A mushroom used in Chinese medicine for more than 2,000 years may help conquer obesity by changing the bacteria in the gut. The mushroom Ganoderma lucidum, known to Chinese herbalists as Lingzhi and in Japan as reishi, has been used in traditional medicine to treat asthma, diabetes, and heart problems.

Researchers at Taiwan's Chang Gung University divided mice into two groups. One group was fed a high-fat diet, while a second group received the same diet but were also fed a high dose of the mushroom extract.

After two months, mice that were fed only the high-fat diet reached a weight of 42 grams. Those mice on the high-fat diet with the addition of the mushroom extract weighed only 35 grams.

The researchers found that with the high fat diet, levels of gut bacteria changed and became imbalanced, which led to weight gain. The second group's gut microbes were still in balance. Researchers believe the process is similar in humans.

"Our study shows that G.lucidum mycelium prevents dietary-induced obesity and alleviates inflammation by modulating the composition of the gut microbiota and maintaining intestinal barrier integrity," the researchers said, according to the BBC.

A third group, which ate a normal diet throughout the experiment, remained the slimmest of all three groups, leading experts to emphasize that the mushroom wasn't a magic bullet for weight loss, but should be used in conjunction with traditional methods.

"The microbiome is certainly a key player in weight gain and weight loss, and it's certainly involved in extracting energy from our food," Colin Hill, a microbiologist at Ireland's University College Cork, told the BBC.

"But no intervention will overcome someone drinking lots of fizzy drinks, there won't be a magic pill, and no mushroom extract in a can of coke will help people lose weight."

"Given the good safety records of Lingzhi, and the fact that it is similar in composition to other mushrooms that we consume regularly, Lingzhi may be considered by the general population as a convenient strategy to lose weight, along with other known approaches, such as calorie restriction, regular exercise and a healthy lifestyle," said study co-author John D. Young, according to the BBC.