Trimethylamine N-Oxide is Elevated in Type 2 Diabetes and Correlates with Gut Dysbiosis and Systemic Inflammation in a Nigerian Cohort
DOI:
https://doi.org/10.51152/jbarbiomed.v12i1.261Keywords:
Trimethylamine N-oxide, Gut dysbiosis, Type 2 diabetes, Inflammation, NigeriaAbstract
Background: Trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite linked to cardiometabolic disease, remains understudied in sub-Saharan Africa.
Objectives: To evaluate plasma TMAO concentrations and assess their associations with the Firmicutes/Bacteroidetes (F/B) ratio, pro-inflammatory cytokines, glycemic control, and body mass index in Nigerian T2DM patients.
Methods: This cross-sectional study enrolled 126 participants (63 with T2DM and 63 age-- and sex-matched healthy controls). Gut Firmicutes and Bacteroidetes were quantified by qPCR; dysbiosis was defined as total bacterial load > the 75th percentile of controls. ELISA was used to measure plasma TMAO and cytokines. Associations were tested using the Kruskal–Wallis test, logistic regression, and Spearman's correlation.
Results: TMAO was markedly elevated in T2DM patients compared with controls (medians 7.22 ng/mL in eubiotic T2DM, 6.80 ng/mL in dysbiotic T2DM vs 2.62 ng/mL in controls; η²H = 0.746, p < 0.001). TMAO levels were similarly high in both diabetic subgroups, demonstrating functional dysbiosis despite a normal F/B ratio. Among dysbiotic patients, TMAO showed positive correlations with the F/B ratio (r = 0.407, p = 0.002), Tumer Necrosis Factor-alpha (TNF-α) (r = 0.504, p < 0.001), and Interluken-6 (IL-6) (r = 0.386, p = 0.004). Hyperglycemia was independently associated with elevated TMAO (adjusted OR = 3.12, 95% CI 1.64–5.94, p = 0.001).
Conclusion: The disconnect between TMAO and conventional microbial composition highlights the need for functional microbiome assessment. TMAO may be a modifiable risk marker in this population.
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Copyright (c) 2026 Jafaru Muhammad Bunza, Jidda Muhammad Lawal, Umar Asiya Imam, Aliyu Maimunatu Umar, Dallatu Muhammad Kabiru, Ogunwale Kolawole Ayobami, Yusuf Habeb Demilola, Giwa Jamiah Ikeoluwa, Oladele Blessing Shina
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