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

Relationship between gastrointestinal disturbances, blood lipid levels, inflammatory markers, and preterm birth

BACKGROUND

The challenging incidence of preterm birth, the underlying causes of preterm birth remain unclear. This study determined the relationship between disturbed gastrointestinal symptoms, inflammatory markers, blood lipid levels, and preterm birth.

METHOD

One hundred and twenty pregnant women with preterm labour were compared to 120 pregnant women with full-term deliveries. All subjects underwent lactose breath and serologic testing. The correlation between small intestinal bacterial overgrowth (SIBO)-positivity, gastrointestinal symptoms, inflammatory factors, and blood lipid metabolism and preterm birth was analysed using the Spearman method.

RESULTS

SIBO, hydrogen, and methane levels were significantly higher in the preterm birth (PTB) group than the full-term birth (FTB) group at different time points (P < 0.05); Levels of high-sensitivity C-reactive protein (hs-CRP) (3.95[2.70-5.77] vs. 2.47[1.45-3.83]), Interleukin (IL)-10 (3.05[2.27-4.33] vs. 2.09[1.04-3.47]), IL-6 (5.23[3.95-8.50] vs. 2.98[2.22-4.44]), tumour necrosis factor -alpha (TNF-α) (3.23[1.55-4.90] vs. 1.76[0.98-3.10]), total cholesterol (TC) (5.52[4.97-5.95] vs. 5.24[4.73-5.85]), and triglycerides (TG) (2.58[2.04-3.53] vs. 2.24[1.59-3.05]) were significantly higher in the PTB group than the FTB group (P < 0.05). Abdominal distension (2.67[1.67-3.00] vs. 2.33[1.67-2.67]) and constipation (2.00[1.33-2.00] vs. 1.67[1.33-2.00]) scores were also markedly higher in the PTB group than the FTB group (P < 0.05). Preterm birth was positively correlated with SIBO, TC, and TG levels. Additionally, SIBO was positively correlated with hs-CRP, IL-10, IL-6, and TNF-α levels, abdominal distension, and constipation (P < 0.05). Logistic regression analysis found the close association between positive SIBO, biochemistry indicators and preterm birth.

CONCLUSION

Gastrointestinal disturbances, hyperlipidaemia and SIBO-positivity are more likely to occur among pregnant women with preterm labour. Further research with a large sample size in multi-centers is needed to validate the results.

Small Intestinal Bacterial and Fungal Overgrowth: Health Implications and Management Perspectives

BACKGROUND/OBJECTIVES

Small Intestinal Bacterial Overgrowth (SIBO) and Small Intestinal Fungal Overgrowth (SIFO) are distinct yet often overlapping conditions characterized by an abnormal increase in microbial populations within the small intestine. SIBO results from an overgrowth of colonic bacteria, while SIFO is driven by fungal overgrowth, primarily involving Candida species. Both conditions present with nonspecific gastrointestinal (GI) symptoms such as bloating, abdominal pain, diarrhea, and malabsorption, making differentiation between SIBO and SIFO challenging. This review aims to elucidate the underlying mechanisms, risk factors, diagnostic challenges, and management strategies associated with SIBO and SIFO.

METHODS

A comprehensive review of current literature was conducted, focusing on the pathophysiology, diagnostic modalities, and therapeutic approaches for SIBO and SIFO.

RESULTS

SIBO is commonly associated with factors such as reduced gastric acid secretion, impaired gut motility, and structural abnormalities like bowel obstruction and diverticula. It is frequently diagnosed using jejunal aspirates (≥105 colony forming units (CFUs)/mL) or breath tests. In contrast, SIFO is linked to prolonged antibiotic use, immunosuppression, and gut microbiome dysbiosis, with diagnosis relying on fungal cultures from small intestinal aspirates due to the absence of standardized protocols.

CONCLUSION

The clinical overlap and frequent misdiagnosis of SIBO and SIFO highlight the need for improved diagnostic tools and a multidisciplinary approach to management. This review emphasizes the importance of understanding the mechanisms behind SIBO and SIFO, how they relate to other health outcomes, and potential management strategies to optimize patient care and therapeutic outcomes.

The Role of Bacteria-Derived Hydrogen Sulfide in Multiple Axes of Disease

In this review article, we discuss and explore the role of bacteria-derived hydrogen sulfide. Hydrogen sulfide is a signaling molecule produced endogenously that plays an important role in health and disease. It is also produced by the gut microbiome. In the setting of microbial disturbances leading to disruption of intestinal homeostasis (dysbiosis), the concentration of available hydrogen sulfide can also vary leading to pathologic sequelae. The brain-gut axis is the original studied paradigm of gut microbiome and host interaction. In recent years, our understanding of microbial and host interaction has expanded greatly to include specific pathways that have branched into their own axes. These axes share a principal concept of microbiota changes, intestinal permeability, and an inflammatory response, some of which are modulated by hydrogen sulfide (H2S). In this review, we will discuss multiple axes including the gut-immune, gut-heart, and gut-endocrine axes. We will evaluate the role of H2S in modulation of intestinal barrier, mucosal healing in intestinal inflammation and tumor genesis. We will also explore the role of H2S in alpha-synuclein aggregation and ischemic injury. Finally, we will discuss H2S in the setting of metabolic syndrome as int pertains to hypertension, atherosclerosis and glucose-like peptide-1 activity. Majority of studies that evaluate hydrogen sulfide focus on endogenous production; the role of this review is to examine the lesser-known bacteria-derived source of hydrogen sulfide in the progression of diseases as it relates to these axes.

