TABLE 2.

Enrichment of SCFA and CO₂ after incubation with ¹³CO₂ and unlabeled glucose

Incorporation of 13CO2		Aneg group		Apos group		P valueb
SCFA	Position	% 13C enrichment of C atom	13C concn (mM)a	% 13C enrichment of C atom	13C concn (mM)a
Acetate	CH3	3.60	1.51c	2.08	0.93d	<0.0004
	COOH	5.79	2.38c	3.02	1.32d	<0.00002
	CH3	1.92	0.33	1.10	0.27
Butyrate	CH2	2.48	0.43	1.44	0.36
	CH2	1.90	0.32	1.09	0.27
	COOH	2.79	0.47	1.60	0.40
Propionate	CH3	1.19	0.17	0.63	0.08	<0.0002
	CH2	0.94	0.14	0.46	0.05	<0.0007
	COOH	17.98	2.58	13.86	1.42	<0.002
	CO2	21.70		26.20		<0.00002

^aCalculated by multiplying the SCFA concentration shown in Table 1 by the percent ¹³C enrichment divided by 100. 

^bProbability that the Aneg group and Apos group values are different, as determined by Student’s t test. 

^cThe methyl and carboxyl group values are significantly different (P < 9 × 10⁻¹³), as determined by Student’s t test. 

^dThe methyl and carboxyl group values are significantly different (P < 0.0002), as determined by Student’s t test.