et al 2001). Therefore, a diagnostics for this condition could have major impact, given the potential for advice that would increase the quality of

**7. Stratification of patients with respect to gut microbiota in clinical trials** 

It has recently been discovered that the gut microbiota plays a major role in the human metabolome (Nicholson et al 2005), and that the effects of drugs can be dependent on the gut microbiota (Clayton et al 2009). Combined with recent evidence that the human microbiome may consist of only three enterotypes (Arumugam et al 2011), diagnostics of such enterotypes is expected to provide important information with respect clinical trials. Enterotypes represent clusters of bacteria with a high frequency of co-occurrence, suggesting different states of the microbiota with different functionalities. There are several evidences for gut microbiota metabolism of important drugs, such as drugs against

Combined with the enterotype knowledge we believe that stratification will be a highly interesting field for gut microbiota diagnostics. This will be in line with the recent developments of personalized drugs –drugs adapted to individuals. Clearly, a major part of defining an individual would be the composition of gut microbiota. Information about the

The diet plays a major role in stratifying the gut microbiota (Muegge, 2011). This gives promise for food related gut microbiota perturbations. Manipulation of the gut microbiota through the diet is an old concept, either through probiotic live bacteria, or through

Even though there is a range of products on the marked, there have been challenges in documenting the effect of these products. Diagnostic products that will help in substantiating the potential health claims would be of great benefit to the food industry. A main reason for the lack of documentation could actually be the lack of proper tools to

Given proper documentation, the marked for pro- and prebiotics is very large. In particular, documentation that can be used in marketing would have a high commercial value. New diagnostic approaches could also potentially enable the discovery of new pro- and prebiotic

gut microbiota may therefore help to increase the success rate of clinical trials.

**8. Manipulation of gut microbiota with pro- and prebiotics** 

describe the microbiota, rather than that the products have no effect.

potential for intervention and treatment.

help in dietary interventions.

life through reducing discomforts.

Alzheimer (Pieper et al., 2009)

prebiotic oligosaccharides.

products.
