'Nanners and Rummy Raisin Ice Cream"' by ulterior epicure under a CC license |
The interesting thing is that the more we look into our intestinal population the more links we find between their existence and our lives. Yesterday, the New Scientist was highlighting research findings on rats, which suggest that the composition of the gut flora has an effect on appetite, initially, and, later on, changes in the body weight: Changing the gut flora of obesity-resistant rats to that of the obesity-inclined one increased the appetite, firstly, and the weight, secondly, of the former.
Weight changes and the composition of the gut flora is nothing new. In 2006, the New Scientist featured a corresponding article. It was based again on research carried out on mice. That time they compared normal μmice with ones that had been living in sterile conditions and, thus, had no microorganisms within their digestive track. Those mice tended to stay slim. Having their gut populated by the flora of the normal mice lead to a body weight increase of about 25%. If the flora used was similar to that of obese mice, the weight gain was much higher. That observation was attributed to the effect of the gut flora on the food that passes via the intestines; the microorganisms living there help metabolize it more efficiently, thus producing more energy the mass unit than without their intervention. The more efficient the microorganisms are, the higher the weight gain for mice.
Combining the two observations there are several questions that come to mind:
- Let's assume that gut flora that is more efficient in processing the food we normally eat leads to us getting more calories out the food. Temporarily, that will lead to weight increase unless we either reduce our food intake or increase our physical activity. However, it is suggested in the 2012 article that the appetite (of rats) is enhanced. Does this mean that the flora microorganisms mess with the energy intake - appetite mechanism of the host? And if yes, is that a temporary effect? What pathway does it messes up with?
- Since the gut flora lives on what food we consume and on the metabolites secreted by our cells, locally, do they have any mechanism to "encourage" us to eat the food that is most nutritious to them? I don't necessarily refer to "mind-control" but to any pleasant or unpleasant symptom that may encourage or discourage us from eating stuff that "tastes" nice or not-so nice, respectively, to our intestinal guests.
- Is it possible to sustainably change one's gut flora in such a way that it will lead to better weight control? Can this be done in a safe way? What will be the catches (because, surely, there will be at least one downside!)?
'Strawberry Panna Cotta' by Matthew S. Cain under a CC license |
Ice-cream is a good example. The idea has been explored a few years ago and there seems to be little concern for technological limitations. Household-oriented recipes have also been available for - say - yoghurt ice-cream or more exotic stuff, such as kefir-based chocolate ice-cream.
Having said that, I find the path of "slimming" foods to be a potentially slippery one. Regardless of how pleasant the thought is of devouring tons of yummy ice-cream and, still, lose weight, the wise thing to do is seek for a healthy, balanced diet and live a life with plenty of physical activity. And then, why not, enjoy the occasional scoop or two of our favourite dairy vice....