Assessment of Biochemical, Inflammatory Biomarkers and Ultra-Processed Food Consumption in Children with Small Intestinal Bacterial Overgrowth: A Cross-Sectional Study

OBJECTIVE

This study evaluated anthropometric, biochemical, and inflammatory biomarkers, as well as dietary intake in Brazilian children diagnosed with small intestinal bacterial overgrowth (SIBO) and compared them with their counterparts without SIBO.

METHODS

This was a cross-sectional study with 106 children aged 7 to 10 years. A glucose-hydrogen breath test was performed to diagnose small intestinal bacterial overgrowth (SIBO). Anthropometric and dietary characteristics were assessed. Blood samples were collected and serum biochemical parameters and cytokines were measured.

RESULTS

The occurrence of SIBO was 13.2%. Age, BMI, BMI/age WC, BFP, sex and biochemical markers were similar between SIBO-positive and SIBO-negative children (p > 0.05). High consumption of ultra-processed foods tended to be higher in SIBO-positive compared to SIBO-negative children (47.8 ± 8.2 vs. 42.6 ± 9.5, p = 0.06). Serum levels of IL-17 were higher in SIBO-positive than in SIBO-negative children [69.5 (5.4-125.7) vs. 53.4 (2.3-157.7), p = 0.03], while serum levels of IL-10 were lower in SIBO-positive than in SIBO-negative children [2.3 (0.6-7.2) vs. 5.7 (0.5-30.8), p = 0.04]. Finally, in a logistic regression adjusted for sex, BMI and age, consumption of ultra-processed foods (p = 0.03) and IL-6 levels (p = 0.003) were found to contribute to the occurrence of SIBO.

CONCLUSION

this study identified for the first time an occurrence of 13% of SIBO in children living in the northeastern region of Brazil and showed that consumption of ultra-processed foods and serum levels of IL-6 may influence the occurrence of the SIBO in the pediatrics population.

Identification of SIBO Subtypes along with Nutritional Status and Diet as Key Elements of SIBO Therapy

Small intestinal bacterial overgrowth (SIBO) is a pathology of the small intestine and may predispose individuals to various nutritional deficiencies. Little is known about whether specific subtypes of SIBO, such as the hydrogen-dominant (H+), methane-dominant (M+), or hydrogen/methane-dominant (H+/M+), impact nutritional status and dietary intake in SIBO patients. The aim of this study was to investigate possible correlations between biochemical parameters, dietary nutrient intake, and distinct SIBO subtypes. This observational study included 67 patients who were newly diagnosed with SIBO. Biochemical parameters and diet were studied utilizing laboratory tests and food records, respectively. The H+/M+ group was associated with low serum vitamin D (p < 0.001), low serum ferritin (p = 0.001) and low fiber intake (p = 0.001). The M+ group was correlated with high serum folic acid (p = 0.002) and low intakes of fiber (p = 0.001) and lactose (p = 0.002). The H+ group was associated with low lactose intake (p = 0.027). These results suggest that the subtype of SIBO may have varying effects on dietary intake, leading to a range of biochemical deficiencies. Conversely, specific dietary patterns may predispose one to the development of a SIBO subtype. The assessment of nutritional status and diet, along with the diagnosis of SIBO subtypes, are believed to be key components of SIBO therapy.

The relationship between small intestinal bacterial overgrowth and constipation in children - a comprehensive review

Small intestinal bacterial overgrowth (SIBO) is characterized by an increase in the bacterial population of the small intestine due to an imbalance between the amount of bacteria and the intestinal barrier. Pediatric SIBO presents with a wide spectrum of symptoms, ranging from mild gastrointestinal complaints to malabsorption or malnutrition. Breath tests are commonly used as noninvasive diagnostic tools for SIBO, but a standardized methodology is currently unavailable. Intestinal flora produces methane which slows intestinal transit and increases the contractile activity of small intestine. Emerging literature suggests a correlation between overgrowth of methanogenic bacteria in the intestines and constipation. Treatment of SIBO involves administration of antibacterial therapy in addition to management of underlying conditions and optimal dietary adjustments. However, research on antibiotic treatment for pediatric patients with constipation and SIBO is limited and has yielded conflicting results. In the current review, we summarize the state-of-the-art of the field and discuss previous treatment attempts and currently used regimens for SIBO patients with constipation, with a focus on pediatric populations.

