Herbs for gut health

Good gut health is essential to overall health, so Jane Wrigglesworth lists herbs that could help.

What to grow and how to use them, according to Jane Wrigglesworth.

The gastrointestinal tract has such a complex network of neurons (nerve cells) that it’s often referred to as our second brain. Hidden in the lining, from the oesophagus to the anus, are some 100 million neurons that control gastrointestinal homeostasis and digestion.

This second brain is simpler than the one in our head, but in conjunction with the brain – via the gut-brain axis, which involves biochemical signalling between the gastrointestinal tract and the central nervous system (CNS) – it strongly influences our body and emotions. Just as stress and anxiety can trigger certain health issues such as diarrhoea or an upset stomach, studies show that irritation in the gut may send signals to the CNS that alter mood.

For example, it’s been found that people with irritable bowel syndrome (IBS) and other functional bowel problems (where there is an impairment of function but one which is not caused by structural abnormalities) have a higher-than-normal chance of developing depression and anxiety. And a surprising treatment by doctors for IBS is antidepressants. Because of the direct route along the gut-brain axis, certain antidepressants may soothe IBS symptoms by acting on gut, as well as brain, nerve cells.

Many things can irritate the lining of the gastrointestinal tract, including sugar, alcohol, processed foods and, for some, gluten. A 2019 study showed that the risk of inflammatory bowel disease increased after just two days of sugar bingeing in mice, with signs of tissue damage and an inadequate immune response. They also found that short-chain fatty acids (SCFA), usually produced by the “good” bacteria in our guts, mitigated this response.

So it follows that we should look to accommodate these friendly gut flora. Fibre feeds good bacteria, so a high-fibre, reduced sugar diet can aid gut health. Conversely, diets high in sugar (and low in fibre) feed the “bad” bacteria such as E coli.

Herbs for a healthy gut

Herbs contain glycosides, pectin, resin and fibre, all of which can be used by probiotics and metabolised into short-chain fatty acids.

Certain herbs can indirectly promote SCFA production. Just as carbohydrates are utilised by good bacteria to make SCFA (SCFAs are produced by anaerobic fermentation of undigested complex carbohydrates – or prebiotics), so too can herbs be metabolised into SCFA. Herbs contain carbohydrates such as glycosides, pectin, resin and fibre, all of which can be utilised by probiotics and metabolised into SCFA.

For example, red ginseng (the steamed root of Panax ginseng) was shown to promote the growth of the probiotics Bifidobacterium and Lactobacillus while inhibiting the growth of some pathogen strains in vitro. Polysaccharide peptides from turkey tail fungus

For a DIY prebiotic mix 1 part elecampane root powder, 1 part liquorice root powder and 1 part marshmallow root powder with 1 part honey.

( Trametes versicolor), which is used as a medicinal mushroom in China and Japan, were also found to increase Bifidobacterium and Lactobacillus, and reduce harmful Clostridium, Staphylococcus and Enterococcus. As well, berberine, which is a chemical found in the bark, roots and stems of many plants, including plants in the berberis family (a long-used medicinal plant) increased the SCFA-producing bacteria Blautia, Allobaculum and Bacteroides.

Other prebiotic herbs

Chicory root, popular with the alternative-coffee crowd, is high in the prebiotic fibre inulin. If you look on the label of many of the probiotic supplements today, you will find they contain inulin.

Dandelion greens are rich in inulin too and make an excellent addition to a green salad. So too do the roots, but as gardeners will know, the strong taproots of dandelion are difficult to dig up! But if you persevere, they are a very good source of prebiotics.

Garlic has prebiotics in the form of inulin and fructooligosaccharides, (FOS) and has been found to increase Bacteroides and Bifidobacteria.

Likewise, onions contain inulin and FOS, as does burdock and yacon ( Smallanthus sonchifolius) roots.

Other herbs with soluble fibre beneficial to probiotics are elecampane root, liquorice root and marshmallow root.

But do note that you need to take them in powdered form. If you consume them in a tea or decoction, you won’t be getting the fibre.

Best of all, all these herbs can be grown in your own backyard right here in New Zealand.

Elecampane ( Inula helenium) looks similar to the sunflower with its high-rise yellow blooms, but it’s an herbaceous perennial, dying down over winter then reappearing in spring. It is typically used in the treatment of respiratory ailments, particularly bronchitis and whooping cough, and studies have shown extracts from the roots are active against many pathogens, including Staphylococcus aureus,

E coli and Candida albicans. The two- to three-year-old roots are dug in autumn.

Liquorice ( Glycyrrhiza glabra) has been used in herbal medicine for thousands of years. The active compound, glycyrrhizin, which gives liquorice its flavour, is responsible for the healing of gastrointestinal ulcers and inflammatory conditions of the digestive tract.

Liquorice is also useful for treating dry coughs, for expelling mucus, and for soothing irritated and inflamed tissues like that of sore throats and bronchial inflammation. For general use, however, liquorice is a great tonic.

A deciduous perennial growing to about 1.5m high, the roots are harvested in autumn in their third or fourth year.

Marshmallow ( Althea officinalis) is easy to grow. Both the leaves and the roots contain loads of mucilage and are used medicinally to soothe and protect irritated mucous membranes of the respiratory and digestive tracts. The roots are collected in autumn from plants that are at least two years old.

To give yourself a daily dose prebiotic goodness, make your own: Mix together 1 part elecampane root powder, 1 part liquorice root powder and 1 part marshmallow root powder with 1 part honey. Take a teaspoon of this each day for gut health.

Note: Avoid liquorice if you have high blood pressure or low potassium levels, or are pregnant. Also check with your doctor first if taking medications, as liquorice can interfere with several pharmaceuticals, including birth control pills and other hormonal medications.

Caution is required when taking marshmallow if you are also on medication for diabetes, as it may interfere with blood sugar levels.

Avoid elecampane when breastfeeding.