Table 2.

Results of subgroup analyses of the effects of probiotics on lumbar spine BMD.

Subgroup		Lumbar spine BMD
		Effect size	95% CI	I2	P value
T score < -2.5	No (n = 8)	0.76	0.17, 1.36	93.9%	0.012
	Yes (n = 3)	0.19	-0.46, 0.84	80.9%	0.559
Intervention duration	≤ 6 months (n = 7)	0.36	-0.14, 0.86	86.1%	0.155
	> 6 months (n = 4)	1.03	0.06, 2.00	96.4%	0.037
Types of probiotics	Single-strain (n = 4)	0.77	-0.13, 1.66	93.7%	0.095
	Multiple-strain (n = 7)	0.51	-0.08, 1.10	92.3%	0.091
Region	Asia (n =6)	0.40	-0.18, 0.98	88.0%	0.173
	Europe (n = 5)	0.84	0.05, 1.63	95.2%	0.037
Dosage of probiotics	≥1 x 10^9 CFU/d (n = 8)	0.76	0.13, 1.39	93.9%	0.018
	< 1 x 10^8 CFU/d (n = 3)	0.22	-0.35, 0.79	82.5%	0.451

BMD, bone mineral density; CFU, colony forming unit; CI, confidence interval.