Probiotics and the Immune System- What’s the Link?

It is fairly well known that probiotics are the beneficial bacteria that live in our gut and are essential to help us digest food. However their benefits are much greater than that. There has been much interest lately in the connection between the health of our gut flora and immunity. How is it that probiotics affect our immune system, supporting our immunity, fighting off infections and reducing autoimmune reactions?

Probiotic bacteria in the lining of the small and large intestine compete with harmful bacteria for space and access to the cells lining the gut and to the bloodstream. In addition to this, probiotics can support the immune cells in the gut wall. According to Optibac, a leading manufacturer of probiotics, their strain of L. acidophilus supports immune cells and also creates lactic acid, which inhibits harmful bacteria such as Listeria. Some strains of Bifidobacteria, which live in the colon, specifically B. longum, B. breve and B. infantis encourage the body’s production of antibodies, as well as competing with harmful bacteria for space.

In a randomized controlled trial over the winter of 2006-2007, Optibac’s powdered probiotic supplement “for your child’s health” was found to reduce incidence of common childhood infections by 25% in 135 school age children. Dr Gary Huffnagle, a researcher at the University of Michigan, says that, “Some bacteria produce their own antibiotics. These chemicals don’t affect us, but they inhibit the growth of other bacteria. Also as microbes digest food, their metabolic by-products may have adverse effects on their competitors.”

Disturbance in gut flora balance has been linked to autoimmune problems, as an inadequate population of probiotics can lead to a “leaky gut”, in which poorly digested food proteins can pass across the gut lining into the bloodstream, where they trigger an immune reaction, leading to symptoms such as inflammation. Foreign proteins of this size are not normally present in the blood, so the immune system tags them as potentially harmful invaders.

Dr Huffnagle explains the immune link between the gut and the respiratory system as “everything we inhale, we also swallow”. As we inhale pollen, it gets trapped in mucus, and much of it is swallowed. So a “leaky gut” may cause an autoimmune response to pollen particles. A healthy gut flora may help to prevent this. Probiotic levels may be highly significant in allergy development. Also the gut flora support the production of regulatory immune cells, that wind down immune reactions after infection, and prevent excessive inflammation.

Healthy gut bacteria can be encouraged through a diet high in soluble fibre, also known as “prebiotics’, as well as through consuming yogurt and taking probiotics. Prebiotics, present also in some probiotic supplements, feed the growth of our own natural, varied gut flora.


Low Milk Supply when Breastfeeding

If your baby is having a growing spurt you may have times when it seems like you can’t satisfy him. If you allow the baby to feed on demand, your supply should increase in a day or two. Also it may be worth checking if the baby is latching on correctly, so that the let-down, or milk-ejection reflex is stimulated. Feeding on demand, being relaxed about it and trusting your body, helps to maintain a good milk supply. If you are experiencing problems and think you may have a low milk supply, talk to a breastfeeding counsellor, as the problem can usually be sorted out. If you are going to be away from your baby for a while, and are unable to feed as usual, expressing milk will help to keep your supply going. If the above measures are not sufficient, or if you wish to breastfeed an adopted baby, or are restarting lactation the following suggestions may help, along with frequent feeding and expressing.

The first and most important thing is to make sure you are drinking enough water. The average person loses one litre of water every day through urine, sweat, breathing etc. Giving birth and breastfeeding take even more. Drinking adequate water can make a significant difference to how you feel as well as helping to maintain a good milk supply. Dehydration can make you feel tired and irritable. Water is the best thing to rehydrate you properly, rather than tea and coffee. However in her book “Mother Food” (2004) Hilary Jacobson says that drinking too much water can reduce the milk supply. She advises mothers to “drink to thirst”. Studies have shown that drinking a little above or below your thirst doesn’t affect milk supply, but drinking far above thirst levels causes a drop in milk supply. I think the important thing is to be aware of your thirst and not to forget to drink or confuse thirst with hunger. Coconut water is naturally isotonic, which means it contains mineral salts needed by the body that can be low when dehydrated.

Some herbs can help to increase your milk flow. Herbs with this action are known as galactagogues. They also benefit your health in a variety of ways. Herb teas of raspberry leaf (Rubus idaeus), nettle (Urtica dioica), borage (Borago officinalis) and dandelion leaf (Taraxacum officinale) provide essential nutrients, especially minerals, such as calcium or iron. Raspberry leaf, vervain (Verbena officinalis) and borage are relaxing and strengthening to the nervous system. Some galactagogue herbs have a beneficial action on the liver, for example, milk thistle (Silybum marianum) , holy thistle (Cnicus benedictus) and vervain.
Sometimes after a difficult birth, if the mum is particularly exhausted and run down, or separated from her baby, it can be difficult to establish or maintain a good milk supply. Feeling tense and anxious may inhibit the let-down reflex. Relaxing and nourishing herbs can help in these situations. Green oat tincture is nourishing and supportive to the nervous system.

The following is a list of common herbs to use, that are generally easy to obtain (you may have some in your kitchen cupboard or garden!) These can be taken as teas, tablets, capsules, tinctures or used in cooking. Tinctures are strong and are quickly and well absorbed by the body but do not extract the mineral content of herbs as well as the other forms.

Raspberry leaf
Caraway seed
Milk thistle
Fennel seed
Celery seed
Fenugreek seed
Dandelion leaf
Fresh coriander leaf

To make fennel seed tea, use one teaspoon seeds per cup of boiling water and leave to infuse for 10-20 minutes. As well as increasing milk flow, it helps to ease after-pains for mums and aids the digestion of both mother and baby. Be aware however that after the first few days of colostrums, when your milk “comes in”, you may have too much milk rather than too little to begin with, until your milk flow adjusts to your baby’s needs.

There are also foods you can include in your diet to help you milk supply and enrich your milk. Whatever your diet is like, unless you are severely malnourished, your milk will be good for your baby, but if you have an unhealthy diet, it is your health that may suffer, as nutrients go to the baby first, in a similar way to when you were pregnant.

Foods to include are:
Oats, barley, beans, pulses, onions, leeks, nuts (avoid peanut due to allergy risk for baby), sunflower seeds, sesame seeds, linseeds, most fruits, watercress, cress, alfalfa, spring onion, quinoa.