{"id":857,"date":"2015-10-20T15:19:50","date_gmt":"2015-10-20T15:19:50","guid":{"rendered":"http:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/?p=857"},"modified":"2017-08-21T11:27:01","modified_gmt":"2017-08-21T11:27:01","slug":"primary-care-corner-with-geoffrey-modest-md-international-travel-and-gut-microbiome-changes","status":"publish","type":"post","link":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/10\/20\/primary-care-corner-with-geoffrey-modest-md-international-travel-and-gut-microbiome-changes\/","title":{"rendered":"Primary Care Corner with Geoffrey Modest MD: International Travel and Gut Microbiome Changes"},"content":{"rendered":"<p><strong>By Dr. Geoffrey Modest<\/strong><\/p>\n<p>Last March I sent out a blog reviewing a Finnish study that found\u00a0changes in intestinal colonization in those traveling to a variety of places,\u00a0including\u00a0South\u00a0Asia and Sub-Saharan\u00a0Africa,\u00a0looking at a few specific resistant bacteria (extended-spectrum beta-lactamase-producing\u00a0Enterobacteriaceae and carbapenemase-producing\u00a0Enterobacteriaceae), and finding significant colonization overall but especially in those who developed traveler&#8217;s diarrhea and even much more so in those who took antibiotics for it\u00a0(see\u00a0<a href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/03\/19\/primary-care-corner-with-geoffrey-modest-md-travelers-diarrhea-the-treatment-may-be-worse-than-the-disease\/\">https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/03\/19\/primary-care-corner-with-geoffrey-modest-md-travelers-diarrhea-the-treatment-may-be-worse-than-the-disease\/<\/a> ).<\/p>\n<p>The current study adds greatly to the concern about GI microbiome changes with travel by looking at the larger microbiome, not just a couple of concerning species as above\u00a0(see\u00a0doi:10.1128\/AAC.00933-15\u200b).<\/p>\n<p>Details:<\/p>\n<ul>\n<li>They used &#8220;explorative shotgun metagenomic sequencing&#8221; (???? you might ask &#8212; turns out to be a new technology to do quantitative analysis of pretty much all known antibiotic-resistance genes, &gt;300 genes, in a single assay\u00a0looking at the total DNA of the gut, whether the bacteria is cultivable or not) in 35 Swedish students aged 23-34, 74% female, comparing their fecal samples before and after exchange programs in the Indian peninsula\u00a0(n=18) or in Central Africa (n=17), from 2010-2013. The median travel duration was 34 days. None were exposed to antibiotics, though 23 of the 35 did participate in hospital-based patient work. In doing the metagenomic sequencing, they limited their assessment to genes conferring verified resistance phenotypes (i.e., those genes\u00a0known to be associated with resistant bacterial infections).<\/li>\n<li>69% (12 of 17 going to\u00a0Central Africa and 12\/18 to\u00a0the Indian peninsula) had travelers&#8217; diarrhea for a\u00a0median of 4 days.<\/li>\n<li>None were exposed to antibiotic treatment in the 6-month period\u00a0before or during the travel, though those who went to Central Africa did have antimalarial chemoprophylaxis (mostly mefloqine, which may have some broader antibacterial effect).<\/li>\n<\/ul>\n<p>Results:<\/p>\n<ul>\n<li>The overall taxonomic diversity and composition of the microbiome was pretty stable from before to after travel, though there was an increase in\u00a0Proteobacteria\u00a0in 25 of the\u00a035 students (Proteobacteria have been associated with inflammatory conditions in the large bowel, including ulcerative colitis, difficile enteritis, and\u00a0chronic HIV).<\/li>\n<li>BUT, there was an overall increase in the abundance of\u00a0antibiotic resistance genes, especially for those encoding resistance to:\n<ul>\n<li>\u200bSulfonamides (2.6-fold increase)<\/li>\n<li><span style=\"font-style: inherit;font-weight: inherit\"> Trimethoprim\u00a0(7.7-fold increase)<\/span><\/li>\n<li>Beta-lactams\u00a0(2.6-fold increase)<\/li>\n<li><span style=\"font-style: inherit;font-weight: inherit\"> And\u00a0significant increases, but less profound, for aminoglycosides and tetracycline<\/span><\/li>\n<li>Of\u200b those traveling to the Indian peninsula, 12 acquired extended-spectrum beta-lactamase-producing (ESBL) E. coli,\u00a0though none from Africa. Of some concern,\u00a0these were not picked up on the above genetic\u00a0sequencing, likely because the sensitivity of the assay was insufficient for low-abundant genes.<\/li>\n<li>The above microbiome\u00a0changes were not significantly related to those who reported experiencing traveler&#8217;s diarrhea (and, as mentioned, none had taken antibiotics)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>So, a few observations:<\/p>\n<ul>\n<li><span style=\"font-style: inherit;font-weight: inherit\"> This metagenomic technique appears to be pretty powerful in assessing microbiome changes, though not perfect (e.g., it missed some\u00a0ESBL E. coli)<\/span><\/li>\n<li><span style=\"font-style: inherit;font-weight: inherit\"> In general, we think of the major changes in microbiome being from use of antibiotics, poor infection prevention\/control within health care systems, poor sanitation, antibiotic pollution of the environment (e.g. massive use of\u00a0antibiotics for animals), international food trade and travel. I\u00a0would add to this list other medications and dietary\/lifestyle changes (as delineated in prior blogs), though I\u00a0think this study does raise the issue of travel-acquired changes\u00a0even more.\u00a0We do not know if there was any transmission of antibiotic-resistant\u00a0genes back home or even if the microbiome changes continued\/for how long (the final stool samples were a median of\u00a03\u00a0weeks\u00a0after\u00a0return from travel, with\u00a0max of\u00a04 months). We don&#8217;t even know if the quantitative increase in antibiotic resistance genes is associated with clinical disease.\u00a0In addition, it would be useful to know if others living with the travelers had any changes in their microbiomes. but, overall,\u00a0the microbiome changes from travel\u00a0are\u00a0still concerning and have the very real potential to lead to difficult-to-treat diseases spreading throughout the world, and doing so more often as more\u00a0antibiotic resistance continues to\u00a0develop.<\/span><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Primary Care Corner with Geoffrey Modest MD: International Travel and Gut Microbiome Changes [&#8230;]<\/p>\n<p><a class=\"btn btn-secondary understrap-read-more-link\" href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/10\/20\/primary-care-corner-with-geoffrey-modest-md-international-travel-and-gut-microbiome-changes\/\">Read More&#8230;<\/a><\/p>\n","protected":false},"author":148,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[14283],"tags":[],"class_list":["post-857","post","type-post","status-publish","format-standard","hentry","category-archive"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/857","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/users\/148"}],"replies":[{"embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/comments?post=857"}],"version-history":[{"count":0,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/857\/revisions"}],"wp:attachment":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/media?parent=857"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/categories?post=857"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/tags?post=857"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}