If you’re like most North Americans, you don’t eat enough fibre. And that means you’re
short-changing your good gut bacteria a special type of fibre – called resistant starch – they need to thrive and keep you healthy.
Without a steady supply of resistant starch, the healthy microbes that reside in your gut can die off, increasing the load of disease-causing bacteria. Running down the good guys may also increase the risk of allergies, type 2 diabetes, obesity and inflammatory bowel disease.
Why your microbiota matters
Your intestines are home to trillions and trillions of microbes, the vast majority of them residing in the large intestine. Collectively, these bacteria, yeasts and fungi make up what’s called your microbiota.
The terms microbiota and microbiome are often used interchangeably, but there’s a subtle difference. The gut microbiome refers to the gut microbes themselves (microbiota) plus the genes they contain.
Our gut microbiota extracts energy and nutrients from fibre, synthesizes certain vitamins, activates disease-fighting phytochemicals, regulates immune function and protects the lining of the gut. Growing evidence suggests this microbial community also plays a role in inflammatory bowel disease, mental health, weight control, even food cravings.
A gut microbiota that contains a diverse community of microorganisms is defined as a healthy one because it increases the likelihood of beneficial species and fewer pathogenic bacteria.
Each person’s microbiota is unique and always changing. Genetics, antibiotic use, hygiene, stress and illness can shape the make-up of our microbiota.
Diet and your microbiota
Your diet is considered the most powerful tool that can alter the composition and activity of gut microbes.
A Western-style diet, high in animal protein, saturated fat and refined carbohydrates and low in fibre has been linked to a loss of microbiota diversity. Plant-based diets, on the other hand, have been associated with a richer, more diverse microbiota.
Large changes in your diet can alter your microbiota in just one or two days. Even so, it’s your long term dietary habits that count when it comes to the composition of your microbiota.
What is resistant starch?
Resistant starch escapes digestion in the small intestine and makes its way to the large bowel, where it’s slowly fermented and broken down by good bacteria.
Fermentation creates short chain fatty acids, compounds that feed gut bacteria, fuel colon cells, prevent the growth of harmful bacteria, fortify the intestinal lining and help regulate immune function.
Good sources of resistant starch include white beans, chickpeas, lentils, green peas, cashews, unripe bananas, plantain, whole grain pumpernickel bread, whole meal rye bread, barley, raw oats and muesli.
The longer you cook a food and the higher the temperature used, the more resistant starch will be lost.
Rice, potato, yams and pasta that have been cooked and cooled are decent sources of resistant starch, though. Cooling cooked starches changes their structure making them resistant to digestion in the small intestine.
If you don’t eat enough resistant starch, good bacteria can feed on other things, which can damage the gut. The microbiota of mice starved of fermentable fibre have been shown to feed on the mucus lining of the gut, making it thinner and more vulnerable to infection-causing bacteria.
Increase your intake of resistant starch gradually, over a period of weeks, you allow your gut bacteria to adjust.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.