Showing posts with label Clostridium difficile. Show all posts
Showing posts with label Clostridium difficile. Show all posts

Wednesday, July 6, 2016

This Month in Blastocystis Research (JUN 2016) - FMT Edition

From time to time, I've been touching upon the concept of faecal microbiota transplantion (FMT) in my blog posts. Now, there is a chance to familiarize yourself a lot more with this therapeutic approach to treating recurrent Clostridium difficile infection and other types of gastrointestinal diseases.

In my opinion, one of the more interesting aspects of FMT is to obtain knowledge about what microbes are actually being transferred (what microbes are allowed in stool selected for FMT?), and what are in fact the components in faecal transplants resulting in the high treatment success rates generally observed?

I dedicate this month's post to the launching of an online course in Faecal Microbiota Transplantation (FMT) supported and developed by United European Gastroenterology (UEG) in collaboration with leading Italian gastroenterologists, including Dr Gianluca Ianiro, who was recently appointed as a new member of the UEG Young Talent Group. I was lucky to involved in the editing of the course.

Targeted learners include not only gastroenterologists, but also endoscopists, internists, paediatricians, endocrinologists, surgeons, infectious disease specialists and clinical microbiologists who are interested in gut microbiota and who deal with diseases associated with gut microbiota perturbation (recurrent CDI, IBD, IBS, obesity, diabetes and other metabolic disorders).

If you wish to take the course, it can be accessed through your myUEG account.

For general information about UEG, please go here. And for more information on UEG Education, please go here.

Thursday, May 5, 2016

This Month in Blastocystis Research (APR 2016)

I thought I’d give examples of some of the Blastocystis-related activities in which I was involved in April.

I was lucky to be invited as part of the faculty for this year’s ECCMID conference in Amsterdam. I had an opportunity to give a talk on Detection of protozoans using molecular techniques in routine clinical practice (click link to watch it). I also co-authored a poster with the title Blastocystis colonization correlates with gut bacterial diversity which is one of several studies recently performed by our group that suggest that Blastocystis is a biomarker – or an indicator if you wish – of a healthy gut microbial environment and high gut microbiota diversity. 

This very topic was one of the two major topics of my colleague Lee O’Brien Andersen’s PhD work; Lee just defended his thesis this Friday and being involved in his work is some of the most interesting, rewarding, and challenging professional activities I’ve experienced so far. I will soon provide a link to an electronic version of his thesis here on this site. I hope that we will be able to fund his post doc aiming to expand his work on comparative Blastocystis genomics, since he only just started this work. Also, I hope that we will be able to do much more research on Blastocystis’ impact on host immunity and gut microbiota using in vitro and in vivo models. We need to know much more about to which extent Blastocystis can actually induce changes in bacterial communities and what these changes are. We also need to know whether manipulation of gut bacteria in a Blastocystis carrier can lead to eradication of the organism. 

Last week, I was so fortunate to oversee the production of an e-learning course in faecal microbiota transplantation (FMT) for Unite European Gastroenterology (UEG), which will probably appear online already in June. FMT is currently used primarily for treating recurrent Clostridium difficile infections, but the application range may extend far beyond this. The presentations included both theoretical and live sessions, and it was a lot of fun to do, not only because of the topic, but also because my colleagues at the Agostino Gemelli University Hospital in Rome were extremely professional, enthusiastic and well-organised. The reason why FMT is interesting in a Blastocystis context includes the fact that while there are quite standardized guidelines as to what is not allowed in donor stool, there is no consensus on what is actually allowed in the stool. Obviously, Blastocystis will often be present in donor stool, and when conventional microbiological methods are used to screen donor stool for pathogens, Blastocystis will only rarely be picked up. Hence recipients may receive stool containing Blastocystis. And so of course we would like to know whether to recommend using or excluding stool positive for Blastocystis (and other common parasites such as Dientamoeba) for FMT.

Sunday, May 5, 2013

More on 'Bugs as Drugs'

This morning, I was doing a lazy ramble through my favourite blogs and found a post by Carl Zimmer on 'Bugs as Drugs' - primarily on probiotics. And I just came to realise that there is a very interesting tendency these years of using bugs as drugs in a variety of fields.

We are all very much aware of the worries about the increase in antibiotic resistance in bacterial and other pathogens. Moreover, it appears that sometimes antibiotic treatment leads to imbalance in the intestinal microbiota (dysbiosis); a well-known example is intractable Clostridium difficile infections which can potentially lead to pseudomembranous colitis.

