{"id":911,"date":"2015-12-03T22:05:36","date_gmt":"2015-12-03T22:05:36","guid":{"rendered":"http:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/?p=911"},"modified":"2017-08-21T11:15:37","modified_gmt":"2017-08-21T11:15:37","slug":"primary-care-corner-with-geoffrey-modest-md-longterm-microbiome-changes-with-antibiotics","status":"publish","type":"post","link":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/12\/03\/primary-care-corner-with-geoffrey-modest-md-longterm-microbiome-changes-with-antibiotics\/","title":{"rendered":"Primary Care Corner with Geoffrey Modest MD: Longterm Microbiome Changes with Antibiotics"},"content":{"rendered":"<p><strong>By Dr. Geoffrey Modest<\/strong><\/p>\n<p>A small study was done looking at antibiotic exposure and changes in both the salivary and gut microbiomes (see\u00a0<a href=\"http:\/\/mbio.asm.org\/content\/6\/6\/e01693-15.full.pdf+html,\">http:\/\/mbio.asm.org\/content\/6\/6\/e01693-15.full.pdf+html,<\/a> or\u00a0\u00a0doi:10.1128\/mBio.01693-15\u200b). This study involved 2 clinical sites, one in Sweden and one in the UK, randomly assigned to placebo vs different\u00a0antibiotics, and looking at changes in the microbiomes both before <strong>a single antibiotic exposure<\/strong>\u00a0and for up to one year after.<\/p>\n<p>Details:<\/p>\n<ul>\n<li>30 people in the Swedish site were randomized to placebo, ciprofloxacin, or clindamycin; 44 people in the UK were randomized to placebo, amoxicillin, or minocycline (dosage not stated).<\/li>\n<li>For the Swedish site:\n<ul>\n<li>The fecal microbiome diversity was significantly reduced for up to 4 months in the clindamycin group, and up to 12 months in the ciprofloxacin group.<\/li>\n<li>The salivary microbiomes in the same groups\u00a0showed only a short-term reductions in diversity and only immediately after the clindamycin or ciprofloxacin\u00a0exposure.<\/li>\n<\/ul>\n<\/li>\n<li>For the UK site:\n<ul>\n<li>\u200bThere was a significant reduction in microbiome diversity in both the fecal and saliva samples only\u00a0at the 1 week samples\u00a0after the\u00a0minocycline\u00a0exposure, which resolved by the 1 month analysis. Amoxicillin was not associated with any change in the microbiome in\u00a0saliva or the gut.<\/li>\n<\/ul>\n<\/li>\n<li>The changes in the microbiome were largely a reduction in the production of the\u00a0short-chain fatty acid\u00a0butyrate\u00a0in the gut, especially by clindamycin and ciprofloxacin,\u00a0and butyrate production has the positive effect of inhibiting inflammation, carcinogenesis and oxidative stress in the gut. (Butyrate production was decreased in correspondence to the decreased gut population of many different bacterial species, such as Faecalibacterium, &#8212; see the article for the details).<\/li>\n<li>Prior to antibiotic exposure they detected antibiotic resistant genes in both the saliva and gut microbiomes, even in this healthy population.<\/li>\n<\/ul>\n<p>So,\u00a0it is unclear why the 2 microbiomes behaved differently, with the salivary microbiome being minimally affected and quite resilient and the gut microbiome having prolonged changes of up to a year after a single exposure to antibiotics (ciprofloxacin being the worst of those studied). However, this type of study reinforces the need to minimize antibiotic usage (also reinforced by the presence of antibiotic resistant genes evident in the gut of these healthy volunteers even prior to the antibiotics), and\u00a0preferentially\u00a0to use \u200bantibiotics which have lesser microbiome effects (in this case, penicillins). One wonders if there is a &#8220;tipping-point&#8221; of repeated broad-spectrum\u00a0antibiotic administration leading to more permanent changes in the microbiome.<\/p>\n<p>See\u00a0<a href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/category\/microbiome\/\">https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/category\/microbiome\/<\/a> for an array of prior blogs on the microbiome; \u00a0<a href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/08\/03\/primary-care-corner-with-geoffrey-modest-md-antibiotic-overprescribing-2\/\">https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/08\/03\/primary-care-corner-with-geoffrey-modest-md-antibiotic-overprescribing-2\/<\/a> about antibiotic overprescribing; and\u00a0<a href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/02\/28\/primary-care-corner-with-geoffrey-modest-md-pharyngitis-and-fusobacterium\/\">https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/02\/28\/primary-care-corner-with-geoffrey-modest-md-pharyngitis-and-fusobacterium\/<\/a>\u200b which argues that penicillin is the drug-of-choice for pharyngitis, over azithromycin.\u200b<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Primary Care Corner with Geoffrey Modest MD: Longterm Microbiome Changes with Antibiotics [&#8230;]<\/p>\n<p><a class=\"btn btn-secondary understrap-read-more-link\" href=\"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/2015\/12\/03\/primary-care-corner-with-geoffrey-modest-md-longterm-microbiome-changes-with-antibiotics\/\">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-911","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\/911","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=911"}],"version-history":[{"count":0,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/posts\/911\/revisions"}],"wp:attachment":[{"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/media?parent=911"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/categories?post=911"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stg-blogs.bmj.com\/bmjebmspotlight\/wp-json\/wp\/v2\/tags?post=911"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}