title: Correlations between Lumbricus terrestris survival and gut microbiota.
abstract: BACKGROUND
  The interplay between diet, gut bacteria and health still remain enigmatic. Here, we addressed this issue through the investigation of the effect of crystalline cellulose on the earthworm Lumbricus terrestris gut microbiota composition and survival.
  
  
  METHODS
  Earthworm gut contents were analyzed after 14 days of feeding using a mixed 16S rRNA gene sequencing approach, in addition to direct measurements of cellulase activity. The survival of earthworms was followed each week for 17 weeks.
  
  
  RESULTS
  We found a tendency that the crystalline cellulose fed earthworms survived better than the high energy fed earthworms (p=0.08). Independent of feeding we found that the bacterial group related to Ferrimonadaceae was correlated to an increased lifespan (p=0.01). We also found a positive correlation between Ruminococcaceae related bacteria and cellulase activity in the earthworm gut (p=0.05). Surprisingly, however, the cellulase activity was not correlated to the feeding regime.
  
  
  CONCLUSIONS
  Taken together, the interactions between diet, gut microbiota and lifespan seem complex.
authors.affiliation: Department of Natural Sciences and Technology, Hedmark University College, Hamar, Norway ; Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.
authors.forename: Knut
authors.initials: K
authors.lastname: Rudi
authors.forename: Knut Olav
authors.initials: KO
authors.lastname: Strætkvern
keywords: 16S rRNA gene; cellulose; earthworm; gut