Small Intestinal Transit Time Is Delayed in Small Intestinal Bacterial Overgrowth.

BACKGROUND: Altered small intestinal motility is thought to contribute to the development of small intestinal bacterial overgrowth (SIBO). The clinical manifestations of SIBO and consequent malabsorption are wide ranging and include abdominal pain, bloating, diarrhea, weight loss, and nutritional deficiencies. However, due to the nonspecific nature of symptoms, the diagnosis may often be overlooked. To date, few studies have illustrated a direct relationship between impaired small intestinal motility and SIBO. In addition, further study has been limited by the technical challenges and lack of widespread availability of antroduodenal manometry. The development of a wireless motility capsule (WMC) (SmartPill) that evaluates pressure, pH, and temperature throughout the GI tract offers the potential to identify patients with small bowel transit delays who may be at risk for bacterial overgrowth. AIMS: The primary aims of this study were to: (1) characterize the relationship of prolonged small bowel transit time (SBTT) in patients undergoing WMC with SIBO as based on a positive lactulose breath testing (LBT); and (2) to assess the relationship of prolonged gastric, colonic, and whole gut transit times (WGTT) and additional motility parameters with SIBO (positive LBT). We also sought to evaluate the relationship of small bowel motility parameters (SB motility index, contractions per minute, and SB peak amplitudes) with LBT results. METHODS: We performed a retrospective study of consecutive patients who were referred for wireless motility testing at a single, tertiary care institution from April 2009 to December 2012. Of the 72 total patients identified, 34 underwent both WMC and LBT. Gastric, small bowel, colonic, WGTT, and SB motility parameters were measured and correlated with LBT results. Statistical methods utilized for data analysis include ANOVA, 2-sample t tests, nonparametric Kruskal Wallis test, Wilcoxon rank-sum test, and the Fisher exact test. RESULTS: Of the 37 patients who underwent both WMC and LBT, 24 (65%) were LBT positive. The mean SBTT among those who were LBT positive was 6.6 hours as compared with 4.2 hours in those who were LBT negative (P=0.04). Among patients who were LBT positive, 47.6% had prolonged SBTT (≥6 h), whereas only 7.7% of those who were LBT negative had a delay in their SBTT (P=0.01). In addition, patients who were LBT positive were more likely to have prolongation of both colonic and WGTT versus those who were LBT negative (CTT: positive LBT=64.4 h vs. negative LBT=35.5 h, P=0.02; WGTT: positive LBT=70.5 h vs. negative LBT=44.1 h, P=0.02). However, there were no statistical differences observed between the groups for gastric emptying times or other small intestinal motility parameters (SB motility index, contractions per minute, and peak amplitudes) between the 2 groups. CONCLUSIONS: Patients with underlying SIBO have significant delays in SBTT as compared with those without. The association between prolonged SBTT and positive LBT may be useful in identifying those patients with SIBO diagnosed by LBT and potentially target therapeutic options for those refractory to standard therapy. Interestingly, patients with positive LBT did not necessarily have a generalized gastrointestinal motility (similar GETs among groups), suggesting that small bowel transit specifically predisposes to the development of SIBO. Future, prospective studies are needed to further characterize intestinal dysmotility and other contributing pathophysiological mechanisms in SIBO and to investigate the potential benefits of prokinetics in this challenging patient population.

Low ileocecal valve pressure is significantly associated with small intestinal bacterial overgrowth (SIBO).

BACKGROUND: Small intestinal bacterial overgrowth (SIBO) is a significant and increasingly recognized syndrome. While the development may be multifactorial, impairment of the ileocecal valve (ICV), small bowel motility, and gastric acid secretion have been hypothesized to be risk factors. ICV dysfunction remains largely unexplored using standard technology. The wireless motility capsule (WMC) that evaluates pressure, pH, and temperature throughout the GI tract provides the ability to assess these parameters. AIMS: The primary aims of this study were to assess the relationship of ICV pressures, small bowel transit time (SBTT) and intestinal pH with lactulose hydrogen breath testing (LBT) results in subjects with suspected SIBO. METHODS: We retrospectively studied consecutive patients referred to our institution for WMC and LBT from 2010-2012. Ileocecal junction pressures (IJP), as a surrogate for ICV pressures, were defined as the highest pressure over a 4-min window prior to the characteristic ileocecal pH drop. SBTT and pH were calculated and compared with LBT results. RESULTS: Twenty-three patients underwent both WMC and LBT, with positive results observed in 15 (65.2%). IJP were significantly higher in LBT(-) negative vs. LBT(+) (79.9 vs. 45.1, p < 0.01). SBTT was significantly longer in LBT(+) versus LBT(-) (5.82 vs. 3.81 h, p = 0.05). Among LBT(+) subjects, gastric pH was significantly higher versus LBT(-) subjects (2.76 vs. 1.63, p = 0.01). There was poor correlation between IJP and other parameters (SBTT, small bowel pH, and gastric pH). CONCLUSIONS: Low IJP is significantly associated with SIBO. While this is physiologically plausible, to our knowledge, this is the first study to make this connection. Prolonged SBTT and higher pH are also independently associated with SIBO. Our findings add value of the WMC test as a diagnostic tool in patients with functional gastrointestinal complaints and suggest re-focus of attention on the ileocecal valve as a prominent player in intestinal disorders.

Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth.

OBJECTIVE: Patients with small intestine bacterial overgrowth (SIBO) have chronic intestinal and extraintestinal symptomatology which adversely affects their quality of life. Present treatment of SIBO is limited to oral antibiotics with variable success. A growing number of patients are interested in using complementary and alternative therapies for their gastrointestinal health. The objective was to determine the remission rate of SIBO using either the antibiotic rifaximin or herbals in a tertiary care referral gastroenterology practice. DESIGN: One hundred and four patients who tested positive for newly diagnosed SIBO by lactulose breath testing (LBT) were offered either rifaximin 1200 mg daily vs herbal therapy for 4 weeks with repeat LBT post-treatment. RESULTS: Three hundred ninety-six patients underwent LBT for suspected SIBO, of which 251 (63.4%) were positive 165 underwent treatment and 104 had a follow-up LBT. Of the 37 patients who received herbal therapy, 17 (46%) had a negative follow-up LBT compared to 23/67 (34%) of rifaximin users (P=.24). The odds ratio of having a negative LBT after taking herbal therapy as compared to rifaximin was 1.85 (CI=0.77-4.41, P=.17) once adjusted for age, gender, SIBO risk factors and IBS status. Fourteen of the 44 (31.8%) rifaximin non-responders were offered herbal rescue therapy, with 8 of the 14 (57.1%) having a negative LBT after completing the rescue herbal therapy, while 10 non-responders were offered triple antibiotics with 6 responding (60%, P=.89). Adverse effects were reported among the rifaximin treated arm including 1 case of anaphylaxis, 2 cases of hives, 2 cases of diarrhea and 1 case of Clostridium difficile. Only one case of diarrhea was reported in the herbal therapy arm, which did not reach statistical significance (P=.22). CONCLUSION: SIBO is widely prevalent in a tertiary referral gastroenterology practice. Herbal therapies are at least as effective as rifaximin for resolution of SIBO by LBT. Herbals also appear to be as effective as triple antibiotic therapy for SIBO rescue therapy for rifaximin non-responders. Further, prospective studies are needed to validate these findings and explore additional alternative therapies in patients with refractory SIBO.