研究顯示 口腔細菌竟可引發腸道癌大綱

Brushing your teeth regularly could help to prevent bowel cancer, a study suggests.

一項研究顯示，定期刷牙可有助於預防腸道癌。

This is because the mouth bacteria that cause bleeding gums can travel via the blood to the bowel where they could trigger cancer or worsen existing tumours.

這是因爲，人口中有可以引起牙齦出血的細菌，而這些細菌能夠通過血液進入腸道，從而引發癌症或者惡化已有的腫瘤症狀。

The bug fusobacterium has been found to be hundreds of times more common in cancerous tumours than in normal cells. Now researchers have found that the microbes can make pre-cancerous growths in the bowel turn cancerous. They can also make any existing tumours in the bowel grow larger. Scientists are investigating how the bacteria make their way to the gut through the bloodstream.

和正常細胞相比，在惡性腫瘤細胞中發現“梭桿菌”的機率要高几百倍。現在研究人員們已經發現，這種細菌能夠使得腸道中的良性腫瘤惡化演變成爲癌症。此外，它們還會使得腸道內已經存在的腫瘤生長得更大。目前，科學家們正在研究這種細菌到底是如何通過血液循環進入腸道的。

The researchers found that the bacteria have a protein that allows them to stick to sugar molecules attached to benign growths called polyps as well as cancer tumours in the bowel. The bacteria are anaerobic – they do not breathe oxygen – so are well suited to live in the bowel.

研究人員發現，這種細菌攜帶一種蛋白質，這種蛋白質使得它們可以黏在糖分子上，從而依附在腸道內，促進息肉或者癌症腫瘤的生長。這種細菌是一種厭氧菌（不蓄意呼吸氧氣），因此它們很適合在腸道內生存。

After sticking to the polyps or tumours, the presence of the bacteria promotes their growth, according to the research published in Cell Growth and Microbe.

據這份發表在《細菌生長與微生物》雜誌上的研究來看，在附着在息肉或者腫瘤上之後，這種細菌將會促進它們的生長。

Co-author Wendy Garrett, a professor at Harvard University's TH Chan School of Public Health, said a greater understanding of the mechanism may help stop people developing cancerous tumours.

來自哈佛大學陳曾熙公共衛生學院的教授溫蒂·加勒特，是這項研究的聯合作者，她表示，對這一機制的更進一步理解有可能幫助人們不再患上癌症。

She added: 'Alternatively, and perhaps more importantly, our findings suggest that drugs targeting the same or similar mechanisms of bacterial sugar-binding proteins could potentially prevent these bacteria from exacerbating colorectal cancer.'

她補充說道：“或者，也許更加重要的是，我們的研究結果表明，如果立足於相同或者相似的細菌糖結合蛋白機制的研究，那麼就有可能防止這些細菌惡化腸癌。”

Fusobacterium worsens gum disease in the mouth because it acts as an 'anchor' around teeth and gums for other bacteria, helping to cause a biofilm – a 'mat' of different bacteria that eat away at the gums, causing inflammation, and loosening the teeth.

口腔內的梭桿菌可以惡化牙齦病，因爲這種細菌就好像其他細菌的“錨”一樣，環繞在牙齒和牙齦的周圍，從而有助於形成一個生物膜--各種細菌在這裏堆積厚厚的一層，把牙齦周圍都侵蝕殆盡，導致發炎、牙齒鬆動。

As well as worsening cancer, the bugs have also been found to worsen the bowel condition ulcerative colitis, which in turn is also linked to cancer.

除了能夠惡化癌症外，這種細菌也能夠惡化腸道環境，導致潰瘍性結腸炎，這反過來又和癌症有關。