Dig Dis Sci. 2022 Jun;67(6):2299-2309. doi: 10.1007/s10620-021-07149-1. Epub 2021 Aug 14.

Ayesha Shah ^{1 2 3 4 5}, Saravana Ruban Gurusamy ^1 2, Teressa Hansen ², Gavin Callaghan ^2 6, Nicholas J Talley ^3 4 5 7, Natasha Koloski ^{1 2 3 4 5 7 8}, Marjorie M Walker ^3 4 5 7, Michael P Jones ^3 4 5 9, Mark Morrison ^{1 3 4 5 10}, Gerald J Holtmann ^{11 12 13 14 15 16}

Author information

¹Faculty of Medicine, University of Queensland, St. Lucia, QLD, Australia.

²Department of Gastroenterology and Hepatology, University of Queensland, Princess Alexandra Hospital, Ipswich Road, Brisbane, Woolloongabba, QLD, Australia.

³Australian Gastrointestinal Research Alliance, Brisbane, Australia.

⁴Australian Gastrointestinal Research Alliance, Newcastle, Australia.

⁵Australian Gastrointestinal Research Alliance, Sydney, Australia.

⁶Department of Pharmacy, Princess Alexandra Hospital, Brisbane, QLD, Australia.

⁷Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia.

⁸Faculty of Health and Behavioural Sciences, University of Queensland, Herston, QLD, Australia.

⁹Department of Psychology, Macquarie University, Sydney, NSW, Australia.

¹⁰Faculty of Medicine, University of Queensland Diamantina Institute, Woolloongabba, QLD, Australia.

¹¹Faculty of Medicine, University of Queensland, St. Lucia, QLD, Australia. g.holtmann@uq.edu.au.

¹²Department of Gastroenterology and Hepatology, University of Queensland, Princess Alexandra Hospital, Ipswich Road, Brisbane, Woolloongabba, QLD, Australia. g.holtmann@uq.edu.au.

¹³Australian Gastrointestinal Research Alliance, Brisbane, Australia. g.holtmann@uq.edu.au.

¹⁴Australian Gastrointestinal Research Alliance, Newcastle, Australia. g.holtmann@uq.edu.au.

¹⁵Australian Gastrointestinal Research Alliance, Sydney, Australia. g.holtmann@uq.edu.au.

¹⁶Faculty of Health and Behavioural Sciences, University of Queensland, Herston, QLD, Australia. g.holtmann@uq.edu.au.

Abstract

Background and aims: Antimicrobial therapy improves symptoms in patients with irritable bowel syndrome (IBS), but the efficacy in functional dyspepsia (FD) is largely unknown. While FD and IBS frequently overlap, it is unknown if concomitant IBS in FD alters the response to antimicrobial therapy in FD. Thus, we aimed to assess and compare the effect of antimicrobial therapy on visceral sensory function and symptom improvement in FD patients with and without IBS.

Methods: Adult patients with FD with or without IBS received rifaximin 550 mg BD for 10 days, followed by a 6-week follow-up period. The total gastrointestinal symptom score as measured by the SAGIS (Structured Assessment of Gastrointestinal Symptoms) questionnaire and subscores (dyspepsia, diarrhea, and constipation), symptom response to a standardized nutrient challenge and normalization of the glucose breath tests were measured.

Results: Twenty-one consecutive adult patients with FD and 14/21 with concomitant IBS were recruited. Treatment with rifaximin resulted in a significant (p = 0.017) improvement in the total SAGIS score from 34.7 (± 15.4) at baseline to 26.0 (± 16.8) at 2 weeks and 25.6 (± 17.8) at 6 weeks post-treatment. Similarly, compared to baseline there was a statistically significant improvement in SAGIS subscores for dyspepsia and diarrhea (all p < 0.05) and effects persisted for 6 weeks post-treatment. Similarly, the symptom score (and subscores) following a standardized nutrient challenge improved significantly (p < 0.001) 2 weeks post-treatment. The presence of concomitant IBS did not significantly influence the improvement of symptoms after antibiotic therapy (all p > 0.5).

Conclusions: In FD patients, the response to antimicrobial therapy with rifaximin is not influenced by concomitant IBS symptoms.