RT Journal Article SR Electronic T1 Adipose tissue derived bacteria are associated with inflammation in obesity and type 2 diabetes JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1796 OP 1806 DO 10.1136/gutjnl-2019-320118 VO 69 IS 10 A1 Lucas Massier A1 Rima Chakaroun A1 Shirin Tabei A1 Alyce Crane A1 Konrad David Didt A1 Jörg Fallmann A1 Martin von Bergen A1 Sven-Bastiaan Haange A1 Henrike Heyne A1 Michael Stumvoll A1 Martin Gericke A1 Arne Dietrich A1 Matthias Blüher A1 Niculina Musat A1 Peter Kovacs YR 2020 UL http://gut.bmj.com/content/69/10/1796.abstract AB Objective Bacterial translocation to various organs including human adipose tissue (AT) due to increased intestinal permeability remains poorly understood. We hypothesised that: (1) bacterial presence is highly tissue specific and (2) related in composition and quantity to immune inflammatory and metabolic burden.Design We quantified and sequenced the bacterial 16S rRNA gene in blood and AT samples (omental, mesenteric and subcutaneous) of 75 subjects with obesity with or without type 2 diabetes (T2D) and used catalysed reporter deposition (CARD) – fluorescence in situ hybridisation (FISH) to detect bacteria in AT.Results Under stringent experimental and bioinformatic control for contaminants, bacterial DNA was detected in blood and omental, subcutaneous and mesenteric AT samples in the range of 0.1 to 5 pg/µg DNA isolate. Moreover, CARD-FISH allowed the detection of living, AT-borne bacteria. Proteobacteria and Firmicutes were the predominant phyla, and bacterial quantity was associated with immune cell infiltration, inflammatory and metabolic parameters in a tissue-specific manner. Bacterial composition differed between subjects with and without T2D and was associated with related clinical measures, including systemic and tissues-specific inflammatory markers. Finally, treatment of adipocytes with bacterial DNA in vitro stimulated the expression of TNFA and IL6.Conclusions Our study provides contaminant aware evidence for the presence of bacteria and bacterial DNA in several ATs in obesity and T2D and suggests an important role of bacteria in initiating and sustaining local AT subclinical inflammation and therefore impacting metabolic sequelae of obesity.