Association of Small Intestinal Bacterial Overgrowth (SIBO) in Obese Patients

Sabah Ali Ahmed *¹, Jamil Mahmoud El Chayeb ², Jitendra Jonnagaddala ³

Corresponding Author: Sabah Ali Ahmed,

Copy Right: © 2023 Sabah Ali Ahmed, This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received Date: May 17, 2023

Published Date: June 01, 2023

DOI: 10.1027/margs.2023.0140
 

Introduction

The UAE has one of the highest prevalence of obesity worldwide, with the number of obese patients having doubled in the last 30 years [1]. This dramatic increase in obesity is primarily attributed to significant lifestyle changes, rapid urbanization, overeating, and a decrease in physical exercise.

The prevalence of Small Intestinal Bacterial Overgrowth (SIBO) in obese patients is largely under-reported due to nonspecific symptoms. Clinical diagnosis of this condition remains a significant challenge [2].

Introduction - Research Aims

The primary objective of this study is to explore the risk of small intestinal bacterial overgrowth (SIBO) in obese and overweight patients. The secondary objective is to understand the association between SIBO and comorbidity, presenting symptoms, medications, and procedures involved.

Methods - Sample Population

This is a cross-sectional association study. It encompasses patients who were suspected of having SIBO and had undergone lactulose breath tests for SIBO within the previous three months (from February 2023 to November 2022). The study includes retrospective data from 112 individuals (64 men and 48 women), with information related to their presenting symptoms, comorbidity, medications, and test-related procedures.

Methods - Dataset

This study is a cross-sectional prevalence and associations study. It comprises patients who were suspected of having SIBO and underwent lactulose breath tests for SIBO within the previous three months (from February 2023 to November 2022).

The data includes 112 patients (64 males and 48 females) aged between 15 and 75, all of whom had undergone the lactulose test due to suspicion of small intestinal bacterial overgrowth (SIBO). For the purpose of this study, a Body Mass Index (BMI) greater than 25 is considered indicative of obesity.

Methods – Sample size calculations

Sample size for cross-sectional study design two proportion independent groups

Methods - Statistical Analyses

Data Reprocessing:

1) Categorical "text" data has been converted into binary format (0 and 1).

2) Multiple records of symptoms, comorbidity, medications, and surgical procedures have been merged into a single record for each patient.

3) Each patient has been classified as 0 or 1, where 0 represents "no symptom" and 1 represents "symptom". The same binary classification has been implemented for comorbidity, medications, and procedures.

Bivariate and Multivariate Analyses:

1) Bivariate analysis was conducted using the Chi-square test to examine the relationship between two variables.

2) Multivariate analysis was performed using logistic regression to control for potential confounding variables and to understand the relationship between multiple variables and the dependent variable (SIBO presence).

Results – Baseline characteristics

Results- Bivariate Analysis Association between OBESITY and SIBO

Bivariate analysis showed no significant association between SIBO and Obesity (p = 0.114)

Results – Multivariate Analysis: Association between SIBO and Obesity

A multivariate analysis was performed by selecting dependent and independent variables. For this analysis, we selected 10 dependent variables and one target variable.

The logistic regression algorithm was used as the base model to predict the categorical outcome: obese or non-obese.

Discussion

Small Intestinal Bacterial Overgrowth (SIBO) is a clinical condition characterized by malabsorption syndrome due to an increase in microorganisms to a level exceeding 105 bacteria/mL of jejunal juice. The cornerstone of the treatment of SIBO is antibiotic therapy. Rifaximin was approved for treatment of SIBO in 2015, and recent reports have upheld its efficacy. An excess of bacteria in the small intestine is rare, typically not exceeding 1000 org/mL. This can be attributed to gastric acid secretion and intestinal motility that limit the overgrowth of bacteria in the small intestine.

Conclusion

After eradicating unwanted intestinal bacteria, symptoms of Irritable Bowel Syndrome (IBS), such as bloating, abdominal pain, and diarrhea, improved. However, SIBO isn't exclusive to individuals with IBS-like symptoms. Non-digestive symptoms, such as fatigue, may be the primary concern. Some alternative medicine practitioners suggest that SIBO may play a role in Chronic Fatigue Syndrome, Irritable Bowel Disease (IBD), Fibromyalgia, allergies, arthritis, lupus, and other autoimmune diseases. Small intestinal bacterial overgrowth is a condition that may be present for years without causing obvious symptoms.

This study focuses on the association of SIBO with obesity, a global health concern, particularly in Gulf countries. The involvement of gut microbiota brings additional complexity to the occurrence and development of obesity.

SIBO is associated with chronic digestive problems such as gas, bloating, diarrhea, and/or constipation and is often misdiagnosed as IBS. Our NMC Royal Abu Dhabi examined 112 obese patients (64 males and 48 females, aged 15 to 75), all of whom had undergone the lactulose hydrogen test due to suspicion of SIBO. Obesity was defined as having a BMI > 25.

We found that 69 112 patients (65%) had bacterial overgrowth. The primary cause of obesity was identified as a sedentary lifestyle, with less association with alcohol and smoking in comparison to Western countries. This study provides further insight into the role of SIBO in obesity and other related chronic diseases.

References

1. Nawar, R., et al., Understanding the Gaps in Obesity Management in the UAE: Perceptions, Barriers, and Attitudes. Dubai Diabetes and Endocrinology Journal, 2021.27(2): p. 37-49.

2. Sheeza Imtiaz., et al., Prevalence of Small Intestinal Bacterial Overgrowth in People with Gastrointestinal Signs and Symptoms Using Glucose Breath Test. Acta Scientific Nutritional Health, 2021. 5(12): p. 127-137.

3. Nuttall, F.Q., Body Mass Index: Obesity, BMI, and Health: A Critical Review. Nutrition Today, 2015.50(3).

4. Fitriakusumah, Y., et al., The Role of Small Intestinal Bacterial Overgrowth (SIBO) in Non-alcoholic Fatty Liver Disease (NAFLD) Patients Evaluated Using Controlled Attenuation Parameter (CAP) Transient Elastography (TE): a Tertiary Referral Center Experience. BMC Gastroenterology, 2019. 19(1): p.43.