Gut and immunity: four guides, built on the studies

Short answer. The habits with the clearest human evidence are sleep, regular movement, enough protein and fibre, and a little fermented food most days. Bone broth, pickles and home remedies can be part of that, but the studies behind them are smaller. Each guide below shows what was actually found, and how strong the evidence is.

Evidence labels used in every guide: Strong consistent controlled trials or an authorised EU claim · Moderate controlled trials or large studies, with limits · Early small, pilot, laboratory or single studies.

Brine or vinegar pickles

Which ones are fermented, what that changes, the salt question, and a home recipe in grams.

Fermented foods, food by food

Sourdough, kefir, yoghurt, sauerkraut, kimchi, kombucha: what the trials found and how to start.

Bone broth

Gut, joints, collagen, bones and muscle: what broth gives you, what it does not, and how to make it.

Immunity, ranked by the evidence

Sleep, movement, stress, probiotics, vitamin D, zinc, honey, garlic, and the WITH ME honey macerate.

If you only do five things this week

1. Sleep 7 hours or morePeople sleeping under 6 hours were 4.2 times more likely to catch a cold after exposure to the virus.

2. Move on most daysAdults doing aerobic exercise 5 or more days a week had 43% fewer days with cold symptoms.

3. One fermented food a dayLive yoghurt or kefir, then add 30 g sauerkraut or brine pickles. Build up slowly.

4. Protein and fibre at every mealYour gut bacteria live on fibre; your immune cells are built from protein.

5. Check vitamin D in winterTest first, then correct a shortfall with your doctor.

Every figure here is explained, with its study, in the immunity and fermented foods guides.

Related guides

Gut rebuild guide: the two non-negotiables and the full gut plan for clients.
Sprouts and microgreens at home: growing, safety and 71 recipes in grams.
SIBO and IBD: read these first if you have either, because fermented foods are not always well tolerated.
Sleeping Beauty: the sleep guide behind point 1.

This page is nutrition coaching information, not medical advice. It does not recommend any product.

Want someone to read the numbers with you?

1:1 nutrition coaching with Alexandra Lasconi

Apply for a complimentary intro call All tools & guides