Mannose's unexpected effects on the microbiome and weight gain

September 18, 2018, Sanford Burnham Prebys Medical Discovery Institute
Hudson Freeze, Ph.D., director and professor of the Human Genetics Program at Sanford Burnham Prebys Medical Discovery Institute (SBP). Credit: Sanford Burnham Prebys Medical Discovery Institute (SBP)

Scientists continue to unravel links between body weight and the gut microbiome. Now, researchers from Sanford Burnham Prebys Medical Discovery Institute (SBP) report an unexpected finding: mice fed a fatty diet and mannose, a sugar, were protected from weight gain, leaner, and more fit—and this effect tracked with changes in the gut microbiome. The study published today in Cell Reports.

"Obesity and related diseases, such as nonalcoholic steatohepatitis (NASH), are on the rise—and scientists are on the hunt for new treatments, particularly for individuals who are unable to exercise," says Hudson Freeze, Ph.D., senior author of the paper and director and professor of the Human Genetics Program at SBP. "Better understanding of mannose's effects on the may lead to new therapies for treating obesity."

Freeze and his team were studying mannose in the context of a rare disease called a congenital disorder of glycosylation (CDG). People with a specific form of the disease can be treated with mannose. While conducting their research, the scientists observed the anti-obesity effects of mannose feeding.

A closer look revealed the mice were also protected from typical negative effects of a fatty diet. They had less body fat, reduced fat in their liver, stable blood sugar—and even improved fitness. Surprisingly, these benefits were only seen when the mice received mannose early in life—older mice didn't benefit from mannose.

"The gut is very dynamic in early life," says Vandana Sharma, Ph.D., lead author of the paper and staff scientist in Freeze's laboratory. "Because only young mice that received mannose exhibited leaness, we thought the microbiome might be involved."

Despite eating the same amount of , mannose-fed mice absorbed fewer nutrients-and instead excreted them. Further work showed the gut microbial composition mirrored that of lean mice fed a regular diet. When mannose was removed, the mice on the regained weight, and their gut microbiome composition shifted to resemble that of the that ate fatty food but didn't receive mannose. The scientists also found that the gut microbes of the mannose-fed were less efficient at processing carbohydrates—an energy source.

"These findings further confirm the important role of the gut microbiome in metabolism," says Freeze. "The microbiome partially explains the beneficial effects of mannose, but how exactly it affects the body's metabolism remains a mystery."

Explore further: Regardless of weight, mannose levels point to diabetes risk

More information: Cell Reports (2018). DOI: 10.1016/j.celrep.2018.08.064

Related Stories

Regardless of weight, mannose levels point to diabetes risk

June 27, 2016
Even if you are not overweight, your mannose levels may indicate whether you're at risk for type 2 diabetes (T2D) or insulin resistance (IR), a Swedish study shows.

Depleting microbiome with antibiotics can affect glucose metabolism

July 23, 2018
A new study from the Salk Institute has found that mice that have their microbiomes depleted with antibiotics have decreased levels of glucose in their blood and better insulin sensitivity. The research has implications for ...

Researchers uncover potential new role of long noncoding RNA in fatty liver disease

July 30, 2018
Scientists at the University of Michigan Life Sciences Institute have uncovered a potential new role for long noncoding RNA in obesity and nonalcoholic fatty liver disease—an accumulation of too much fat in the liver that ...

Gut microbes may contribute to depression and anxiety in obesity

June 18, 2018
Like everyone, people with type 2 diabetes and obesity suffer from depression and anxiety, but even more so. Researchers at Joslin Diabetes Center now have demonstrated a surprising potential contributor to these negative ...

Recommended for you

New inflammation inhibitor discovered

November 16, 2018
A multidisciplinary team of researchers led from Karolinska Institutet in Sweden have developed an anti-inflammatory drug molecule with a new mechanism of action. By inhibiting a certain protein, the researchers were able ...

Gut hormone and brown fat interact to tell the brain it's time to stop eating

November 15, 2018
Researchers from Germany and Finland have shown that so-called "brown fat" interacts with the gut hormone secretin in mice to relay nutritional signals about fullness to the brain during a meal. The study, appearing November ...

Brain, muscle cells found lurking in kidney organoids grown in lab

November 15, 2018
Scientists hoping to develop better treatments for kidney disease have turned their attention to growing clusters of kidney cells in the lab. One day, so-called organoids—grown from human stem cells—may help repair damaged ...

How the Tasmanian devil inspired researchers to create 'safe cell' therapies

November 15, 2018
A contagious facial cancer that has ravaged Tasmanian devils in southern Australia isn't the first place one would look to find the key to advancing cell therapies in humans.

Researchers discover important connection between cells in the liver

November 15, 2018
University of Minnesota Medical School researchers have made a discovery which could lead to a new way of thinking about how disease pathogenesis in the liver is regulated, which is important for understanding the condition ...

Precision neuroengineering enables reproduction of complex brain-like functions in vitro

November 14, 2018
One of the most important and surprising traits of the brain is its ability to dynamically reconfigure the connections to process and respond properly to stimuli. Researchers from Tohoku University (Sendai, Japan) and the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.