Enzyme May Be a Key in Fat Absorption, Study Finds

March 23, 2009

An enzyme found in human intestines that helps absorb fat may be the key to actually reducing it.

An enzyme found in human intestines that helps absorb fat may be the key to actually reducing it.

The enzyme acyl CoA—monoacylglycerol acyltransferase 2, or Mgat2—acts as a catalyst for a critical step in the production of triglyceride. Robert V. Farese, Jr, MD, and colleagues at the Gladstone Institute of Cardiovascular Disease used mice that were genetically modified to lack Mgat2 to test the enzyme.

The mice lacking Mgat2 remained “normal” on a low-fat diet, according to the Gladstone release. When fed a high-fat diet, the mice still did not gain weight nor develop other complications of obesity, such as glucose intolerance, hypercholesterolemia, or fatty livers. The number of calories these mice took in was the same as other normal mice, and were all fully absorbed.

The researchers said that the lack of Mgat2 could lessen the uptake of fat in the small intestine, delaying the fat’s arrival in the bloodstream. This process “may dissociate fat from carbohydrate absorption and insulin secretion and ultimately lower the amount of fat stored and used.”

Though it was not clear to the researchers how this happened, one idea that they’ve theorized is “that the absorbed fat is partitioned more to tissues where it is burned up.”

“Differences in Mgat2 expression may contribute to the propensity of some people to gain weight from diets rich in fat,” said Eric Yen, PhD, lead author of the study. “Our findings suggest that inhibiting this enzyme in the small intestine might be an effective way to treating metabolic diseases that result from excessive fat intake.”

Findings of the study were published in the current issue of the journal Nature Medicine.