If you’re lactose intolerant, then you know: one scoop of ice cream is all it takes to
experience a gut-wrenching sensation. But what if lactose intolerance wasn’t solely about dairy?
New research suggests that your gut bacteria might be playing a leading role in those post-dairy
blues (Brandao Gois et al., 2020).
Let’s start with a quick refresher: lactose intolerance is usually the result of missing
lactase, the enzyme that digests lactose, the sugar in milk. Without lactase, lactose just stays in
your gut, leading to bloating, gas, and discomfort (Misselwitz et al., 2019). However, scientists
are finding that the gut microbiome, the community of trillions of bacteria in your digestive tract,
might be more involved than previously thought. One genus in particular, Bifidobacterium,
seems to be a prime suspect (Brandao Gois et al., 2020).
Bifidobacterium and other bacteria in the gut are capable of fermenting lactose. You
might think that’d help, but their “help” creates gas and byproducts that can sometimes make
lactose intolerant symptoms even worse (Misselwitz et al., 2019). In other words,
Bifidobacterium is basically acting like that overly enthusiastic friend at a karaoke party –
well-meaning, but a little too intense.
A study from the Lifelines-DEEP Dutch population cohort dove into this theory by
analyzing 959 participants. They found that people with the genetic LI variant (a particular gene
combo called G/G on SNP rs4988235) had higher Bifidobacterium populations in their gut.
Additionally, the more Bifidobacterium, the higher the frequency of GI complaints – specifically
abdominal pain, discomfort, and bloating (Brandao Gois et al., 2020). So, instead of simply
digesting lactose, these bacteria are throwing a party in your stomach (Leon, S. D., 2021).
A second study noted that Bifidobacterium actually correlates positively with dairy intake
in people with lactose intolerance but not in those without it (De Vrese et al., 2001). In other
words, the real problems seem to start when dairy enters the picture, activating these
lactose-loving bacteria, and triggering all those uncomfortable symptoms.
So what’s the takeaway? Avoiding dairy might still be your safest bet for now, but the
future might hold other options. Imagine, rather than going dairy-free, managing
Bifidobacterium levels in your gut could allow you to indulge without regretting it later.
Scientists are actively exploring gut-modifying treatments – from probiotics to dietary tweaks –
which could one day give lactose-intolerant folks a pathway to enjoy dairy without a hitch. Until
then, though, you might not want that extra scoop.
Reviewed By: Aman Meredia
Designed By: Ashley Gutierrez-Torres
References
1. Brandao Gois, M. F., Sinha, T., Spreckels, J. E., Vila, A. V., Bolte, L. A., Weersma, R. K.,
Wijmenga, C., Fu, J., Zhernakova, A., & Kurilshikov, A. (2020). Role of the gut
microbiome in mediating lactose intolerance symptoms. Gut.
2. De Vrese, M., Stegelmann, A., Richter, B., Fenselau, S., Laue, C., & Schrezenmeir, J.
(2001). Probiotics – compensation for lactase insufficiency. The American Journal of
Clinical Nutrition.
3. Foster, P. (2019, April 11). Can changing the microbiome reverse lactose intolerance?.
Department of Biology.
https://biology.indiana.edu/news-events/news/2019/foster-lactose-intolerance.html
4. Leon, S. D. (2021, June 18). Lactose intolerance: Bacteria that causes it and how to treat
it. Floré by Sun Genomics. https://flore.com/blogs/learn/lactose-intolerance-bacteria-that-causes-it-and-how-to-treat-it?srsltid=AfmBOoq-gZlTLRZ2ksgmFhYTKeTTUQ3FNjeSxvEiGs5-eFgfyrPH12o9
5. Misselwitz, B., Butter, M., Verbeke, K., Fox, M. R., & Vanner, S. J. (2019). Update on
lactose malabsorption and intolerance: Pathogenesis, diagnosis, and clinical management.
Gut and Liver.
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