Scientists discover thousands of unknown viruses in dirty baby nappies

Over the last few years, we’ve all been witness to the power of a brand-new virus and now scientists have found almost 10,000 new, mostly “ally” viruses lurking in babies’ dirty nappies.

In a study conducted by researchers in Denmark, hundreds of babies’ soiled nappies were collected and their contents were examined revealing a huge amount about the essential gut microbiome.

The gut biome is believed to play a large part in the onset of chronic diseases such as asthma and diabetes in later life, but it is only now that scientists have been able to reveal just how much viruses are involved.

In the study in Denmark, a multidisciplinary team of researchers analysed the makeup of poo of 647 healthy 1-year-olds. The children had also been enrolled in a long-term study of asthma and chronic inflammatory disease.

The findings were published in the Nature Microbiology journal and revealed that within a baby’s gut are up to 10,000 viral species.

While it was already well-known that healthy gut bacteria make up a large part of the gut biome, in babies, there are on average 10 times more viruses than bacterial species.

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Of the 248 viral families discovered in the study, a whopping 232 were unknown until now. Thankfully, 90 per cent of the viruses detected were bacteriophages – a type of virus that attacks potentially harmful bacteria. They are known as “allies” by scientists since they do not cause illness or disease.

Professor Dennis Sandris Nielsen, one of the study’s authors, told Phys.org: “This means that, from early on in life, healthy children are tumbling about with an extreme diversity of gut viruses, which probably have a major impact on whether they develop various diseases later on in life.”

The remaining 10 per cent are eukaryotic viruses that attach themselves to human cells but do not appear to make the children sick.

Nielsen explained: “We just know very little about what’s really at play. My guess is that they’re important for training our immune system to recognize infections later. But it may also be that they are a risk factor for diseases that we have yet to discover.”

The study’s lead author and a senior researcher at Copenhagen Prospective Studies on Asthma in Childhood, Shiraz Shah, hypothesized that perhaps these viruses exist in the gut as a backup defence whilst the bacterial gut microbiome and immune system are still developing.

Shah explained: “Our hypothesis is that, because the immune system has not yet learned to separate the wheat from the chaff at the age of one, an extraordinarily high species richness of gut viruses emerges, and is likely needed to protect against chronic diseases like asthma and diabetes later on in life.”

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