Microbiota of the nose and throat: phylum-level similarities, species-level differences

There’s more than one way to skin a cat - even bacteria know this is true. The latest paper from mBio reveals that although the bacterial phyla in the nose and throat are somewhat consistent from person to person, the individual species vary a great deal, indicating there is more than one ideal community for these niches, and more than one way to carry out the functions those communities perform.

Lemon et al. used 16S rRNA gene microarrays and clone libraries to tease apart the microbiota of the nostrils and oropharynx (the back of the throat) in seven volunteers. (Haven’t you always wanted to know who was living in your oropharynx? How do I sign up for the next round of testing?) At the phylum level, the nostril and oropharynx show distinct distribution patterns:

• The nostril was dominated by Actinobacteria and Firmicutes, much like the skin, and
• The distribution of Firmicutes, Proteobacteria and Bacteroidetes in the oropharynx was similar to the distribution of these phyla in saliva.

Hence, in each niche, the big picture was similar in different people, but at the species level the story was very different, suggesting that multiple species might be able to perform discrete and essential funtions at these sites and that functional redundancy within communities might indicate community stability and could, potentially, be a biomarker for human health.

There are also indications that some bacteria don’t play nice together: in the nostril, there was an inverse relationship between the Firmicutes family Staphylococcaceae and the Actinobacteria families. The authors suggest that because of variation in attachment sites and substrates or competition for attachment sites and small molecule-mediated inhibition, a healthy population of Actinobacteria in your nostrils could protect against picking up Staphylococcaceae, a phylum that includes many human pathogens.

This article gives me a million-dollar idea: “ACTI-NOSE”. A probiotic nasal squirt for fending off Staphylococcus aureus. Remember, you read it here first, so cut me in on the royalties, okay?