Saccharomyces cerevisiae CNCM I-3856 in irritable bowel syndrome: An individual subject meta-analysis

Table 1 Characteristics of the trials

Trial	Type of IBS	Criteria	Sample size	Probiotic	Probiotic dosage1	Control	Duration of treatment	Follow-up
Pineton de Chambrun et al[10] 2015	All types	Rome III	200	Saccharomyces cerevisiae CNCM I-3856	1 capsule (500 mg) of S. cerevisiae/d	Placebo	8 wk	3 wk
					8 × 109 CFU/g
Spiller et al[11] 2015	All types	Rome III	379	Saccharomyces cerevisiae CNCM I-3856	2 capsules of 500 mg of S. cerevisiae/d	Placebo	12 wk	-
					8 × 109 CFU/g

¹The capsules contained viable yeast cells only, no excipient has been added. Probiotic products should contain the adequate amount of living cells to be efficient. Then, it is needed to maintain a suitable level of viable cells during the product’s shelf life. This living yeast cells count is expressed most of time as a minimum of colony forming unit per gram. This count of the yeast strain CNCM I-3856 cells after manufacturing was around 8 × 10⁹ CFU/g. It could slightly vary within the specification limits at release depending on the batch even if the manufacturing process and the microbiological methods are validated. This variation is due to the type of products (microbiological products obtained by fermentation) and due to the method variability of viable cell counts (± 0.5 log). Moreover, it has to be considered that viable cell count slightly decreases with time (sensitivity to humidity and temperature), which has already been confirmed by a stability test program performed according international conference on harmonisation guidelines. That is why, an overdose is commonly adopted for probiotics. Based on these considerations, efficacy of probiotics is considered by the scientific community as similar when dosage remains within the same log. CFU: Colony forming unit; IBS: Irritable bowel syndrome.

Table 2 Patient characteristics for the 2 trials n (%)

	Placebo group	Active group
Subjects, n	287	292
Age (yr), mean ± SD	45.3 ± 14.03	44.4 ± 14.79
Subject weight (kg), mean ± SD	64.6 ± 12.37	65.8 ± 13.75
Subject height (cm), mean ± SD	164.3 ± 7.75	164.9 ± 8.19
Subject BMI (kg/m²), mean ± SD	23.9 ± 3.93	24.1 ± 4.53
Heart rate (bpm), mean ± SD	70.2 ± 9.10	70.6 ± 9.08
Female	244 (85.0)	245 (83.9)
Smoker	65 (22.6)	75 (25.7)
IBS-C	134 (46.7)	130 (44.5)
IBS-C with an abdominal pain/discomfort score ≥ 2 at baseline	111 (38.7)	111 (38.0)
IBS-D	55 (19.2)	56 (19.2)
IBS-M	96 (33.4)	103 (35.3)

BMI: Body mass index; IBS: Irritable bowel syndrome.