TABLE 6.

Summary of the mixed SCFAs studies design, participant and intervention characteristics and glycemic outcome analyzed¹

		Participant's characteristics				Intervention characteristics
Reference	Study design	Health status	Sample size (M/F)	Age, years	BMI, kg/m2	Amount given (acetate, propionate, butyrate)	Route of administration	Time-course	Control	Glycemic outcomes analyzed
Mixed SCFAs (acute)
Wolever et al., 1988 (65)	RCT, XO	HV	6 (3/3)	33.0	NI	Acetate 90 mmol/L + 30 mmol/L Propionate or Acetate 180 mmol/L + 60 mmol/L Propionate	Rectal	120 minutes	Saline	PBG PI
Wolever et al., 1991 (66)	RCT, XO	HV	6	29.0	24.1	Acetate (180 mmol/L) + propionate (60 mmol/L)	Rectal	120 minutes	Saline	PBG PI
Laurent et al., 1995 (36)	RCT, XO	HV	6 (3/3)	22	21.2	Acetate 12 mmol/h Propionate 4 mmol/h	Intragastric (infusion)	300 minutes	Saline	PBG PI
Alamowitch et al., 1996 (67)	RCT, XO	HV	6	26.0	20.9	90 mmol/L (Acetate: propionate: butyrate; 60,25,15 mmol/L)	Ileal	18 hours	Saline	Basal hepatic glucose production insulin sensitivity
Canfora et al., 2017 (68)	RCT, XO	HV	12 (12/0)	36.0	25–35	200 mmol/L (high acetate: 24, 8, 8 mmol/L) (high butyrate: 8, 8, 24 mmol/L) (high propionate: 8, 24, 8 mmol/L)2	Rectal	300 minutes	Saline	PBG PI Carbohydrate oxidation

¹Abbreviations: HV, healthy volunteers; NI, no information; PBG, postprandial blood glucose; PI, postprandial insulin; RCT, randomized controlled trial; XO, crossover.

²The second enema was given 3 hours after the first infusion and given with 75 g of oral glucose load to represent the postprandial state.