NOTICIAS DIARIAS

Neonatal Rotavirus Infection Worsened by Sugars and Microbiome in Mother’s Milk

Pathology & Microbiology

Using a multidisciplinary approach, an international team of researchers from several institutions, including Baylor College of Medicine, reveals that complex interactions between sugars and the microbiome in human milk influence neonatal rotavirus infection. Reported in the journal Nature Communications, this study provides new understanding of rotavirus infections in newborns and identifies maternal components that could improve the performance of live, attenuated rotavirus vaccines.

"Rotavirus infection causes diarrhea and vomiting primarily in children younger than 5, with the exception of babies younger than 28 days of age, who usually have no symptoms. However, in some places, infections in newborns are associated with severe gastrointestinal problems."

"What factors mediate differences between newborns with and without symptoms are not clearly understood," said first and corresponding author Dr. Sasirekha Ramani. "We began our investigation years ago by determining that a particular strain of rotavirus was associated with both asymptomatic infections and clinical symptoms in newborns."

Rotavirus studies

In the lab, the researchers investigated whether components of the mother's breast milk could inhibit infection of MA104 cells, a well-established model for rotavirus studies, with the particular strain of rotavirus they had identified in the neonatal nurseries in India. Unexpectedly, they discovered that specific sugars present in mother's milk enhanced infection of cells in culture with the neonatal rotavirus strain.

"We found that some of the same specific sugars in breast milk that increase infectivity of cells in culture are present in the milk of mothers of newborns with symptomatic infection," Ramani said. In addition, the researchers found an association between the microbiome in the mothers' milk and gastrointestinal symptoms in newborns, which prompted new questions, Ramani explained. How does the microbiome contribute to the differences in gastrointestinal symptoms?

"What is most interesting to us is that these sugars also increase the replication of the rotavirus attenuated, live vaccine that is similar to the neonatal virus that we are studying," Ramani said. "Enhanced viral replication can potentially translate into a more effective immune response against the virus, which would lead to better protection for the infant. This is something we want to explore in the future because it could illuminate strategies to improve the effectiveness of rotavirus vaccines in parts of the world where they do not do well."

Unexpected findings 

"One of the most important things to us is that these unexpected findings are tightly linked to public health," said co-author Dr. Mary K. Estes. "The multidisciplinary nature of our team of researchers has allowed us to answer questions about how this unique rotavirus strain infects neonates, confirm the findings in the field and open possibilities to improve the effectiveness of rotavirus vaccines where they are needed the most."

"These discoveries are a prime example of the urgent need to improve our understanding of the composition and variation in breast milk components," said co-author Dr. Lars Bode. "Understanding how rotavirus and other pathogens can take advantage of breast milk components will guide the development of new vaccination strategies to stay ahead in the host-pathogen arms race."