Showing posts with label gastroenterology. Show all posts
Showing posts with label gastroenterology. Show all posts

Wednesday, June 30, 2021

Personal Post-Conference Thoughts on Future Blastocystis Research

I'm still on a high after the 3rd Int'l Blastocystis Conference! The Scientific Committee is in the process of putting together a TrendsTalk paper for Trends in Parasitology to provide a brief summary of the different topics presented at the conference, including some important updates.

I personally think Blastocystis research has come a long way since I entered the field back in 2004, but I would like to call for more cross-disciplinary approaches to studying the parasite.

In particular, we need to stimulate a research interest in bioinformaticians, vets, food microbiologists, and gastroenterologists.

The bioinformatics people should help us analyze NGS data (shotgun, metabarcoding) and provide some robust and  guidelines for cut-offs for e.g. Blastocystis positivity and negativity in NGS data.

Vets should be interested in studying the differences in Blastocystis colonization across different animal populations and find out what drives colonization and the impact is has on the host and host gut microbiota. Studying the relationships of these microbes in animals can help us understand these relationships in humans. Vets should help us find out why Blastocystis is so common in ruminants and so rare in carnivores.

To this end, food microbiologists should take an interest to study associations and interactions between Blastocystis, the gut microbiota and the host. Including metabolomics. Diet as a driver of colonization should be investigated.

Finally, gastroenterologists should take an interest in Blastocystis to identify its positive or negative association to various GI diseases (IBS, IBD, microscopic colitis, coeliac disease, diverticulosis, colon cancer, etc, etc.)

We should take advantage of the fact that Blastocystis is one of the few intestinal parasites that can easily be cultured, which means that cells can be used for in vivo and in vitro experiments. Protocols should be developed for encystment, and cyst production on a larger scale should be enabled, since cysts can be used for oral administration. 

The current shift in paradigm that reflects the recognition of Blastocystis as marker of intestinal eubiosis could be supported and expanded by increasing the involvement of these types of professions.

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.

Monday, June 13, 2016

This Month in Blastocystis Research (MAY 2016)

Very much belated, I'm back to give you the MAY entry of the 2016 "This Month in Blastocystis Research" blog series.

I'm basically just going to highlight a few papers and some other interesting things.

Ever since our metagenomics paper came out, it's as if the interest in Blastocystis in a gut microbiota context is exploding. If you put "Blastocystis microbiota" into the search box in PubMed, today you will get 20 hits, most of which papers are extremely interesting and of course very central to this type of research. Given the number of times I've addressed the relevance of studying Blastocystis in relation to gut microbiota diversity on this blog, I'll try not to flog it to death this time!

Over at Gut Microbiota For Health, a blog was posted a week ago summarising the recent findings of Audebert and colleagues and comparing them to data coming out from our lab. You can read the blog here. Using the Ion Torrent PGM sequencing platform, 16S rDNA gene sequencing was performed on genomic DNAs extracted from Blastocystis-positive and - negative stool samples. What Audebert hypothesised was that if Blastocystis is associated to intestinal disease such as for instance diarrhoea, one would expect to find a higher degree of microbiota perturbation (dysbiosis) in Blastocystis carriers than in non-carriers. Meanwhile, and similar to what we have have published, they reported that gut microbiota diversity is higher in Blastocystis carriers than in non-carriers, indicating that Blastocystis is generally a marker of a healthy gut microbiota rather than a perturbed one. Again similar to what we found in the metagenomics paper, Audebert et al. saw that the bacterial families Ruminococcaceae and Prevotellaceae were also more abundant in carriers than in Blastocystis-negative patients, while Enterobacteriaceae were enriched in Blastocystis-negative patients. What is also really interesting is the fact that the genera Faecalibacterium and Roseburia had a significantly higher abundance in Blastocystis-positive patients. These genera contain bacteria that produce butyrate which has a lot of important and beneficial functions. Loss of butyrate producers is seen for instance in patients with inflammatory bowel disease. The group used some of the same methods as we used in our study presented recently at ECCMID, including rarefaction analysis and calculation of Chao1 indices.

Together with colleagues at the Technical University of Denmark, we were lucky to have The European Journal of Clinical Microbiology and Infection publish our novel data on associations between common single-celled intestinal parasites--Blastocystis and Dientamoeba--and groups of intestinal bacteria, as evidenced by qPCR assays. We confirmed the findings from our metagenomics study, by finding a relatively lower abundance of Bacteroides in the parasite-positive samples than in the -negative ones.

By the way, on the Gut Microbiota For Health site you will find an e-learning course on Microbiota provided by the Gut Microbiota and Health Section of the European Society of Neurogastroenterology and Motility (ESNM) and developed for gastroenterologists.

