Blastocystis hominis and Dientamoeba fragilis in patients fulfilling irritable bowel syndrome criteria

Abstract

Studies have suggested a possible role for Blastocystis hominis and Dientamoeba fragilis in the etiology of irritable bowel syndrome (IBS). We studied the prevalence of B. hominis and D. fragilis in patients with IBS-diarrhea (IBS-D). Three hundred and thirty patients were enrolled, 171 (52%) with IBS-D and 159 (48%) were controls, respectively. Stool microscopy, culture, and polymerase chain reaction (PCR) for B. hominis and D. fragilis were done. B. hominis was positive by stool microscopy in 49% (83/171) of IBS compared to 24% (27/159) in control (p < 0.001). B. hominis culture was positive in 53% (90/171) in IBS compared to 16% (25/159) in control (p < 0.001). B. hominis PCR was positive in 44% (75/171) in IBS compared to 21% (33/159) in control (p < 0.001). D. fragilis microscopy was positive in 3.5% (6/171) in IBS-D compared to 0.6% (1/159) in control (p = 0.123). D. fragilis culture was positive in 4% (7/171) in IBS compared to 1.3% (2/159) in control (p = 0.176). D. fragilis PCR was positive in 4% (6/171) in IBS-D compared to 0% (0/159) in control (p = 0.030). B. hominis is common, while D. fragilis was less prevalent in our patients with IBS-D. B. hominis and D. fragilis culture had a better yield compared to stool microscopy and PCR.

Treatment of Dientamoeba fragilis in Patients with Irritable Bowel Syndrome

“…Both compare the prevalence of D. fragilis in IBS-patients and controls. 35,36 One study found that D. fragilis was more prevalent in IBS-patients compared with controls (4% versus 0%), 35 whereas the other study showed the exact opposite (2% versus 27%). 36 Methodological differences make the results difficult to compare.…”

“…Clinical response rate in patients co-infected with Blastocystis was low, and we failed to eradicate D. fragilis and Blastocystis from two patients. Blastocystis has previously been associated to IBS, 27,35,36 and further studies into the relevance of this parasite in IBS are warranted. Because of the limitations of the study no firm conclusions can be made, and results can primarily serve a hypothesis-generating purpose.…”

“…Effect of eradication of D. fragilis on gastrointestinal symptoms has also been described in non-IBS populations. 26,34 Epidemiological studies report prevalence rates of D. fragilis in IBS patients of 2-4%, 35,36 with the one study finding an association between D. fragilis and IBS, 35 which was not confirmed by the other. 36 Therefore, the role of D. fragilis in IBS symptoms remains to be clarified.…”

Parasitosis y síndrome de intestino irritable

“…Infectología al Día las mismas técnicas (p < 0,001) 42 . Pese a estos resultados, otros estudios no logran demostrar la asociación entre SII y B. hominis [43][44][45][46] .…”

Possible Association between Blastocystis hominis and Bowel Disorders among Iraqi Patients in Kirkuk Province

“…IBS is undoubtedly a heterogeneous disorder and may, indeed, encompass a number of distinct entities (Loftus, 2004). It comes as no surprise, therefore, that over the years a number of factors have been proposed as relevant to the etiopathogenesis of IBS and its various symptoms such as psychological and environmental agents besides infection with different agents (Drossman et al, 2010;Ji et al, 2005;Spiller et al, 2009). Later, studies have described a possible role for protozoan parasites, such as Blastocystosis hominis, Dientamoeba fragilis, and others in the etiology of IBS or IBD (Tungtrongchitr et al, 2004;Yakoob et al, 2010). Hence, it is essential that all patients with IBS undergo routine parasitological investigations in order to rule out the presence of protozoan parasite as the causative agents of clinical signs.…”