Context: Previous population studies in evaluating the beneficial effects of capsaicin (CAP) have yielded inconclusive results, and the mechanisms responsible for possible benefit remain unclear.
Objective: The objective was to assess the effect of dietary CAP on metabolic and immune profiles and its potential associations with gut microbial patterns in healthy adults.
Design: In a 6-week controlled feeding trial, subjects were given the weight maintenance diet sequentially contained with 0, 5, 0, and 10 mg/d CAP from chili powder.
Setting and participants: The study was conducted in 12 healthy subjects enrolled in Third Military Medical University in Chongqing.
Main outcome measures: At the end of each period, anthropometric and basal metabolism measures together with blood and fecal samples were collected. Plasma metabolic and inflammatory markers and gut microbial ecology of each subject were subsequently assessed.
Result: Dietary CAP increased the Firmicutes/Bacteroidetes ratio and Faecalibacterium abundance, accompanied with increased plasma levels of glucagon-like peptide 1 and gastric inhibitory polypeptide and decreased plasma ghrelin level. Further enterotype analysis revealed that these subjects could be clustered into Bacteroides enterotype (E1) and Prevotella enterotype (E2), and the above beneficial effects were mainly obtained in E1 subjects. Moreover, E1 subjects had significantly higher fecal Faecalibacterium abundance and butyrate concentration after CAP interventions than those in E2 subjects.
Conclusion: Our study showed that gut enterotypes may influence the beneficial effects of dietary CAP, providing new evidence for the personalized nutrition guidance of CAP intervention on health promotion linking with gut microbiota patterns.