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MMC Select - Why It May Be Important For Your Constipation Dominant IBS Patients

08/01/2018 - Product Newsletter #316

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Certainly one of the true epidemics seen with chronically ill patients today is irritable bowel syndrome (IBS).  From a broad-based standpoint, IBS can be subdivided into two major forms - diarrhea predominant IBS (IBS-D) and constipation predominant IBS (IBS-C).  While both forms are affecting more and more Americans, it has been suggested that IBS-C may be more common. 

Of course, given the high incidence of IBS-C, it is no surprise that many remedies, both nutraceutical and pharmaceutical, have been developed over the years, all demonstrating varying degrees of efficacy depending on the patient.  From a nutraceutical standpoint, many fiber-based products have been helpful by adding bulk to the stool.  In addition, many herbals have been effective based on their ability to stimulate peristalsis, the rhythmic movement of the intestine.  Finally, you are undoubtedly aware that microflora imbalances can be a major cause of IBS-C.  While these microfloral imbalances can take many forms, the one that seems to be most prevalent right now with IBS-C is small intestine bacterial overgrowth (SIBO). 

As I can personally attest, the ability to diagnose SIBO via breathe testing and treat via the use of low FODMAP diets and herbal antimicrobial formulations has been a major contribution to efforts to assist patients suffering from chronic IBS-C.  Countless IBS-C patients have reported major improvements with optimal SIBO diagnosis and treatment. 

However, as many of you who treat large numbers of IBS-C patients may have noticed, not all respond optimally to the above mentioned modalities.  While there may be many reasons for this, one reason that has become more apparent and well-known by functional medicine practitioners is there is another form of intestinal movement besides peristalsis that can become dysfunctional and contribute to IBS-C.  What is this other form of intestinal movement?  It is called the migrating motor complex (MMC).  Our new product, MMC Select, is designed to optimize function of the MMC, which can be very helpful with these difficult IBS-C patients.  The technical bulletin on MMC Select that can be found on the Moss Nutrition website describes the constituents of the product and why they assist in the optimization of MMC function. 

It is my guess, though, that many of you may still be unfamiliar with the exact nature of the MMC.  Therefore, I would now like to present some highlights from an excellent review on the subject that specifically defines the MMC and its significance clinically.

An in depth examination of the migrating motor complex (mmc)

The reference for this examination of the MMC will be "The migrating motor complex: control mechanisms and its role in health and disease" by Deloose et al (Deloose E et al. Nat Rev Gastroenterol Hepatol, Vol 9, pp. 271-285, May 2012).  The first quote I would like to feature differentiates the MMC from peristalsis, which tends to occur after food ingestion:

"The migrating motor complex (MMC) is a cyclic, recurring motility pattern that occurs in the stomach and small bowel during fasting: it is interrupted by feeding."

The next quote points out that the MMC occurs in phases:

" by Code and Marlett divided the gastric motor activity into four phases: phase I is the quiescent phase with no contractions; phase II is characterized by random contractions; phase III has a sudden onset and ends with a burst of contractions with maximal amplitude and duration; and phase IV is characterized by the rapid decrease of contractions."

In addition:

"When Code and Marlett studied the MMC in more detail, it became clear that it is a recurrent event that moves from the stomach to the terminal ileum, over a period of 1.5-2h."

However, as noted in the following quote, it is important to note that the MMC only occurs in the fasted state:

"Distension of the stomach interrupts MMC activity in the stomach and the upper part of the small bowel, while the presence of fluid and nutrients in the small bowel interrupts MMC activity over the entire small bowel."

Interestingly, we have all noticed the presence of the MMC without even knowing it was the MMC:

"Gastrointestinal rumbling, which is mainly noticed during fasting, is associated with the MMC."

Thus, when our stomachs "growl" before eating when we are hungry is actually the MMC in action.

The next quote points out interesting relationships between MMC activity, gastric pH, and exocrine pancreatic function:

"Gastric pH fluctuates during the MMC, with the antral pH being lowest just prior to the start of phase III contractions, and with alkalinization occurring at the start of phase I.  This change in pH is due to an increase in acid and pepsin secretion that accompanies phase III of the MMC, and bile-free, bicarbonate reflux from the duodenum, which occurs mainly through duodenal contractions with some retrograde migration.  Intestinal and pancreatic secretion of water, bicarbonate and pancreatic enzymes increases during phase III contractions of the small intestine.  The integrated secretory activity that occurs in parallel with the motility phases has been referred to as the secretory component of the MMC."

Before continuing, I would like to comment on the important clinical implications of the above quote.  First, contrary to conventional thinking that HCl and digestive enzyme production and activity only occur at the time of or immediately after food ingestion, in actuality, production and activity also occurs during the fasted state when MMC contractions occur.  Second, with the assumption that this digestive activity during the fasted state via MMC contractions represents ideal GI digestive function, suboptimal MMC activity as often seen with IBS-C patients could be the reason that these patients seem to demonstrate poor digestive function after meals.  More simply, it could be suggested that, because of suboptimal MMC function, poor HCl and digestive enzyme production and activity after meals may be partially due to poor HCl and digestive production and activity before meals.

Another important aspect of the MMC is that it follows a circadian rhythm:

"Studies in humans have shown a reduction in propagation velocity of the MMC in the proximal small bowel at night, suggesting that the MMC has a circadian pattern.  In addition, the length of the MMC cycle is shorter at night because of a nearly absent phase II."

What controls MMC activity?  Deloose et al point out:

"The autonomic nervous system is...involved in the regulation of the MMC."

