Table 1.

Characteristics of studies included in the review.

Reference and type of study	n patients	Symptoms pre	GFD	Challenge	Gluten (g)	Gluten vehicle	Symptoms post
(Biesiekierski et al., 2011)	34	IBS	6 w	6 w	16	muffin	GI + extra GI
DBRPCT according Salerno's criteria
(Carroccio et al., 2012)	920	NCGS	4 w	2 w	20	cps	GI
DBRPCT with cross-over
(Biesiekierski et al., 2013)	37	NCGS	6 w	3 d	16	meal	GI + fatigue
DBRPCT with cross-over
(Brottveit et al., 2013)	22	NCGS	variable	3 d	4.4	bread	GI
Open trial
(Shahbazkhani et al., 2015)	72	IBS	6 w	6 w	52	flour	GI + fatigue
DBRPCT according Salerno's criteria
(Di Sabatino et al., 2015)	59	NCGS	11 m	1 w	4.4	cps	GI + extra GI
DBRPCT with cross-over
(Zanini et al., 2015)	35	NCGS	6 m	10 d	7.9	flour	GI + extra GI
DBRPCT with cross-over
(Capannolo et al., 2015)	364	NCGS	6 m	1 m	ns	ns	GI + extra GI
Open trial
(Elli et al., 2016)	97	IBS	3 w	1 w	5.6	cps	GI
DBRPCT with cross-over
(Picarelli et al., 2016)	26	NCGS	1 w	1 d	10	cookie	GI + extra GI
DBRPCT
(Rosinach et al., 2016)	18	NCGS	12 m	6 m	16.2	flour	GI
DBRPCT according Salerno's criteria

DBRPCT, double-blind randomized placebo controlled trial; IBS, irritable bowel syndrome; w, weeks; cps, capsule; ns, not specified; GI, gastro-intestinal