chapter 13: putting it all together

Our fast-paced and modern lifestyles tend to stress our gut microbiomes and immune systems rather than helping to support them. By making the right nutrition choices, exercising appropriately, managing stress, ensuring optimal sleep and sufficient sunshine exposure, we can achieve strong and balanced gut health and immunity. Food choice is one of the greatest opportunities to improve your immunity and health – it is all in your control.

The Immunity Plan

This is an easy go-to table that summarizes all the guidance in the book (recommendations are based on UK government daily dietary guidelines for adults aged 18–64).

	How much	Food sources
Energy (kcal/day)	2500 (men) / 2000 (women)
Macronutrients
Carbs	333g (men) / 267g (women) 30g fibre (men and women)	Vegetables, fruits, wholegrains, legumes, nuts and seeds.
Protein	56g (men) / 45g (women)	Meat, poultry, fish, eggs, dairy products, soy, nuts and seeds.
Fats (less than) Saturated Fat Monounsaturated Fat Polyunsaturated Fat Omega 3	97g (men) / 78g (women) 31g (men) / 24g (women) 36g (men) / 29g (women) 18g (men) / 14g (women) 2 portions of fatty fish a week (men and women)	Focus on the ‘healthy’ fats found in foods such as avocado, olive oil, nuts such as walnuts, seeds such as flax seeds (linseeds), fatty fish such as wild salmon, mackerel, sardines and trout.
Salt	6g or less a day (men and women)	Natural food sources include meat, seafood and eggs. It is also found in a lot of processed foods, such as bread, so do read the labels carefully.
Micronutrients
Vitamin A	0.7mg (men) / 0.6mg (women)	Liver, full-fat (whole) milk and cheese are dietary sources of retinol (‘preformed’ vitamin A). Dark green leafy vegetables and orange-coloured fruits and vegetables, e.g. carrots, sweet potato, butternut squash, cantaloupe melon and papaya, are dietary sources of carotenoids, which can be converted to vitamin A by the body.
Vitamin C	40mg (men and women)	Citrus fruits, blackcurrants, strawberries, papaya, kiwi, green vegetables, (bell) peppers and tomatoes.
Vitamin D	10mcg (men and women)	Oily fish, eggs, fortified breakfast cereals, fortified spreads and fortified dairy products, and some mushrooms.
Vitamin E	4mg (men) / 3mg (women)	Wheat germ, nuts, seeds, avocado and spinach.
Selenium	75mcg (men) / 60mcg (women)	Nuts and seeds (for example Brazil nuts, cashews and sunflower seeds), eggs, offal (variety meats), poultry, fish and shellfish.
Zinc	9.5mg (men) / 7mg (women)	Meat, poultry, cheese, shellfish (including crab and mussels), nuts and seeds (in particular pumpkin seeds and pine nuts), wholegrain breakfast cereals and wholegrain and seeded breads.
Other nutrients
Prebiotics	N/A	Jerusalem artichokes, chicory (endive), apples, bananas, cauliflower, garlic, leeks, onions, black beans, butter (lima) beans, chickpeas (garbanzo beans) and camomile tea.
Probiotics	N/A	Fermented foods such as sauerkraut, kimchi, kefir and natural live yoghurt.
Lifestyle	How much	Examples
Exercise	30 minutes moderate activity every day (if possible).	Walking, swimming, cycling and dancing.
Sleep	7–9 hours per night.	(If you are recovering from an infection or undergoing significant stress you will potentially need more.)
Sunlight	10–15 minutes of exposure several times a week – ensure your face and arms are exposed, if possible.	Try to get out in the sunshine for a walk during the morning.
Stress Management	Adopt the most appropriate stress management technique for you.	Exercise, yoga, mindfulness practice, meditation, catching up with friends and laughing!

Appendix I

Micronutrients and their role in our immune systems

Nutrient	Role
Vitamin A	Helps support T cells (a type of white blood cell that helps identify pathogens).
Vitamin C	Helps immune cells attack pathogens, helps get rid of immune cells from the site of infection; also helps to maintain the skin, which is our external barrier to infection.
Vitamin D	Has numerous effects on immune system cells, and low status is associated with reduced immune response.
Vitamin E	This antioxidant is important for the normal function of the immune cells.
Selenium	Helps produce new immune cells and can help to strengthen response to infection.
Zinc	Helps produce new immune cells; also encourages the development of NK cells that help to combat viruses. Zinc also supports the communication between our different immune cells.

Adapted from British Nutrition Foundation, 2020

Appendix II

Phytonutrient-rich foods featured in the recipes

Foods	Phytonutrients
Apples	Catechins, flavonols and tartaric acid
Artichokes	Carotenoids
Beetroot (beets)	Carotenoids
Berries	Anthocyanins and anthocyanidins, lignans and tannic acid
Broccoli (also Brussels sprouts, cabbage, cauliflower and kale)	Allylic sulfides, carotenoids, lignans and vitamin C
Cantaloupe melon	Carotenoids
Carrots	Carotenoids and lignins
Chilli peppers	Capsaicin
Cocoa and dark chocolate	Flavonols and catechins
Flax seeds (linseeds) and oil seeds	Lignans
Garlic	Limonene, flavonols and allylic sulfides
Legumes	Catechins, carotenoids, flavonols, lignans, omega fatty acids and saponins
Nuts and seeds	Phytic acid, phytosterols and stilbenes (resveratrol)
Olive oil	Hydroxytyrosol, oleuropein and oleocanthal
Onions	Flavonols and allylic sulfides
Pumpkin	Carotenoids and lignans
Red cabbage	Anthocyanins and anthocyanidins
Red grapes (and wine)	Catechins, ellagic acid, flavonols and stilbenes (resveratrol)
Soy	Isoflavones, phytic acid, phytosterols and saponins
Spinach	Carotenoids and lignins
Squash and sweet potatoes	Carotenoids
Tomatoes	Carotenoids and vitamin C
Whole grains	Lignins, organo or allylic sulfides and saponins
(Bell) Peppers	Carotenoids and vitamin C