Choline is metabolized by the gut microbiota into trimethylamine (TMA), the precursor of pro-atherosclerotic molecule trimethylamine N-oxide (TMAO). Reduction of TMA formation has been shown to provide to cardioprotective effects, and some phytochemicals may produce such reduction. This study aimed to develop an optimized, high-throughput anaerobic fermentation methodology to study inhibition of choline microbial metabolism into TMA by phenolic compounds with healthy human fecal starter. Optimal fermentation conditions were: 20 % fecal slurry (1:10 in PBS), 100 M choline, and 12 h fermentation. Also, 10 mM of 3,3-dimethyl-1-butanol (DMB) was defined as a positive TMA production inhibitor, achieving a ~50 % reduction in TMA production. Gallic acid and chlorogenic acid reported higher TMA inhibitory potential (maximum of 80 -90 % in. TMA production inhibition), with IC50 around 5 mM. Nor DMB neither gallic acid and chlorogenic acid reduced TMA production through cytotoxic effects, indicating mechanisms such as altered TMA lyase activity or expression.

Type 2 diabetes (T2D) is characterized by hyperglycemia and insulin resistance. Cocoa may slow T2D development and progression. This study employed male and female BTBR.Cg-Lepob/ob/WiscJ and wild type (WT) controls to assess the potential for cocoa to ameliorate progressive T2D and compare responses between sexes. Mice received diet without (WT, ob/ob) or with cocoa extract (ob/ob + c) for 10 weeks. Glucose and insulin tolerance tests (GTT/ITT) were conducted at weeks 1, 5 and 2, 6, respectively. Cocoa provided mild non-significant protection against weight gain vs. ob/ob control in males but not females. Male ob/ob + c had increasing fasting glucose at weeks 1 and 5 GTTs, with significantly higher levels of fasting glucose than ob/ob control at week 5. This was not seen in females. Cocoa protected against elevated 4-hour fasting glucose in week 2, but not week 6, ITTs. Cocoa partly suppressed hyperinsulinemia in males but significantly amplified it in females and protected against loss of beta cell area in females only. The mechanisms of these sex-specific effects remain to be elucidated. This study informs additional experiments with larger sample sizes and demonstrates that sex differences must be considered when designing dietary interventions for T2D.