The relationship between dyspepsia and trimethylamine N-oxide and short-chain fatty acids

Dyspepsia is a common gastrointestinal disorder caused by organic and functional factors. This study aimed to investigate the levels of short-chain fatty acids (SCFAs: butyrate and caproate), trimethylamine N-oxide (TMAO), and inflammatory markers including interleukin-6 (IL-6), interleukin-10 (IL-10), and interleukin-1 beta (IL-1β) in dyspepsia groups. Comparisons were made between groups to better understand the roles of these parameters in the pathophysiology of dyspepsia. A total of 100 individuals were included in the study, consisting of 20 patients with organic dyspepsia (OD), 20 with postprandial distress syndrome (PDS), 20 with epigastric pain syndrome (EPS), and 40 healthy controls. Demographic and anthropometric data were collected from all participants, and blood samples were analyzed for TMAO, butyrate, caproate, and cytokine levels. Of the participants, 63 were female and 37 were male, with a mean age of 37.91 ± 11.92 years. Butyrate levels were found to be significantly lower in dyspepsia groups compared to the control group; however, no significant difference was observed between the organic and functional dyspepsia subgroups. No significant differences were found in caproate or TMAO levels among the groups. Among the inflammatory markers, only IL-10 levels were significantly lower in dyspepsia groups compared to the control group, with no significant difference between the organic and functional dyspepsia subgroups. Similarly, no statistically significant differences were observed in IL-6 and IL-1β levels among the groups. The decrease in butyrate and IL-10 levels may be associated with microbial and inflammatory mechanisms underlying dyspepsia. The findings emphasize the importance of microbiota- and inflammation-focused approaches in the management of dyspepsia. Keywords: dyspepsia, gut microbiota, trimethylamine N-oxide, short-chain fatty acids, inflammation, cytokines