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

Mild traumatic brain injury (mTBI) accounts for most TBI cases, the leading cause of morbidity and mortality worldwide. Despite its high incidence, mTBI pathophysiology remains largely unknown. Recent studies have shown that the inflammatory response is activated early after mTBI and can persist for several weeks or months. However, limited evidence on the utility of inflammatory biomarkers as predictors of clinical outcomes in mTBI has been previously provided. Thus, this systematic review and meta-analysis aims to provide an overview of the current knowledge on the role of inflammation in the pathogenesis of mTBI and the potential of some inflammatory biomolecules as biomarkers of mTBI. In this regard, eight studies comprising 1184 individuals were selected. Thus, it was shown that the increase in IL-6, TNF-α, and IL-1β plasma levels could be implicated in the development of early post-concussion symptoms. On the other hand, the persistence of the increased plasmatic concentrations of IL-10 and IL-8 for as long as six months following the brain injury event could suggest chronic inflammation leading to neuroinflammation and late or persistent symptoms. In this context, our findings showed that inflammatory biomarkers could be relevant in diagnosing or predicting recovery or long-term outcomes of mTBI.

Influence of Body Composition and Specific Anthropometric Parameters on SIBO Type

Recent observations have shown that Small Intestinal Bacterial Overgrowth (SIBO)affects the host through various mechanisms. While both weight loss and obesity have been reported in the SIBO population due to alterations in the gut microbiome, very little is known about the influence of SIBO type on body composition. This study aimed to evaluate whether there is a link between the three types of SIBO: methane dominant (M+), hydrogen dominant (H+), and methane-hydrogen dominant (H+/M+) and specific anthropometric parameters. This observational study included 67 participants (W = 53, M = 14) with gastrointestinal symptoms and SIBO confirmed by lactulose hydrogen-methane breath tests (LHMBTs) using the QuinTron device. Participants underwent a body composition assessment by Bioelectrical Impedance Analysis (BIA) using the InBody Analyzer. In the H+/M+ group, body weight (p = 0.010), BMI (p = 0.001), body fat in kg (p = 0.009), body fat in % (p = 0.040), visceral fat (p = 0.002), and mineral bone content (p = 0.049) showed an inverse correlation with hydrogen (H2) gas production. These findings suggest that body weight, BMI, body fat, and mineral bone content may be inversely linked to the production of hydrogen and the risk of hydrogen-methane SIBO.

Gut Microbiome and Dietar Considerations

The gut microbiome represents a complex microbial ecosystem that exerts direct and indirect effects on other organ systems and contributes to both health and disease. It is sensitive to various stimuli such as childhood immunity, medications, diet, stressors, and sleep. Modulating the gut microbiome can prevent and even treat certain disease states. Although no definitive guidelines exist to support a healthy microbiome, there are several evidence-based interventions proved to improve gut health and reduce the risk for numerous chronic diseases.

Proton pump inhibitor-induced gut dysbiosis and immunomodulation: current knowledge and potential restoration by probiotics

Proton pump inhibitors (PPIs) are the most commonly prescribed drugs for the treatment of non-erosive reflux disease (NERD), ulcers associated with non-steroidal anti-inflammatory drugs (NSAIDs), esophagitis, peptic ulcer disease (PUD), Zollinger-Ellison syndrome (ZES), gastroesophageal reflux disease (GERD), non-ulcer dyspepsia, and Helicobacter pylori eradication therapy. The drugs have the effect of inhibiting acid production in the stomach. According to research, PPIs can affect the composition of gut microbiota and modulate the immune response. Recently, there has been a problem with the over-prescription of such drugs. Although PPIs do not have many side effects, their long-term use can contribute to small intestinal bacterial overgrowth (SIBO) or C. difficile and other intestinal infections. Probiotic supplementation during PPIs therapy may provide some hope in the reduction of emerging therapy side effects. This review aims to present the most important effects of long-term PPI use and provides critical insights into the role of probiotic intervention in PPI therapy.

The Role of Small Intestinal Bacterial Overgrowth in Obesity and Its Related Diseases

Obesity has become a major public health problem worldwide and its occurrence is increasing globally. Obesity has also been shown to be involved in the occurrence and development of many diseases and pathological conditions, such as nonalcoholic fatty liver disease (NAFLD), type 2 diabetes mellitus (T2DM), insulin resistance (IR). In recent years, gut microbiota has received extensive attention as an important regulatory part involved in host diseases and health status. A growing body of evidence suggests that gut microbiota dysbiosis has a significant adverse effect on the host. Small intestinal bacterial overgrowth (SIBO), a type of intestinal microbial dysbiosis, has been gradually revealed to be associated with obesity and its related diseases. The presence of SIBO may lead to the destruction of intestinal barrier integrity, increased intestinal permeability, increased endotoxin levels, activation of inflammatory responses, and translocation of bacteria from the colon to the small intestine. However, the causal relationship between SIBO and obesity and the specific mechanisms have not been well elucidated. This review discusses the cross-talk between SIBO and obesity and its related diseases, and expounds its potential mechanisms and interventions, which may help to discover new therapeutic targets for obesity and its related diseases and develop treatment options.