Reports show that 75% of adults experience some degree of lactose intolerance. While children of breastfeeding age do not experience such an intolerance. As far as is known 100% of non-human animals lose their ability to digest milk after weaning. And in fact, the ability to digest lactose in humans is most likely derived from a evolutionary genetic mutation in peoples whose ancestors relied heavily on dairy farming for survival.
And though lactose intolerance is mainly a matter of genetics, there is growing evidence that the microbiome may play a role and that by altering the microbiome it may be possible to lessen the symptoms of lactose intolerance. We will discuss how in the following sections:
- What causes lactose intolerance?
- The role of the microbiome in lactose intolerance
- Treating lactose intolerance through the microbiome
First let’s discuss how lactose intolerance develops.
What causes lactose intolerance?
As one gets older and weans off of breast milk their body stops producing lactase – the enzyme needed in order to break down and properly digest lactose (the sugar in dairy). And though lactose intolerance is so prevalent it is not often bad enough for people to stop enjoying milk, cheese and other dairy products.
In adulthood the gene responsible for creating lactase is chemically modified and switched off. This modification, wherein the gene is turned off, does not occur in a lactose tolerant person. Though this change may not be the only thing responsible for you ability or inability to consume dairy. Even if you no longer carry lactase, the gut microbiota may further inhibit or improve your ability to consume lactose and altering that microbiota may allow more people to enjoy lactose without intolerance.
The role of the microbiome in lactose intolerance
Cases have been reported of people who were previously lactose tolerance becoming intolerant after gut traumas or use of heavy antibiotics. And though it is clear that lactose tolerance or intolerance is mostly dependent on your genes, such cases provide evidence that there may also be a microbiome connection to the sustaining of that tolerance.
If you are lactose intolerant the lactose you consume moved undigested into the colon, where water enters to dilute the concentration of lactose, producing diarrhea. The lactose in the colon is then eaten by microbes that produce, as byproducts, gases that can cause cramping, bloating and other unpleasant symptoms.
What research is showing now, is that those symptoms associated with lactose being broken down by microbes, may be relieved by altering the microbiome. Through introducing microbes to the gut that can better digest lactose without producing gases.
Treating lactose intolerance through the microbiome
Studies into the microbiomes influence on lactose intolerance have began by testing out probiotics for lactose intolerance. In a study out of Israel researchers showed that a novel probiotic was able to reduce the symptoms of lactose intolerance in participants. A probiotic with β-galactosidase induced improved tolerance of lactose in most patients in an 8 patient study.
It should be noted that all participants were female with an average age of 18 years, so the study was quite small and limited. A larger randomized trial is needed to confirm the results of the study. The study does show promise for probiotic or other bacterial solutions to the symptoms of lactose intolerance.