SIBO: Causes, Symptoms, Diagnosis and Treatment

What is SIBO?

Small Intestine Bacterial Overgrowth (known as SIBO) occurs when there is an abnormal increase in the total amount of bacteria in the small intestine, especially types of bacteria that are not normally found in this part of the system. digestive. This condition may also be called blind loop syndrome.

Bacterial overgrowth in the small intestine usually occurs when certain circumstances, such as surgery or illness, slow the movement of food and waste through the digestive tract, creating an environment conducive to the proliferation of bacteria. Excess bacteria is often associated with diarrhea symptoms and can lead to weight loss and malnutrition.

Although bacterial overgrowth in the small intestine often occurs as a complication after abdominal surgery, it can also be related to structural problems and certain diseases. In some cases, surgery may be necessary to address this problem, but the most common treatment involves the use of antibiotics.

What are the symptoms of SIBO?

Signs and symptoms of small intestine bacterial overgrowth often include:

• Loss of appetite

• Abdominal pain

• Nausea

• Swelling

• Uncomfortable feeling of fullness after eating

• Diarrhea

• Unintentional weight loss

• Malnutrition

When should I see a doctor to find out if I have SIBO?

Bloating, nausea, and diarrhea are signs and symptoms of many intestinal problems. See your doctor for a complete evaluation, especially if you have had abdominal surgery, if you have the following:

• Persistent diarrhea

• Rapid and unintentional weight loss

• Abdominal pain that lasts more than a few days

If you have severe abdominal pain, seek immediate medical attention.

What are the causes of SIBO?

Small intestinal bacterial overgrowth (SIBO) can be caused by:

• Complications of abdominal surgery, including gastric bypass for obesity and gastrectomy to treat peptic ulcers and stomach cancer

• Structural problems in and around the small intestine, including scar tissue (intestinal adhesions) that can wrap around the outside of the small intestine, and bulging pockets of tissue that protrude through the wall of the small intestine (intestinal diverticulosis)

• Certain medical conditions, including Crohn's disease, radiation enteritis, scleroderma, celiac disease, diabetes, or other conditions that may slow the movement (motility) of food and waste products through the small intestine.

How does bacterial overgrowth develop in the small intestine?

The small intestine, which is the largest section of the digestive system, is approximately 6.1 meters long. In this part of the digestive system, food is combined with digestive juices and its nutrients are absorbed into the bloodstream.

Unlike the large intestine or colon, the small intestine generally houses relatively few bacteria. This is due to the speed with which the contents move through it and the presence of bile. However, when bacterial overgrowth occurs in the small intestine, food trapped in this section becomes an ideal environment for bacteria to grow. These bacteria can generate toxins and hinder the absorption of nutrients. Additionally, byproducts of bacterial breakdown of food can trigger bouts of diarrhea.

What are the risk factors for SIBO?

Factors that increase the risk of bacterial overgrowth in the small intestine include:

• Gastric surgery to treat obesity or ulcers

• A structural defect in the small intestine

• An injury to the small intestine

• An abnormal passageway (fistula) between two segments of the intestine

• Crohn's disease, intestinal lymphoma, or scleroderma involving the small intestine

• History of radiotherapy to the abdomen

• Diabetes

• Diverticulosis in the small intestine

• Adhesions caused by previous abdominal surgery

What complications can SIBO cause?

Bacterial overgrowth in the small intestine can lead to a number of problems including:

1. Difficulties in nutrient absorption: Fats, carbohydrates and proteins are not absorbed properly due to the breakdown of bile salts, which are normally required for the digestion of fats. This leads to inefficient digestion of fats and results in bouts of diarrhea. In addition, the products generated by bacterial activity can damage the intestinal mucosa, decreasing the absorption of carbohydrates and proteins.

2. Competition for nutrients: Bacteria can compete for available nutrients in the small intestine. Additionally, byproducts of bacterial breakdown of food trapped in this area can trigger bouts of diarrhea. These combined effects of bacterial overgrowth contribute to diarrhea, malnutrition, and weight loss.

3. Vitamin deficiency: Due to incomplete absorption of fats, the body cannot fully absorb fat-soluble vitamins A, D, E and K. Bacteria in the small intestine synthesize and use vitamin B-12, which is essential for normal function. normal nervous system, blood cell production and DNA. Bacterial overgrowth can result in a B-12 deficiency, which can manifest as weakness, fatigue, tingling in the hands and feet, and, in advanced cases, mental confusion. Damage to the central nervous system due to a lack of B-12 may be irreversible.

