Probiotics in Health and Disease

People are ecosystems. A healthy adult can harbor about 100 trillion bacteria in his gut alone, which is 10 times as many as the number of cells in his body. In exchange for raw materials and shelter, the body’s commensal bacteria or “microbiome” feed and protect their hosts. The “normal” microbiome digests dietary fiber, generating short fatty acids that serve as fuel for certain cells’ metabolic needs, or are also stored as fat.

In addition to Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), Antibiotic-Associated Diarrhea, and Infectious Diarrhea, an altered microbiome has also been associated to Atherosclerotic Heart Disease, Obesity, Diabetes, Metabolic Syndrome, Non-Alcoholic Steato-Hepatitis and various presumably “auto-immune” diseases such as Type 1 Diabetes, Eczema, Multiple Sclerosis and even Autism. Modifying microbiomes with antibiotics in specially bred mice predisposed to hardening of the arteries significantly reduces their Atherosclerosis. In Multiple Sclerosis, researchers have shown in mice that gut bacteria trigger the reaction that causes the immune system to turn against certain nerve cells and strip away their insulation in precisely the way that leads to multiple sclerosis.

If gut bacteria are making you ill, can swapping them make you healthy? The yogurt industry has been answering this question for many years. Indeed probiotics – which are live micro-organisms that when administered in adequate amounts, confer a health benefit to the host – are found in yogurt. Although it is commonly recommended as a source of probiotics, not all of the live cultures contained in yogurt survive well in an acidic environment, nor do they colonize the microbiome efficiently. Some yogurt preparations in the United States are pasteurized, which kills the bacteria. Furthermore, the residual lactose contained in yogurt can increase symptoms in patients with lactose intolerance, including those that develop secondary lactose intolerance following an episode of acute gastroenteritis.

Since yogurts are limited in the range and amount of bacteria they can transmit, different concentrated probiotic formulations have been developed and studied scientifically. Some of the most commonly available include: VSL#3, Align, Culturelle, DanActive, Mutaflor and Florastor. Unfortunately, very few studies have hinted that probiotic pills may improve your health, and scientists claim that there is not enough proof and more research is needed. Hence, these pills should not be taken unless recommended by your physician.

However, there is no harm in eating yogurt products that have “active cultures” which have probiotics in them. A low-fat yogurt can always be part of a healthy diet. The downside is that probiotics are not regulated by the FDA and therefore the manufacturers do not have to prove that the ingredients listed on the label are actually in the bottle. Furthermore, probiotics are expensive and not covered by insurance (except for VSL#3 DS in “pouchitis”) and there is a small chance that they can cause infections in people with weak immune systems.

Dealing with Gas and Bloating

Functional gastrointestinal disorders such as Irritable Bowel Syndrome (IBS) are very common, ranking second in the causes of absence from work or school. Bloating is one of the most common manifestations of IBS, caused by distension of the gut lumen by gas leading to pain, the sensation of bloating and visible abdominal distension. The amount of gas in your gut depends on the amount of air you swallow and bacterial production in the distal small and proximal large bowel. Increased production can be the result of bacterial digestion of carbohydrates incompletely digested by enzymes in the intestines allowing bacteria to digest them, as occurs with lactose intolerance. However, most people who complain of excessive gas and bloating do not produce more gas than the average person – they are just more aware of it because of increased sensitivity to gas, one of the hallmarks of IBS.

If you eat too fast, gulp liquids, drink lots of carbonated beverages, chew gum, smoke or swallow saliva constantly, you can end up swallowing too much air. Fortunately, most swallowed air can be eliminated when sitting up by belching. Eating peppermint, chocolate and fats relax the lower esophageal sphincter and may help. However, if lying down some of the gas tends to pass into the intestine which can cause excessive passage of gas. This swallowed air is mainly nitrogen together with the byproducts of the digestion of carbohydrates by the intestinal flora like carbon dioxide, hydrogen and methane, which are odorless. Traces of sulfur compounds are responsible for the occasional unpleasant odor.

Most people with gas and bloating do not need to have any testing unless there are alarm symptoms such as diarrhea, weight loss, abdominal pain, anemia, blood in the stool, lack of appetite, fever or vomiting. If this is the case you should see a gastroenterologist to get further testing such as a blood test for celiac disease, a hydrogen breath test for lactose and/or fructose intolerance or even an endoscopic evaluation of your gastrointestinal tract.

Restrictions of dietary components that can lead to luminal distension, due to poor proximal absorption and subsequent fermentation by bacteria more distally in the intestines, form the basis of the low FODMAP diet approach to the management of functional gastrointestinal symptoms.

FODMAP stands for:


Oligosaccharides (fructans and galactans)

Disaccharide (lactose)

Monosaccharide (fructose) And

Polyols (sorbitol)

Food lists are available emphasizing suitable alternatives, and the best outcomes are achieved in a one-to-one setting with a dietitian. Although there are no controlled studies supporting efficacy, several OTC medications are available to help reduce bothersome gas such as simethicone (which breaks up bubbles), activated charcoal (adsorbent), Beano (breaks down complex carbohydrates) and bismuth (reduce odor).