Obesity is associated with the intestinal microbiota in man but the underlying mechanisms are yet to be fully understood. Our previous phylogenetic study showed that the faecal microbiota profiles of non-obese versus obese and morbidly obese individuals differed. Here, we have extended this analysis with a characterisation of the faecal metaproteome, in order to detect differences at a functional level.
The researchers describe this as “the chicken-or-the-egg question”: Is the microbiota causing a difference in metabolism that leads to an energetic misbalance, or are differences in metabolism and/or eating habits causing a change in microbiota?
It is like a very fast form of evolution going on in there. As you eat a certain type of food, the bacteria that is best suited to thrive off of that food will reproduce like crazy. So the more you eat of something, the better you get at processing it. This means two things: eat like crap, and your body gets better at absorbing all of that shit (that’s bad). But if you eat healthy, even though your body may fight it initially, eventually it will refine itself to process the healthy food (that’s good).
This research unfortunately doesn’t lead immediately to any kind of clinical recommendation. What it does suggest is that what the bacteria in one’s gut are doing, and what genes they express, is more diagnostically relevant than who they are–so hopefully by focusing on this distinction, future research could more quickly come up with an answer to how to manage weight.
Scientists have known for a while that gut bacteria can play a profound role in the weight of mice. Now we have a case report in humans that is not entirely surprising: A woman gained 36 pounds and became obese in the 16 months after a fecal transplant.
…It’s impossible to draw conclusions from any single patient, of course, but this case is interesting against the broader context of what we know about the gut microbiota and weight. A decade of studies in mice have found that those implanted with the gut microbiota of obese humans will become obese, too, despite eating the same diet as those given the microbiota of non-obese humans. Gastric bypass surgery in mice also drastically shifts the gut microbiota, and it could be one reason for why the surgery is so effective for losing weight.