你注定就是胖子嗎？

你注定就是胖子嗎？

為什么有人怎么吃都胖不了？為什么還有人喝口涼水都長肉？一項對腸道微生物的深入研究，找到你天生是胖或是瘦的線索。

測試中可能遇到的詞匯和知識：

gut內臟；腸子；劇情[g?t]

bacteria[微] 細菌[b?k't??r??]

slender細長的；苗條的；微薄的['slend?]

gluttons酷愛…的人；貪吃的人['gl?t(?)n]

fungi真菌；菌類[?f??ɡa?]

endocrinology內分泌學[,end??kr?'n?l?d??]

ferment發(fā)酵；酵素[f?'ment]

visceral內臟的；出于本能的；粗俗的['v?s(?)r(?)l]

abdominal腹部的；有腹鰭的[?b'd?m?n(?)l]

visceral fat內臟脂肪

faeces 糞便；糟粕（等于feces）['fi?si?z]

Are you prone to obesity? The clues are in your gut bacteria（563words）

By Charles Wallace

Have you ever wondered why some people remain enviably slender while others,eating the same diet,gain weight like gluttons? Or why it is so much easier to put on weight than lose it?

The answers could lie deep in the human gut,inhabited by the 100tn bacteria,viruses and fungi that,it turns out,may affect how many calories are absorbed from your diet.

Only a few years ago these microscopic creatures were dismissed as waste products,but the microbiome is now becoming one of the hottest areas of medical research,thought to be associated with a host of health issues ranging from depression to Parkinson’s disease.

Now two fascinating studies provide clues as to how gut bacteria may be directly connected to the growing worldwide problem of obesity.

The first paper,published in the Journal of Clinical Endocrinology and Metabolism showed that lean children and young teens had a different mix of gut microbiota than their obese peers.

Nicola Santoro,a scientist in endocrinology at the Yale School of Medicine in the US and one of the study’s authors,explained a key finding: the gut microbes in the obese young people were better at fermenting digestive fibre to produce short-chain fatty acids. This suggests that overweight people accumulate more fat because their gut microbes absorb energy from food with greater efficiency — not because the obese lack willpower.

Another clue about obesity came from a paper published in Genome Biology that associated the gut microbiome with the amount of visceral fat in the body — the fat that sits around the organs in the abdominal cavity and has been linked to metabolic diseases such as diabetes and arteriosclerosis.

Michelle Beaumont,a research associate in the Twins Research and Genetic Epidemiology Department at King’s College London and the paper’s main author,said the study had found 70 per cent of the risk of obesity to be genetic.

Her research found that visceral fat was“highly heritable”and had a higher association than previously thought with the state of the microbes in faeces. But inheriting a predisposition towards obesity,she added,does not necessarily mean becoming obese.

“If you maintain a wide,healthy diet,and if you continue doing lots of exercise,even though you have genetic disposition towards obesity you won’t become obese,because you are taking in less energy than you consume,”she said.

One area the two papers agreed on is that obesity is associated with too little variety in the types of bacteria in the microbiome. Looking at the gut as an ecosystem,it can either be as diverse as the Brazilian rainforest or relatively less diverse like desert areas. Depletion of gut bacteria can be caused by too little fibre in the diet or by taking antibiotics.

While we wait for the billion-dollar probiotic pill or procedure that promises to make obese people lean,there are already ways to measure microbe diversity in the gut. You can have your own microbiome quantified through such organisations as the American or British Gut Projects,or commercial outfits like Ubiome,which serves customers around the world and charges $89 for a test kit.

In general,according to Miss Beaumont,you need to eat as many different types of plants and meats as possible,which will provide the bacteria in your body with the widest assortment of fibre to maintain your gut’s ecosystem.