4. Weakening of bones (osteoporosis): Over time, damage to the intestine caused by abnormal bacterial growth can lead to inadequate calcium absorption, which can eventually result in bone diseases such as osteoporosis.

5. Kidney stone formation: Poor calcium absorption can also increase the risk of developing kidney stones at a later stage due to mineral buildup in the kidneys.

How is SIBO diagnosed?

To diagnose small intestinal bacterial overgrowth (SIBO), you may have tests to check for small intestinal bacterial overgrowth, fat malabsorption, or other problems that may be causing your symptoms. symptoms or contributing to them. Common tests include:

• Breath test. This type of non-invasive test measures the amount of hydrogen or methane that is exhaled after drinking a mixture of glucose and water. A rapid increase in exhaled hydrogen or methane may indicate an overgrowth of bacteria in the small intestine. Although widely available, the breath test is less specific than other types of tests for diagnosing bacterial overgrowth.

• Small intestine aspirate and fluid culture. This is currently the main standard test for bacterial overgrowth. To obtain the fluid sample, doctors pass a long, flexible tube (endoscope) down the throat and through the upper digestive tract to the small intestine. A sample of intestinal fluid is removed and then analyzed in a laboratory to see if there is bacterial growth.

In addition to these tests, your doctor may recommend a blood test to look for vitamin deficiency or a stool evaluation to check for fat malabsorption. In some cases, your doctor may recommend imaging tests, such as X-rays, CT scans, or MRIs, to look for structural abnormalities of the intestine.

What is the treatment of SIBO?

Whenever possible, doctors treat bacterial overgrowth in the small intestine by treating the underlying problem, for example, surgically repairing a postoperative loop, stricture, or fistula. But the handle cannot always be reversed. In that case, treatment focuses on correcting nutritional deficiencies and eliminating bacterial overgrowth.

1. Antibiotic therapy

For most people, the initial way to treat bacterial overgrowth is with antibiotics. Doctors may begin this treatment if your symptoms and medical history strongly suggest this is the cause, even when test results are inconclusive or no testing was performed. Tests may be done if antibiotic treatment is not effective.

A short course of antibiotics often significantly reduces the number of abnormal bacteria. But the bacteria can reappear when the antibiotic is stopped, so treatment may need to be long-term. Some people with a disease in the small intestine can go for long periods without needing antibiotics, while others may need them regularly.

Doctors can also alternate between different antibiotics to help prevent bacterial resistance. Antibiotics kill most intestinal bacteria, both normal and abnormal. As a result, antibiotics can cause some of the problems they are trying to solve, including diarrhea. Alternating between different drugs can help avoid this problem.

2. After remission, SIBO can reappear. Some options are suggested to maintain remission: medications that promote intestinal motility (since motility is a determinant of intestinal flow and stasis); low FODMAP diet : to date, there is no study that verifies the effects of this type of diet on SIBO, however, saccharide intolerances are common SIBO, and theoretically, a diet low in fermentable foods decreases the probability of overgrowth bacteria due to an environment less favorable for it.

Therefore, at a dietary level, it seems to be the most reasonable option to maintain the SIBO remission achieved with the diet.

FODMAP is the acronym for fermentable oligosaccharides, disaccharides, monosaccharides and polyols.

The low FODMAP diet encourages eating a diet without these compounds, that is, it is actually a diet free of or without FODMAP foods.

These fermentable substances are simple or complex carbohydrates found in foods, although not all carbohydrates or sugars are fermentable and are categorized within the FODMAP list.

What type of diet could help me improve SIBO?

What foods are best to avoid or reduce on a low FODMAP diet?

On a low FODMAP diet, it is advisable to limit certain vegetables that tend to cause discomfort, such as: artichokes, asparagus, cabbage, cauliflower, Brussels sprouts, broccoli, garlic, leeks, onion, peas, green beans, fennel, beets, mushrooms and other varieties of mushrooms.

