This has just been published: Efficacy of probiotics, prebiotics and synbiotics in irritable bowel syndrome: a systematic review and meta-analysis of randomized, double-blind, placebo-controlled trials [Sep 2023]

I have done a strikethru on items that are likely waste of money (based on P Value). 0.001 is better than .04.

	Number of trials	Number of patients	RR of persistence of global symptoms (95% CI)	P value for the difference	I2 (P value for χ2)
All patients
All combination probiotics	32	3369	0.78 (0.71–0.87)	<.001	71% (<.001)
VSL#3	4	155	0.78 (0.53–1.16)	.23	47% (.13)
Lactobacillus paracasei ssp paracasei F19, Lactobacillus acidophilus La5, and Bifidobacterium lactis Bb12	3	269	0.92 (0.76–1.11)	.38	14% (.31)
Enterococcus faecalis DSM16440 and Escherichia coli DSM17252	2	686	0.71 (0.33–1.51)	.37	97% (<.001)
LacClean Gold S	2	130	0.59 (0.37–0.93)	.02	0% (.56)
Duolac 7s	2	76	0.62 (0.43–0.89)	.009	0% (.62)
All Lactobacillus strains	16	1498	0.84 (0.72–0.98)	.03	69% (<.001)
Lactobacillus plantarum 299V	5	453	0.73 (0.59–0.92)	.007	59% (.04)
All Bifidobacterium strains	5	1161	0.82 (0.67–1.02)	.07	74% (.004)
Bifidobacterium bifidum MIMBb75	2	565	0.69 (0.46–1.04)	.07	83% (.01)
All Bacillus strains	3	216	0.44 (0.34–0.57)	<.001	0% (.48)
All Saccharomyces strains	2	469	0.94 (0.80–1.11)	.49	0% (.86)
All Escherichia strains	2	418	0.86 (0.79–0.93)	<.001	0% (.78)
All Blautia strains	1	366	0.93 (0.84–1.03)	.15	N/A
All Clostridium strains	1	200	0.80 (0.64–0.99)	.04	N/A
All Streptococcus strains	1	54	0.72 (0.53–0.99)	.04	N/A
Patients with IBS-D
All combination probiotics	13	1272	0.78 (0.67–0.92)	.002	69% (<.001)
VSL#3	2	49	0.42 (0.04–4.85)	.49	82% (.02)
Duolac 7s	2	76	0.62 (0.43–0.89)	.009	0% (.62)
All Lactobacillus strains	4	157	0.57 (0.36–0.89)	.01	27% (.25)
All Saccharomyces strains	2	169	0.99 (0.76–1.28)	.92	0% (.81)
All Clostridium strains	1	200	0.80 (0.64–0.99)	.04	N/A
All Blautia strains	1	202	0.94 (0.82–1.08)	.36	N/A
All Escherichia strains	1	54	1.00 (0.57–1.74)	1.00	N/A
All Bifidobacterium strains	1	44	0.64 (0.36–1.16)	.14	N/A
All Bacillus strains	1	40	0.57 (0.31–1.05)	.07	N/A
Patients with IBS-C
All combination probiotics	4	295	1.01 (0.89–1.14)	.87	8% (.35)
All Saccharomyces strains	1	180	0.82 (0.62–1.08)	.16	N/A
All Blautia strains	1	164	0.92 (0.78–1.07)	.26	N/A
All Escherichia strains	1	35	0.84 (0.41–1.73)	.64	N/A