The
gut1 microbe Akkermansia muciniphila may hold the key to better
metabolic2 health and healthier body fat distribution in people who are overweight or
obese3, reveals a small study published online in the journal Gut. The microbe seems to be linked to lower levels of fasting blood
glucose4 and fats--key factors involved in the development of
diabetes5 and heart disease--and healthier distribution of body fat, the findings indicate.
In healthy people A. muciniphila makes up around 3-5% of the gut's
bacterial6 ecosystem7 and is associated with a diet rich in insoluble fibre.
The evidence to date suggests that a wide range of gut microbes and the chemical processes that sustain life--
metabolism8--have an important role in the development of
obesity9 and potentially harmful metabolic
disorders10.
A. muciniphila has already been linked to healthier glucose metabolism and leanness in mice, but it has not been clear whether this also applies to people.
The researchers therefore wanted to find out if the microbe was linked to bacterial diversity in the gut and a lower health risk profile in people who were overweight/obese.
They assessed levels of gut A. muciniphila and other bacteria, as well as fasting blood glucose and blood fats, and
indicators11 of body fat distribution--waist:hip ratio and the amount of fat beneath the skin--in 49 obese or overweight adults.
These
assessments12 were made before and after a dietary
intervention13: 6 weeks of a low calorie diet with extra protein and fibre followed by 6 weeks of a stabilisation diet. Calorie
restriction14 is known to alter the composition of gut bacteria.
They found that at the start of the dietary intervention, those with evidence of abundant A. muciniphila in their
guts15 had lower fasting blood glucose and insulin levels, a smaller waist:hip ratio, and a smaller fat cell volume beneath their skin than those with low levels of the microbe.
Those who had abundant A. muciniphila as well as a greater diversity of microbes in their gut to start with, had the healthiest metabolic profile--particularly for fasting blood glucose, triglycerides (blood fats), and body fat distribution.
After 6 weeks of calorie restriction, those with a greater abundance of A. muciniphila to start with showed stronger improvement in their metabolic profile and body fat distribution than those with lower levels.
Calorie restriction was associated with a reduction in the abundance of A. muciniphila across the board, but these levels still remained 100 times higher in people in whom the microbe was more abundant to start with.
The researchers suggest that the by-products of A. muciniphila may act as a fuel for other beneficial gut bacteria.