The short answer to the question of whether GPs should advise patients to add probiotic supplements to their diets is that practitioners need to consider each individual when deciding on supplements versus food.
If there are no published efficacy studies on a probiotic, but it seems to help, the decision about whether or not to continue it is a personal choice.
What we do know is that the potential benefits of probiotics are promising – whether from food, drink or supplement.
Probiotics are live bacteria found naturally in the gut, as well as in select foods and supplements. When taken in adequate amounts, they provide a health benefit to the person.
Here is more background on probiotics in order to help you provide an informed response to patients.
What do probiotics do?
Probiotics rarely colonise in the gut, but rather interact with resident microbes. As they pass through the gut, they interact with gut cells, immune cells and food substances, exerting their benefits.
Research has shown that probiotics can support digestive health and immune function, including reducing antibiotic‐associated diarrhoea, improving resilience to infections, and improving digestion of lactose. Other benefits include reducing the risk of eczema and colic in infants, as well as necrotising enterocolitis.
There is also some early evidence of benefits in managing weight and glycaemic control, depression and anxiety.
Are probiotics safe?
Probiotic foods and supplements have been determined to be safe for use in the general healthy population at recommended doses.
How do you choose a good probiotic product?
Not all probiotics are the same, and not all provide the same benefit to different patients. Most are from the genera Lactobacillus or Bifidobacterium or yeast.
It is best to find a product containing the strain(s) that have demonstrated the best evidence for the benefit you are seeking.
Are probiotics best acquired via food or supplement?
It is early days in terms of probiotic supplementation and, while there is some emerging evidence, more work needs to be done.
Pros and cons of probiotic supplements should be considered for each patient.
- Pros: Some strains have a clinical impact in some disorders, such as inflammatory bowel disease (IBD) and immunity post-antibiotic treatment (eg VSL#3). They are well tolerated and provide bacterial diversity, and most provide high amounts of colony forming units (CFUs) – the number of viable bacteria in sample serve.
- Cons: Technological advances are needed before we see a boost in effectiveness. High doses can result in symptoms such as gas, bloating, constipation or diarrhoea. Benefits of fermented foods may go beyond the strains of bacteria (eg the bioavailability of some vitamins and minerals is elevated by the fermentation process of vegetables). What is the effective minimum dose? A product with a larger dose or more strains is not always better. The best dose is one that demonstrates benefits in humans, which typically ranges from 100 million to one trillion CFUs per day.
Are fermented foods a good source of probiotics? Although fermented foods are made with live cultures, they cannot automatically be deemed a ‘probiotic’ unless the strains contained have been studied and shown to confer a health benefit.
- Fermented foods high in ‘good’ bacteria include:
- yoghurt with live cultures – look for one billion probiotics per serve 1 x 10(9) CFU
- kefir (fermented milk or water-based drink) – usually has 30 beneficial strains of good bacteria
- fresh kimchi (Korean fermented vegetables)
- fresh sauerkraut (fermented cabbage).
- Eating a variety of these foods can help cultivate a variety of good bacteria. Look for words such as ‘live’, ‘active’, ‘raw’ or ‘unpasteurised’ on packaging to ensure the manufacturing process has not killed the probiotic strains.
Some manufacturers of pasteurised products will add probiotic strains back into the final product. These will be listed in the ingredients. Studies have shown that the benefits of these probiotic foods are only seen while being consumed.