The study involved giving probiotic beverages containing Lactobacillus paracasei and Lactobacillus rhamnosus (both Nestlé proprietary strains) to mice that had been transplanted with human gut microbes, giving them an intestinal microflora analogous to humans.
Talking to NutraIngredients.com, Dr. Sunil Kochher, a senior scientist at Nestlé Research Center, explained that the study was important because, although probiotics are used in many products, how they work in the human body is not known.
"This is one of the first studies to look at individual metabolic situation," he said.
Using the nutrimetabonomics approach, the researchers followed the metabolic changes in the liver, blood, urine, and faeces.
Supplementation with the probiotics led to changes in host intestinal microflora, they report in the journal Molecular Systems Biology .
These changes were found to subsequently affect energy, lipid and amino acid metabolism.
Indeed, energy recovery from the diet was modified, with subsequent effects on circulating lipids in the plasma and metabolism of glucose in the liver.
Moreover, changes were observed in metabolised bile acids in the animals receiving the probiotics.
This is significant because, if probiotics can influence the way in which bile acids are metabolised, this means they could alter how much fat the body is able to absorb.
"Interestingly the primary influences of the probiotics appear to be via indirect or knock-on effects on the metabolic activities and populations of other gut microbes," explained Prof. Jeremy Nicholson of Imperial College London.
"Additionally, the two probiotics investigated had different metabolic effects in the host, suggesting the possibility of giving probiotic combinations according to a person's individual metabolic profile."
According to Dr. Kochhar the study highlights the potential of nutrimetabonomics for the study of metabolic mechanisms of probiotic action, which leads to the identification of biomarkers for effective nutrition solutions.
"Nestlé can apply this knowledge in the innovation of foods and beverages with probiotics to improve health and wellness," he added.
Conclusion "Significant associations between host metabolic phenotypes and a nutritionally modified gut-microbiota strongly supports the idea that changes across a whole range of metabolic pathways are the product of extended genome perturbations that can be oriented using probiotic supplementation, and which may play a role in host metabolic health," concluded the researchers.
Dr. Kochher confirmed that the team-up with Imperial College London was ongoing, and that a new five-year collaboration had recently started.
ICL's metabonomics expertise was developed for pharmaceutical applications, but the technique has since been applied to nutrition - nutrimetabonomics.
The collaboration has applied the technique to chocolate and tea and coffee, said Dr. Kochher.
Source: Molecular Systems Biology Published on-line ahead of print 15 January 2008, doi:10.1038/msb4100190 "Probiotic modulation of symbiotic gut microbial-host metabolic interactions in a humanized microbiome mouse model" Authors: F.P. Martin, Y. Wang, N. Sprenger, I. Yap, T. Lundstedt, P. Lek, S. Rezzi, Z. Ramadan, P. Bladeren, L.B. Fay, S. Kochhar, J. Lindon, E. Holmes, J.K. Nicholson