A newly discovered virus hiding inside common gut bacteria may be linked to colorectal cancer, according to new research.

Scientists in Denmark found that colorectal cancer patients were about twice as likely to carry a previously unidentified virus within Bacteroides fragilis, a bacterium that normally lives in the human gut, according to the study published in Communications Medicine earlier this month.

Researchers say the discovery could help scientists better understand the role of the gut microbiome in cancer development.

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“These findings highlight the importance of the microorganisms in the gut and their relation to our health,” Dr. Flemming Damgaard, PhD, of the Department of Clinical Microbiology at Odense University Hospital and the University of Southern Denmark, told Fox News Digital. “If we want to understand the full picture, we need to look deep into their genetic material.”

Doctors have known for years that Bacteroides fragilis shows up more often in people with colorectal cancer, which includes cancers of the colon and rectum, but since most healthy people also carry the bacteria, it wasn’t clear why it would be harmful in some cases and not others.

So researchers looked at subtle genetic differences within the bacteria and uncovered something unexpected.

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“We were very surprised to find a whole virus inside the bacteria from the colorectal cancer patients,” Damgaard said. “That was not something we expected when we started our study.”

The virus, known as a bacteriophage, infects bacteria rather than human cells. According to the researchers, the viral type they identified had not previously been documented.

When the team analyzed stool samples from 877 individuals across Europe, the United States and Asia, they found that colorectal cancer patients were approximately twice as likely to carry traces of the virus compared to people without cancer.

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The findings show a strong statistical association, but researchers stress that the study does not prove the virus causes colorectal cancer, and it is too early to draw immediate conclusions.

“The major limitation is that we still don’t know why the virus is linked to colorectal cancer,” said co-author Ulrik Stenz Justesen. “But we are already continuing our research.”

The team is now conducting laboratory experiments and animal studies to determine whether the virus alters the bacterium’s behavior in a way that could influence cancer development.

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Studies have found that the human body contains roughly as many microbial cells as human cells, underscoring how deeply microbes are intertwined with human health.

“Our understanding of [microbial cells] is still in its infancy,” Damgaard said. “There are many health-related discoveries to be made in the human microbiota.”

Colorectal cancer is one of the leading causes of cancer-related deaths worldwide, according to the World Health Organization. Several high-profile celebrity deaths, including James Van Der Beek, Catherine O’Hara, Kirstie Alley, Pelé and Chadwick Boseman, have drawn attention to colorectal cancer’s impact across age groups in recent years.

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While much of colorectal cancer risk is tied to diet and lifestyle, researchers think the bacteria in our gut may also play an important role.

Currently, colorectal cancer screening includes stool tests that check for blood that isn’t visible to the naked eye, as well as colonoscopies. Researchers say that in the future, it may be possible to test stool samples for viral markers like those identified in the study.

Researchers pointed to cervical cancer as an example of how identifying a viral cause can help prevention efforts. After HPV was linked to cervical cancer, vaccines helped drive down new cases. 

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While it’s too early to make that comparison, they said colorectal cancer could one day follow a similar path if a clear viral role is confirmed.

“It is too early to act,” Damgaard said. “We have a lot of hope, and that is what we want people to have at this point.”

Fox News Digital’s Melissa Rudy contributed reporting.

Eric Dane’s death has sparked conversations about the speed and severity of ALS.

Also known as Lou Gehrig’s disease, the progressive illness — officially called amyotrophic lateral sclerosis — is debilitating and fatal. 

While only about 5,000 people in the U.S. are diagnosed each year, the average life expectancy is just two to five years, according to the ALS Association.

Dane, who most famously starred as Dr. Mark “McSteamy” Sloan on ABC’s “Grey’s Anatomy,” announced his diagnosis in April 2025, telling “Good Morning America” in June that his first symptoms began as “some weakness” in his right hand.

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“I didn’t really think anything of it,” the actor said. “At the time, I thought maybe I’d been texting too much, or my hand was fatigued. But a few weeks later, I noticed that it got a little worse.”

“I’m fighting as much as I can,” Dane added. “There’s so much about it that’s out of my control.”

What is ALS?

ALS is a progressive disease where the brain loses connection with the muscles, according to the ALS Association. This slowly strips a person’s ability to walk, talk, eat, dress, write, speak, swallow and, eventually, breathe.

Early signs include muscle weakness, stiffness and cramping. Symptom progression and severity are different for each case, as the association notes there is “no single timeline for ALS.”

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The disease only impacts motor neurons controlling voluntary movement, so the five senses — sight, touch, hearing, taste and smell — are not affected, nor are the eye muscles or bladder control.

Many ALS patients remain “mentally alert and aware” throughout the disease, the ALS Association reported.

Diagnosis typically occurs in people between the ages of 40 and 70. About 20% of patients live five years or longer. Only about 5% live longer than 20 years.

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ALS is typically diagnosed by a neurologist with an electromyography test (EMG), but can also be detected by blood and urine tests, spinal taps, MRIs and other imaging scans, muscle and nerve biopsies, or neurological exams.

There is currently no cure or treatment to stop disease progression, although there are treatments to slow and ease symptoms, per the ALS Association.

Fox News senior medical analyst Dr. Marc Siegel joined “Fox & Friends” on Friday to discuss the prevalence of ALS, suggesting that cases have increased due to “something in the environment that we don’t know yet.”

While ALS is 10% genetic, according to Siegel, 90% of cases do not have a genetic link, pointing toward other risk factors like environmental toxins.

“We’re learning to personalize the approach to this disease.”

“It’s a muscle weakness disease — affecting nerves that innervate muscles — and usually it starts on one side,” the doctor shared. “Then you develop fatigue … You could see a quivering tongue or your arm is quivering, usually one side and then the other side.”

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As the weakness progresses, it impacts speech and ultimately attacks the diaphragm, making it difficult to fully inflate the lungs.

“That’s what happened to [Dane], most likely,” Siegel said. “So, it progresses from your arms, your legs, your speech, your swallowing ability and then your breathing.”

Rising research

ALS progresses “pretty rapidly in most cases,” Siegel said. While scientist Stephen Hawking lived 55 years with the disease, Dane “probably lived about two years with it,” the doctor surmised.

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“I want to point out how courageous [Dane] is — he actually was involved with Target ALS, where he was fighting for new research,” Siegel pointed out. “We’re learning to personalize the approach to this disease, and that’s the future — and he fought for that.”

“We need a lot of money for research for this — [Dane] was asking for a billion dollars from the government.”

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Various research groups and hospital systems are actively working on new ALS therapies that take a personalized approach, Siegel shared.

The estimated cost to develop a drug that would slow or stop disease progression is $2 billion, the ALS Association has reported. The annual estimated out-of-picket cost for care is $250,000.

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Funding for ALS research and awareness has been on the rise for years, with the viral social media ALS Ice Bucket Challenge making a splash in 2014. 

The challenge, supported by the ALS Association, was intended to boost awareness. It ultimately raised $115 million toward ALS research and patient care.

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