Does chewing slowly really help with better digestion?
Chewing well certainly helps form a smooth food bolus and increases saliva production, but whether it actually leads to better digestion in healthy people has not been demonstrated. Take your time with it, but do not expect a major health benefit if you already eat normally.
Chewing does one thing for certain: it physically breaks down food and mixes it with saliva into a smooth bolus that you can safely swallow. That is not a trivial point; without adequate chewing, people swallow larger pieces that are harder to digest. This mechanical effect is well described in the literature on chewing and swallowing physiology.
Saliva contains amylase, an enzyme that begins breaking down starch. More chewing means more saliva, and therefore more contact between amylase and your food. In theory that makes sense, but whether this leads to noticeably better digestion in healthy people in practice has not been demonstrated by the available research. The idea is biologically plausible, nothing more.
What is firmly established is that prolonged chewing produces significantly more saliva. That saliva is also less acidic, which is beneficial for your teeth and oral mucosa. For people with a dry mouth, such as older adults, chewing sugar-free gum can measurably improve saliva production. A systematic review found an average positive effect, although five of the included studies reported no improvement in the sensation of dry mouth. That review was partly funded by a chewing gum manufacturer, which is worth bearing in mind.
In people with Crohn's disease or ulcerative colitis who have intestinal narrowings, careful chewing is recommended as expert advice to help tolerate fibrous vegetables better. This is not the result of randomised research, but rather a practical line of reasoning.
Finally, a lesser-known point: chewing can temporarily introduce bacteria from the mouth into the bloodstream. For healthy people this is harmless, but people with a weakened immune system may be more affected by it.
The claims are based on studies in chewing physiology, saliva research, and a systematic review on dry mouth. There are no RCTs that directly compare 'slow chewing' with 'fast chewing' on digestive outcomes in healthy people.
Does intermittent fasting help your gut health?
For healthy people and people with metabolic syndrome there is reasonably consistent evidence that intermittent fasting has a beneficial effect on gut bacteria and inflammation markers. If you have a chronic bowel disease, discuss fasting with your doctor first, as evidence in that group is still lacking.
Does drinking apple cider vinegar help your digestion?
There is no research whatsoever showing that apple cider vinegar improves digestion. If you want to use apple cider vinegar for blood sugar control in diabetes, discuss this with your doctor, as good evidence is also lacking for healthy people.
Does eating flaxseed help your gut?
Through its fibre and lignans, flaxseed has a plausible positive effect on the gut, but for the gut as a specific target the evidence in humans is still limited. If you want to take concrete action, opt for at least 30 grams of ground flaxseed per day.
What is the role of bile acids in healthy digestion?
Bile acids are indispensable for proper fat digestion and the absorption of fat-soluble vitamins. If you suffer from greasy stools or have had a liver disease or intestinal surgery, discuss this with your doctor, as a bile acid deficiency may be the underlying cause.
Can exercise improve your gut microbiome?
Moderate regular exercise demonstrably improves your gut microbiome, but you need to keep exercising because the effect disappears when you stop. Do not overdo it: very intensive training can actually put gut health under pressure.
Does eating a varied diet help your gut bacteria?
Fermented products have the strongest evidence base for increasing gut bacterial diversity. Eating broadly varied meals also helps, but above all avoid heavily processed products containing emulsifiers such as CMC.