Within this category of fermentable carbohydrates that we should avoid include:

1. Fructose : Found in fruits, honey and syrups.
2. Lactose : Present in dairy products such as milk, cheese and yogurt.
3. Fructans : Found in wheat, garlic, onion, artichokes, peas, asparagus, leeks, chicory and foods with inulin fiber.
4. Galactans : In legumes (including soybeans).
5. Polyols : Present in sweeteners such as isomaltose, mannitol, sorbitol, xylitol, as well as in stone fruits such as avocado, apricots, cherries, nectarines, peaches, plums, among others.

These sugars can cause an increase in the amount of water in the intestine due to osmosis, they may not be digested properly or absorbed efficiently, which can fuel the overgrowth of bacteria in the intestinal microbiota that ferment them. When this occurs, discomforts such as diarrhea, constipation, gas, abdominal bloating and abdominal pain may arise. If you experience any of these symptoms, a low FODMAP diet can help you reduce them. This diet is especially beneficial for people with irritable bowel syndrome and inflammatory bowel diseases such as Crohn's disease.

On a low FODMAP diet, it is also recommended to limit fiber intake as much as possible. Fiber, found, for example, in whole grains, is an indigestible substance that can cause similar symptoms.

In addition, it is advisable to reduce the intake of products containing gluten, although it is not necessary to be extremely strict at this point, since eliminating wheat already represents a significant decrease in the amount of gluten in the diet.

What foods are suitable on a low FODMAP diet?

When following a low FODMAP diet, it is advisable to choose gluten-free cereals or those with low levels of gluten. The most appropriate cereals in this diet are:

• Spelt.
• Rice.
• Oats (make sure they are certified gluten-free).
• Potato.
• Darling.
• Teff.
• Sorghum.
• Quinoa.
• Tapioca.
• Yucca.
• Buckwheat.
• Amaranth.

As for vegetables, it is recommended to start consuming them cooked. Once you tolerate them well, you can gradually introduce raw vegetables as side dishes to your meals.

Recommended fruits on the low FODMAP diet include:

• Banana
• Lemon
• Strawberries
• Tangerine
• Orange
• Melon
• Papaya
• Blueberries
• Raspberries
• Kiwi
• Passion fruit
• Pineapple
• Grape
• Coconut

On this diet, you can consume meat, fish and eggs without restrictions. As for nuts such as almonds, hazelnuts and walnuts, it is important to try them individually to assess your personal tolerance, and they should be consumed in moderation.

Additionally, you can include small amounts of lactose-free or low-lactose dairy products in your diet.

Regarding vegetables and fruits rich in FODMAPs, it is recommended to limit their consumption to a small portion the size of a tennis ball. Eating these small portions twice a day is usually better tolerated than consuming a larger amount in a single meal.

If you experience constipation during the weeks you follow the diet, you can introduce oats, which are low in FODMAPs but high in fiber. Additionally, it is important to increase water intake to improve digestion.

3. SIBO is usually a secondary disease to another, and as long as the cause is not eliminated, the recurrence of SIBO has a high probability. However, it is often impossible to eliminate the primary cause. Here, probiotics, prebiotics and/or synbiotics come into play with the aim of replacing the ?bad? microbiota with the ?good? one. A recent study shows that probiotic supplementation can reduce bacterial overgrowth, reduce hydrogen concentrations, and relieve abdominal pain.

4. A prospective, randomized, single-center study has recently been carried out with SIBO-positive patients with IBS (Irritable Bowel Syndrome) from the Andalusian Functional Digestive Disorder (PDD) Unit with the aim of improving the quality of life of the patients.

The control group followed a low FODMAPS diet.

The intervention group combined the use of supplements from specific strains of Reishi and Lion's Mane, as well as Shiitake and Pleurotus.

In this study, analytical data and the nutritional profile, breath test and complete Bio-Psycho-Social nutritional assessment were collected.

What dietary supplements can help me improve SIBO?

Dietary supplements can improve vitamin deficiencies, reduce intestinal pain, and help with weight gain:

• Nutritional supplements. People with bacterial overgrowth in the small intestine may need intramuscular injections of vitamin B-12, as well as oral vitamins, and calcium and iron supplements.

Sources:

https://www.mayoclinic.org/es/diseases-conditions/small-intestinal-bacterial-overgrowth/diagnosis-treatment/drc-20370172

https://www.mayoclinic.org/es/diseases-conditions/small-intestinal-bacterial-overgrowth/symptoms-causes/syc-20370168

https://www.endocrino.cat/ca/

https://hifasdaterra.com/

https://www.centrojuliafarre.es/dieta-fodmap/