IBS--Free at Last!

How do Probiotics Fit In On a FODMAPs Elimination Diet?

You and I both want to know! I don't have all the answers, but I'd like to share some of my thoughts on this, since it is one of the most frequent queries I receive. I look forward to reader and professional comments on this one.

I think we can all agree that bacterial fermention in the gut is normal and desirable to a certain point. The bacteria in our guts have their own jobs to do for us, and they have to eat--fermentation is how they do it. This normal state of affairs can be disrupted by illnesses, infections, use of antibiotics, or food intolerance or allergies. If too much gas is produced as a result of bacterial imbalance, it can be part of the IBS picture

Or, the bacterial fermentation piece might be perfectly normal, but your nervous system may be so sensitive that you experience normal gas expansion of the colon and abdomen as a painful sensation.

When we use a FODMAPs restricted diet we deprive certain gut bacteria of their favorite foods. This decreases gas production. But we don't want to give up the health benefits of the short chain fatty acids (SCFAs) and other substances that gut bacteria produce for us.

A key point is that each species of bacteria has its own favorite food, and produces a unique combination of gases and SCFAs. People with IBS (and eating a FODMAPs-restricted diet) need a gut stocked with critters that like to ferment non-FODMAPS carbohydrates, don't produce gas, and do produce large amounts of desirable SCFAs. Oh, and it wouldn't hurt if they could also control gut pH, help the immune system function properly, and "box out" bad bacteria. And they should be safe, of course. Bifidobacteria appear to be the best candidates.

Enter probiotics. When we take probiotic supplements we are ingesting microbes that we think will help, in large enough quantities to have a medicinal effect. Probiotics in general show a lot of promise for treatment of IBS, but we have much, more more to learn about them. Specific probiotics that have been studied and have evidence showing a good treatment effect are: Bifidobacterium infantis (best), Bifidobacterium animalis, and VSL#3 (a patented blend of different species of bacteria).

People who are immunocompromised (due to illness or immune-suppressing drugs) or who are critically ill should not take probiotics without discussing the risks and benefits with a health care provider.

My next post will cover the nitty-gritty of how and when to take probiotics when using my FODMAPS-elimination diet program. Stay tuned!

Please Pass the Gas--Compare Yourself to the Norm

A major reason for doing a FODMAPs-restricted diet is to learn how to manipulate gas output by the bacteria that live in your gut. They are powerful and numerous. Did you know that bacterial cells in the body outnumber human cells 10 to 1? How about this fun fact: bacteria make up at least 30% of the volume of your stool. Yep, that is the normal state of affairs in your gut: bacterial growth and fermentation of sugars and fibers in the healthy human gut is 100% natural. According to the National Digestive Diseases Information Clearinghouse, most people produce 1 to 4 pints of gas a day, and pass gas about 14 time a day. Bacterial fermentation is even desirable. During the fermentation process, important substances called short chain fatty acids (SFCA) are produced. SCFA have their own very important role to play in your health, so we want to manage the fermentation process, not squelch it altogether.

Ideally, there is a fine balance between the types, amount and location of bacteria in the gut, the amount of "edible" carbohydrates (FODMAPS) they have access to, the amount and type of gas that is produced. Normally, there is no pain response to the gentle expansion of the colon--maybe an awareness, but not pain. If any of this gets out of whack it can contribute to IBS.

A FODMAPs-restricted diet can help. Taking the right probiotics can help. My next post will summarize what I learned last week when I attended an amazing probiotics workshop at Yale University. Follow me on twitter and I'll let you know when that post is up!

 

 

What is Fermentation?

What is fermentation and why should you care? If you have IBS or suffer from excess flatulence, bloating, or gassy abdominal pain, you can benefit from knowing a little bit about fermentation.

