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Keeping an eye on bacteria in your stomach

Intestinal health doesn’t have the sexy connection to overall health, but evidence has steadily accumulated to suggest that looking after the bacteria in your intestines can in turn look after you. This also raises an exciting possibility for the slimming industry: Weight management may be influenced by the makeup of that same bacteria. 

Julie Godfrey

Julie Godfrey

A study looking at the effect of fiber on gut bacteria found that consuming more could help prevent diseases such as type 2 diabetes, inflammatory bowel diseases and colon cancer. Bacteria feed on soluble fiber that has arrived in the large intestine, creating substances known as short-chain fatty acids, which are responsible for strengthening immunity and helping to control inflammation, as well as influencing metabolism and the composition of fat tissue linked to weight management. By maintaining a good intake of fiber from different sources, you create an environment within your intestines become a bacteria production site. 

So how much fiber should you munch, and which foods are best to eat? Aim for the recommended 25 grams (adult women) or approximately 35 grams of fiber (adult men) by including fruits, vegetables and unprocessed grains and seeds in your diet. An example of a good breakfast might include whole oats, a spoonful of ground flaxseeds, plain live yoghurt and banana; lunch might be tuna and garbanzos on salad leaves, a few pickles plus an apple; and dinner could involve grilled fish with whole potatoes, lightly steamed carrots and spinach. Snacks: dried fruits with nuts, or on fresh fruits such as mandarin, pear or strawberries.

If you find that increasing fiber intake results in excess bloating and flatulence, either you could be taking in too much insoluble fiber such as bran, or the increase was too sudden, especially if your previous diet was high in processed foods. Foods in a more natural state require a diverse range of bacteria to break them down, whereas processed foods are mostly absorbed in the small intestine, leaving nothing to be worked on in the large intestine. It’s a case of use-it-or-lose-it, as the variety of bacteria in the large intestine will decline. Upping your fiber intake with a reduced variety and volume of bacteria can result in fermentation without the benefits (just gas).

The way forward is to not only increase the quantity of fiber consumed slowly, by a few grams a week, but to simultaneously ingest good bacteria, ideally in the form of fermented foods. In addition to fermented dairy products (live yoghurt, yoghurt drinks, leche agria), look for pickled vegetables and sauerkraut in supermarkets while some specialized shops such as Chinese supermarkets may have kimchi and pickled vegetables. However, commercial products can be unpredictable in terms of levels of live bacteria, so you may want to experiment and have a go at making some yourself by trying some of the many online recipes.

Finally, if you have difficulties in successfully adjusting your diet, seek out expert help. Gut health is quite complicated, and often best managed on a case-by-case basis.

Julie Godfrey BSc (Hons) is a Nutritional Therapy Practitioner and full member of the British Association of Applied Nutrition and Nutritional Therapy (BANT). See or email

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