Is chewing gum bad for your gut?

The chew...the bad...and the ugly!

(I really got to work on my sub-title game…..I’m actually sorry!)

Mr. P….He’s 33.

Marketing manager…Office based job.

Three pieces of mint gum on the train in. Two more before lunch. Another with coffee. He’s lost count by 3pm.

He came to clinic with bloating he couldn’t explain. Loose stools two or three times a week. A vague ache low in the abdomen. Bloods normal. Stool tests, normal. Coeliac screen, normal. Diet, broadly sensible.

I asked the question as I watched him pop another Extra peppermint piece.

How much gum do you chew?

He paused. “A lot, I guess.”

Chewing gum is everywhere. School bags, gym bags, glove compartments, gastroenterology clinics.

It freshens breath, kills the urge to snack, helps some people focus.

The global market sits around £30 billion a year.

Yet very few patients ever mention it when listing what they eat. It feels too small to count.

Let’s look at it properly.

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What is gum, actually?

Modern gum is a small piece of food chemistry.

The gum base is the chewy bit. Originally chicle, the latex of a Central American tree. Today it’s mostly synthetic polymers…polyvinyl acetate, polyethylene, polyisobutylene. Food-grade plastics, in other words.

Then the sweeteners. Sugar, or sugar alcohols (sorbitol, xylitol, mannitol, maltitol), or high-intensity sweeteners like aspartame and sucralose. Most “sugar-free” gum leans heavily on sorbitol and xylitol.

Add softeners to keep it pliable (glycerin, vegetable oils), flavourings (mint oils, menthol, esters), emulsifiers (usually lecithin), colourings, and preservatives like BHT to stop the oils going rancid.

A short ingredient list…..but a lot to unpick here.

This is a Ficus Elastica…a type of fig tree! Please note….gum is not made from this type of tree anymore.

The good

Some of the evidence here genuinely surprised me.

Postoperative ileus. After abdominal surgery the bowel can go stagnant. Patients can’t pass wind, can’t open their bowels, can’t go home.

Chewing gum acts as sham feeding. The brain thinks food is coming. The vagus nerve fires. The gut wakes up.

A 2013 meta-analysis of 17 RCTs (1,374 patients) found chewing gum reduced time to first flatus by 7 hours, time to first bowel motion by 12 hours, and length of hospital stay by nearly a full day.

A 2020 meta-analysis in colorectal surgery showed the incidence of ileus nearly halved (RR 0.55). Cheap. Safe. It now sits inside Enhanced Recovery After Surgery (ERAS) pathways.

Reflux and GORD. Saliva is your body’s natural antacid. Alkaline. Buffering. Clearing. Chewing gum roughly doubles salivary flow.

A 2005 RCT at King’s College London (Journal of Dental Research) gave 31 reflux patients a refluxogenic meal. Half an hour of sugar-free gum afterwards reduced the time the oesophagus spent below pH 4 from 5.7% to 3.6% (p=0.001). An earlier study by von Schönfeld (1997) cut acid clearance time from 6.9 minutes to 2.3.

For mild postprandial reflux, that’s not nothing.

Dental caries. A 2020 systematic review by Newton (JDR Clinical & Translational Research) pooled 12 studies. Sugar-free gum produced a prevented fraction of 28% for caries; xylitol-only gum, 33%. The American Dental Association and the European Food Safety Authority both endorse sugar-free gum as an adjunct to brushing.

There’s softer evidence too.

Modest appetite suppression. Better attention on small RCTs. Symptom relief in xerostomia (dry mouth), especially in older patients on multiple medications.

So far, so reasonable.

https://forestray.dentist/news/is-gum-bad-for-your-teeth-sugar-free-vs-regular/

The bad

Now the gut bit.

Aerophagia. When you chew, you swallow. When you swallow, air follows. Repeat for hours and you’ve got a small balloon growing in your gut. Aerophagia is an under-recognised cause of bloating, distension and burping, particularly in patients already labelled with IBS.

The treatment is often embarrassingly simple. Chew less. Sip less fizzy water. Slow the swallows.

Sugar alcohols. Sorbitol, xylitol and mannitol are FODMAPs. Poorly absorbed in the small bowel. They pull water in. Colonic bacteria ferment them. Gas. Cramping. Loose stools.

Around 5–20g of sorbitol a day produces gas, urgency and bloating in many people. Above 20g, frank diarrhoea is common.

One stick of typical sugar-free gum contains around 1.25g of sorbitol. A 16-piece pack? Roughly 20g. A whole pack across a working day, which I have seen, sits squarely in the laxative range!!

Xylitol behaves similarly. The non-effective dose is around 0.4g/kg body weight, so roughly 25–30g for a 70kg adult. In IBS patients, who are often more sensitive to FODMAPs, the threshold is lower still.

If you have IBS, IBD or unexplained loose stools, the gum packet is one of the first things I ask about.

If you are having 15 sugar free gums per day…..get used to this view

The ugly

Microplastics. A 2025 pilot study from UCLA (Lowe and Mohanty), presented at the American Chemical Society Spring meeting and published in Journal of Hazardous Materials Letters, measured microplastic release into saliva during chewing. Each gram of gum shed between 4 and 636 microplastic particles.

Ninety-four per cent were released in the first 8 minutes. A daily chewer could ingest around 30,000 microplastic particles a year from gum alone. Synthetic and “natural” gums shed similar amounts.