C. difficile infection can lead to pseudomembranous colitis
Earlier this year, an article appeared in the renowned The New England Journal of Medicine on a randomised, controlled treatment study on duodenal infusion of donor faeces for recurrent C. difficile. The researchers found that the infusion of donor faeces was significantly more effective for the treatment of recurrent C. difficile infection than the use of vancomycin, the drug usually recommended in this situation. In fact 15/16 patients had resolution of C. difficile-associated diarrhoea upon first or second infusion; however, it might be worthwhile 'shopping around' for the right donor.

And so, how are these faecal transplants developed and administered? Well, it appears that donors are volunteers who have been through a selection process based on a questionnaire on risk factors of infectious diseases. Then donor faeces is screened for parasites (including Blastocystis and Dientamoeba - yes, it warms my heart to see this so explicitly spelled out in the paper... but I wonder which methods were used - it doesn't say!) and enteropathogenic bacteria. Moreover, blood samples from donors are screened for e.g. HIV, hepatitis and antibodies against e.g. Entamoeba histolytica and Strongyloides. Next, a donor pool is created with repeated screening every 4 months. On the day of infusion, faeces is collected by the donor and immediately brought to the hospital, where it is diluted with 500 mL of sterile saline. The solution is stirred, and the supernatant strained and poured in a sterile bottle. Within 6 h after collection of the faecal sample by the donor, the solution is infused through a nasoduodenal tube (2 to 3 mintues per 50 mL). Patients are subsequently monitored for 2 h. Apparently, this is how it works!

Sunday, August 19, 2012

The Potential Role of Our Microbiome Ecosystems

For those who like these pop-sci articles on the still somewhat conjecture-like but very inspiring theories about the role of our intestinal microbiome in health and disease, here's a link to an article from The Economist (18 AUG 2012):

The Human Microbiome: Me, myself, us

And let me reiterate: We still don't know much about mikro-eukaryotes in all this... do they play a role as well? And how do they cope with different types of microbiomes?

Anyways, enjoy!

Saturday, June 9, 2012

On Faecal Bacteriotherapy

For those of you who read my most recent blog post and who went on to read Carl Zimmer's article in The New York Times about gut flora transplantation on a woman suffering from chronic Clostridium difficile diarrhoea: The concept of faecal bacteriotherapy is maybe not that new. Allegedly, it dates back to Pliny the Elder and others, who prescribed orally ingested faeces to cure maladies! Stools were, however, incinerated first, and only the ashes ingested.

Pliny the Elder and others with him allegedly recommended  ingesting the ashes of faeces to cure disease.

In less ancient times - in 1989 to be more precise - Tvede and Rask-Madsen from Copenhagen, Denmark (Statens Serum Institut and The Danish State Hospital) reported on bacteriotherapy for chronic relapsing C. difficile diarrhoea in six patients. They hypothesised that absence of Bacteroides results in chronic relapsing C. difficile diarrhoea, and that its presence may prevent colonisation by C. difficile. In the current issue of Microbe Magazine, Young and Aronoff describe some of the mechanisms that may be involved in our indigenous gut flora's ability to prevent the colonisation of potentially pathogenic bacteria such as C. difficile. These include: (1) occupying space (physically preventing contact by newly arrived microbes with the host), (2) directly impairing the growth or germination of C. diffıcile, (3) withholding nutrients or germinants from C. diffıcile, and (4) shaping the host adaptive and innate immune responses.

Hence, the concept of dysbiosis and the ideas of manipulating the gut flora in order to "restore order" have been going on for a long time. Metagenomics, however, will assist us in exploring exactly what is happening in much more detail and in a much broader and standardised context than previously possible. We will be able to predict shifts in the structure, function and interaction of microbial communities - hopefully including micro-eukaryotes such as fungi (the "mycobiome") and common protists such as Blastocystis and Dientamoeba (maybe we can call it the "protistome"?), - and any influence of diet, pro- and antibiotics.

And fortunately, the focus on metagenomics continues: While CMI just launched a themed issue on metagenomics advances (see previous blog post), even Science and Science Translational Medicine now dedicated an entire joint issue to "The Gut Microbiota", and I hope to be able to address one or two of these papers soon. Until then, here's a bit of suggested reading:

'Bugs as Drugs'

Tvede, M., & Rask-Madsen, J. (1989). Bacteriotherapy for chronic relapsing Clostridium difficile diarrhoea in six patients The Lancet, 333 (8648), 1156-1160 DOI: 10.1016/S0140-6736(89)92749-9

Young and Aronoff (2012). Clostridium difficile linked to disrupted gut microbiota. Microbe Magazine (ASM): 

Mueller, K., Ash, C., Pennisi, E., & Smith, O. (2012). The Gut Microbiota Science, 336 (6086), 1245-1245 DOI: 10.1126/science.336.6086.1245