ARTICLE
Microbiome diversity
and faecal transplantation :
An interview with Dr Johan Van Den Bogaerde
This article has been adapted from a podcast interview with Dr Van Den Bogaerde by Andrew Whitfield-Cook . This interview is republished with permission of FxMed .
Dr Johan Van Den Bogaerde completed his undergraduate training in South Africa with postgraduate training in the United Kingdom at Cambridge , St . Marks , and Hammersmith Hospitals . In 1998 , he was appointed professor and seconded to St . Mark ' s Hospital , where he held joint positions in the Department of Physiology , and as a consultant in the Department of Gastroenterology and Internal Medicine . He ' s held positions as conjoint senior lecturer and conjoint associate professor with the University of New South Wales and still maintains links with his local University of the Sunshine Coast , Queensland . Dr Van Den Bogaerde believes gastroenterology is an exciting and important field and has very broad interests , including the study of the microbiome , oesophageal pathology , motility disturbances , inflammatory bowel disease , and functional bowel disease .
Johan : It ' s extraordinary what is going on in the gut and the extraordinary new stuff coming out is absolutely amazing . They ' ve very recently described a new complete branch of organisms in the gut , called the ‘ CPR branch ’. Now , to think about a branch of animals , it ' s really important that the one branch is the eukaryotic branch , which includes plants , animals , all multi-cellular organisms . Then you get bacteria as a second branch . And then you get archaea or archaic type of bacteria as a third branch . And now the fourth branch is the CPR branch , which is a completely different type of bacterial structure . It ' s a tiny bacterium , and it represents 30 % to 40 % of bacterial diversity . And we ' ve only recently discovered this and discovered that this is actually present in the gut ... If you look at the microbiome literature there ' s more than 17,000 publications at the moment and growing as you say , every day . The microbiome is not simply the gut . It includes seven different types of microbiomes , including the lung , the skin , the oral , the vaginal , the penile . The skin microbiome , for instance , contains 10 million organisms per centimetre of skin . So we are in fact , host to very common organisms that we ' ve known about for a long time . But we ' re also host to viruses , fungi , and organisms , which are completely unknown to science and are only now being discovered .
Andrew : Every day , there is a new discovery in our microbiota / microbiome , which we need to take heed of . I think it poignantly shows us just how little we know about our gut . But let ' s delve a little bit into , at least something that we know of , and that ' s the rest of the microbiota , not just the bacteria , but the fungi , the bacteriophages , and viruses . Can you tell us a little bit about how much they comprise , what do we know , and what don ' t we know ?
Johan : So , when you look at the organisms in a typical human gut , we know that our bodies have 30 trillion cells . And there ' s approximately 39 trillion , let ' s say ‘ other cells ’ in our gut . So , the bacteria and the organisms in the gut outnumber our body cells , and certainly , their genes outnumber our body cells by 100 to 1 at least , because each of these has a different genetic component . Viruses and phages are filled in the gut and funguses are also all over in the gut . We have no real idea how these work . We know that some bacteria control fungi , so for instance some of your bacteria will produce
32 | vol27 | no1 | JATMS