Small Intestine Bacterial Overgrowth Can Form an Indigenous Proinflammatory Environment in the Duodenum: A Prospective Study

Abstract

Small intestinal bacterial overgrowth (SIBO) contributes to the formation of an inflammatory environment in various intestinal and extraintestinal diseases. Cytokines that participate in these mechanisms are yet to be examined. Upper gastrointestinal endoscopy with duodenal aspiration was performed in 224 patients. Quantitative cultures of aerobic species were performed, concentrations of interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) were measured, and loads of Escherichia coli, Klebsiella pneumoniae, Methanobevibacter smithii, and Aeromonas spp. were detected via real-time PCR in the duodenal fluid. Analysis showed that the odds ratio (OR) for elevated IL-1β levels was 2.61 (1.06–6.43, p = 0.037) among patients with SIBO compared to patients without SIBO, while there was no significant difference at elevated IL-6 and TNF-α levels between patients with and without SIBO, using ≥10³ cfu/mL as a cut-off. The presence of all three elevated cytokine levels has OR 3.47 (1.06–11.34, p = 0.030) among patients with SIBO. Klebsiella pneumoniae detection was positively related with IL-6 and TNF-α levels, when Methanobevibacter smithii was positively related with IL-1β levels. The presence of SIBO is associated with elevated IL-1β levels in the duodenal fluid. There is a high prevalence of all three proinflammatory cytokine levels elevated (IL-1β, IL-6, and TNF-α) in the duodenal fluid among patients with SIBO.

Influence of Body Composition and Specific Anthropometric Parameters on SIBO Type

“…The deregulation of any of these protective mechanisms can lead to microbiota dysbiosis, a potential pathway for the development of Small Intestinal Bacterial Overgrowth (SIBO) [ 2 , 3 ]. SIBO is characterized by increased colonization of anaerobic and aerobic microorganisms within the small intestine, predominantly Gram-negative species including Klebsiella pneumoniae, Escherichia coli , Streptococcus gramineus , Prevotella , Clostridium spp, and Methanobrevibactersmithii [ 4 , 5 , 6 ]. Depending on the dominant composition of the bacterial overgrowth, the production of gases as a result of bacterial fermentation, such as hydrogen (H 2 ), methane (CH 4 ), or hydrogen sulfide (H 2 S) is observed.…”

A Systematic Review and Meta-Analysis of the Inflammatory Biomarkers in Mild Traumatic Brain Injury

“…IL-1β has also been implicated in the pathophysiology of TBI and its associated symptoms [25]. The studies from this meta-analysis suggest that the significantly increased IL-1β levels reported in mTBI patients are associated with the acute phase of inflammatory response and could indicate its role in the pathophysiology of mTBI.…”

“…IL-1β is involved in various physiological and pathological processes, including inflammation, fever, tissue repair, and immunity, acting on various target cells, including endothelial cells, fibroblasts, and immune cells, by binding to the IL-1 receptor (IL-1R) and activating intracellular signaling pathways. IL-1β promotes the production of other proinflammatory cytokines, such as TNF-α and IL-6, and induces the expression of adhesion molecules and chemokines, which attract immune cells to the site of injury or infection [25]. Changes in IL-1β functions have been implicated in various diseases, including rheumatoid arthritis, type 2 diabetes, and Alzheimer's disease.…”

Inflammatory Biomarkers in mTBI

“…IL-1β is involved in various physiological and pathological processes, including inflammation, fever, tissue repair, and immunity, acting on various target cells, including endothelial cells, fibroblasts, and immune cells, by binding to the IL-1 receptor (IL-1R) and activating intracellular signalling pathways. IL-1β promotes the production of other proinflammatory cytokines, such as TNF-α and IL-6, and induces the expression of adhesion molecules and chemokines, which attract immune cells to the site of injury or infection [25]. Changes in IL-1β functions have been implicated in various diseases, including rheumatoid arthritis, type 2 diabetes, and Alzheimer's disease.…”