Timing of complementary feeding is associated with gut microbiota diversity and composition and short chain fatty acid concentrations over the first year of life

Table 3 Unadjusted and multivariable-adjusted mean difference in short-chain fatty acid concentrations (μmol/g), from infant stool provided at 3 and 12 months of age, according the timing of complementary food introduction

	Butyric Acid^±		Propionic Acid^±		Acetic Acid		Total SCFAs
	Mean difference (95% CI)		Mean difference (95% CI)		Mean difference (95% CI)		Mean difference (95% CI)
	Crude	Adjusted	Crude	Adjusted	Crude	Adjusted	Crude	Adjusted
Infants at 3 months
Complementary foods > 3 months (n = 47)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)
Complementary foods ≤3 months (n = 18)	0.19 (−0.26, 0.64)	0.11 (−0.31, 0.53)	0.01 (− 0.39, 0.41)	0.04 (− 0.36, 0.44)	0.29 (−17.4, 18.0)	− 0.36 (−18.6, 17.9)	3.88 (−20.2, 27.9)	2.82 (−21.8, 27.4)
Infants at 12 months
Complementary foods > 3 months (n = 36)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)	0.0 (ref)
Complementary foods ≤3 months (n = 13)	0.67*** (0.30, 1.04)	0.65** (0.27, 1.04)	0.35* (0.03, 0.68)	0.31 (−0.03, 0.65)	21.0* (0.65, 41.4)	21.3 (−0.42, 43.0)	40.5** (11.3, 69.8)	38.8* (7.83, 69.7)

^±Natural log + 1 transformation used for butyric acid and propionic acid at 3 and 12 months
Multivariable-adjusted model includes adjustment for breastfeeding (ever vs. never), delivery mode, gestational age, and birth weight
Total SCFAs includes butyric acid, propionic acid, acetic acid, isobutyric acid, valeric acid, isovaleric acid, heptanoic acid, and hexanoic acid. * = p < 0.05, ** = p < 0.01, and *** = p < 0.001

ISSN: 1471-2180