Clinical efficacy of fecal microbiota transplantation for patients with small intestinal bacterial overgrowth: a randomized, placebo-controlled clinic study

Abstract

Background: Small intestinal bacterial overgrowth (SIBO) is characterized by the condition that bacteria overgrowth in the small intestine. Fecal microbiota transplantation (FMT) has been applied as an effective tool for reestablishing the structure of gut microbiota. However, whether FMT could be applied as a routine SIBO treatment has not been investigated.

Methods: In this trial, 55 SIBO patients were enrolled. All participants were randomized in two groups, and were given FMT capsule or placebo capsules once a week for 4 consecutive weeks. Measurements including the lactulose hydrogen breath test gastrointestinal symptoms, as well as fecal microbiota diversity were assessed before and after FMT therapy.

Results: Gastrointestinal symptoms significantly improved in SIBO patients after treatment with FMT compared to participants in placebo group. The gut microbiota diversity of FMT group had a significant increase, while placebo group showed none.

Conclusions: This study suggests that applying FMT for patients with SIBO can alleviate gastrointestinal symptoms, indicating that FMT may be a promising and novel therapeutic regimen for SIBO. Trial registry This study was retrospectively registered with the Chinese Clinical Trial registry on 2019.7.10 (ID: ChiCTR1900024409, http://www.chictr.org.cn ).

Keywords: Fecal microbiota transplantation; Lactulose breath test; Small intestinal bacterial overgrowth; Therapeutic efficacy.

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1

Flow chart of patients included and excluded from analysis. FMT, fecal microbiota transplantation

Fig. 2

a SIBO-GSRS score between groups and their change over time. FMT, fecal microbiota transplantation; GSRS, Gastrointestinal Symptom Rating Scale. *month 1, 3 and 6 vs month 0 in FMT group (P < 0.05); # FMT group vs placebo group in different time-point (P < 0.05). b–f Average score of abdominal pain, reflux, indigestion, diarrhea and constipation in FMT and placebo group, significant difference was compared between FMT group vs placebo group in different time-point (*: P < 0.05; **: P < 0.01; ***: P < 0.001; ****: P < 0.0001)

Fig. 3

Comparison of LHBT at baseline and after FMT therapy at month 6. a The outcomes of LHBT of 53 patients pre- and post-FMT were represented as mean ± SD, respectively. According to the results of LHBT, the H2 concentration were found increased followed with time compared to the results at baseline, but there was no significant change in CH4 concentration. *FMT-baseline vs FMT-Month 6 (P < 0.05), # FMT-Month 6 versus placebo-month 6 (P < 0.05)

Fig. 4

a α-diversity of donor, pre-FMT, pre-placebo, pro-FMT, pro-placebo. Black line represented median α-diversities (chao 1), the boxes range from the lower to the upper quartiles. * pre-FMT vs pro-FMT (P < 0.05). b β-diversity plots (unweighted UniFrac distance) of donor, pre-FMT, pre-placebo. c β-diversity plots (unweighted UniFrac distance) of donor, pre-FMT, pre-placebo, pro-FMT, pro-placebo (pcoa). d Enterotype in gut microbiota community of different groups. e The difference of gut microbiota at the level of genus in the pre- and pro-FMT group. f The plot of correlation gut microbiota at the level of species