The gastrointestinal tract is populated by billions and billions of bacteria. That is normal. Fermentation is the breakdown of carbohydrates by these microbes. The bacteria need energy to survive, and they get it by consuming carbohydrates in the human diet. In the process, they produce hydrogen, methane and other gases. The gases make the intestines expand; picture a tube-shaped balloon expanding as it is blown up. The abdominal wall gently expands to accommodate this, and the gas is eventually either passed as flatus or absorbed into the blood stream. In IBS, the expansion of the intestine is experienced as a painful sensation. Why? Some possibilities:

• Some carbohydrates are fermented more rapidly than others (FODMAPs!); a diet loaded with FODMAPS might cause excessive gas production.
• Lactose and fructose (FODMAPs, again!) can be poorly absorbed in some people, which presents excess "food" to the intestinal bacteria.
• Fast intestinal transit time due to a virus, inflammatory bowel disease, celiac disease or non-FODMAPs food sensitivity. If the dietary carbohydrates are rushing past your small intestine before they can be absorbed, again, excess "food" may be presented to the bacteria in the large intestine.
• Tight clothing can prevent the natural expansion of the abdominal wall--consider this one if you've gained a few pounds and are still trying to fit into your skinny clothes.
• Traveling or at work? Maybe you are holding on to some of that gas you should be passing. Time for a quick "walk" around the block!
• Bacterial overgrowth can occur or bacterial growth can be present in the small intestine where it doesn't belong. This condition is known as small intestine bacterial overgrowth (SIBO) and is sometimes treated successfully with Rimaxifin as discussed in my previous post. It stands to reason than limiting fermentable carbohydrates (FODMAPs) would cut down on the gas that bacteria in either the small or large intestine.

News about IBS and Rifaximin

Last night my WebMD newsfeed popped up a story entitled 2 Weeks of Antibiotic Therapy Relieves IBS. Interesting! Even better, the lead author of the study is Dr. Mark Pimentel, who is also author of A New IBS Solution, a widely read book that suggesting that small intestinal bacterial overgrowth (SIBO) is the root cause of many IBS symptoms.

In a nutshell, the research findings in the New England Journal of Medicine found that as a group, patients with diarrhea-predominant IBS experienced statistically significant improvement in their symptoms after treatment with Rifaximin. The improvement was sustained during the 3-month length of the study. Rifaximin is an oral antibiotic that stays in the gut, and targets a broad spectrum of bacteria there. In this paper, unlike Dr. Pimentels book, there is no discussion of SIBO, and the patients were not evaluated to see if SIBO was part of their IBS clinical picture.

A few of my own thoughts as I read this paper:

• The findings support the idea that the life and death of bacteria in the GI tract do matter, and that antibiotic treatments targeting the intestinal flora can improve symptoms of diarrhea and gas, at least in some people.
• Although the findings are statistically significant, I have to wonder whether they are clinically meaningful. The results of the study showed that for every 100 carefully selected IBS patients treated with Rifaximin, 41 of them had significant relief of symptoms. But hold on: 32 of the patients who did NOT get the Rifaximin ALSO had significant relief of symptoms. This would clearly be meaningful if you were one of the 9 extra people who got relief of symptoms on the drug, but I think it poses some real questions about widespread use of this therapy.
• We need a better way to determine which individual patients would be the ones to benefit most from this treatment.
• Diet was not part of this study, and the authors do not comment on the role of dietary carbohydrates in the life cycle of the bacteria that cause symptoms of IBS (or SIBO, for that matter). 
• It is a fact, however, that most species of intestinal bacteria, no matter where they are located, consume dietary carbohydrates and produces a variety of gases through the process of fermentation. There is a growing body of evidence that reducing the load of fermentable carbohydrates (FODMAPS) in the diet can reduce IBS symptoms. I think that at low FODMAPS diet would be an excellent complement to Rifaximin therapy in clinical practice. Depriving these bacteria of their favorite foods in a very low-risk way to suppress their production of gas.

If you are scientifically inclined, you can read the original research for yourself, thanks to the generosity of the New England Journal of Medicine. (It's so refreshing to be able to read peer-reviewed journal articles online for free!)