Speaking of e-learning and gastroenterology: For a couple of years, I've had the immense pleasure of being part of the United European Gastroenterology e-learning task force. We host a resource - UEG Education - developed mainly for gastroenterologists, boasting e-learning courses, "Decide-on-the-Spot" series, "Mistakes in..." series, blogs, and other features. I have included a UEG widget in the right side bar of my blog - please click it!

Back to Blastocystis! Graham Clark and I published a personal view on the current status of Blastocystis in Parasitology International, in which we summarise the development and recent advances in Blastocystis research. The article is expected to form part of a special section/issue dedicated to Blastocystis to commemorate last year's 1st International Blastocystis Symposium in Ankara.

My colleague Juan-David Ramirez and his colleauges published data from a subtyping study from South America including 346 samples. More than 85% of the subtypes found belonged to either ST1, ST2, and ST3 as expected, while the rest belonged to ST4, ST5, ST6, ST7, ST8, ST12 and what they call a new subtype. I think this is the first time ST12 has been reported in humans. Despite the fact that the authors accounted for the databases that they used for subtype and allele calling, there is no mention on the criteria by which the subtypes were called in the NCBI database (i.e., in those cases where no hits could be found at the online Blastocystis database). For instance, what level of similarity was used to identify three samples as ST12? On the same note, which level of similarity was used to identify nine samples as belonging to a "novel subtype" (also, - was it the same sequence across the nine samples?). When dealing with a potentially novel subtype, usually the entire SSU rRNA gene is seqeunced and subjected to phylogenetic analysis, and sequences have not yet been made public in GenBank, so there is no possibility to work with the data so as to validate the findings (which are highly accurate, I'm sure). I think this information is critical to interpreting the data. Nontheless, the work that went into the sampling and the lab work should be highly accredited.

References:

Andersen LO, Bonde I, Nielsen HB, & Stensvold CR (2015). A retrospective metagenomics approach to studying Blastocystis. FEMS microbiology ecology, 91 (7) PMID: 26130823

Audebert C, Even G, Cian A, Blastocystis Investigation Group, Loywick A, Merlin S, Viscogliosi E, & Chabé M (2016). Colonization with the enteric protozoa Blastocystis is associated with increased diversity of human gut bacterial microbiota. Scientific reports, 6 PMID: 27147260  

O'Brien Andersen L, Karim AB, Roager HM, Vigsnæs LK, Krogfelt KA, Licht TR, & Stensvold CR (2016). Associations between common intestinal parasites and bacteria in humans as revealed by qPCR. European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology PMID: 27230509 

Ramírez JD, Sánchez A, Hernández C, Flórez C, Bernal MC, Giraldo JC, Reyes P, López MC, García L, Cooper PJ, Vicuña Y, Mongi F, & Casero RD (2016). Geographic distribution of human Blastocystis subtypes in South America. Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 41, 32-5 PMID: 27034056

Stensvold CR, & Clark CG (2016). Current status of Blastocystis: A personal view. Parasitology international PMID: 27247124   

Thursday, October 16, 2014

UEG Week 2014

The United European Gastroenterology (UEG) Week 2014 in Vienna is just around the corner. The conference kicks off on Saturday the 18th of October and judging from the program it will be a very interesting and inspiring event with so much to choose from that you will hardly be able to make up your mind about what to attend.

The general UEG website has now changed to the UEG Week Live site, which can be accessed here; however, you can still access the regular site here.

The programme for the entire venue can be downloaded here. There is also a very useful conference app (look for 'UEG Week 2014' in iTunes or go here), and a pathways tool, which you can download here.

However, I would like to invite you on a guided tour of some of the #UEGWeek topics for your inspiration. So, if you're interested in the clinical management and research developments in upper GI diseases, particularly in Helicobacter pylori, you may want to visit this blog post.

There's a panoply of interesting presentations and discussions on the menu for those who, like me, take an interest in the role of gut microbiota in health and disease, and to guide you through the jungle of treats, we developed this post. I doubt that there will be a lot on common intestinal microbial eukaryotic communities, but I'll try and see if I can stimulate the debate here and there...!


Thursday, May 29, 2014

Happy World Digestive Health Day!

Today is World Digestive Health Day!

The theme is 'Gut Microbes -  Importance in Health and Disease'.

United European Gastroenterology (UEG), a professional non-profit organisation combining all the leading European societies concerned with digestive diseases, has launched a short video to raise awareness of such diseases:



In 2000, 600 million patients suffered from a gastrointestinal disease. By 2025, this is predicted to double to 1.2 billion (source).

For those interested (and with access!), there is a special issue on 'The Gut Microbiome in Health and Disease' in the journal Gastroenterology, one of the most renown and established journals in the field.

I would also like to bring your attention to the 5th ASM Conference on Beneficial Microbes, September 27-30 in Washington DC. Deadline for submission of abstracts is July 14.

Wishing everyone a nice World Digestive Health Day!