糖的隱藏力量：替代抗生素治癒傷口
在津巴布韋東部高地農村地區長大的窮孩子穆蘭多（Moses Murandu），從小習慣摔跤受傷或有割傷時，用鹽來擦拭創面。不過有時走運的話，他父親多花些錢能買對傷口刺激小得多的東西——糖。
穆蘭多一直留意到，傷口上用糖時比什麼都不用時癒合得較快。因此，1997年當他受僱在英國國民醫療服務體系（NHS）機構當護理師時，他很驚訝糖並沒有被用作任何官方醫療手段，他有了改變這一現狀的念頭。
如今，穆蘭多的想法終於受到到重視了。穆蘭多現是伍爾弗漢普頓大學（University of Wolverhampton）成人護理系的高級講師，他完成了一項初步試驗性研究。該研究主要聚焦於糖在傷口癒合中的應用，並在2018年3月獲得了《傷口護理雜誌》（Journal of Wound Care）的獎項。
在世界上一些地方，這種治療手段可能非常關鍵，因為那兒很多人買不起抗生素。在英國，這種方法也同樣引發了關注。因為一旦傷口感染，抗生素有時並不起作用。
穆蘭多說，用糖來治療傷口就是把糖灑在傷口上，再纏上繃帶。糖分顆粒會吸走傷口上的水分，而細菌需要水分才能繁殖。沒有了細菌，傷口便能更快癒合。穆蘭多在實驗室的研究為此提供了依據，而越來越多來自全球各地的案例研究也支持他的發現，其中也包括許多用糖治癒抗生素耐藥性傷口的成功案例。即便如此，穆蘭多仍面臨著艱巨的挑戰——獲得後續研究的資金支持以實現終極目標，說服英國國民醫療服務體系使用糖作為抗生素的替代方案。然而，大部分的醫學研究由製藥公司提供贊助。穆蘭多認為，這些公司通常不會贊助他們無法獲得藥物專利權的研究，因為無利可圖。
穆蘭多的研究中所使用的糖就是最普通的顆粒狀砂糖，人們日常喝茶調味的那種。他也發現，體外試驗時使用甘蔗糖或甜菜糖，本質上差別不大，而使用金砂糖（紅糖的一種）效用則不顯著。
實驗性研究表明，菌株可以在低純度糖環境中繁殖，但高純度糖會抑制菌株生長。穆蘭多記錄了在津巴布韋、博茲瓦訥、萊索托（他最初接受護理訓練的地方）等國家的多個臨牀案例。其中的一個案例中，患者是一名住在哈拉雷（津巴布韋首都）的女性。
他介紹說，「我外甥給我打電話時，這位女患者已經做了殘端測量，要進行截肢手術了。她的傷口非常嚴重，長達五年之久。醫生建議截肢。我指導她先清洗傷口，然後在上面敷糖，留置一段時間，再重覆。」
「這名患者的腿最終保住了。」
他說，這個案例也反映出為何「糖療法」會在很多地方備受關注，特別是一些人們買不起抗生素的國家和地區。穆蘭多在英國地區共開展了41宗臨牀案例研究。目前他還沒發表試驗結果，但已在一些英國或國際會議上做了相關分享。研究中，他無法規避的一個問題是，這種"糖療法"是否也適用於糖尿病患者？糖尿病患者常患有腿部或足部潰爛，但他們又需要控制血糖值。表面上看，這種方法對糖尿病患者並不適用。
但穆蘭多發現，糖尿病患者也可以使用"糖療法"且血糖水平不會升高。他說，「治療中使用的糖是蔗糖（一種雙糖），在酵素的催化才會轉化為葡萄糖（單糖）。」而蔗糖酵素是人體體內才有的，糖被人體吸收後才會轉化。將糖外用在傷口上，並不會產生同樣的轉化。
穆蘭多在英國繼續其人類患者臨牀試驗之時，在大西洋彼岸的美國一位獸醫麥克邁克爾（Maureen McMichael）已用這種方法治療動物好多年。
在伊利諾大學獸醫學院附屬醫院工作的麥克邁克爾，於2002年首次在動物傷口上使用糖和蜂蜜。她說，這種療法方法簡單且價格低廉。對於付不起常規治療方法的診療費與鎮定劑等藥物費用的寵物主人，非常有吸引力。
麥克邁克爾談到，他們一直在手術中使用糖和蜂蜜，經常用於貓、狗等寵物的治療，偶爾也以此治療農場牲畜。蜂蜜的治癒效用與糖相似。有一項研究表明蜂蜜比糖更能抑制傷口細菌繁殖，只是蜂蜜價格較貴。麥克邁克爾介紹道，「這種療法的成功案例非常之多！」其中一個臨牀案例是一條被治癒的流浪狗。它是一種訓練比特鬥牛犬的誘餌犬，身子被吊起來，讓一隻受訓的比特鬥牛犬攻擊。它被送來時，每條腿上多達四十處咬傷，但八周後它就痊癒了。
麥克邁克爾說： 「因為它是一隻流浪狗，沒有主人付錢治療。我們用蜂蜜和糖幫它敷傷口，它的恢復能力驚人，現在都已經痊癒了。」
除了價格低廉外，「糖療法」區別於抗生素治療的另一個好處是，使用抗生素次數越多，人體產生的抗藥性越強。
麥克尼爾（Sheila MacNeil）是英國謝菲爾德大學的一名人體組織工程學的專家。她的研究方向之一是人體自然產生的糖分如何促進血管再生。這個研究來自於她對腫瘤的研究。她發現某種從DNA分解提取出來的特殊糖分（2-脫氧-d-核糖）會不斷再生。據麥克尼爾發現，團隊實驗人員將這種單糖放置於雞胚胎薄膜中，它促進了血管細胞的再生，細胞數量比沒有糖分的對照組要高出一倍。
當然，我們身體中自然產生的這些糖與穆蘭多研究中日常使用的糖的類型完全不同。麥克尼爾說，「最理想的結果」當然是能夠找到一種既能治癒傷口又能促進細胞再生的糖。她認為這是下一步研究的目標。
目前在伍爾弗漢普頓大學的穆蘭多計劃開一家使用這種「糖療法」的私人診所。他希望未來糖作為傷口癒合劑不僅在英國國民醫療服務體系的機構裏廣泛使用，在他工作過的其他一些國家的公立醫院也能得到應用。如今的他常常收到來自世界各地的郵件，徵求診療意見。他也會通過郵件或短信的形式遠程指導患者。遠在其他地區的患者會在痊癒後發來療癒的照片，並對他表示感激之情。
