The Relationship Tooth Loss and IBS

Man with a missing tooth
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An study out of Iran poses an intriguing question, "Does having less teeth in your mouth increase your risk for IBS?" Of course, this leads me to an immediate question of my own, "Why would they even think that?" Let's take a look.

It turns out the reason that these researchers put themselves to the trouble of answering this question is because other studies have shown a possible connection between missing teeth and several other digestive disorders.

Any possible link between tooth loss and IBS had not been studied prior to this current study.

The Theory Behind the Study

The basic premise is that tooth loss results in poor chewing and thus interferes with the proper breakdown of foods. Such food then has lessened exposure to the enzymes in saliva, which may affect adequate secretion of other digestive acids and enzymes further along in the digestive process. The thinking is that this impaired digestion can lead to an increased risk of digestive disorders.

Another theoretical concern is that a state of unhealth in the microbiome within the mouth can affect the health of the rest of the digestive tract. However, this particularly study does not offer any information as to these theoretical problems, it only looked at a correlation between tooth loss and the presence of an IBS diagnosis.

The Study

The study consisted of self-administered questionnaires given to 4669 Iranian adults, ages 19 to 70.

These individuals were all "non-academic staff" working across 50 health centers in Iran, and thus were thought to comprise a fairly good cross-section of people. Using the answers to the questionnaires, IBS was diagnosed using a version of the Rome III criteria for IBS modified for Persians. Study participants were also asked about the status of their teeth.

Participants were split into five groups:

  • No loss of teeth
  • Denture wearer
  • Loss of one to two teeth
  • Loss of three to five teeth
  • Loss of half of a jaw or more

The Results

Statistical analysis indicated that those who lost one to two teeth had a 35% greater chance for having IBS as compared to people who had all of their teeth, while those that lost three to five teeth had a 33% greater chance. People who had dentures had an extremely higher risk of having IBS.

Gender analysis pointed to an association between the loss of one to two teeth and IBS in men, with a particular increased risk for IBS-C. As for women, those who lost three to five teeth had a 34% greater chance of having IBS than those who had a full mouth of teeth. Women who had dentures were more likely to have IBS-C.

What This Means

What this means is that very little is known about the relationship between IBS and tooth loss. This is one study, consisting of self-report, that only points to some correlations. This study does not provide any evidence that tooth loss causes IBS. The findings may only be applicable to this particular study population, and there may be a wide variety of factors to account for any seen associations.

However, a study like this does remind us of the importance of good dental hygeine - for one's overall, oral, and digestive health.

So, brush your teeth and see your dentist regularly!


Esmaillzadeh, A., "Is tooth loss associated with irritable bowel syndrome?" Journal of Oral Rehabilitatiomn 2015 42:503-511.

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