Study warns junk food plus sugar-free snacks could equal an upset stomach

By Sharin Hussain via SWNS

A junk food diet combined with eating sugar-free snacks can lead to an upset stomach, a new study claims.

The artificial sweetener sorbitol, a sugar alcohol used in sweets and chewing gum is difficult to digest due to changes in the gut microbiome caused by high-fat foods and antibiotics.

First author of the study Dr. Jee-Yon Lee, of University of California Davis said: “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.”

Sorbitol is used to make sugar-free gum, mints and other sweets. It is also found naturally in fruits like apricots and apples and plants like avocados.

Sorbitol can cause bloating, cramps and diarrhea at high levels. For some people, even a small amount causes an upset stomach, a condition known as sorbitol intolerance.

The experiment, published in the journal, Cell, found that mice taking antibiotics, combined with a high-fat diet reduced the number of Clostridia gut microbes breaking down sorbitol.

The researchers found that gut microbes that belong to the class Clostridium have genes that make the enzyme that breaks down sorbitol.

They also identified which of those gut bacteria were at high levels before but not after antibiotic treatment.

The researchers found that after the mice were given antibiotics and fed a saturated fat diet, the cells lining the gut used less oxygen.

This created a higher level of oxygen in the gut, decreasing Clostridia which doesn't like environments with oxygen.

Without enough Clostridia, sorbitol was not broken down in the gut.

The researchers performed several experiments to try to restore the gut bacteria so it could break down sorbitol again.

They fed the mice anaerostipes caccae, a gut bacterium that produces butyrate.

Butyrate is a short-chain fatty acid produced as part of the normal fermentation process in the gut.

It enhances oxygen usage by the cells that line the gut, the epithelial lining, which reduces oxygen levels in the large intestine.

Regulating the oxygen level with anaerostipes caccae restored the normal levels of Clostridia, which protected the mice from sorbitol-induced diarrhea, even after the butyrate-producing bacteria had been cleared from the mouse’s digestive system.

Dr. Lee added: “This discovery is crucial, given the prevalent use of sorbitol and similar sugar alcohols in the production of keto-friendly diet foods that are high in fat content.

“It also highlights the importance of oxygen consumption by the epithelial lining in the intestines in maintaining a healthy balance of gut bacteria, especially Clostridia, for proper digestion of certain sugars.”

Professor Andreas Bäumler, vice chair of research in the UC Davis Department of Medical Microbiology and Immunology said: “Our study provides a completely new starting point for approaches to diagnose, prevent and treat sorbitol intolerance.”