用糖治癒傷口是一種古老的療法，也是許多發展中國家窮人非正式使用的方法。但對穆蘭多來說，他到了英國才意識到糖在醫學界的意義。他把這視作是他將故鄉津巴布韋的「土智慧」與英國現代研究設施的一種結合。
他說，「就像糖一樣，這些知識是原在津巴布韋土生土長，但在英國『提純』，再回到非洲去幫助那裏的人們。」
As a child growing up in poverty in the rural Eastern Highlands of Zimbabwe, Moses Murandu was used to having salt literally rubbed in his wounds when he fell and cut himself. On lucky days, though, his father had enough money to buy something which stung the boy much less than salt: sugar.
Murandu always noticed that sugar seemed to help heal wounds more quickly than no treatment at all. So he was surprised when, having been recruited to come to work as a nurse for the UK’s National Health System (NHS) in 1997, he found that sugar wasn’t being used in any official capacity. He decided to try to change that.
Now, Murandu’s idea finally is being taken seriously. A senior lecturer in adult nursing at the University of Wolverhampton, Murandu completed an initial pilot study focussed on sugar’s applications in wound healing and won an award from the Journal of Wound Care in March 2018 for his work.In some parts of the world, this procedure could be key because people cannot afford antibiotics. But there is interest in the UK, too, since once a wound is infected, it sometimes won’t respond to antibiotics.
To treat a wound with sugar, all you do, Murandu says, is pour the sugar on the wound and apply a bandage on top. The granules soak up any moisture that allows bacteria to thrive. Without the bacteria, the wound heals more quickly.
Evidence for all of this was found in Murandu’s trials in the lab. And a growing collection of case studies from around the world has supported Murandu’s findings, including examples of successful sugar treatments on wounds containing bacteria resistant to antibiotics. Even so, Murandu faces an uphill battle. Funding for further research would help him reach his ultimate goal – to convince the NHS to use sugar as an alternative to antibiotics. But a great deal of medical research is funded by pharmaceutical companies. And these companies, he points out, have little to gain from paying for research into something they can’t patent.
