PT  - JOURNAL ARTICLE
AU  - Maria I. Rojas
AU  - Giselle S. Cavalcanti
AU  - Katelyn McNair
AU  - Sean Benler
AU  - Amanda T. Alker
AU  - Ana G. Cobián-Güemes
AU  - Melissa Giluso
AU  - Kyle Levi
AU  - Forest Rohwer
AU  - Sinem Beyhan
AU  - Robert A. Edwards
AU  - Nicholas J. Shikuma
TI  - A Distinct Contractile Injection System Found in a Majority of Adult Human Microbiomes
AID  - 10.1101/865204
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 865204
4099  - http://biorxiv.org/content/early/2019/12/05/865204.short
4100  - http://biorxiv.org/content/early/2019/12/05/865204.full
AB  - An imbalance of normal bacterial groups such as Bacteroidales within the human gut is correlated with diseases like obesity. A current grand challenge in the microbiome field is to identify factors produced by normal microbiome bacteria that cause these observed health and disease correlations. While identifying factors like a bacterial injection system could provide a missing explanation for why Bacteroidales correlates with host health, no such factor has been identified to date. The lack of knowledge about these factors is a significant barrier to improving therapies like fecal transplants that promote a healthy microbiome. Here we show that a previously ill-defined Contractile Injection System is carried in the gut microbiome of 99% of individuals from the United States and Europe. This type of Contractile Injection System, we name here Bacteroidales Injection System (BIS), is related to the contractile tails of bacteriophage (viruses of bacteria) and have been described to mediate interactions between bacteria and diverse eukaryotes like amoeba, insects and tubeworms. Our findings that BIS are ubiquitous within adult human microbiomes suggest that they shape host health by mediating interactions between Bacteroidales bacteria and the human host or its microbiome.