These microbiota remain dynamic throughout our lives, continually changing as we grow older. It is possible, according to the report, that as we age, the changes in our gut microbiome may contribute to our aging and increased vulnerability to disease and frailty, thought our understanding of these changes are still not well understood. Just like our bodies age, so do our gut microbiome, and they weaken over time and incur damage. Our younger bacteria support a stronger immune defense, while the efficacy of aging bacteria is compromised. Younger bacterial strains carry adaptive variants and mutations, enabling it to adapt to changing environments.
More details around studies backing these assertions are available here, https://doi.org/10.1371/journal.ppat.1007727 .