{"id":621413,"date":"2026-02-28T03:53:38","date_gmt":"2026-02-28T03:53:38","guid":{"rendered":"https:\/\/www.europesays.com\/us\/621413\/"},"modified":"2026-02-28T03:53:38","modified_gmt":"2026-02-28T03:53:38","slug":"hidden-virus-found-in-gut-bacteria-is-linked-to-colorectal-cancer-sciencealert","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/621413\/","title":{"rendered":"Hidden Virus Found in Gut Bacteria Is Linked to Colorectal Cancer : ScienceAlert"},"content":{"rendered":"<p>Researchers have made a significant step forward in understanding how gut bacteria, and specifically a newly discovered  <a href=\"https:\/\/www.sciencealert.com\/virus\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73053\" data-postid=\"193268\" rel=\"nofollow noopener\" target=\"_self\">virus<\/a>, can contribute to <a href=\"https:\/\/www.sciencealert.com\/colorectal-cancer-is-rising-in-young-people-heres-how-to-lower-your-risk\" rel=\"nofollow noopener\" target=\"_blank\">colorectal cancer<\/a> \u2013 one of the most common forms of  <a href=\"https:\/\/www.sciencealert.com\/cancer\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73077\" data-postid=\"193268\" rel=\"nofollow noopener\" target=\"_self\">cancer<\/a> in the developed world.<\/p>\n<p>The researchers, from institutions in Denmark and Australia, wanted to take a closer look at an association <a href=\"https:\/\/doi.org\/10.1038\/nrmicro2819\" rel=\"nofollow noopener\" target=\"_blank\">previously identified<\/a> between colorectal cancer and a bacterium called <a href=\"https:\/\/en.wikipedia.org\/wiki\/Bacteroides_fragilis\" rel=\"nofollow noopener\" target=\"_blank\">Bacteroides fragilis<\/a>.<\/p>\n<p>This bacterium often shows up in healthy people too, so the team wanted to see if there was a crucial difference in the bacterium in individuals who <a href=\"https:\/\/www.sciencealert.com\/why-millennials-face-higher-cancer-risk-than-their-parents-and-how-to-reduce-it\" rel=\"nofollow noopener\" target=\"_blank\">develop cancer<\/a> \u2013 and that&#8217;s exactly what they found.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2026\/02\/BacteriaGroup.jpg\" alt=\"Bacteria groupings\" width=\"642\" height=\"482\" class=\"wp-image-193271 size-full\"   loading=\"lazy\"\/>The researchers cataloged bacteria, and  <a href=\"https:\/\/www.sciencealert.com\/virus\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73053\" data-postid=\"193268\" rel=\"nofollow noopener\" target=\"_self\">viruses<\/a> inside bacteria. (Damgaard et al., Commun. Med., 2026)<\/p>\n<p>&#8220;It has been a paradox that we repeatedly find the same bacterium in connection with colorectal cancer, while at the same time it is a completely normal part of the gut in healthy people,&#8221; <a href=\"https:\/\/www.sdu.dk\/en\/om-sdu\/fakulteterne\/sundhedsvidenskab\/nyheder-2026\/nyopdaget-virus-kobles-til-tarmkraeft\" rel=\"nofollow noopener\" target=\"_blank\">says<\/a> microbiologist Flemming Damgaard, from Odense University Hospital in Denmark.<\/p>\n<p>&#8220;We have discovered a virus that has not previously been described and which appears to be closely linked to the bacteria we find in patients with colorectal cancer.&#8221;<\/p>\n<p>Using genetic sequencing, the researchers analyzed the gut bacteria of <a href=\"https:\/\/www.sciencealert.com\/scientists-want-to-intercept-cancer-decades-before-it-develops-heres-how\" rel=\"nofollow noopener\" target=\"_blank\">cancer patients<\/a> in a large Danish population study. They found that in these patients, B. fragilis often came with a bacteriophage attached. Bacteriophages are viruses that <a href=\"https:\/\/www.sciencealert.com\/century-old-viral-therapy-could-help-us-out-of-an-impending-superbug-crisis\" rel=\"nofollow noopener\" target=\"_blank\">live inside bacteria<\/a>, hijacking these cells to duplicate and spread.<\/p>\n<p>While the initial signal was discovered in a relatively small group of people, the findings were later verified in a larger cohort of 877 people with and without colorectal cancer \u2013 and point to a link that suggests viruses lurking in B. fragilis may tip the scales <a href=\"https:\/\/www.sciencealert.com\/your-risk-of-cancer-could-fluctuate-even-born-youre-born\" rel=\"nofollow noopener\" target=\"_blank\">toward cancer<\/a>.<\/p>\n<p>People with colorectal cancer were twice as likely to have detectable levels of the bacteriophage in their gut bacteria, the data showed. What&#8217;s more, it&#8217;s not a virus that fits the description of anything recorded to date.