The first year of life
Infants are extremely susceptible to infection during their first year of life. Because their gut microbiota and immune systems are not yet fully developed, pathogens like Salmonella and E. coli have an easier time making themselves at home. Studies by researchers at the University of Michigan show that Clostridia bacteria not only help us to digest our food, they are also highly effective in combating such illness-causing microbes.
Thorough testing first
Working in a bacteria-free environment, the researchers bred mice that lack the animals’ natural gut microbiota. These bacteria-free mice were then given gut microbiota from either juvenile or adult ‘regular’ mice. After that, the researchers administered a pathogen to all the mice. The mice with a juvenile gut microbiota became ill or died, while those with a mature gut microbiota survived the illness they have been given. Based on this, the researchers concluded that Clostridia is only present in the intestines from the period when the mice begin transitioning to solid food.
Antibiotics
In a second experiment, the mice with a juvenile gut microbiota were given the Clostridia bacteria, after which they were able to resist the pathogens. The mice with a mature gut microbiota, on the other hand, were given an antibiotic to counter Clostridia, which caused the Clostridia bacteria to be eliminated from their intestines. As it turned out, this gave the pathogens the ‘go-ahead’ to make the mice ill once more.
Better chance of survival
Clostridia, it would seem, play an important role in protecting mice from illness-causing pathogens. This may very well be the case for humans as well, since – like in mice – the Clostridia only become part of our gut microbiota when we start eating solid food. More research is necessary, however, in order to identify which species from class Clostridia are most effective in fighting disease. Once we know more, it could help us improve babies’ chances of survival considerably – for instance, by adding Clostridia to their diet before the infants begin to eat solid food. And that’s something incredible to work towards.
Source: Science