Two studies conducted by the University of Maryland School of Medicine Institute for Genome Sciences and the Center for Vaccine Development found an increase in diversity of gut-bacteria impacted the immune response to a vaccination.
The first study examined how an oral typhoid vaccination affected the microbiota in the human gut. The second study observed how the gut microbiota in monkeys impacted the efficacy of the Shigella vaccine. Both studies showcased microbiota impacting the immune response to the vaccination and were published in the journal PLOS ONE
The first study observed how an oral typhoid vaccination with an attenuated Salmonella enteric serovar Typhi impacted human gut microbiota. In this study, a wide spectrum of scientists, including experts in infectious diseases, enteric pathogens, microbiology, immunology and genomic analysis, found preliminary evidence that more diversity of gut bacteria may result in a stronger immune response to the vaccine.
The second study, led by the same interdisciplinary team, found evidence that the more diversity of gut bacteria present, the more responsive the immune system was to the fight against Shigella dysenteriae 1. This study also observed wild-type S. dysenteriae 1 and noted the same increase in immune response.
"Our research raises the intriguing possibility that the gut microbiota may play an important role in response to vaccines and susceptibility to enteric pathogens, or bacteria that affect the intestinal tract," Senior Author of both papers Claire M. Fraser said. "The results are preliminary and more research is needed. Both S. Typhi and Shigella are still devastating to populations in certain parts of the world. We hope that this work might one day help to provide relief to those areas that still suffer from these diseases."