Gut health and cancer treatment

Keeping your stomach regular has a huge effect on your general well-being and comfort. Dietitian, Berna Harmse, shares tips to keep your gut healthy during active cancer treatment.


It might come as a surprise, but the majority of serotonin (feel-good hormone) receptors in your body are in your colon and not in your brain. This explains why some people have changes in their bowel movements during stressful times. Sometimes it is also our lifestyles that contribute to abdominal discomfort.

Basic lifestyle changes

  • Eat regular meals and never skip a meal.
  • Take time to eat and chew properly. Don’t rush a meal. 
  • Make time to go to the toilet. The best time is usually in the morning after breakfast.
  • Try and limit your intake of alcohol, tea, coffee and fizzy cold drinks.
  • Be as active as you can be and take time to relax. Get enough sleep at night.

Happy colon

Certain food entities play a big role in creating a healthy environment in your colon (gastro-intestinal area): 

1. Fibre

Fibre or dietary fibre is the part of plant food that can’t be fully digested by the small intestine and reaches the colon almost completely intact. It is essential for the body to help regulate bowel movement, maintain a desirable level of friendly bacteria in the colon, and provide a source of fuel for the cells in the colon. There are two types of fibre.

  • Soluble fibre is found in fruit, vegetables, oats and oat bran. This fibre holds water and increases the bulk of the stool. It also creates a feeling of fullness after a meal by delaying stomach emptying. This is useful for weight management and diabetic sugar control. Soluble fibre is also beneficial for cholesterol management and can help control diarrhoea.
  • Insoluble fibre is mainly found in wholegrain products, such as high-fibre breakfast cereals, skins and pips of fruit and vegetables, and mealie kernels. It decreases transit time through the bowel by ‘pulling’ the food through the gut quicker and can help relieve constipation.

A daily total fibre intake of 25-35g is recommended. Try not to exceed a total fibre intake of 50g, as insoluble fibre can bind with certain minerals, such as calcium and iron, which then prevents absorption.

General guidelines of eating fibre

  1. Increase your daily fibre intake gradually, to avoid possible side effects, such as bloating and flatulence. The body will adapt to an increased fibre intake and the side effects will gradually disappear.
  2. Include generous servings of vegetables and aim for at least three servings of fresh fruit daily.
  3. Select fibre from a wide variety of food sources.
  4. Only use a fibre supplement if recommended or prescribed by your dietitian or doctor.

2. Fluid

Adequate fluid is essential! Drink at least eight to 10 glasses of fluid, preferably water every day. A more specific guideline is to drink 30ml for every kilogram you weigh daily. Inadequate fluid with a high fibre intake may cause or worsen constipation.

3. Probiotics

Probiotics are gut friendly bacteria that aid digestion and replace the bad bacteria in your colon. Too much bad bacteria in your colon might lead to symptoms, like bloating, diarrhoea or constipation. Good bacteria work like Pac-Man; their job is to ‘eat’ the bad bacteria in your gut to restore a normal environment. 

Make sure to eat foods like yoghurt and kefir. A probiotic supplement can also be helpful. But always check with your health professional if it is safe to use during the treatment you are receiving, and ask about the specific product to use. 

4. Gas-forming foods

Gas-forming foods can all cause abdominal discomfort. These include dried beans, lentils, cabbage, onions, dried peas, broccoli, cauliflower, peppers, lettuce, cucumber, corn, leeks, radish, soya beans, Brussel sprouts, turnips, apples (raw), apple juice and watermelon.

Avoid strong tea, coffee (both caffeine-containing and decaffeinated), chocolate, cola drinks, cocoa and  other caffeine-containing beverages, especially on an empty stomach.

Avoid using excessive amounts of pepper, spices and seasonings. Examples include curry spices, chilli, cured and smoked foods, pickles, mustard and vinegar.

There are many ways of improving your nutritional status as a person living with cancer. These guidelines are general guidelines. If you have any difficulty with following the guidelines, contact a dietitian to give you information that is perfectly suited to your personal needs.

Berna Harmse is a private practicing dietitian. She holds a MSc in Dietetics, 
and has a special interest in oncology nutrition. She is also an external lecturer at Stellenbosch University Division of Human Nutrition.

MEET OUR EXPERT – Berna Harmse

Berna Harmse is a private practicing dietitian. She holds a MSc in Dietetics, and has a special interest in oncology nutrition. She is also an external lecturer at Stellenbosch University Division of Human Nutrition.


Leave a Reply

Your email address will not be published.