What If I've Tested Negative for Lactose Malabsorption?

If you've tested negative for lactose intolerance, how does that fit into the FODMAPS picture?

First of all, let's review the test for lactose intolerance. The patient consumes a known amount of lactose. If the lactose is poorly digested and absorbed in the small intestine, it continues "down the line" to the large intestine, where it is fermented by the resident bacteria. They produce hydrogen gas as they ferment the lactose. Some of this gas is absorbed into the patients blood stream, where it travels to the lungs and is exhaled. If there is a sharp rise in the amount of hydrogen exhaled after the patient consumes the lactose, that is considered "positive" for lactose malabsorption. One thing to keep in mind is the fact that approximately 20% of us are not colonized by hydrogen-producing bacteria; instead, our resident bacteria many produce other types of gas such as methane or hydrogen sulfide (bad breath, anyone?).  Lactose-malabsorbing individuals in this category will falsely test negative for lactose intolerance on a hydrogen breath test alone, but might be positive if tested for both hydrogen and methane exhalation. The results of the lactose test really need to be viewed together with the patient's history of symptoms after consuming lactose, both during the test and at other times.

If someone has tested negative for lactose malabsorption AND doesn't particularly have a history of symptoms after ingesting milk products, it is pretty safe to say that individual is not lactose-intolerant.

However, even adults who tolerate lactose well in general do have limits to how much lactose they can handle. Because the effects of FODMAPS carbohydrates are additive, excessive lactose intake could put you over the top, and contribute to symptoms mostly caused by the other FODMAPS.

How much lactose is "excessive"? The answer to that question varies from one person to the next, but to put things in perspective, check out these generalizations about the lactose content of milk products:

Fluid milk: 11-14 grams per cup

Lactose-free milk: 0 grams per cup

Evaporated milk: 24 grams per cup

Yogurt: 5 grams per cup

Ice cream: 12 grams per cup

Butter: trace per 1 tsp

Most cheeses: 0-2 grams per ounce

Whey protein concentrate: varies

Whey protein isolate: trace per serving

Click here for more complete info on lactose content of foods and beverages.

To learn more about lactose intolerance and the FODMAPS elimination diet, visit www.ibsfree.net

What happens to the gas and fatty acids produced by bacteria in the gut?

A reader understands that colonic bacteria ferment sugars and complex carbohydrates in the gut. She wonders what happens to the gas and acids that are produced? Could they build up in the blood stream and cause illness?

The short answer is: No. Unlikely to build up in the blood stream of a person with normal respiratory health or to cause harm. The body has many ways get rid of or use up these normal products of fermentation.

The gases that results from fermentation have several possible fates. 

• Some of the bacteria in the colon actually feed on the gases produced in the first round of fermentation. Most of the gases produced are used up that way, provided the right bacteria are present.
• Some of the gas is expelled as flatus (farts).
• Some is absorbed into the blood stream. The gas that is absorbed in the blood stream is carried through the veins to the lungs. It is then exhaled in the breath.

In a person with normal respiratory health, it seems unlikely that gases produced by bacterial fermentation in the gut could build up in the blood or body tissues.

Different colonic bacteria produce different gases during fermentation. Interestingly, studies have shown that IBS patients who exhale methane gas (because they are colonized by methane-producing bacteria) tend to have constipation-predominant IBS. Some people are colonized by bacteria that produce hydrogen sulfide (rotten egg smell). This is pure speculation, but...I have been wondering if one could control bad breath with a FODMAPS elimination diet! Hmmm.

The short chain fatty acids produced during fermentation are actually the preferred energy source for the cells that line the gut, so most are "burned up" right on the spot.  Note that these are FATTY acids, not what you typically think of as tissue damaging acids, such as hydrochloric acid. Although chemically defined as acids, fatty acids do not have a low pH, as do even mild acids like acetic acid (vinegar). Fatty acids are the building blocks of food fat and fatty tissue. It seems unlikely that fatty acids produced in the gut would be capable of causing any harmful effects.

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