Small Intestinal Bacterial Overgrowth: Clinical Presentation in Patients with Roux-en-Y Gastric Bypass.

Area of Science:

• Gastroenterology
• Bariatric Surgery Outcomes
• Microbiome Research

Background:

• Small intestinal bacterial overgrowth (SIBO) is characterized by increased bacteria in the small intestine, diagnosed via glucose breath tests.
• SIBO is frequently observed in patients following abdominal surgeries, notably Roux-en-Y gastric bypass (RYGB).
• SIBO often presents with non-specific gastrointestinal (GI) symptoms, necessitating thorough diagnostic evaluation.

Purpose of the Study:

• To determine the prevalence of SIBO diagnosis in individuals with RYGB anatomy.
• To compare the likelihood of specific GI symptoms between RYGB patients and those with native anatomy.

Main Methods:

• A large, matched cohort study involving patients undergoing glucose breath tests (GBT) for SIBO.
• 1:2 matching was used to compare patients with RYGB anatomy to those with native anatomy.
• Univariate and multivariate analyses identified GI symptoms associated with SIBO in RYGB versus native anatomy groups.

Main Results:

• The study included 17,973 patients; 271 with RYGB were matched with 573 with native anatomy.
• SIBO was diagnosed in 73.4% of RYGB patients with positive GBT versus 36% of native anatomy patients.
• RYGB patients with SIBO reported significantly higher rates of nausea, vomiting, bloating, and diarrhea compared to native anatomy patients.

Conclusions:

• Small intestinal bacterial overgrowth (SIBO) is highly prevalent in patients with Roux-en-Y gastric bypass (RYGB) anatomy.
• Nausea, vomiting, bloating, and diarrhea are more common GI symptoms in RYGB patients with SIBO.
• These symptoms in RYGB patients warrant early SIBO evaluation.