In a Danish study published in the journal Nature Microbiology, researchers from the University of Copenhagen revealed that the gut of babies consists of more than 200 previously unknown viral families within their intestines, which likely plays an important role in protecting children from chronic diseases like asthma and diabetes later on in life.

In the study, the team analyzed and mapped the diaper contents of 647 healthy Danish one-year-olds for over five years. While it has been recognized for decades that gut bacteria in young children are important in protecting them against chronic illnesses later in life, less is known about the many viruses present there.

During the study duration, the team found and mapped 10,000 viral species from the faeces of the infants, which were distributed across 248 different viral families. Out of the total viral species, only 16 species were previously known. The findings of the study also showed that 90% of the viruses were bacterial viruses, also known as bacteriophages.

Meanwhile, the remaining 10% of the viruses were eukaryotic, i.e., they used human cells as hosts. Dr. Shiraz Shah, a senior researcher at Copenhagen Prospective Studies on Asthma in Childhood (COPSAC), stated that an extraordinarily high species richness of gut viruses emerges as a result of an incompetent immune system that has not learned to separate the wheat from the chaff at the age of one. 

(Source: https://www.tribuneindia.com/news/health/scientists-identify-thousands-of-unknown-viruses-in-babies-gut-500473 )