Researchers at Vanderbilt University in Nashville, Tennessee have raised hopes for the possibility of developing of a probiotic to treat obesity and other chronic diseases. The team inhibited weight gain, insulin resistance and various other negative health effects of a high-fat diet in mice by modifying bacteria to produce a therapeutic compound in the gut.
With previous studies having demonstrated that so-called "good" bacteria naturally found in the gut plays a role in obesity, diabetes and cardiovascular disease, Sean Davies, Ph.D., an assistant professor of Pharmacology at Vanderbilt, set out to see if it was possible to manipulate gut microbiota to promote health.
Davies and his team started with E. coli Nissle 1917, which is a safe bacterial strain that colonizes the human gut and has been used as a probiotic treatment for diarrhea for nearly 100 years. They then genetically modified the strain to produce a lipid compound called NAPE, which is normally synthesized in the small intestine when it processes fat and suppresses appetite.
After the NAPE-producing bacteria were added to the drinking water of mice fed a high-fat diet for eight weeks, the researchers found they had dramatically lower food intake, body fat, insulin resistance and fatty liver compared to mice that received control bacteria.
At least four weeks after the NAPE-producing bacteria were removed from the drinking water. the protective effects persisted, with the mice still having a much lower body weight and body fat compared to the control group some 12 weeks after the NAPE-producing bacteria were removed. This is despite no active bacteria persisting after about six weeks. However, Davies says the ultimate goal is to have a one off treatment.
"This paper provides a proof of concept," he said. "Clearly, we can get enough bacteria to persist in the gut and have a sustained effect. We would like for that effect to last longer."
The approach may also provide a way to deliver to therapeutics to parts of the body outside the gut, with the team also observing effects of the NAPE compound in the liver.
"Of course it’s hard to speculate from mouse to human," added Davies. "But essentially, we’ve prevented most of the negative consequences of obesity in mice, even though they’re eating a high-fat diet."
Before it can move onto human studies, the team says it needs to address regulatory issues related to containing the bacteria, such as knocking out genes required for the bacteria to live outside the host.
The team's paper is published in the Journal of Clinical Investigation.
Source: Vanderbilt University
I have also had a glimpse of the future that "Richness of human gut microbiome correlates with metabolic markers"[a] touches on but I expect they under estimate as the tools to fully comprehend the diversity of the number of different organisms in our gut isn't fully developed.
We expect a great deal from this information. I think we underestimate the effect what the micro-flora of our gut does for us.
Gordon
a. http://www.nature.com/nature/journal/v500/n7464/abs/nature12506.html
Another interesting finding was that we know stomach stapling leads to weight loss, what has now been discovered is that somehow it also doubles the gut biome to the level of thin people, why this occurs is still being studied.
There has been some research showing a fecal transplant from a thin person will increase the biome in a fat person and lead to loosing weight.
Overweight people have always been blamed for lack of self control and relegated to a second class status, so if the science has largely disproved this, where will people find another "whipping boy" to look down on and make jokes about?
I think this could really be a great thing, however, if some people would move away from high-fat diets their guts would greatly improve themselves without adding synthetic medications. I know mine has. We recently moved to a more vegetable/fruits/low carb diet and it has greatly improved our overall health.