Whether ingested microplastics harm the human gut is unknown. There are no human trials. We do know we’re swallowing more of them every year.

TMJ pain. Hours of chewing strain the temporomandibular joint. Outside my specialty, but the link is well described.

Looksmaxing community chewing gum on both sides of the jaw to achieve this look? Beware of TMJ pain!

My take

I chew gum. Occasionally. Before a clinic, on a long flight, when my mouth feels like sandpaper. One piece. Maybe two. Sugar-free, but not by the packet.

The evidence is mostly positive.

Post-surgery, it speeds recovery. After meals, it cools reflux and protects teeth.

In (serious) excess, it bloats the gut, loosens stools, possibly sheds microplastics into saliva, and delivers a laxative dose of sorbitol most people never read on the label.

My marketing manager? Two weeks off the gum. Bloating gone. Stools settled. He still chews the odd piece before a meeting. Just the odd piece.

In moderation, I don’t think you need to bin the packet. I just don’t think you should empty it before lunch!!

Struggling with liver or digestive issues that affect your daily life? Invest in your gut health with a private, personalised consultation where I will explore your specific symptoms and develop a targeted treatment plan. Take the first step toward digestive wellness today: https://bucksgastroenterology.co.uk/book-an-appointment/ (I offer both in person and video consultations!)

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References

1. Liu Q, et al. Chewing gum reduces postoperative ileus following abdominal surgery: a meta-analysis of 17 randomized controlled trials. J Gastroenterol Hepatol. 2013;28(7):1122-1132.

2. Su’a BU, et al. Chewing gum and postoperative ileus in adults: a systematic literature review and meta-analysis. Int J Surg. 2015;14:49-55.

3. Roslan F, et al. The Impact of Sham Feeding with Chewing Gum on Postoperative Ileus Following Colorectal Surgery: a Meta-Analysis of Randomised Controlled Trials. J Gastrointest Surg. 2020;24(11):2643-2653.

4. Noble EJ, et al. Gum chewing reduces postoperative ileus? A systematic review and meta-analysis. Int J Surg. 2009;7(2):100-105.

5. Moazzez R, Bartlett D, Anggiansah A. The Effect of Chewing Sugar-free Gum on Gastro-esophageal Reflux. J Dent Res. 2005;84(11):1062-1065.

6. von Schönfeld J, Hector M, Evans DF, Wingate DL. Oesophageal acid and salivary secretion: is chewing gum a treatment option for gastro-oesophageal reflux? Digestion. 1997;58(2):111-114.

7. Newton JT, et al. A Systematic Review and Meta-Analysis of the Role of Sugar-Free Chewing Gum in Dental Caries. JDR Clin Trans Res. 2020;5(3):214-223.

8. Riley P, Moore D, Ahmed F, Sharif MO, Worthington HV. Xylitol-containing products for preventing dental caries in children and adults. Cochrane Database Syst Rev. 2015;(3):CD010743.

9. Lenhart A, Chey WD. A Systematic Review of the Effects of Polyols on Gastrointestinal Health and Irritable Bowel Syndrome. Adv Nutr. 2017;8(4):587-596.

10. Oku T, Nakamura S. Threshold for transitory diarrhea induced by ingestion of xylitol and lactitol in young male and female adults. J Nutr Sci Vitaminol. 2007;53(1):13-20.

11. Mäkinen KK. Gastrointestinal Disturbances Associated with the Consumption of Sugar Alcohols with Special Consideration of Xylitol. Int J Dent. 2016;2016:5967907.

12. Bauditz J, Norman K, Biering H, Lochs H, Pirlich M. Severe weight loss caused by chewing gum. BMJ. 2008;336(7635):96-97.

13. Bian X, et al. Sorbitol: often forgotten cause of osmotic diarrhea. Can Fam Physician. 2019;65(8):557-558.

14. Chassaing B, et al. Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature. 2015;519(7541):92-96.

15. Chassaing B, et al. Dietary emulsifiers directly alter human microbiota composition and gene expression ex vivo potentiating intestinal inflammation. Gut. 2017;66(8):1414-1427.

16. Naimi S, Viennois E, Gewirtz AT, Chassaing B. Direct impact of commonly used dietary emulsifiers on human gut microbiota. Microbiome. 2021;9:66.

17. Bancil AS, et al. Food additive emulsifiers and their impact on gut microbiome, permeability and inflammation: Mechanistic insights in inflammatory bowel disease. J Crohns Colitis. 2021;15(6):1068-1079.

18. Lowe L, Mohanty SK. Ingestion of microplastics during chewing gum consumption. Journal of Hazardous Materials Letters. 2025;6:100164.

19. Allen AP, Smith AP. Effects of chewing gum and time-on-task on alertness and attention. Nutr Neurosci. 2012;15(4):176-185.

20. Hetherington MM, Boyland E. Short-term effects of chewing gum on snack intake and appetite. Appetite. 2007;48(3):397-401.

General Disclaimer

Please note that the opinions expressed here are those of Dr Hussenbux and do not necessarily reflect the positions of Buckinghamshire Healthcare NHS Trust. The advice is intended as general and should not be interpreted as personal clinical advice. If you have problems, please tell your healthcare professional, who will be able to help you. Thank you to the amazing photographers from Unsplash where I get most of my images from.