The sugar Murandu uses is the plain, granulated type you might use to sweeten your tea. In the same in vitro trials, he found that there was no difference between using cane or beet sugar. Demerara, however, wasn’t as effective.
The pilot showed that strains of bacteria grew in low concentrations of sugar but were completely inhibited in higher concentrations. Murandu started recording case studies in Zimbabwe, Botswana, and Lesotho (where he first trained in nursing). Included among them is a woman living in Harare.
“The woman’s foot had been measured, ready to be amputated, when my nephew called me,” Murandu says. “She had had a terrible wound for five years, and the doctor wanted to amputate. I told her to wash the wound, apply sugar, leave it and repeat.
“The woman still has her leg.”
This, he says, is one example of why there is so much interest in his methods, particularly from parts of the world where people can’t afford antibiotics.
In total, Murandu has now carried out clinical studies on 41 patients in the UK. He hasn’t yet published the trial results but has presented them at national and international conferences. One question he had to answer during his research was whether sugar could be used on diabetic patients, who commonly have leg and foot ulcers. Diabetics need to control the level of glucose in their blood so this isn’t an obvious healing method to use on them.
But he found that it worked for diabetics without sending their glucose levels soaring. “Sugar is sucrose – you need the enzyme sucrase to convert that into glucose,” he says. As sucrase is found within the body, it is only when the sugar is absorbed that it is converted. Applying it to the outside of the wound isn’t going to affect it in the same way.
While Murandu continues his research on human patients, across the Atlantic US veterinarian Maureen McMichael has been using this healing method on animals for years.
McMichael, who works at the University of Illinois Veterinary Teaching Hospital, first started using both sugar and honey on pets back in 2002. She said it was a combination of the simplicity of the method and the low cost that attracted her – especially for pet owners who couldn’t afford the usual methods of bringing the animal to the hospital and using sedation.
McMichael says that they keep both sugar and honey in their surgery and often used it on dogs and cats (and occasionally on farm animals). Honey has similar healing properties to sugar (one study found it to be even more effective at inhibiting bacterial growth), though it is more expensive.
“We have had some really great successes with this,” McMichael says. She gave an example of a stray dog that had come to them after being used as “pitbull bait”, hung from a harness and attacked by pitbulls being trained for fighting. The dog came in with up to 40 bite wounds on each limb – and was healed within eight weeks.
“She was a stray so there was no money for her. We treated her with both honey and sugar and she did fabulously,” McMichael says. “She’s all healed now.”
As well as being cheaper, sugar has another upside: as more and more antibiotics are used, we are becoming resistant to them.
As well as being cheaper, sugar has another upside: as more and more antibiotics are used, we are becoming resistant to them
Back in the UK, tissue engineering specialist Sheila MacNeil of the University of Sheffeld has researched how naturally occurring sugars can be used to stimulate the re-growth of blood vessels. Her research stemmed from from her work on tumours, when she noticed that one particular small sugar derived from the breakdown of DNA (2-deoxy-D-ribose) kept cropping up. MacNeil’s team experimented by applying this sugar to the membrane surrounding chick embryos. According to MacNeil, the sugar stimulated double the number of blood vessels than would grow without it.
But of course these types of naturally occurring sugars found in our bodies are a long way from the type of everyday sugar used by Murandu in his experiments. The “dream ticket”, MacNeil says, would be to find a sugar that could be used in both ways. She believes this is the next step research should take.
Meanwhile in Wolverhampton, Murandu’s plan is to set up a private clinic using his sugar method. He hopes that one day sugar will be commonly used, not only by the NHS but also at public hospitals in some of the other countries where he has been working. He continues to get regular emails from around the world, asking for his advice – and guides patients remotely over email and texting. His far-away clients send him photos of their results along with their gratitude when they are healed.
It is an ancient method and one used unofficially by many poor people in developing countries, but for Murandu it was only by coming to the UK that he realised the significance sugar could have in the medical world. He sees it as a blending of his local knowledge with the modern research facilities in Britain.
“Like sugar, the knowledge came raw from Zimbabwe, was refined here – and is now going back to help people in Africa,” he says.
