Ruminococcus torques strain induces GLP-1 and PYY release in healthy overweight humans, mirroring rodent findings

The gut microbiota significantly influences host biology, particularly metabolism. The Ruminococcus torques (RT) ATCC 27756 strain, a commensal bacterium, synthesizes polypeptides (RORDEP1, RORDEP2) that improve metabolism in rodents. Current metabolic interventions often fall short or have side effects, creating a need for novel approaches. This study aimed to explore if the metabolic effects of this specific bacterial strain observed in rodents could be replicated in humans, focusing on feasibility and physiological responses.

This double-blind, placebo-controlled, randomized cross-over trial included 32 healthy overweight adults. Participants received either 3.1 × 10^11 colony forming units of the live RT ATCC 27756 strain or placebo, infused into the duodenum. The observation period lasted 6 hours, including a 2-hour oral glucose tolerance test. The primary endpoint was Matsuda Insulin Sensitivity Index, with secondary endpoints including intestinal hormone levels, glucose tolerance, and energy expenditure.

The duodenal infusion of the RT ATCC 27756 strain was safe and well-tolerated, with no reported adverse events. However, the study found no effects on the primary endpoint, Matsuda Insulin Sensitivity Index. Despite this, significant changes in intestinal hormone profiles were observed: > Compared to placebo, short-term RT infusion induced a relative rise in plasma concentrations of glucagon-like-peptide-1 (GLP-1) and peptide YY (PYY), while simultaneously causing a relative decline in gastric inhibitory polypeptide (GIP). These hormonal responses align with previous findings in rats. Furthermore, plasma levels of secondary bile acids and a plasma marker of bone remodeling both increased after RT infusion compared to placebo. Measures of glucose tolerance, energy expenditure, cutaneous thermography, and systemic low-grade inflammation markers remained unchanged.