Eating for Good Gut Health Sue Baic MSc RD, Registered Dietitian by Sue Baic, Registered Dietitian
The links between gut health and diet is one the fastest growing areas in nutrition research and makes for fascinating reading! We now know that a healthy gut promotes both physical and mental wellbeing and can offer huge potential health benefits.
There’s particular interest in the “gut microbiome” – the colony of bacteria and yeasts – which live in our gut and can weigh as much as 5 pounds. This microbiome helps us digest our food, compete against other harmful bacteria, such as those causing food poisoning, and produces some of the vitamins our bodies need.
Immunity - the gut's vital role
In addition it plays a role in supporting immunity. Over 70% of the cells in our immune system are linked one way or another to the gut. Chemicals produced by gut bacteria influence our immune cells, including the wonderfully named “natural killer cells”, to act in the appropriate way. For instance there are several studies showing links between a healthy microbiome and reductions in frequency and duration of respiratory infections such as colds and flu. However there’s no evidence to date that it can prevent or treat coronavirus infections such as COVID-19.
Links with the brain and ageing
As if that weren’t enough we now also know that the gut microbiome plays a role in mental health linking with our brain via a complex communication system known as the gut- brain axis.
The healthy balance of the microbiome can be upset by a variety of factors such as medication, ageing, illness and interestingly by having a poor diet. Researchers believe that one of the most important strategies for good gut health is to include a variety of different plant foods in the diet. In fact the recently published and ground breaking American Gut Health project suggested that around 30 different plant foods per week was the ideal .Plant foods including many fruit , vegetables , cereals , beans , nuts and seeds contain types of fibre known as prebiotics . These act as a fertiliser or food promoting growth of the good bacteria.
Much research has also focussed on the general health benefits of including probiotics (the good bacteria themselves) in the diet. These can come from fermented foods such as sauerkraut or kefir, from dairy foods fortified with them or from supplements
Both prebiotics and probiotics may also help some people with problematic gut symptoms including abdominal discomfort, bloating, constipation and diarrhoea. Irritable bowel syndrome (IBS) is the term sometimes given to a collection of these symptoms. It can affect as many as 20% of adults in the UK but symptoms type and severity will vary from one person to another.
IBS and other gut conditions: what should you do and other considerations
Before a diagnosis of IBS is made it is important to consult a GP to rule out other medical problems. This is especially important if you have persistent loose or frequent stools, rectal bleeding or blood in stools, severe pain, unintentional weight loss, fatigue or a family history of bowel or ovarian cancer or coeliac disease.
If a diagnosis of IBS is made diet can play an important role and often a few simple changes bring benefit.
These can include:
· Getting enough of the right types of fibre. Wheat bran can make symptoms worse for some people but often rather surprising foods such as kiwi fruit, prunes oats or linseeds can have a benefit
· Drinking enough fluid to allow any fibre to work properly. Beware that caffeine, alcohol and fizzy drinks can all provoke gut symptoms in some people
· Considering lifestyle changes such as the timing of meals, reducing the speed of eating , learning to relax or taking more regular exercise
· Cutting out certain foods such as those which are very spicy or fatty, wind producing vegetables (such as pulses, beans and brassicas) or milk if lactose intolerance is suspected.
A food and symptom diary can help identify potential culprits. If staple foods are excluded it’s important to replace the nutrients e.g. calcium fortified plant based dairy alternatives or low lactose dairy foods
Other exclusion diets and low FODMAP foods
Another approach that has had some recent success is a diet which trials the exclusion of short chain fermentable carbohydrates (also known as a low FODMAP diet).This involves temporarily avoiding and later reintroducing foods that are not easily broken down by the gut, such as some types of:
· Fruit and vegetables
· Wheat products
This diet needs specialist help ensure the diet is nutritionally adequate and doesn’t end up less healthy and overly restrictive.
Want to know more? Sign up for our webinar
Gut Health How to Have a Happy Healthy Digestive System on October 8th 7.30 – 9 p.m.? Click here for details.
This event will help those who have gut symptoms or anyone looking to be healthier and to improve their diet and weight management. Also useful for health professionals wanting to know more about nutrition and gut health.
Gui Q et al (2020) Effects of probiotic supplementation on natural killer cell function in healthy elderly individuals: a meta-analysis of randomized controlled trials Eur J Clin Nutr 8: 1-8 https://pubmed.ncbi.nlm.nih.gov/32514029/ (Last accessed August 26 2020)
Gut Microbiota for Health. Public information service from European Society of Neurogastroenterology and motility
https://www.gutmicrobiotaforhealth.com/en/about-gut-microbiota-info/ ( Last accessed August 26 2020)
NHs Choices Irritable Bowel syndrome https://www.nhs.uk/conditions/irritable-bowel-syndrome-ibs/ (Last accessed August 26 2020)
Yan F & Polk D (2011) Probiotics and immune health. Curr Opin Gastroenterol 27: 496-501