Levothyroxine therapy and impaired clearance are the strongest contributors to small intestinal bacterial overgrowth: Results of a retrospective cohort study

Table 4 Immunological factors

	SIBO		Non-SIBO		χ2 test	OR	RR
	n = 175	%	n = 1634	%	P value
IgA-deficiency	0 of 6	0.0	13 of 75	17.3	0.337	-	-
IgG-deficiency	3 of 5	60.0	15 of 52	28.8	0.175	-	-
IgM-deficiency	0 of 5	0.0	15 of 54	21.7	0.311	-	-
5-Aminosalicylates	24	13.7	183	11.2	0.191	-	-
Steroid use	36	20.6	222	13.6	0.0101	1.647	0.660
Immunosuppressant use	8	4.6	31	1.9	0.0291	2.477	0.415
Azathioprin use	7	4.0	31	1.9	0.0672	2.155	0.474
Metotrexate use	3	1.7	0	0.0	0.0011	n/a	n/a
Any drug-induced immunosuppression	39	22.3	230	14.1	0.0041	1.751	0.632
Steroid plus immunosuppressant	7	4.0	23	1.4	0.0211	2.918	0.352

¹Statistical significant with P value P < 0.05;

²Statistical tendency with P value 0.05 < P < 0.1 χ² test each. Deficiencies of immunoglobulins were not associated with a higher prevalence of SIBO. On the other hand, pharmacologically induced immunosuppression with steroids alone, with an immunosuppressant alone or with both in combination lead to a higher risk of developing of SIBO. SIBO: Small intestinal bacterial overgrowth.