Table 1.

Meta-analyses of the efficacy of probiotics counteracting intestinal barrier disruptions secondary to cancer treatment

Study aim	Number of trials/patients	Primary diagnosis	Outcome	Reference
To evaluate the efficacy of probiotics on the intestinal mucosa barrier indices	17/1242	Colorectal cancer	Probiotics significantly affect L/M ratio: SMD = 3.83, p = 0.001 Bifidobacterium/Escherichia ratio (SMD = 3.91, p = 0.000) Ocludin ratio (SMD = 4.74, p = 0.000) Bacterial translocation (SMD = 3.12, p = 0.002) SIgA level (SMD = 2.91, p = 0.004) CRP level (SMD = 4.21, p = 0.000) – probiotics do not influence IL-6 level (SMD = 1.33, p = 0.184)	[115]
To assess whether probiotics may prevent cancer therapy-induced diarrhea	7/1091		Probiotics do not prevent or reduce the overall incidence of diarrhea (RR = 0.81, 95% CI: 0.60-1.09, p = 0.16)	[116]
To establish a link between probiotics and the incidence of cancer surgical infection	7/816	Colorectal cancer	Probiotics significantly affected: bacteria in blood: OR = 0.4069 (95% CI: 0.2662-0.6222, p < 0.0001) infectious complications: OR = 0.5388 (95% CI: 0.4058-0.7154, p < 0.0001)	[117]
To assess whether probiotics may support H. pylori eradication	14/1671	H. pylori infection	Probiotic therapy significantly increases rate of H. pylori eradication: OR = 1.84 (95% CI: 1.34-2.54)	[118]
	30/4302	H. pylori infection	Probiotics significantly improve H. pylori eradication rates (APP: RR = 1.122; 95% CI: 1.091-1.153; p < 0.001; ITT: RR = 1.141; 95% CI: 1.106-1.175; p < 0.001)	[119]

SMD – standardized mean difference, ITT – intention to treat, APP – as-per-protocol, L/M – lactulose/mannitol, RR – relative risk, OR – odds ratio, CI – confidence interval, CRP – C-reactive protein, H. pylori – Helicobacter pylori