This isn’t hot off the press (a 2012 review article by Tosh & McDonald) but it’s probably more important now than when first published, given our rapid advances in understanding of the importance of the microbiome in human health over the last year or two.
A couple of clear principles emerge from the review:
- A happy, healthy human microbiome is characterized by diversity (both in terms of number of different species, and diversity within the species), and composed mainly of bacteria that we’re not familiar with – Fermicutes and Bacteroidetes).
- Antibiotics have a profound and sustained effect on the human microbiome (even those that are typically associated with no or few side effects). This results in a reduction in both diversity and change in composition, which is bad news for human health. In particular, this leave the gut more open to colonization with unwanted intruders aka antibiotic resistant bacteria.
The future of anti-infective therapy according to Tosh and McDonald is in:
(1) Developing and using more microbiome-sparing antimicrobial therapy. The idea of ‘selective digestive decontamination’ flies in the face of this objective.
(2) Developing techniques to maintain and restore indigenous microbiota. A lot of progress has been made here, for example, in the case of faecal microbiota transplantation (FMT) for the treatment of recurrent CDI.
(3) Discovering and exploiting host protective mechanisms normally afforded by an intact microbiome.
Rather than obliterate our microbiome with overuse of antibiotic “Atomic bombs”, we need to carefully tend individual and collective microbiomes in order to make them resistant to the increasing queue of antibiotic resistant colonizers!
Image credit: Modified from ‘Mushroom cloud‘.