2022 - SIBO - Small Intestinal Bacterial Overgrowth

2022 Research Articles

Overview

Small Intestinal Bacterial Overgrowth. PMID: 31536241
Asian-Pacific consensus on small intestinal bacterial overgrowth in gastrointestinal disorders: An initiative of the Indian Neurogastroenterology and Motility Association PMID: 36214973

Causes/ Risk Factors
Diseases

The prevalence of small intestinal bacterial overgrowth in diabetes mellitus: a systematic review and meta-analysis PMID: 35086065
Severe small intestinal bacterial overgrowth syndrome after jejunal feeding requiring surgical intervention: a case report and review of the literature. PMID: 35725375
Small Intestinal Bacterial Overgrowth in Patients with Roux-en-Y Gastric Bypass and One-Anastomosis Gastric Bypass PMC9672017

Food/Water Poisoning

Campylobacter infection and the link with Irritable Bowel Syndrome: on the pathway towards a causal association. PMID: 35134916 Results: “In rodent models, Campylobacter jejuni 81-176 can cause loose stool months after the infection is cleared, and share common pathophysiology as IBS patients, such as elevated intestinal TLR-4 and IL-8, antibodies to CdtB and vinculin, increased intraepithelial lymphocytes, and small intestinal bacterial overgrowth.”

Surgery

The Effects of One Anastomosis Gastric Bypass Surgery on the Gastrointestinal Tract PMID: 35057486
SMALL INTESTINAL BACTERIAL OVERGROWTH (SIBO) REMAINS A FREQUENT SCOURGE OF SYMPTOMATIC GASTRIC BYPASS PATIENTS BASED ON JEJUNAL ASPIRATES: Mo1600 Summary: 96% rate of SIBO after gastric bypass (in those with GI symptoms)

Pathophysiology

Small Intestine Bacterial Overgrowth Can Form an Indigenous Proinflammatory Environment in the Duodenum: A Prospective Study. PMID: 35630404
Small Intestinal Bacterial Overgrowth Pathophysiology and its Implications for Definition and Management doi.org/10.1053/j.gastro.2022.04.002
Immune responses in the irritable bowel syndromes: time to consider the small intestine.
PMID: 35354471
The human microbiome in disease and pathology. PMID: 35393656
SUBCUTANEOUS INOCULATION WITH CYTOLETHAL DISTENDING TOXIN B IN A RAT MODEL OF POST-INFECTIOUS IBS PRODUCES PROFOUND CHANGES IN THE SMALL BOWEL MICROBIOME: Tu1383 Summary: In an animal model, food poisoning can cause 2 different types of SIBO: 1) Desulfovibrio overgrowth/Hydrogen Sulfide SIBO, with increased small intestine diversity from increased stool microbes (fecalization of the small intestine), 2) E. coli overgrowth/Hydrogen SIBO, with decreased small intestine microbiome diversity.

COMPREHENSIVE CHARACTERIZATION OF THE GASTROINTESTINAL LUMINAL ARCHAEOME: DATA FROM THE REIMAGINE STUDY: Sa1644 Summary: In this methanogen microbiome study of 14 subjects, methanogens were more common in the small intestine (100%) vs the large intestine (50%).
EXAMINING THE ROLE OF SULFATE REDUCING BACTERIA AND METHANOGENS ON MICROBIOME, SYMPTOMS, AND BREATH TESTING 169 Summary: A) IBS-Constipation subjects have higher Methane breath levels, and increased abundance of Methanogens, especially M. smithii. 89% IBS-Constipation patients with positive methane have M. smithii in their stool vs. only 17.5% of IBS-Diarrhea patients. B) IBS-Diarrhea subjects have higher Hydrogen and Hydrogen Sulfide breath levels, and increased abundance of Hydrogen Sulfide producers Fusobacterium and Desulfovibrio.

BACTERIAL-ARCHAEAL SYMBIOSIS AND HYDROGEN-METHANE ECONOMY IN METHANOGENIC SMALL INTESTINAL BACTERIAL OVERGROWTH: Mo1210

Methanogens and Hydrogen Sulfide Producing Bacteria Guide Distinct Gut Microbe Profiles and Irritable Bowel Syndrome Subtypes. PMID: 36114762 Summary: Introduces new term "Microtypes" indicating distinct microorganism profiles in each type of IBS. This links the newest research on which microbes are overgrown in each type of SIBO/IMO, with the IBS subtypes.
"What is new here:
- Distinct gut microtypes are linked to breath gas patterns in IBS-C and IBS-D subjects,
- In CH4+ IBS-C subjects, increased breath CH4 correlated with increased gut microbial diversity,
- In IBS-D subjects, increased breath H2 correlated with lower microbial diversity, and increased breath H2S correlated with increased predominance of H2S-producers, including Fusobacterium and Desulfovibrio species,
- The predominant H2-producers in IBS-C subjects were Ruminococcaceae and Christensenellaceae, which include known bacterial syntrophs for methanogens [they make the hydrogen for the methanogens],
- Predicted microbial metabolic pathway analysis indicated enrichment of pathways associated with methanogenesis in IBS-C/CH4+ subjects, and enrichment of pathways associated with H2S production in IBS-D subjects"
Antimicrobial treatment improves tryptophan metabolism and mood of patients with small intestinal bacterial overgrowth.
PMID: 36167589
Patients with breath test positive are necessary to be identified from irritable bowel syndrome: a clinical trial based on microbiomics and rifaximin sensitivity. PMID: 36070467
Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth PMID: 35956393
CME Exam 2: Small Intestinal Bacterial Overgrowth—Pathophysiology and Its Implications for Definition and Management doi.org/10.1053/j.gastro.2022.06.079Get

Associated Conditions
Asthma

A Metabolic Activity Recovery of the Intestinal Microbiota in the Patients with Bronchial Asthma PMID: 36247882

Cancer

Celiac Disease

Links between celiac disease and small intestinal bacterial overgrowth: A systematic review and meta-analysis PMID: 35734803 Summary: Largest meta-analysis on Celiac and SIBO with 14 studies.
- “Utilizing breath tests, SIBO prevalence in CeD [Celiac Disease] patients was 20.8%"
- Surprisingly they found: "....SIBO prevalence in CeD patients nonresponsive to a gluten free diet (GFD) was not statistically higher as compared with those responsive to GFD. And "SIBO in celiac disease was not associated with more severe changes in small intestinal histology or celiac serology.”
- "Antibiotic therapy of SIBO positive CeD patients resulted in improvement in gastrointestinal symptoms in 95.6% and normalization of breath tests."
- "Thus, the small intestinal dysbiosis [SIBO] is potentially the cause of unexplained gastrointestinal symptoms in at least a proportion of patients with celiac disease. Thus, testing and treating SIBO in patients with celiac disease with unexplained gastrointestinal symptom could potentially improve symptoms and reduce the likelihood of malnutrition."