We have known for a while that obesity has a microbial component. Now, a team of scientists led by Patrice D. Cani reports a novel bacterium isolated from the human gut that counteracts diet-induced obesity, inflammation and glucose dysregulation in mice.

Gut microbiota alterations in obesity remain the subject of debate. Writing in Nature, Vieira-Silva and colleagues found that the undesirable Bacteroides 2 enterotype was more frequent in people with a higher body mass index, but not if they were taking statins.

Large inter-individual variability exists regarding how our gut microbiota responds to dietary intervention. New findings in mice and people with obesity show that ‘responders’ to inulin may be identifiable from their gut microbiota before they receive the intervention.