<\/p>\n<p><a href=\"https:\/\/www.sciencealert.com\/newsletter?utm_source=promo_generic_health\" rel=\"nofollow noopener\" target=\"_blank\"><img decoding=\"async\" src=\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/11\/Generic-Health-Promo-Final-642x273.jpg\" alt=\"Subscribe to ScienceAlert's free fact-checked newsletter\" width=\"642\" height=\"273\" class=\"alignnone wp-image-182810 size-medium\"   loading=\"lazy\"\/><\/a><\/p>\n<p>However, the researchers can&#8217;t prove direct cause and effect yet. This is a notable association that will be useful for <a href=\"https:\/\/www.sciencealert.com\/a-common-medicine-may-stop-colorectal-cancer-from-returning\" rel=\"nofollow noopener\" target=\"_blank\">studying colorectal cancer<\/a> and potential treatment targets, but there may be much more going on.<\/p>\n<p>&#8220;It is not just the bacterium itself that seems interesting,&#8221; <a href=\"https:\/\/www.sdu.dk\/en\/om-sdu\/fakulteterne\/sundhedsvidenskab\/nyheder-2026\/nyopdaget-virus-kobles-til-tarmkraeft\" rel=\"nofollow noopener\" target=\"_blank\">says<\/a> Damgaard. &#8220;It is the bacterium in interaction with the virus it carries.&#8221;<\/p>\n<p>&#8220;We do not yet know whether the virus is a contributing cause, or whether it is simply a sign that something else in the gut has changed.&#8221;<\/p>\n<p>Around 80 percent of colorectal cancer risk has been assigned to environmental factors, including <a href=\"https:\/\/www.sciencealert.com\/fragments-of-bacteria-in-our-gut-may-lull-our-brains-to-sleep-at-night\" rel=\"nofollow noopener\" target=\"_blank\">gut bacteria composition<\/a>. That means a better understanding of these factors and how they influence each other could impact millions of cancer cases.<\/p>\n<p>Studying the mix of bacteria in the gut is no easy task, though. These incredibly complex microbiomes are both indicators of what else is going on in the body and influencers that can impact everything from <a href=\"https:\/\/www.sciencealert.com\/study-of-over-400000-people-links-gut-bacteria-with-insomnia-risk\" rel=\"nofollow noopener\" target=\"_blank\">sleep quality<\/a> to <a href=\"https:\/\/www.sciencealert.com\/something-inside-your-gut-could-be-like-a-natural-ozempic\" rel=\"nofollow noopener\" target=\"_blank\">weight loss<\/a>.<\/p>\n<p>Now there&#8217;s an extra layer that future studies can examine: not just bacteria, but the viruses living inside them. One question the researchers are keen to look at next is exactly how B. fragilis might be affected by its bacteriophage lodgers.<\/p>\n<p><strong>Related: <\/strong><a href=\"https:\/\/www.sciencealert.com\/scientists-link-gut-bacteria-to-bipolar-depression-in-mouse-study\" rel=\"nofollow noopener\" target=\"_blank\"><strong>Scientists Link Gut Bacteria to Bipolar Depression in Mouse Study<\/strong><\/a><\/p>\n<p>This research is still very much in the early, experimental stage, but anything that helps experts understand how cancer gets started can also help in the development of targeted treatments \u2013 though that may take years.<\/p>\n<p>The team behind this study suggests that their findings might also be used for colorectal <a href=\"https:\/\/www.sciencealert.com\/exciting-new-cancer-blood-test-results-hide-a-concerning-problem\" rel=\"nofollow noopener\" target=\"_blank\">cancer screening<\/a>. With further research, stool sample scans could be developed to look for this B. fragilis virus, for example.<\/p>\n<p>&#8220;The number and diversity of bacteria in the gut is enormous,&#8221; <a href=\"https:\/\/www.sdu.dk\/en\/om-sdu\/fakulteterne\/sundhedsvidenskab\/nyheder-2026\/nyopdaget-virus-kobles-til-tarmkraeft\" rel=\"nofollow noopener\" target=\"_blank\">says<\/a> Damgaard. &#8220;Previously, it has been like looking for a needle in a haystack. Instead, we have investigated whether something inside the bacteria \u2013 namely viruses \u2013 might help explain the difference.&#8221;<\/p>\n<p>&#8220;In the short term, we can investigate whether the virus can be used to identify individuals at increased risk.&#8221;<\/p>\n<p>The research has been published in <a href=\"https:\/\/doi.org\/10.1038\/s43856-026-01403-1\" rel=\"nofollow noopener\" target=\"_blank\">Communications Medicine<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Researchers have made a significant step forward in understanding how gut bacteria, and specifically a newly discovered virus,&hellip;\n","protected":false},"author":3,"featured_media":621414,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[210,352,67,132,68],"class_list":{"0":"post-621413","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-health","8":"tag-health","9":"tag-msft-content","10":"tag-united-states","11":"tag-unitedstates","12":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/116146243874850577","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/621413","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=621413"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/621413\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/621414"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=621413"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=621413"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=621413"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}