Digestion 101: everything you need to know from a nutritionist 

two people sharing food off a plate

Ever wonder what happens in your body after you scarf down that bagel and cream cheese? Or perhaps you’re seeking answers to an even bigger mystery… how can corn leave your digestive tract perfectly intact?  Understanding your digestive system is the first step to keeping it in great shape (hey- an amazing microbiome is something to brag about).  

Here we cover the basics of digestion and share our top tips on how to keep your digestion healthy.  

How digestion works

Let’s magic school bus our way into the digestive tract, which starts in your mouth where enzymes break down your food. Not only does chewing achieve the obvious result of breaking your food into smaller pieces, but it also signals your stomach to start producing acid.  

Once your food is swallowed, your stomach has the important job of extracting nutrients from your food and getting it ready to be absorbed in the small intestines. As you age, your body tends to produce less stomach acid, which can actually make it harder to absorb certain nutrients, like B12 and calcium citrate. What does that mean? You may need to up your intake or seek out a supplement to help fill the gaps. 

But back to our magic school bus ride… After the stomach, food bits, now called chyme (yum!) head into the small intestine. This is where the majority of your nutrients get absorbed with the help of enzymes from the pancreas and small intestines.  

Finally, what’s left of your food moves into the large intestines where it’s packaged as waste. Your stool doesn’t just contain undigested foods, it also contains fluids, old cells from the gut lining, and digestive waste products (like cholesterol!). Healthy stools should be soft yet formed and easy to pass.  

How to keep your digestive tract healthy 

1. Drink plenty of water 

Does going #2 sometimes feel like a workout? Staying hydrated doesn’t just help soften your stools so they’re easier to pass, but water can also promote a balance of probiotics, good bacteria that live in your gut. One large study found that differences in water intake can lead to differences in gut microbiota composition.1  

2. Get into a routine 

Sticking to a schedule isn’t just good for your sanity- it can also help keep your gut healthy. Your circadian rhythm influences your digestion, sleep, mood and if your circadian rhythm is thrown off, say by changes in your sleep patterns, it may disrupt your digestion and even put you at greater risk for constipation.2  

To promote regularity and digestive health make sure you’re sticking to regular mealtimes and a sleep schedule. Even going to the bathroom at the same time each day (like 15-20 minutes after your first meal) can help cue your body to go #2.    

3. Fill up on fiber  

Want your insides to thrive? Look no further than fiber, a type of indigestible carbohydrate that does everything from fueling healthy gut bacteria to easing constipation. Foods like oatmeal, popcorn, seeds, nuts, fruits and vegetables are great sources of fiber and adding fiber-rich foods can promote regularity and help defend against constipation, according to some research.3  

4. Eat your fruits and veggies 

For real though. Eat your fruits and vegetables. They’re not only a great source of fiber, to help with constipation (which roughly 16% of us suffer from), but they’re also full of flavonoids. These are compounds found in plants that influence your intestinal immune function and support a balanced inflammatory response.4 

5. Get moving

You don’t have to be a fitness freak to reap the benefits of exercise. Even light to moderate movement can help keep your stools moving and relieve constipation. Plus, regular exercise has been linked to a healthier microbiome. 5 So whether you like walking outside or dancing in a class, find an activity you enjoy and can stick with for a long-term. Our new motto: move your body, move your bowels.  

6. Go easy on the alcohol 

Not to be a party pooper…but alcohol, especially chronic consumption, promotes intestinal hyperpermeability- aka leaky gut. Excessive alcohol is also linked to an imbalance in the microbiome, which may have consequences for your overall health. 6,7 But, as they say: everything in moderation. That’s one drink a day for women and 2 for men. Pour one out for your gut!  

7. Limit processed and fast food 

Sure, there are lots of reasons to avoid processed and fast foods so you can go ahead and add keeping your microbiome healthy to the list. In a study with 1,425 people in the Netherlands, researchers said that those who consumed a diet high in processed and animal-derived fatty foods had greater levels of destructive bacteria that produce toxins that harm the gut. 7 Opt for cooking at home when you can.  

8. Consider a supplement 

If you’re looking to up your gut health, certain supplements can help you out like a probiotic, digestive enzymes or garlic.  

Check out our top 7 supplements for gut health!  

About Agnes  

Agnes is an accredited nutritionist by SNDA (Singapore Nutrition & Dietetics Association). Prior to Persona, she worked in community settings, providing training and managing events. She loves working with people and is passionate about changing people’s lives through nutrition.  

Do you have questions about supplements? Reach out to one of our experts, or take Persona’s free nutrition assessment, and learn exactly what you need to take your wellness to the next level.     


*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.      


This information is not intended as a substitute for the advice provided by your physician or other healthcare professional, or any information contained on or in any product label or packaging. Do not use the information from this article for diagnosing or treating a health problem or disease, or prescribing medication or other treatment. Always speak with your physician or other healthcare professional before taking any medication or nutritional, herbal, or homeopathic supplement, or using any treatment for a health problem. If you have or suspect that you have a medical problem, contact your health care provider promptly. Do not disregard professional medical advice or delay in seeking professional advice because of something you have read in this article.        



  1. Vanhaecke T, Bretin O, Poirel M, Tap J. Drinking Water Source and Intake Are Associated with Distinct Gut Microbiota Signatures in US and UK Populations. J Nutr. 2022;152(1):171-182. doi:10.1093/jn/nxab312 
  2. Voigt RM, Forsyth CB, Keshavarzian A. Circadian rhythms: a regulator of gastrointestinal health and dysfunction. Expert Rev Gastroenterol Hepatol. 2019;13(5):411-424. 
  3. Yang J, Wang HP, Zhou L, Xu CF. Effect of dietary fiber on constipation: a meta analysis. World J Gastroenterol. 2012;18(48):7378-7383. doi:10.3748/wjg.v18.i48.7378 doi:10.1080/17474124.2019.1595588 
  4. Pei R, Liu X, Bolling B. Flavonoids and gut health. Curr Opin Biotechnol. 2020;61:153-159. doi:10.1016/j.copbio.2019.12.018 
  5. Gubert C, Kong G, Renoir T, Hannan AJ. Exercise, diet, and stress as modulators of gut microbiota: Implications for neurodegenerative diseases. Neurobiol Dis. 2020;134:104621. doi:10.1016/j.nbd.2019.104621  
  6. Engen PA, Green SJ, Voigt RM, Forsyth CB, Keshavarzian A. The Gastrointestinal Microbiome: Alcohol Effects on the Composition of Intestinal Microbiota. Alcohol Res. 2015;37(2):223-236. 
  7. Bolte LA, Vich Vila A, Imhann F, et al. Long-term dietary patterns are associated with pro-inflammatory and anti-inflammatory features of the gut microbiome. Gut. 2021;70(7):1287-1298. doi:10.1136/gutjnl-2020-322670 



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