A small preliminary study of irritable bowel syndrome patients has found that this group has a high degree of microbial fermentation in the gut and that combined treatment with antibiotics and probiotics successfully reduces both fermentation and symptoms.
Previous studies have found an association between irritable bowel syndrome (IBS) and abnormally high levels of gut fermentation attributed to overgrowth of bacterial populations in the upper gut - a condition known as small intestinal bacterial overgrowth (SIBO). Researchers such as those at the G.I. Motility Program at Cedars-Sinai Medical Center, Los Angeles, have found treatment with the non-absorbable antibiotic rifaximin can address SIBO and reduce symptoms of IBS while being well tolerated.
Building on this work, scientists in Argentina have recently published the results of a study in which they added a course of probiotics subsequent to rifaximin treatment and monitored effects on both fermentation and symptoms of IBS.
The researchers recruited 15 patients who met the Rome III criteria for IBS.
Each participant underwent a lactulose breath test (LBT) prior to the commencement of the treatment protocol. This involves measurement of hydrogen gas in a person's breath following consumption of the non-absorbed sugar lactulose and is the standard test used to assess levels of gut fermentation and whether a patient suffers from SIBO.
Study participants also completed a standard questionnaire to assess the severity of their symptoms. Both the LBT and questionnaire were repeated following treatment.
Each of the 15 participants then received sequential antibiotic and probiotic therapy - 7 days rifaximin treatment followed by a 10 day course of a probiotic supplement.
The LBT and questionnaire results at thirty days after the end of treatment revealed 14 of the 15 participants (93%) experienced a significant improvement in their symptoms which corresponded to a significant reduction in gut fermentation as indicated by reduced hydrogen concentrations on the LBT.
The researchers conclude that "Sequential treatment with rifaximin/probiotics seems to be effective for symptom and fermentative profile improvement in irritable bowel syndrome patients."
It should be noted however that while the these results are encouraging, firm conclusions cannot be drawn from a study involving such a small number of participants. It is hoped larger studies in the future will confirm these results and provide more conclusive evidence in support of this treatment approach for IBS.
Source: Dima G Peralta D Novillo A Lasa J Besasso H Soifer L (2012) Variation of intestinal fermentative profile after sequential therapy with rifaximin/probiotics Acta Gastroenterologica Latinoamericana 42(2):99-104