Balancing your gut bugs

MouseCould those so-called “bio” yogurts and milk-type drinks with Scandinavian sounding names actually do you any good? Possibly.

According to a study published in the journal Molecular Systems Biology this week, microbial flora in the gut can profoundly affect how you absorb nutritients from your food and your overall health. Jeremy Nicholson and colleagues at Imperial College London suggest that keeping a balanced gut flora may prove important to prevent some human metabolic diseases. Those active yogurts and one-day milk substitutes containing live microbes could play a role in helping you maintain the balance.

Our guts are an internal ecosystem all their own. Quite bizarrely, the microbial community living in our intestines has 100 times as many genes as the whole of the human genome. It is almost as if those living inside you outrank you yourself. However, we rely on these microbes for the normal processes of digestion and waste disposal just as much as the microbes themselves need the lining of our intestine as their stamping ground. We, and all other mammals, are not so much individuals as “superorganisms”, a collective, a symbiotic biological system.

Nicholson and his team used metabolic profiling techniques to monitor changes in bile acid composition and lipid (fatty molecule) metabolism in mice whose gut flora had been replaced by human bacterial flora. Perhaps not surprisingly, the mice showed alteration in the composition of their bile acids and circulating lipoprotein levels, and displayed symptoms such as lipid accumulation in the liver that would eventually lead to disease. Closer inspection of the mouse gut, revealed that the human gut microbes could not form a strong and stable ecosystem.

Nicholson’s findings demonstrate that gut microbes control the absorption and storage of nutrients from our food and help us harvest its energy. They also show that the wrong type of microbes can lead to disease by affecting the chemical and metabolic balance of the gut and liver.

So, should you drink those liquid bio yogurts? If you can pronounce them easily then there is probably no harm in asking for them at your healthfood store, but the message is clear: steer well away from mice.