What is SIBO?
Small Intestinal Bacterial Overgrowth (SIBO) occurs when there's an imbalance in the gut microbiome, particularly in the small intestine. Excess or improper types of bacteria accumulate and disrupts normal digestive functions. One significant issue with bacterial overgrowth is that these bacteria metabolize substrates not intended for them, such as carbohydrates, vitamin B12, proteins, bile salts, and excessive FODMAPs (FODMAPs or fermentable oligosaccharides, disaccharides, monosaccharides, and polyols are short-chain carbohydrates that are poorly absorbed in the small intestine and ferment in the colon.) This microbial activity can impair the body's ability to effectively digest food and absorb essential nutrients. In the short term, these disruptions lead to gastrointestinal symptoms such as abdominal pain, nausea, bloating, excessive gas, and diarrhea. Over time, prolonged nutrient malabsorption can result in malnutrition and unintentional weight loss.1
SIBO arises when the normal chemical and mechanical functions of the digestive system are disrupted. Diminished gastric acid production, certain medications, small intestinal dysmotility, or structural abnormalities can all contribute to this condition.1 Additionally, numerous cases of SIBO are attributed to excessive carbohydrate intake, particularly in the form of sugars.4
A study by Xiaoying et al. reported a positive SIBO rate of 63.3% in patients with pancreatic cancer and 46.7% in those with cholangiocarcinoma, suggesting that SIBO may be a contributing factor in the pathogenesis of these malignancies.2 SIBO has also been linked to pancreatitis, a potentially life-threatening condition, in a bidirectional relationship: SIBO can contribute to the onset of pancreatitis, while the pancreatitis-related inflammation can aggravate SIBO.3
Diagnosis of SIBO poses significant challenges due to the symptom overlap with other gastrointestinal disorders, which can lead to misdiagnosis by healthcare providers. The primary diagnostic method is a breath test that measures hydrogen and/or methane levels in exhaled air. Elevated concentrations of these gases suggest an overgrowth of gas-producing bacteria in the small intestine. Blood tests, imaging, and stool tests may also be used.
For individuals managing SIBO, healthcare providers may recommend a temporary elimination diet, which involves cutting out all carbohydrates to deprive the bacteria of their primary energy source. An elimination diet can help identify foods that may trigger SIBO symptoms, but it is not a substitute for prescribed treatments. According to the American College of Gastroenterology, most SIBO-focused diets aim to reduce fermentable foods, such as high-fiber items, sugar alcohols, artificial sweeteners like sucralose, and prebiotics like inulin. One common approach is a low-FODMAP diet, which limits carbohydrates that are difficult to digest and are fermented by gut bacteria in the colon. However, it is crucial to work with a registered dietitian to carefully plan the approach and ensure it aligns with each individual’s health goals.1, 2
For a more intense approach, the elemental diet is often recommended. This is a liquid diet made up of pre-digested nutrients that gives your body the nutrition it needs while leaving the bacteria with nothing to feed on. In the elemental diet, several nutrients like proteins, fats, and carbohydrates are metabolized into their “building blocks”, such as amino acids, short-chain triglycerides, and short-chain maltodextrins, along with essential vitamins, minerals, and electrolytes. The significance of this approach lies in the fact that these broken-down nutrients are absorbed in the upper digestive tract, enabling the remainder of the digestive system to heal and recover. Importantly, this diet should only pursued under a doctor's supervision.1, 2, 3
Meet the author
R&D MICROBIOLOGIST II at HARDY DIAGNOSTICS
Geovanni Ruiz, B.S. Biological Science
Geovanni graduated from San Jose State University in 2020 with a degree in Biological Science and minor in Chemistry. His professional journey began as an Analytical Chemist at an esteemed environmental and oilfield testing laboratory, where he meticulously operated a variety of instruments to detect metals in solid and water samples. Seeking to broaden his expertise, Geovanni transitioned to a Microbiologist position at a prominent food testing laboratory. Here, he applied his knowledge to analyze food and beverage samples for the presence of microorganisms. In November 2023, Geovanni joined Hardy Diagnostics as an R&D Microbiologist II, marking a significant step forward in his career. In this role, he spearheads new product development initiatives, troubleshoots existing product issues, evaluates raw materials, and oversees small-scale pilot batches. Outside of his professional endeavors, Geovanni is passionate about music, playing guitar in his leisure time. He finds solace and inspiration in gardening, enjoys dancing as a form of creative expression, and finds adventure in mountain biking. Geovanni's dedication to scientific excellence, combined with his multidisciplinary background and creative pursuits, positions him as a valuable asset in the field of microbiology and beyond.
