Medium-chain triglycerides reduce diarrhea with improved immune status and gut microbiomics in tunnel workers in China.

ABSTRACT

BACKGROUND AND OBJECTIVES: Adverse environmental factors in tunnels increase the occurrence of respiratory and intestinal inflammatory disease, which is seriously harmful to worker health. It is reported that medium-chain triglycerides (MCT) can improve immune status and alter the gut microflora. This study investigates MCT effects on immune status and gut microbiota among tunnel workers. METHODS AND STUDY DESIGN: Forty-five workers were randomly divided into an MCT group (n=30) and control group (n=15), where they ingested MCT-milk or a placebo milk for 12 weeks, respectively. The primary outcome measure was the incidence of respiratory infection and diarrhea. Secondary outcomes were changes in serum immune-related markers and changes in gut microbiota. RESULTS: The incidence of diarrhea in MCT group was significantly decreased after 4 weeks (p<0.01), with no significant differences in the control group. MCT reduced the level of pro-inflammatory cytokines (TNF-α, CRP, and IL-6) and enhanced the anti-inflammatory cytokines (IL-10, C3, C4, IgA, IgG, and IgM), respectively (p<0.01). The Chao index was reduced (p<0.01) and microbiota composition changed significantly after 12 weeks of MCT intervention. MCT reduced the abundance of Bacteroides, Roseburia, Ruminococcus_1, Lachnospira and increased that of Blautia and Fusicatenibacter at the genus level (p<0.01). CONCLUSIONS: The consumption of MCT reduces diarrhea occurrence and improves serum immune profiles together with gut microbiomics in tunnel workers.