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.
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 harmful ones.
Diet and your microbiota
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.
Eating for a healthier microbiome
Research on how foods alter the microbiota and, in turn, influence health is in the very early stages, but it’s accelerating at a rapid pace. The following tips can help nourish your microbiome.
Eat more plants
A study published this month in the journal Cell Host & Microbe found that, compared to people who ate a typical American diet, those who followed a lower calorie, mostly plant-based diet had a far more diverse microbial community in their gut.
Aim for your meals to be 75 per cent plant-based. Fill three-quarters of your plate with foods such as whole grains, vegetables, fruit, legumes and nut and seeds.
Ditch the high protein diet
A high-protein, low-carb diet won’t cultivate a robust microbiota. Findings from a 2011 study conducted in overweight men suggested that such a diet reduced beneficial short chain fatty acids and antioxidants.
It’s also thought that undigested proteins that reach the colon may promote the growth of harmful bacteria.
Increase resistant starch
Foods such as white beans, chickpeas, lentils, green peas, cashews, unripe bananas, plantain, whole grain pumpernickel bread, barley, raw oats and muesli are good sources of resistant starch, fuel that allows good gut bacteria to flourish.
Cooked and cooled rice, potato, yams and pasta also contain resistant starch. Add leftover grains and pasta to salads to boost your fermentable fibre intake.
Add prebiotics
Studies show that supplementing your diet with non-digestible carbohydrates known as prebiotics can fuel the growth of Bifidobacteria and Lactobacilli, two common probiotic bacteria.
Prebiotic foods include asparagus, bananas, Jerusalem artichokes, jimica, rye, barley, kefir, leeks, onions, garlic and chicory root. Foods high in resistant starch are considered prebiotics.
Consider probiotic supplements
Taking a good quality probiotic supplement can help diminish microbiome damage caused by antibiotics. Specific species and strains of probiotics have also been shown to lower LDL cholesterol, manage constipation and ease bloating.
There’s no conclusive evidence, though, that taking probiotics provides health benefits to healthy people.
Limit artificial sweeteners
Findings from experiments published in the journal Nature (2014) showed that consuming artificial sweeteners led to glucose intolerance in mice and humans by disrupting the composition of gut bacteria. (The volunteers consumed the maximum acceptable daily intake of saccharin for a week, equivalent to eight packets of sweetener per day.)
It’s thought that certain intestinal bacteria react to artificial sweeteners by secreting substances that trigger inflammation and impair the body’s ability to utilize blood sugar.
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.