Gut Bacteria Obesity Loop Discovered!
Recent research has shown that the gut microbiome of obese people is different from thin people, but this still poses the question of does obesity cause the difference in gut bacteria or does different gut bacteria cause obesity?
A recent study by Dr R.J. Perry and colleagues at Yale University makes the case that a high fat diet can change the gut microbiome profile. The change in gut bacteria causes an increase in acetate, a fatty acid that doesn’t usually cause any problems.
Earlier research has shown a connection between acetate and obesity, but it wasn’t until Dr. Perry’s research group used new techniques that detected increased acetate in the blood of experimental rats fed a high fat diet and the acetate was coming from the rat’s gut bacteria.
High acetate levels caused signals to the brain through the parasympathetic nervous system, which unconsciously control eating, digesting and resting. The acetate signals caused production of hunger hormones and insulin. This increased insulin production (hyperinsulinemia) and increased production of hunger hormones, all of which lead to eating more and promoting obesity.
To confirm the effect of acetate Dr Perry’s group fed rats a diet containing acetate and they found that these rats consumed twice as many calories, doubled their weight gain, experienced a threefold increase in hunger hormone production, and suffered insulin resistance and fat deposition in the liver and skeletal muscle.
According to Dr. Perry, “It is entirely reasonable to think that the high calorie consumption of the typical U.S. diet may increase gut microbiota acetate production, promoting obesity,”
I think that this research has clearly provided some valuable insight into how important our microbiome is and how important it is too have good gut bacteria. As we learn more about our gut bacteria it is clear that, although SCFA’s are a good by product of a healthy microbiome, they can also become a bad actor if they are produced in large amounts by the wrong kind of gut bacteria.