Abstract
Background
Branched‐chain amino acids (BCAAs) are established biomarkers of insulin resistance. However, their relationship with gut microbiota composition, dietary patterns, and systemic inflammation in African populations with Type 2 diabetes mellitus (T2DM) remains unexplored. This study investigated the association between plasma BCAAs, gut dysbiosis, dietary practices, and proinflammatory cytokines in T2DM patients in Sokoto, Nigeria.
Methods
This cross‐sectional study enrolled 126 participants: 63 T2DM patients and 63 age‐ and sex‐matched healthy controls. We quantified gut Bacteroidetes and Firmicutes using qPCR and defined dysbiosis as a bacterial load above the 75th percentile of controls—a structured questionnaire captured dietary patterns, including meal‐specific food choices. Plasma BCAAs, tumor necrosis factor alpha (TNF‐
α
), and interleukin‐6 (IL‐6) were measured by ELISA. We compared biomarker levels across groups (eubiosis, dysbiosis, controls) using the Kruskal–Wallis test with Dunn′s post hoc correction and assessed correlations using Spearman′s rank correlation.
Results
Plasma BCAAs were significantly elevated in T2DM patients with dysbiosis (median 100
μ
mol/L, IQR 11.69–14.57) compared with eubiotic T2DM patients (88.1
μ
mol/L, IQR 9.29–13.84) and controls (70.6
μ
mol/L, IQR 7.46–10.64) (
H
= 41.77,
p
η
2
H
= 0.323). Dietary analysis of participants who consumed rice/swallow as breakfast shows the highest dysbiosis prevalence (83.3%,
A
O
R
= 0.31, 95
%
C
I
: 0.21–0.91,
p
= 0.038). Notably, all participants who consumed oats at dinner or lunch presented with 100% dysbiosis prevalence. Vegetable/fruit consumption at lunch showed 82.8% dysbiosis prevalence (
χ
2
= 44.594,
p
χ
2
= 107.471,
p
A
O
R
= 2.41, 95
%
C
I
: 1.92–3.81). Among dysbiotic patients, the Firmicutes/Bacteroidetes (F/B) ratio correlated negatively with BCAAs (
r
= –0.452,
p
= 0.008). BCAAs correlated positively with TNF‐
α
(
r
= 0.489,
p
= 0.001) and IL‐6 (
r
= 0.401,
p
= 0.003) in the dysbiosis group. Hyperglycemic patients had significantly higher BCAAs than normoglycemic participants (
p
Conclusion
Plasma BCAAs are elevated in Nigerian T2DM patients with gut dysbiosis and correlate positively with systemic inflammation. The negative correlation between the F/B ratio and BCAAs challenges the simple paradigm that higher Firmicutes abundance uniformly drives BCAA elevation, suggesting that specific microbial taxa or functional pathways may be more relevant. Dietary patterns, particularly oat consumption, show strong associations with dysbiosis, warranting careful interpretation and further investigation. These findings support the gut–BCAA–inflammation axis in the pathophysiology of T2DM.