You might be familiar with the beneficial by-products that result from our gut bacteria feeding on indigestible carbohydrates, like fiber. But, what happens to undigested protein that ends up in your large intestine (aka your colon), and why should you care?
A new review article titled “Insights into colonic protein fermentation, its modulation and potential health implications” investigated the harmful effects of protein fermentation and their relationship to irritable bowel syndrome, ulcerative colitis, colorectal cancer, and foul-smelling farts (sorry, folks).
Although our bodies are well-equipped to efficiently break down protein, some of it still escapes digestion and ends up in the colon.
A few factors that increase protein delivery to the large intestine include:
- Antacid therapy (e.g. Proton pump inhibitors)
- Rapid gastrointestinal transit
- A diet high in protein-rich sources, especially red meat
- Crohn’s disease of the small intestine
- Untreated celiac disease
When the undigested proteins reach the large intestine, they can be fermented by colonic bacteria to produce toxic end-products, such as ammonia and hydrogen sulfide, to name a couple.
These gases have been shown to erode the protective barrier of the colon and initiate inflammation. Both of these outcomes, among others discussed in the article, might contribute to the development and/or progression of ulcerative colitis and colorectal cancer.
Plus, hydrogen sulfide is mostly to blame for foul-smelling gas, which is a common complaint among people following a high protein, low carbohydrate diet.
High protein, low carb diets have also been shown to favor the growth of harmful pro-inflammatory bacteria and inhibit the growth of beneficial anti-inflammatory bacteria.
Fortunately for you meat lovers, research suggests that eating a variety of plants along with the animal protein reduces protein fermentation.
The article delves into much greater detail about protein fermentation and what that means for gut health, and I highly recommend it for those of you with an affection for science jargon and the GI tract.
For everyone else, these findings support what we already know about healthy eating, which is to eat less animal products and more plants.