3. Feed the good guys with prebiotics and resistant starch
The existing probiotics in our gut need to be nourished and supported, and this can be done by eating or supplementing with prebiotics.
Prebiotics are substances that humans can't digest, so they pass through our gastrointestinal tract and promote the growth of many different strains of good bacteria in our lower bowel. They are essentially food for the good bacteria in our intestines.
Dr. Phil Burnet, a neurobiologist at Oxford University, published a paper in 2015 showing that people who ingested prebiotics have lower levels of cortisol, a key stress hormone, and focused more on positive feedback and less on negative stimuli. He said the results were very similar to when people take anti-depressants and anti-anxiety medication, but without the side effects.
Other research by Burnet shows that prebiotics support overall brain health in humans and foster the growth of probiotics in mice, which leads to increased levels of several neurotransmitters that reduced anxiety-like behaviour (19, 20, 21, 22).
Prebiotic-rich foods include sweet potatoes, carrots, onions, asparagus and squash. These foods are included in my free grocery shopping guide for optimal brain health and you should be eating them regularly. If you feed the good bacteria, you will feel healthier physically and mentally.
Resistant starch is one of the most potent ways to boost your prebiotic intake, and it’s been shown to help prevent and manage chronic disease (18).
A convenient way to incorporate more resistant starch into your diet is by using Unmodified Potato Starch. I’ve tried and recommend it. It's one of the easiest and cheapest ways to incorporate more resistant starch into your diet. It is bland so you can simply add it to beverages, smoothies and meals. It has to stay raw though, so don’t cook it.
Other high-quality resistant starches that I’ve tried include banana flour, plantain flour and waxy maize. I usually rotate between them.