In addition:

"The regulation of the MMC...involves different gut hormones and activation of the parasympathetic and enteric nervous system."

Clinical implications of suboptimal MMC function

To begin this section consider the following:

"Although early studies suggested a correlation with hunger sensations, the role of the MMC has mainly been studied in patients with gastrointestinal motility disorders.  In humans, the absence of decreased occurrence of phase III contractions has been associated with small intestinal bacterial overgrowth."

MMC and SIBO - The authors continue their discussion of MMC and SIBO:

"On the basis of initial observations, the MMC was proposed to be the housekeeper of the gastrointestinal tract.  This proposed function was based on the finding that patients with small intestinal bacterial overgrowth had an absent or disordered pattern of their MMC.  Symptoms associated with small intestinal bacterial overgrowth include abdominal cramps, abdominal bloating, diarrhea, gas, steatorrhea and weight loss."

Do disturbances in MMC activity cause SIBO or does the reverse occur where SIBO causes disturbances in MMC activity?  Deloose et al comment:

"...a disturbed MMC predisposes to small intestinal bacterial overgrowth, rather than bacterial overgrowth disturbing MMC."

As I hope you can see, this fact has tremendous clinical implications.  As you all know, the most common way of treating SIBO currently is use of antimicrobial nutraceuticals and pharmaceuticals to reduce the amount of bacteria in the small intestine.  However, as suggested in the above quote, this type of intervention does not eliminate the cause of SIBO, which can lead to the increasingly common recurrence of SIBO after antimicrobial therapies are concluded.  Therefore, if antimicrobial therapies are employed with SIBO patients, even if the antimicrobial therapies are successful in eliminating SIBO-related symptoms, it is highly advised after cessation of antimicrobial therapy to make efforts to increase suboptimal MMC activity with a product such as MMC Select.

MMC and IBS - In the section on MMC and IBS, Deloose et al discuss the differences in MMC activity between IBS-C and IBS-D patients:

"Interdigestive motility patterns have been studied in patients with IBS.  During sleep, no difference was found in the occurrence of the MMC between healthy individuals and patients with diarrhea-predominant IBS or constipation-predominant IBS.  During the day, however, patients with IBS had a shorter duration of postprandial motor activity compared with healthy individuals.  Daytime measurements also demonstrated a difference between diarrhea-predominant and constipation-predominant IBS - patients with diarrhea-predominant IBS had shorter intervals between consecutive MMCs than patients with constipation-predominant IBS."

Therefore, as you might expect, there tends to be increased MMC activity with IBS-D patients and decreased MMC activity with IBS-C patients.

MMC and aging - Is age a factor with MMC activity?  Deloose et al point out:

"In healthy elderly individuals (81-91 years) the MMC does not differ substantially from young adults; the propagation velocity of phase III is slower compared with younger adults, but the amplitude and frequency of phase II contractions is not different."

Pharmaceutical therapy for suboptimal MMC activity

As noted by Deloose et al, poor gut motility, or gastroparesis (which includes low MMC activity) has been recognized as a treatable clinical entity for years:

"Compounds that induce (gastric) phase III activity might be beneficial for the treatment of hypomotility disorders, especially gastroparesis, or for the treatment of small intestinal bacterial overgrowth.  On the basis of this hypothesis, a number of motilin and ghrelin analogues are being developed as new gastroprokinetic agents."

Common pharmaceutical prokinetics are actually antibiotics:

"...erythromycin is a prokinetic agent used in the treatment of (diabetic) gastroparesis.  Azithromycin is another macrolide antibiotic that stimulates gastrointestinal motility."

Some final thoughts on MMC:

As I mentioned in the beginning of this discourse on MMC, the technical bulletin gives an excellent overview of how MMC Select can help stimulate MMC activity, which can be vital for patients suffering from IBS-C.  However, given that many in the nutritional and functional medicine community may not be aware of the existence and importance of the MMC (I was not aware until only about one year ago), it is my hope that this literature review and commentary on the subject makes it clear that, especially for many IBS-C patients, we must go beyond the usual antimicrobial and GI support and make optimization of MMC activity a key consideration.


As we hope you are well aware, Moss Nutrition differs from most professional supplement companies in many ways.  One of those ways is that, unlike many of the professional supplement companies that have been purchased by large corporations that are often headed by business people with little or no experience in clinical nutrition and/or functional medicine, Moss Nutrition is a small, family-owned company where the co-owner and founder, Jeffrey Moss, DDS, CNS, DACBN, has been and continues to be active in both clinical nutrition and functional medicine.  More specifically:

  1. Dr. Moss, even though he retired from full time clinical practice in 1985, has since that time maintained a small nutritional and  functional medicine practice, advising patients (often referred by customers of Moss Nutrition) on ways to improve health through supplementation and lifestyle modification.
  2. Dr. Moss reviews current research on clinical nutrition, functional medicine, and patient health on a daily basis and frequently authors papers and presents lectures on these subjects.
  3. Finally, unlike many of the corporate overseers of the above mentioned 'pro' supplement companies, Dr. Moss enjoys meeting and talking with practitioners about the use of Moss Nutrition products to practically and cost- and time-effectively improve patient quality of life. 

If you would like to meet with Dr. Moss about the use of Moss Nutrition products to improve the health of your patients, he would very much enjoy meeting with you.  If you would like to arrange to meet with him at your office, please e-mail him at to set up a date and time.  Or call 800-851-5444 x 108.