title: Host lifestyle affects human microbiota on daily timescales.
abstract: BACKGROUND
  Disturbance to human microbiota may underlie several pathologies. Yet, we lack a comprehensive understanding of how lifestyle affects the dynamics of human-associated microbial communities.
  
  
  RESULTS
  Here, we link over 10,000 longitudinal measurements of human wellness and action to the daily gut and salivary microbiota dynamics of two individuals over the course of one year. These time series show overall microbial communities to be stable for months. However, rare events in each subjects’ life rapidly and broadly impacted microbiota dynamics. Travel from the developed to the developing world in one subject led to a nearly two-fold increase in the Bacteroidetes to Firmicutes ratio, which reversed upon return. Enteric infection in the other subject resulted in the permanent decline of most gut bacterial taxa, which were replaced by genetically similar species. Still, even during periods of overall community stability, the dynamics of select microbial taxa could be associated with specific host behaviors. Most prominently, changes in host fiber intake positively correlated with next-day abundance changes among 15% of gut microbiota members.
  
  
  CONCLUSIONS
  Our findings suggest that although human-associated microbial communities are generally stable, they can be quickly and profoundly altered by common human actions and experiences.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: David
authors.forename: Arne C
authors.initials: AC
authors.lastname: Materna
authors.forename: Jonathan
authors.initials: J
authors.lastname: Friedman
authors.forename: Maria I
authors.initials: MI
authors.lastname: Campos-Baptista
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Blackburn
authors.forename: Allison
authors.initials: A
authors.lastname: Perrotta
authors.forename: Susan E
authors.initials: SE
authors.lastname: Erdman
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Alm
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000382:microbiology*; D019049:Developed Countries; D003906:Developing Countries; D005243:Feces / Q000382:microbiology*; D014644:Genetic Variation; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D064307:Microbiota; D010802:Phylogeny; D012463:Saliva / Q000382:microbiology*; D017422:Sequence Analysis, DNA