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Why sugar-free candy and sugar-free gum give many people gas

Sorbitol, a common sugar alcohol found in various sugar-free products and natural foods, has long puzzled those who experience gas and discomfort upon consumption.

Researchers at UC Davis have made significant strides in understanding the root cause of sorbitol intolerance, shedding light on how changes in the gut microbiome can affect one’s ability to digest this compound. Their findings point to a promising new direction for treating and managing this condition.

The culprit: A common sugar-free ingredient

Sorbitol is widely used in sugar-free gum, candies, and diet foods, and occurs naturally in fruits like apricots, apples, and avocados.

While beneficial for those seeking lower-calorie options, sorbitol can cause bloating, cramps, and diarrhea at high levels.

A condition known as sorbitol intolerance arises in some individuals from even minimal intake, leading to significant discomfort.

Sorbitol and the gut microbiome

The study conducted on mice revealed a fascinating interaction between antibiotics, a high-fat diet, and the gut microbiome’s ability to process sorbitol.

Specifically, such a diet, when combined with antibiotic use, diminishes the population of Clostridia — a key group of gut microbes responsible for breaking down sorbitol.

Jee-Yon Lee is the study’s lead author and an assistant project scientist at the UC Davis Department of Medical Microbiology and Immunology

She explains, “Our research suggests that microbial sorbitol degradation normally protects the host against sorbitol intolerance. However, an impairment in the microbial ability to break down sorbitol causes sorbitol intolerance.”

Role of oxygen in the gut microbiome

The team utilized metagenomic analysis to identify gut bacteria equipped with genes for producing the enzyme needed to digest sorbitol.

Their research highlighted the drastic reduction in Clostridium bacteria, which thrive in low-oxygen environments, following antibiotic treatment.

Following antibiotic administration and a high-saturated fat diet, the cells lining the gut consumed less oxygen. This led to increased oxygen levels in the gut, which adversely affected Clostridia populations, impairing sorbitol digestion.

To counteract this, the researchers experimented with reintroducing specific gut bacteria to restore sorbitol digestion capabilities.

One successful method involved administering Anaerostipes caccae, a bacterium that produces butyrate.

This compound improves oxygen consumption by gut lining cells, thereby reducing oxygen levels in the intestine and allowing Clostridia levels to normalize.

This adjustment helped protect mice from sorbitol-induced diarrhea, showcasing a potential pathway for treating sorbitol intolerance in humans.

New perspective on guilt-free treats

The study suggests that mesalazine, a drug commonly used for treating inflammatory bowel diseases, could offer a new treatment avenue for sorbitol intolerance.

By mimicking the oxygen-lowering effects of butyrate-producing bacteria, mesalazine could encourage a gut environment where Clostridia can thrive, mitigating sorbitol intolerance symptoms.

“This discovery is crucial, given the prevalent use of sorbitol in keto-friendly diet foods and other high-fat content products,” Lee added.

Highlighting the importance of oxygen consumption in the gut’s epithelial lining, the research underscores the delicate balance required among gut bacteria for effective digestion of certain sugars.

However, the researchers caution that mice, unlike humans, possess a cecum that aids in digesting carbohydrates, allowing them to tolerate higher levels of sorbitol.

Clinical studies are necessary to confirm whether mesalazine could effectively treat sorbitol intolerance in humans.

“Our study provides a completely new starting point for approaches to diagnose, prevent, and treat sorbitol intolerance,” said Andreas Bäumler, the study’s senior author and a distinguished professor at UC Davis.

Improving our lives in a sugar-free future

In summary, this discovery by the team at UC Davis offers new insights into the causes of sorbitol intolerance and opens up promising avenues for its treatment.

By identifying the critical role of gut microbiome composition and oxygen levels in the digestion of sorbitol, this study offers innovative approaches to manage and alleviate the discomfort associated with sorbitol intolerance.

The potential application of mesalazine as a treatment underscores the importance of ongoing research in understanding gut health and its impact on our overall well-being.

With further clinical studies, these findings could lead to more effective strategies for those affected by sorbitol intolerance, enhancing the quality of life for many.

The full study was published in the journal Cell.


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