(P04-070-24) Improved Gut Health by a Green Tea Extract Confection in Metabolic Syndrome and Healthy Adults Occurred Without Affecting Short-Chain Fatty Acids and Microbiota Diversity

Objectives: We reported that catechin-rich green tea extract (GTE) decreased intestinal permeability and inflammation in obese rodents and in metabolic syndrome (MetS) and healthy persons. For the present study, we hypothesized that the observed improvements in gut barrier function by GTE would be attributed to a prebiotic activity that favorably regulates fecal microbiota composition and short-chain fatty acids (SCFAs).

Methods: We previously conducted a randomized, double-blind, placebo-controlled crossover study in MetS (n = 21; 40 ± 3 y) and healthy (n = 19; 34 ± 2 y) adults. They consumed gelatin-based confections without or with GTE (1 g; 890 mg/d total catechins) for 28-d with >95% compliance while following a low-polyphenol diet that was verified with 3-d food records on day 0 (PRE), 14 (MID), and 28 (POST). At POST, non-digestible sugar probes were ingested and analyzed in 24-h urine to assess intestinal permeability. SCFAs were analyzed by LC/MS in fecal samples collected at POST. Gut microbiota composition was determined by 16S rRNA sequencing.

Results: Compared with PRE, polyphenol and fiber intakes were lower at MID and POST regardless of treatment arm and health status. Fecal concentrations of total SCFAs were higher in MetS (P=0.024) regardless of treatment due to higher acetate (P=0.045), propionate (P=0.017), valerate (P=0.0002) and butyrate (P=0.07). Percent abundance of each SCFA was therefore calculated to examine their relationships with biomarkers of gut health previously reported to be improved by GTE. Total straight-chain SCFAs (%) positively correlated with total fiber (P=0.07) and soluble fiber (P=0.05), but neither total nor specific SCFAs correlated with fecal calprotectin, fecal myeloperoxidase, or intestinal permeability. Although α- and β- diversity and Firmicutes/Bacteroidetes differed by health status, each was unaffected by GTE.

Conclusions: GTE did not affect microbiota diversity and fecal SCFAs, nor were the SCFAs related to intestinal inflammation or permeability. Previously observed improvements in gut barrier function by GTE likely occurred independent of a prebiotic activity that alters SCFAs.

Funding Sources: USDA-NIFA, USDA-HATCH, and the Ohio Agricultural Research and Development Center at The Ohio State University